This document describes the design and analysis of a planar positioning stage based on a redundantly actuated parallel linkage with six degrees of freedom (three translations and three rotations). The kinematics and workspace analysis of the linkage are presented. A static analysis method to calculate the actuator torques required for a given end-effector force and trajectory is also described. MATLAB programs were developed to analyze the workspace and perform the static analysis. The results show that the redundant actuation can help improve the workspace characteristics and prevent singular configurations compared to non-redundant parallel manipulators. The stage design has potential applications in micro-positioning.
Design and analysis of x y- positioning stage based on redundant parallel li...eSAT Journals
Abstract This paper presents the concept of a planar positioning stage based on a kinematically redundant parallel linkage. Basic kinematics and workspace analysis of base redundant manipulator is initially explained and the procedure of static analysis to predict the actuated joint torques is described. As there are six actuators in the linkage, the redundancy can be overcome by proper selection of the base joint variables. Also it is assumed that the motion is at a constant speed. A numerical example is shown with a straight line trajectory to illustrate the workspace and joint force calculation aspects of this linkage. The possible arrangement of the stage with electrostatic actuation and sensing are finally highlighted. Keywords: Kinematic redundancy, Parallel mechanism, Static analysis, and Workspace characteristics
A Review of Shortcomings of Driving principle for Spherical Drive Systemspaperpublications3
This document reviews the shortcomings of different driving principles for spherical drive systems. It discusses three main principles: barycenter offset (BCO), conservation of angular momentum (COAM), and outer shell transformation (OST). For BCO systems, it identifies drawbacks like limited torque from inability to shift barycenter outside sphere, and power losses from friction. Non-frictional BCO systems using pendulums avoid these issues but allow only non-holonomic motion. COAM and OST principles are also discussed briefly. The document aims to provide a comprehensive list of limitations to help researchers evaluate and improve spherical drive system designs.
This document summarizes the kinematics analysis of a 3-UPU (universal-prismatic-universal) parallel robot. Each of the robot's three legs consists of two universal joints connected by a prismatic joint. The document establishes recursive matrix relations for solving the inverse kinematics problem given the position of the mobile platform. Simulation graphs are generated for the input displacements, velocities, and accelerations. The kinematics analysis determines the nine independent variables that define the robot's configuration based on vector-loop equations relating the joint parameters and platform position.
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology.
The Effect of Arm Stiffness on the Elasto-Kinematic Properties of Single-Axle...theijes
The paper is focused on the stiffness analysis of the longitudinal arm of single-axle suspension on elastokinematic behaviour of the vehicle axle which is highly important when considering the handling characteristics related tovehicle safety.The elasto-kinematic behaviour of the axle determines the course of the geometrical parameters of wheel suspension, the toe angle and camber as the function of wheel movement during force loading. This paper presents the complex MBS (Multi-Body Simulation)model of the wheel suspension with nonlinear characteristics of rubber-metal bushings. The model also comprises force elements such as springs, shock absorbers, stops and the transverse stabilizer. The model of flexible arm is implemented in the MBS model using the Craig-Bampton method, which represents a flexible body based on the synthesis of its own modal shapes. Subsequently,elasto-kinematic simulations are performed with the help ofthe computational system Hyperwork. The computational part of the paper presents the results of the elasto-kinematic behaviour of wheel axle for the flexible arm with different sheet metal thicknesses (2, 3 and 4 mm) and different materials (steel and aluminium alloy AlSi7Mg). Individual calculation models are compared to each other and also to the model of suspension with therigidarm. Elasto-kinematic analyses are also validated by the measurement inthe testing stage.
The effect of rotor disc clearance on the lift performance of contra rotating...eSAT Publishing House
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
The International Journal of Engineering and Science (The IJES)theijes
The International Journal of Engineering & Science is aimed at providing a platform for researchers, engineers, scientists, or educators to publish their original research results, to exchange new ideas, to disseminate information in innovative designs, engineering experiences and technological skills. It is also the Journal's objective to promote engineering and technology education. All papers submitted to the Journal will be blind peer-reviewed. Only original articles will be published.
COMPARISON OF RESPONSE TO UNBALANCE OF OVERHUNG ROTOR SYSTEM FOR DIFFERENT SU...IAEME Publication
Rotor unbalance is most common fault found in the rotating machines. Methods
are adopted to analyze the position of unbalance and to bring its effect into acceptablelimit. Vibration analysis is the most common technique used to analyze the rotor
system. Research have been performed on rotor supported atboth ends, however lessstudy has been done for overhung rotor. In this paper the response of overhung rotoron isotropic support and anisotropic support subject tounbalance has been presented.and equations aresolved using MATLAB programming. The effect of unbalancehas been studied on thebode plot. Forward and Reverse whirl are observed through Campbell diagram andmode shapes are plotted.
Design and analysis of x y- positioning stage based on redundant parallel li...eSAT Journals
Abstract This paper presents the concept of a planar positioning stage based on a kinematically redundant parallel linkage. Basic kinematics and workspace analysis of base redundant manipulator is initially explained and the procedure of static analysis to predict the actuated joint torques is described. As there are six actuators in the linkage, the redundancy can be overcome by proper selection of the base joint variables. Also it is assumed that the motion is at a constant speed. A numerical example is shown with a straight line trajectory to illustrate the workspace and joint force calculation aspects of this linkage. The possible arrangement of the stage with electrostatic actuation and sensing are finally highlighted. Keywords: Kinematic redundancy, Parallel mechanism, Static analysis, and Workspace characteristics
A Review of Shortcomings of Driving principle for Spherical Drive Systemspaperpublications3
This document reviews the shortcomings of different driving principles for spherical drive systems. It discusses three main principles: barycenter offset (BCO), conservation of angular momentum (COAM), and outer shell transformation (OST). For BCO systems, it identifies drawbacks like limited torque from inability to shift barycenter outside sphere, and power losses from friction. Non-frictional BCO systems using pendulums avoid these issues but allow only non-holonomic motion. COAM and OST principles are also discussed briefly. The document aims to provide a comprehensive list of limitations to help researchers evaluate and improve spherical drive system designs.
This document summarizes the kinematics analysis of a 3-UPU (universal-prismatic-universal) parallel robot. Each of the robot's three legs consists of two universal joints connected by a prismatic joint. The document establishes recursive matrix relations for solving the inverse kinematics problem given the position of the mobile platform. Simulation graphs are generated for the input displacements, velocities, and accelerations. The kinematics analysis determines the nine independent variables that define the robot's configuration based on vector-loop equations relating the joint parameters and platform position.
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology.
The Effect of Arm Stiffness on the Elasto-Kinematic Properties of Single-Axle...theijes
The paper is focused on the stiffness analysis of the longitudinal arm of single-axle suspension on elastokinematic behaviour of the vehicle axle which is highly important when considering the handling characteristics related tovehicle safety.The elasto-kinematic behaviour of the axle determines the course of the geometrical parameters of wheel suspension, the toe angle and camber as the function of wheel movement during force loading. This paper presents the complex MBS (Multi-Body Simulation)model of the wheel suspension with nonlinear characteristics of rubber-metal bushings. The model also comprises force elements such as springs, shock absorbers, stops and the transverse stabilizer. The model of flexible arm is implemented in the MBS model using the Craig-Bampton method, which represents a flexible body based on the synthesis of its own modal shapes. Subsequently,elasto-kinematic simulations are performed with the help ofthe computational system Hyperwork. The computational part of the paper presents the results of the elasto-kinematic behaviour of wheel axle for the flexible arm with different sheet metal thicknesses (2, 3 and 4 mm) and different materials (steel and aluminium alloy AlSi7Mg). Individual calculation models are compared to each other and also to the model of suspension with therigidarm. Elasto-kinematic analyses are also validated by the measurement inthe testing stage.
The effect of rotor disc clearance on the lift performance of contra rotating...eSAT Publishing House
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
The International Journal of Engineering and Science (The IJES)theijes
The International Journal of Engineering & Science is aimed at providing a platform for researchers, engineers, scientists, or educators to publish their original research results, to exchange new ideas, to disseminate information in innovative designs, engineering experiences and technological skills. It is also the Journal's objective to promote engineering and technology education. All papers submitted to the Journal will be blind peer-reviewed. Only original articles will be published.
COMPARISON OF RESPONSE TO UNBALANCE OF OVERHUNG ROTOR SYSTEM FOR DIFFERENT SU...IAEME Publication
Rotor unbalance is most common fault found in the rotating machines. Methods
are adopted to analyze the position of unbalance and to bring its effect into acceptablelimit. Vibration analysis is the most common technique used to analyze the rotor
system. Research have been performed on rotor supported atboth ends, however lessstudy has been done for overhung rotor. In this paper the response of overhung rotoron isotropic support and anisotropic support subject tounbalance has been presented.and equations aresolved using MATLAB programming. The effect of unbalancehas been studied on thebode plot. Forward and Reverse whirl are observed through Campbell diagram andmode shapes are plotted.
Comparative study of a flexible and rigid two degree of freedom half car modeleSAT Journals
Abstract Ride quality is concerned with the feel of the passenger in the environment of a moving vehicle. It is one of the key indices in determining comfort levels of a vehicle. Although, “ride comfort” evaluation is subjective in nature, researchers have developed mathematical models to study and evaluate vehicle ride performance. Some popular models for vehicle ride analysis are – quarter car model, two dof (degree of freedom) and four dof half car model. These models model the chassis as a rigid body. This work removes this assumption and models the chassis of the vehicle as a flexible beam on a spring damper system at the front and rear using Euler beam theory. This elastic model has two dof – vehicle bounce and pitch, and has been compared with the rigid two dof model. Euler beam theory and Lagrangian mechanics are used to derive the equations of motion. Finite element method is used to validate this model. Experimental validation of the natural frequencies of this flexible beam is presented. Keywords: Flexible ride model, Elastic ride model
International Journal of Computational Engineering Research(IJCER)ijceronline
International Journal of Computational Engineering Research (IJCER) is dedicated to protecting personal information and will make every reasonable effort to handle collected information appropriately. All information collected, as well as related requests, will be handled as carefully and efficiently as possible in accordance with IJCER standards for integrity and objectivity.
Aplanning algorithm offive-axis feedrate interpolation based on drive and jer...IJRES Journal
CNC technology marks the core of modern manufacturing, and CNC interpolation module is one of the most important numerical control technology modules. Avery important feature of the CNC is to implement the feed rate that consists in producing the set points based on a NC program. In the high speed machining, the feed rate is restricted by the velocity, acceleration, and jerk. And the NURBS curve is a free curve, due to the many advantages of NURBS curves, it can be well applied to the CNC feed rate interpolation. The algorithm can get more smooth feed rate curves, which makes better use of kinematical characteristics of the machine. Finally, according to each machine axis capability, one can use the feed rate control method which is verified by simulation analysis and processing to test this method. The results show that the algorithm can effectively control the speed, acceleration and jerk.
The formula cars need high tire grip on racing challenge by reducing rolling displacement at corner or
double change lands. In this case study, the paper clarifies some issues related to suspension system with
inerter to reduce displacement and rolling angle under impact from road disturbance on Formula SAE
Car. We propose some new designs, which have an advance for suspension system by improving dynamics.
We optimize design of model based on the minimization of cost functions for roll dynamics, by reducing the
displacement transfer and the energy consumed by the inerter. Base on a passive suspension model that we
carried out quarter-car and half-car model for different parameters which show the benefit of the inerter.
The important advantage of the proposed solution is its integration a new mechanism, the inerter, this
system can increase advance in development and have effects on the vehicle dynamics in stability vehicle.
Offset effect on the S-Bend structure losses and optimization of its size for...IJECEIAES
The S-Bend structures are heavily exploited to join optical components. Reducing the power loss caused by the curve is the main objective in the design step of these components. However integrated optical circuits require S-Bend waveguide to be low loss and compact sized. In this paper, we present a contribution to link the curved structure to the straight waveguide by using the simulated bend function available in the Beam propagation tool of the Rsoft commercial software package. Simulation results confirm that this approach allows a reduction of the size of the curved structure with offset with relatively minimum of losses for photonic field.
Algorithm for the Dynamic Analysis of Plane Rectangular Rigid Frame Subjected...Oyeniyi Samuel
This document presents an algorithm for dynamically analyzing a plane rectangular rigid frame subjected to ground motion. The algorithm involves:
1) Using a matrix stiffness method and static condensation to reduce the global stiffness matrix size.
2) Deriving a characteristic polynomial equation from the condensed matrix and mass matrix.
3) Solving the polynomial equation using Newton-Raphson iteration to obtain eigenvalues and eigenvectors.
4) Calculating modal responses like shear force and overturning moment, which provide dynamic responses of the frame.
The algorithm aims to simplify dynamic analysis calculations that typically require software. It was applied to a three-story frame example.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
This work presents the kinematics model of an RA-
02 (a 4 DOF) robotic arm. The direct kinematic problem is
addressed using both the Denavit-Hartenberg (DH) convention
and the product of exponential formula, which is based on the
screw theory. By comparing the results of both approaches, it
turns out that they provide identical solutions for the
manipulator kinematics. Furthermore, an algebraic solution of
the inverse kinematics problem based on trigonometric
formulas is also provided. Finally, simulation results for the
kinematics model using the Matlab program based on the DH
convention are presented. Since the two approaches are
identical, the product of exponential formula is supposed to
produce same simulation results on the robotic arm studied.
Keywords-Robotics; DH convention; product of exponentials;
kinematics; simulations
This document discusses modal analysis of rotating structures using active magnetic bearings. It begins by introducing modal analysis and its importance for analyzing high-speed rotating machinery. It then describes the experimental setup which uses active magnetic bearings to both levitate and excite a test rotor. Natural frequencies and mode shapes are identified for the free-free rotor both with and without bearing stiffness. Introducing bearing stiffness is found to increase natural frequencies and introduce additional modes. The document concludes by explaining how the active magnetic bearings can be used to artificially excite the rotor to measure its frequency response functions and identify its dynamic characteristics.
—This paper presents a new image based visual servoing (IBVS) control scheme for omnidirectional wheeled mobile robots with four swedish wheels. The contribution is the proposal of a scheme that consider the overall dynamic of the system; this means, we put together mechanical and electrical dynamics. The actuators are direct current (DC) motors, which imply that the system input signals are armature voltage applied to DC motors. In our control scheme the PD control law and eye-to-hand camera configuration are used to compute the armature voltages and to measure system states, respectively. Stability proof is performed via Lypunov direct method and LaSalle's invariance principle. Simulation and experimental results were performed in order to validate the theoretical proposal and to show the good performance of the posture errors. Keywords—IBVS, posture control, omnidirectional wheeled mobile robot, dynamic actuator, Lyapunov direct method.
Attitude Control of Quadrotor Using PD Plus Feedforward Controller on SO(3)IJECEIAES
This paper proposes a simple scheme of Proportional-Derivative (PD) plus Feedforward controller on SO(3) to control the attitude of a quadrotor. This controller only needs the measurement of angular velocity to calculate the exponential coordinates of the rotation matrix. With rotation matrix as an error variable of the controller, the simulation shows that the controller is able to drive the attitude of the quadrotor from hovering condition to desired attitude and from an attitude condition goes to the hovering condition, despite the system is disturbed. When the system is convergent, the rotation error matrix will be a 3 3 identity matrix.
This document analyzes an axial-flux permanent magnet synchronous machine with contra-rotating rotors under unbalanced load conditions using 3D finite element analysis. It discusses how the back electromotive force (EMF) produced by each rotor combines to produce a distorted total back EMF when the rotors are at different angular positions. 3D FEA is used to model the machine and simulate its operation under unbalanced loads to obtain characteristics of the back EMF and torque production. The analysis aims to better understand performance issues like torque ripple and current oscillation that occur under unbalanced loads.
SIMULTANEOUS OPTIMIZATION OF SEMIACTIVE QUARTER CAR SUSPENSION PARAMETERS USI...ijmech
In present paper, a methodology is presented related to the optimization of semi-active quarter car model
suspension parameters having three degrees of freedom, subjected to bump type of road excitation.
Influence of primary suspension stiffness, primary suspension damping, secondary suspension stiffness and
secondary suspension damping are studied on the passenger ride comfort, taking root mean square (RMS)
values of passenger seat displacement and settling time into account. Semi-active quarter car model
assembled with magneto-rheological (MR) shock absorber is selected for optimization of suspension
parameters using Taguchi method in combination with Grey relational analysis. Confirmatory results with
simulation run indicates that the optimized results of suspension parameters are helpful in achieving the
best ride comfort to travelling passengers in terms of minimization of passenger seat displacement and
settling time values.
IRJET - Design and Optimization based on Surrogate Model of a Brushless Direc...IRJET Journal
This document describes the design and optimization of a brushless direct current motor (BLDCM) for a light electric vehicle application. It aims to achieve high efficiency under typical load conditions. The design process involves determining requirements based on vehicle specifications, selecting a motor configuration, and estimating initial dimensions. A 24-slot, 14-pole configuration is chosen. Dimensions like stator outer diameter, length, airgap, and permanent magnet thickness are calculated. Surrogate modeling and particle swarm optimization techniques are used to optimize the motor design while reducing computational cost compared to traditional finite element analysis-based optimization.
Matthew Audley is pursuing a PhD in track maintenance decision making under the supervision of Professor John Andrews. The study analyzes six years of UK rail network track geometry and maintenance data to understand the effects of maintenance on track deterioration. A Weibull approach is used to model the time it takes track geometry to degrade after maintenance. The results show that traffic speed and maintenance history impact deterioration rates. The second half of the PhD develops a track state modeling tool using Petri nets to determine optimal inspection intervals, maintenance criteria, and resource allocation to minimize life cycle costs.
Study on transmission energy losses and finding the hazards using what if ana...eSAT Publishing House
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
This document discusses a randomized LSB hiding approach for nested digital image watermarking. It proposes encrypting one watermark image using Blowfish before embedding it into another watermark image using randomized LSB hiding. This nested watermark is then encrypted again using Blowfish before being embedded into the cover image for increased security. Randomized LSB hiding is used for embedding as it has lower complexity and is more robust than direct LSB hiding. The approach aims to improve security and embedding capacity for copyright protection of digital images.
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
Comparative study of a flexible and rigid two degree of freedom half car modeleSAT Journals
Abstract Ride quality is concerned with the feel of the passenger in the environment of a moving vehicle. It is one of the key indices in determining comfort levels of a vehicle. Although, “ride comfort” evaluation is subjective in nature, researchers have developed mathematical models to study and evaluate vehicle ride performance. Some popular models for vehicle ride analysis are – quarter car model, two dof (degree of freedom) and four dof half car model. These models model the chassis as a rigid body. This work removes this assumption and models the chassis of the vehicle as a flexible beam on a spring damper system at the front and rear using Euler beam theory. This elastic model has two dof – vehicle bounce and pitch, and has been compared with the rigid two dof model. Euler beam theory and Lagrangian mechanics are used to derive the equations of motion. Finite element method is used to validate this model. Experimental validation of the natural frequencies of this flexible beam is presented. Keywords: Flexible ride model, Elastic ride model
International Journal of Computational Engineering Research(IJCER)ijceronline
International Journal of Computational Engineering Research (IJCER) is dedicated to protecting personal information and will make every reasonable effort to handle collected information appropriately. All information collected, as well as related requests, will be handled as carefully and efficiently as possible in accordance with IJCER standards for integrity and objectivity.
Aplanning algorithm offive-axis feedrate interpolation based on drive and jer...IJRES Journal
CNC technology marks the core of modern manufacturing, and CNC interpolation module is one of the most important numerical control technology modules. Avery important feature of the CNC is to implement the feed rate that consists in producing the set points based on a NC program. In the high speed machining, the feed rate is restricted by the velocity, acceleration, and jerk. And the NURBS curve is a free curve, due to the many advantages of NURBS curves, it can be well applied to the CNC feed rate interpolation. The algorithm can get more smooth feed rate curves, which makes better use of kinematical characteristics of the machine. Finally, according to each machine axis capability, one can use the feed rate control method which is verified by simulation analysis and processing to test this method. The results show that the algorithm can effectively control the speed, acceleration and jerk.
The formula cars need high tire grip on racing challenge by reducing rolling displacement at corner or
double change lands. In this case study, the paper clarifies some issues related to suspension system with
inerter to reduce displacement and rolling angle under impact from road disturbance on Formula SAE
Car. We propose some new designs, which have an advance for suspension system by improving dynamics.
We optimize design of model based on the minimization of cost functions for roll dynamics, by reducing the
displacement transfer and the energy consumed by the inerter. Base on a passive suspension model that we
carried out quarter-car and half-car model for different parameters which show the benefit of the inerter.
The important advantage of the proposed solution is its integration a new mechanism, the inerter, this
system can increase advance in development and have effects on the vehicle dynamics in stability vehicle.
Offset effect on the S-Bend structure losses and optimization of its size for...IJECEIAES
The S-Bend structures are heavily exploited to join optical components. Reducing the power loss caused by the curve is the main objective in the design step of these components. However integrated optical circuits require S-Bend waveguide to be low loss and compact sized. In this paper, we present a contribution to link the curved structure to the straight waveguide by using the simulated bend function available in the Beam propagation tool of the Rsoft commercial software package. Simulation results confirm that this approach allows a reduction of the size of the curved structure with offset with relatively minimum of losses for photonic field.
Algorithm for the Dynamic Analysis of Plane Rectangular Rigid Frame Subjected...Oyeniyi Samuel
This document presents an algorithm for dynamically analyzing a plane rectangular rigid frame subjected to ground motion. The algorithm involves:
1) Using a matrix stiffness method and static condensation to reduce the global stiffness matrix size.
2) Deriving a characteristic polynomial equation from the condensed matrix and mass matrix.
3) Solving the polynomial equation using Newton-Raphson iteration to obtain eigenvalues and eigenvectors.
4) Calculating modal responses like shear force and overturning moment, which provide dynamic responses of the frame.
The algorithm aims to simplify dynamic analysis calculations that typically require software. It was applied to a three-story frame example.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
This work presents the kinematics model of an RA-
02 (a 4 DOF) robotic arm. The direct kinematic problem is
addressed using both the Denavit-Hartenberg (DH) convention
and the product of exponential formula, which is based on the
screw theory. By comparing the results of both approaches, it
turns out that they provide identical solutions for the
manipulator kinematics. Furthermore, an algebraic solution of
the inverse kinematics problem based on trigonometric
formulas is also provided. Finally, simulation results for the
kinematics model using the Matlab program based on the DH
convention are presented. Since the two approaches are
identical, the product of exponential formula is supposed to
produce same simulation results on the robotic arm studied.
Keywords-Robotics; DH convention; product of exponentials;
kinematics; simulations
This document discusses modal analysis of rotating structures using active magnetic bearings. It begins by introducing modal analysis and its importance for analyzing high-speed rotating machinery. It then describes the experimental setup which uses active magnetic bearings to both levitate and excite a test rotor. Natural frequencies and mode shapes are identified for the free-free rotor both with and without bearing stiffness. Introducing bearing stiffness is found to increase natural frequencies and introduce additional modes. The document concludes by explaining how the active magnetic bearings can be used to artificially excite the rotor to measure its frequency response functions and identify its dynamic characteristics.
—This paper presents a new image based visual servoing (IBVS) control scheme for omnidirectional wheeled mobile robots with four swedish wheels. The contribution is the proposal of a scheme that consider the overall dynamic of the system; this means, we put together mechanical and electrical dynamics. The actuators are direct current (DC) motors, which imply that the system input signals are armature voltage applied to DC motors. In our control scheme the PD control law and eye-to-hand camera configuration are used to compute the armature voltages and to measure system states, respectively. Stability proof is performed via Lypunov direct method and LaSalle's invariance principle. Simulation and experimental results were performed in order to validate the theoretical proposal and to show the good performance of the posture errors. Keywords—IBVS, posture control, omnidirectional wheeled mobile robot, dynamic actuator, Lyapunov direct method.
Attitude Control of Quadrotor Using PD Plus Feedforward Controller on SO(3)IJECEIAES
This paper proposes a simple scheme of Proportional-Derivative (PD) plus Feedforward controller on SO(3) to control the attitude of a quadrotor. This controller only needs the measurement of angular velocity to calculate the exponential coordinates of the rotation matrix. With rotation matrix as an error variable of the controller, the simulation shows that the controller is able to drive the attitude of the quadrotor from hovering condition to desired attitude and from an attitude condition goes to the hovering condition, despite the system is disturbed. When the system is convergent, the rotation error matrix will be a 3 3 identity matrix.
This document analyzes an axial-flux permanent magnet synchronous machine with contra-rotating rotors under unbalanced load conditions using 3D finite element analysis. It discusses how the back electromotive force (EMF) produced by each rotor combines to produce a distorted total back EMF when the rotors are at different angular positions. 3D FEA is used to model the machine and simulate its operation under unbalanced loads to obtain characteristics of the back EMF and torque production. The analysis aims to better understand performance issues like torque ripple and current oscillation that occur under unbalanced loads.
SIMULTANEOUS OPTIMIZATION OF SEMIACTIVE QUARTER CAR SUSPENSION PARAMETERS USI...ijmech
In present paper, a methodology is presented related to the optimization of semi-active quarter car model
suspension parameters having three degrees of freedom, subjected to bump type of road excitation.
Influence of primary suspension stiffness, primary suspension damping, secondary suspension stiffness and
secondary suspension damping are studied on the passenger ride comfort, taking root mean square (RMS)
values of passenger seat displacement and settling time into account. Semi-active quarter car model
assembled with magneto-rheological (MR) shock absorber is selected for optimization of suspension
parameters using Taguchi method in combination with Grey relational analysis. Confirmatory results with
simulation run indicates that the optimized results of suspension parameters are helpful in achieving the
best ride comfort to travelling passengers in terms of minimization of passenger seat displacement and
settling time values.
IRJET - Design and Optimization based on Surrogate Model of a Brushless Direc...IRJET Journal
This document describes the design and optimization of a brushless direct current motor (BLDCM) for a light electric vehicle application. It aims to achieve high efficiency under typical load conditions. The design process involves determining requirements based on vehicle specifications, selecting a motor configuration, and estimating initial dimensions. A 24-slot, 14-pole configuration is chosen. Dimensions like stator outer diameter, length, airgap, and permanent magnet thickness are calculated. Surrogate modeling and particle swarm optimization techniques are used to optimize the motor design while reducing computational cost compared to traditional finite element analysis-based optimization.
Matthew Audley is pursuing a PhD in track maintenance decision making under the supervision of Professor John Andrews. The study analyzes six years of UK rail network track geometry and maintenance data to understand the effects of maintenance on track deterioration. A Weibull approach is used to model the time it takes track geometry to degrade after maintenance. The results show that traffic speed and maintenance history impact deterioration rates. The second half of the PhD develops a track state modeling tool using Petri nets to determine optimal inspection intervals, maintenance criteria, and resource allocation to minimize life cycle costs.
Study on transmission energy losses and finding the hazards using what if ana...eSAT Publishing House
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
This document discusses a randomized LSB hiding approach for nested digital image watermarking. It proposes encrypting one watermark image using Blowfish before embedding it into another watermark image using randomized LSB hiding. This nested watermark is then encrypted again using Blowfish before being embedded into the cover image for increased security. Randomized LSB hiding is used for embedding as it has lower complexity and is more robust than direct LSB hiding. The approach aims to improve security and embedding capacity for copyright protection of digital images.
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
Noise tolerant color image segmentation using support vector machineeSAT Publishing House
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology.
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology.
Investigation on effective thermal conductivity of foams using transient plan...eSAT Publishing House
The document describes an experimental setup used to determine the effective thermal conductivity of various foam materials (polyurethane foam, latex rubber foam, synthetic foam) using the transient plane heat source method. Thermal conductivity measurements were taken for each foam material at different concentrations (obtained by compressing the foam to different thicknesses). The results showed that increasing the concentration of the material (decreasing porosity) led to an increase in the effective thermal conductivity, as compressing the foam evacuated more of the low conductivity air pockets within the material.
1. Pounding is a major cause of damage to adjacent buildings during earthquakes when they are constructed close together without sufficient separation.
2. The study analyzes seismic pounding forces between buildings of different heights and floor levels using software. It finds that pounding damage increases when buildings have different dynamic properties or are inadequately separated.
3. Pounding can cause non-structural to severe structural damage. The required minimum separation between buildings according to codes is 15-30 mm depending on building type, but may need to be larger.
Directly coupled microstrip array antennas for wideband applicationeSAT Publishing House
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
This document summarizes a research paper that proposes a system to detect uncontrolled crowd motion behavior using computer vision techniques. The system analyzes surveillance videos from mass gatherings using a holistic approach, where the crowd is treated as a single entity rather than tracking individuals. Optical flow is computed using the Lucas-Kanade method to estimate velocities across subsections of video frames. Congested areas where crowd movement is slow or stopped can be identified based on low optical flow magnitudes. The system was developed using MATLAB and could help security personnel monitor crowds and prevent disasters by detecting dangerous crowd conditions. Future work may include using multiple camera views and improved tracking techniques.
Smart analysis of most build multistoried rcc building of gulbarga regioneSAT Publishing House
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology.
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology.
Appraisal of multilevel car parking facility at kg road cbd area, bengaluru cityeSAT Publishing House
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology.
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
A review of various technologies and transmission modes for design and develo...eSAT Publishing House
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology.
A geophysical insight of earthquake occurred on 21 st may 2014 off paradip, b...eSAT Publishing House
1) A 6.0 magnitude earthquake occurred off the coast of Paradip, Odisha in the Bay of Bengal on May 21, 2014 at a depth of around 40 km.
2) Analysis of magnetic and bathymetric data from the area revealed the presence of major lineaments in NW-SE and NE-SW directions that may be responsible for seismic activity through stress release.
3) Movements along growth faults at the margins of large Bengal channels, due to large sediment loads, could also contribute to seismic events by triggering movements along the faults.
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
Quality of service parameter centric resource allocation for lte advancedeSAT Publishing House
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
Optimized mapping and navigation of remote area through an autonomous roboteSAT Publishing House
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
This document investigates how changing the position of the tool point on the moving platform affects the dynamic performance of a 3RRR planar parallel manipulator. Lagrange-d'Alembert formulation is used to develop the dynamic model. The manipulator's dimensions and parameters remain the same, while only the tool point position is changed. Simulation results show that locating the tool point at an optimal position reduces the generalized forces and energy consumption of the manipulator, improving its dynamic performance.
The performance evaluation is one of most important issues in the analysis and design of parallel manipulators.
Characteristics such as manipulability and minimum singular value are used to determine the performance of the manipulators. The performance indices are used to eliminate the singularity and it’s near configurations. In this paper 6-UPS spatial parallel manipulator is considered and its performance indices such as condition number, manipulability and minimum singular value are determined for different structures.
This document discusses stiffness analysis of flexible parallel manipulators. It presents the forward kinematics analysis of a 3-RRR planar parallel manipulator using genetic algorithms and neural networks to minimize positional errors. The Jacobian and platform stiffness matrices are evaluated within the defined workspace. A pseudo-rigid body model with frame and plate elements is used to analyze the flexible link configuration and compliant joints. Stiffness indices are obtained and validated using commercial finite element software. The methodology is illustrated for a 3-RRR flexible parallel manipulator to study the effects of link flexibility and joint compliance on stiffness.
This document presents the forward and inverse kinematic analysis and dynamic analysis of a 2 degree of freedom robotic arm manipulator. It includes:
- Deriving the forward kinematics equations relating joint angles to end effector position.
- Determining the inverse kinematics and discussing issues like multiple solutions and singularities.
- Analyzing the manipulator performance in terms of condition number, mobility index, and singular configurations.
- Modeling the dynamics using Lagrangian and Newton-Euler approaches and deriving the equations of motion relating joint torques to accelerations.
Pick and place task is one among the most important tasks in industrial field handled by “Selective
Compliance Assembly Robot Arm” (SCARA). Repeatability with high-speed movement in horizontal plane is
remarkable feature of this type of manipulator. The challenge of design SCARA is the difficulty of achieving
stability of high-speed movement with long length of links. Shorter links arm can move more stable. This
condition made the links should be considered restrict then followed by restriction of operation area
(workspace). In this research, authors demonstrated on expanding SCARA robot’s workspace in horizontal area
via linear sliding actuator that embedded to base link of the robot arm. With one additional prismatic joint the
previous robot manipulator with 3 degree of freedom (3-DOF), 2 revolute joints and 1 prismatic joint is become
4-DOF PRRP manipulator. This designation increased workspace of robot from 0.5698m2 performed by the
previous arm (without linear actuator) to 1.1281m2 by the propose arm (with linear actuator). The increasing
rate was about 97.97% of workspace with the same links length. The result of experimentation also indicated
that the operation time spent to reach object position was also reduced.
Influence of joint clearance on kinematic and dynamic parameters of mechanismIOSR Journals
Kinematic joints for dynamic analysis of multi-body mechanical systems assumed ideal or perfect.
However, in a real mechanical kinematical joint clearance is always present. Such clearance is necessary for
the component assemblage and to allow the relative motion between the connected bodies. This clearance is
inevitable due to the manufacturing tolerances, material deformations, wear, and imperfections. The presence of
such joint clearance degrades the performance of mechanical systems in virtue of the contact and impact forces
that take place at the joint. Contact analysis is a computational bottleneck in mechanical design where the
contact changes. Manual analysis is time-consuming and prone to error. To address these problems, a
geometrical contact analysis method based on kinematic simulation, using CAD software is developed. An
equivalent kinematic linkage mechanism is constructed according to contact position of pin and hole assembly.
Results of kinematic and dynamic analysis of a four bar linkage with joint clearance shows that the contribution
of joint forces at slower input speed also degrades the performance of mechanism
The International Journal of a Mechanical Engineering Research and Technology is that an international online journal published Quarterly offers fast publication schedule whilst maintaining rigorous peer review. The use of recommended electronic formats for a article delivery expedites the process of All submitted research articles are subjected to the immediate rapid screening by editors consultation with Editorial Board or others working in the field of appropriate to ensure that they are likely to be the level of interest and importance of appropriate for the journal.
The International Journal of Mechanical Engineering Research and Technology is an international online journal in English published Quarterly offers a speed publication schedule with maintaining rigorous peer review and the use of recommended electronic formats of article delivery expedites the process of All submitted research articles are subjected to immediate rapid screening by the editors consultation with the Editorial Board or others working in the field of appropriate to ensure that they are similarly to be the level of interest and importance of appropriate for the journal.
Assessment of Robotic Arm and it’s ParametersIRJET Journal
This document provides an overview of robotic arm parameters and applications. It examines features such as the number of axes, degrees of freedom, kinematics, payload, speed and acceleration. Robotic arms are used widely in industrial, commercial and residential settings. While research has enhanced parameters like degrees of freedom and kinematics, gaps still remain around expanding working envelopes and increasing payloads. The document surveys literature on robotic arm studies and identifies opportunities to optimize arms through additional research.
Insect inspired hexapod robot for terrain navigationeSAT Journals
Abstract The aim of this paper is to build a sixlegged walking robot that is capable of basicmobility tasks such as walking forward, backward, rotating in place and raising orlowering the body height. The legs will be of a modular design and will have threedegrees of freedom each. This robot will serve as a platform onto which additionalsensory components could be added, or which could be programmed to performincreasingly complex motions. This report discusses the components that make up ourfinal design.In this paper we have selected ahexapod robot; we are focusing &developingmainly on efficient navigation method indifferent terrain using opposite gait of locomotion, which will make it faster and at sametime energy efficient to navigate and negotiate difficult terrain.This paper discuss the Features, development, and implementation of the Hexapod robot Index Terms:Biologically inspired, Gait Generation,Legged hexapod, Navigation.
Flow Physics analysis of Three-bucket Helical Savonius rotor at 90 degree twi...BBIT Kolkata
This document analyzes the flow behavior of a helical Savonius rotor using computational fluid dynamics (CFD). It constructs a 3D model of a three-bladed helical Savonius rotor with a 90 degree twist angle. CFD simulations are performed to obtain contours of static pressure and velocity around the rotor blades at different rotor angles. The simulations show that high performance is obtained when the advancing blade is upstream of the airflow at a rotor angle of 90 degrees, and maximum positive static pressure is obtained at a rotor angle of 0 degrees, which affects the positive coefficient of static torque.
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology.
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology.
This document discusses vibration suppression of a vehicle-bridge interaction system using multiple tuned mass dampers (TMDs). It presents a mathematical model of a system consisting of a vehicle, bridge beam, and three TMDs placed at different locations on the bridge. The model approximates the bridge deflection using the first four mode shapes. Equations of motion are derived for the vehicle, TMDs, and bridge using Lagrange's equations. It is found that placing TMDs at the anti-nodes of the first and second mode shapes is most effective for vibration suppression.
A Restatement Of The Optimum Synthesis Of Function Generators With Planar Fou...Sherri Cost
This document discusses the problem of optimally synthesizing mechanisms to approximate functions. It frames the problem as one of curve fitting, where the goal is to find the portion of a mechanism's input-output curve that best fits the graph of the target function, while also ensuring good motion transmission characteristics. Examples are given of designing four-bar and slider-crank linkages to generate logarithmic and tangent functions. The document outlines several geometric transformations that can be applied to better fit the mechanism's curve to the target function graph, including translations, scalings, mirroring, and rotations.
Forward and Inverse Kinematic Analysis of Robotic ManipulatorsIRJET Journal
The document discusses forward and inverse kinematic analysis of 5 DOF and 6 DOF robotic manipulators. It presents the Denavit-Hartenberg (DH) parameter modeling approach to determine the homogeneous transformation matrices between links to solve the forward kinematics. The inverse kinematics is solved by multiplying the inverse of the transformation matrices and equating the end effector positions and orientations. Results for 5 DOF manipulator show the joint values that provide different end effector positions and orientations.
Iaetsd design of a robust fuzzy logic controller for a single-link flexible m...Iaetsd Iaetsd
This document describes the design of a fuzzy logic controller for a single-link flexible manipulator. A fuzzy-PID controller is used to control an uncertain flexible robotic arm and its internal motor dynamics parameters. The controller is tested against conventional integral and PID controllers in simulations. The results show the proposed fuzzy PID controller has better robustness under variations in motor dynamics compared to the other controllers.
Identification of dynamic rigidity for high speed spindles supported on ball ...eSAT Journals
Abstract The widespread use of high-speed machining in recent decades has led to a significant area of research on issues that limit its productivity. Regenerative chatter is a well‐known machining problem that results in unstable cutting process, leads to the poor surface quality, reduced material removal rate and damage on the machine tool itself. The main requirement for the stability of system dynamics is the information of tool tip frequency response functions (FRF’s).The present work considered a coupled model of spindle-bearing system by using the angular contact ball bearing forces on stability of machining. Using Timoshenko beam element formulation, the spindle unit is analyzed by including the gyroscopic and centrifugal terms and the bearing contact forces are arrived from Hertzian contact theory. Then, the model is used for studying the effects of viscous damping to obtain the tool point FRF for the dynamic spindle. Index Terms: Spindle dynamics, Stability, High speed effects, Bearing contact forces, Hertzian contact theory, Finite element modeling.
Forward and Inverse Kinematic Analysis of Robotic ManipulatorsIRJET Journal
The document discusses forward and inverse kinematic analysis of 5 DOF and 6 DOF robotic manipulators. It presents the Denavit-Hartenberg parameters to model the link lengths, twist angles, offsets etc. of the manipulators. Forward kinematics is used to calculate the position and orientation of the end effector given the joint angles, while inverse kinematics is used to determine the required joint angles to achieve a desired end effector pose. Results for a 5 DOF manipulator using forward and inverse kinematic equations are presented.
Kineto-Elasto Dynamic Analysis of Robot Manipulator Puma-560IOSR Journals
Current industrial robots are made very heavy to achieve high Stiffness
which increases the accuracy of their motion. However this heaviness limits the robot speed and in masses the
required energy to move the system. The requirement for higher speed and better system performance makes it
necessary to consider a new generation of light weight manipulators as an alternative to today's massive
inefficient ones. Light weight manipulators require Less energy to move and they have larger payload abilities
and more maneuverability. However due to the dynamic effects of structural flexibility, their control is much
more difficult. Therefore, there is a need to develop accurate dynamic models for design and control of such
systems.This project presents the flexibility and Kineto - Elasto dynamic analysis of robot manipulator
considering deflection. Based on the distributed parameter method, the generalized motion equations of robot
manipulator with flexible links are derived. The final formulation of the motion equations is used to model
general complex elastic manipulators with nonlinear rigid-body and elastic motion in dynamics and it can be
used in the flexibility analysis of robot manipulators and spatial mechanisms. Manipulator end-effector path
trajectory, velocity and accelerations are plotted. Joint torques is to be determined for each joint trajectory
(Dynamics) .Using joint torques, static loading due to link’s masses, masses at joints, and payload, the robot
arms elastic deformations are to be found by using ANSYS-12.0 software package. Elastic compensation is
inserted in coordinates of robotic programming to get exact end-effectors path. A comparison of paths
trajectory of the end-effector is to be plotted. Also variation of torques is plotted after considering elastic
compensation. These torque variations are included in the robotic programming for getting the accurate endeffect
or’s path trajectory
Similar to Design and analysis of x y-q positioning stage based on (20)
Hudhud cyclone caused extensive damage in Visakhapatnam, India in October 2014, especially to tree cover. This will likely impact the local environment in several ways: increased air pollution as trees absorb less; higher temperatures without tree canopy; increased erosion and landslides. It also created large amounts of waste from destroyed trees. Proper management of solid waste is needed to prevent disease spread. Suggested measures include restoring damaged plants, building fountains to reduce heat, mandating light-colored buildings, improving waste management, and educating public on health risks. Overall, changes are needed to water, land, and waste practices to rebuild the environment after the cyclone removed green cover.
Impact of flood disaster in a drought prone area – case study of alampur vill...eSAT Publishing House
1) In September-October 2009, unprecedented heavy rainfall and dam releases caused widespread flooding in Alampur village in Mahabub Nagar district, a historically drought-prone area.
2) The flood damaged or destroyed homes, buildings, infrastructure, crops, and documents. It displaced many residents and cut off the village.
3) The socioeconomic conditions and mud-based construction of homes in the village exacerbated the flood's impacts, making damage more severe and recovery more difficult.
The document summarizes the Hudhud cyclone that struck Visakhapatnam, India in October 2014. It describes the cyclone's formation, rapid intensification to winds of 175 km/h, and landfall near Visakhapatnam. The cyclone caused extensive damage estimated at over $1 billion and at least 109 deaths in India and Nepal. Infrastructure like buildings, bridges, and power lines were destroyed. Crops and fishing boats were also damaged. The document then discusses coping strategies and improvements needed to disaster management plans to better prepare for future cyclones.
Groundwater investigation using geophysical methods a case study of pydibhim...eSAT Publishing House
This document summarizes the results of a geophysical investigation using vertical electrical sounding (VES) methods at 13 locations around an industrial area in India. The VES data was interpreted to generate geo-electric sections and pseudo-sections showing subsurface resistivity variations. Three main layers were typically identified - a high resistivity topsoil, a weathered middle layer, and a basement rock. Pseudo-sections revealed relatively more weathered areas in the northwest and southwest. Resistivity sections helped identify zones of possible high groundwater potential based on low resistivity anomalies sandwiched between more resistive layers. The study concluded the electrical resistivity method was useful for understanding subsurface geology and identifying areas prospective for groundwater exploration.
Flood related disasters concerned to urban flooding in bangalore, indiaeSAT Publishing House
1. The document discusses urban flooding in Bangalore, India. It describes how factors like heavy rainfall, population growth, and improper land use have contributed to increased flooding in the city.
2. Flooding events in 2013 are analyzed in detail. A November rainfall caused runoff six times higher than the drainage capacity, inundating low-lying residential areas.
3. Impacts of urban flooding include disrupted daily life, damaged infrastructure, and decreased economic activity in affected areas. The document calls for improved flood management strategies to better mitigate urban flooding risks in Bangalore.
Enhancing post disaster recovery by optimal infrastructure capacity buildingeSAT Publishing House
This document discusses enhancing post-disaster recovery through optimal infrastructure capacity building. It presents a model to minimize the cost of meeting demand using auxiliary capacities when disaster damages infrastructure. The model uses genetic algorithms to select optimal capacity combinations. The document reviews how infrastructure provides vital services supporting recovery activities and discusses classifying infrastructure into six types. When disaster reduces infrastructure services, a gap forms between community demands and available support, hindering recovery. The proposed research aims to identify this gap and optimize capacity selection to fill it cost-effectively.
Effect of lintel and lintel band on the global performance of reinforced conc...eSAT Publishing House
This document analyzes the effect of lintels and lintel bands on the seismic performance of reinforced concrete masonry infilled frames through non-linear static pushover analysis. Four frame models are considered: a frame with a full masonry infill wall; a frame with a central opening but no lintel/band; a frame with a lintel above the opening; and a frame with a lintel band above the opening. The results show that the full infill wall model has 27% higher stiffness and 32% higher strength than the model with just an opening. Models with lintels or lintel bands have slightly higher strength and stiffness than the model with just an opening. The document concludes lintels and lintel
Wind damage to trees in the gitam university campus at visakhapatnam by cyclo...eSAT Publishing House
1) A cyclone with wind speeds of 175-200 kph caused massive damage to the green cover of Gitam University campus in Visakhapatnam, India. Thousands of trees were uprooted or damaged.
2) A study assessed different types of damage to trees from the cyclone, including defoliation, salt spray damage, damage to stems/branches, and uprooting. Certain tree species were more vulnerable than others.
3) The results of the study can help in selecting more wind-resistant tree species for future planting and reducing damage from future storms.
Wind damage to buildings, infrastrucuture and landscape elements along the be...eSAT Publishing House
1) A visual study was conducted to assess wind damage from Cyclone Hudhud along the 27km Visakha-Bheemli Beach road in Visakhapatnam, India.
2) Residential and commercial buildings suffered extensive roof damage, while glass facades on hotels and restaurants were shattered. Infrastructure like electricity poles and bus shelters were destroyed.
3) Landscape elements faced damage, including collapsed trees that damaged pavements, and debris in parks. The cyclone wiped out over half the city's green cover and caused beach erosion around protected areas.
1) The document reviews factors that influence the shear strength of reinforced concrete deep beams, including compressive strength of concrete, percentage of tension reinforcement, vertical and horizontal web reinforcement, aggregate interlock, shear span-to-depth ratio, loading distribution, side cover, and beam depth.
2) It finds that compressive strength of concrete, tension reinforcement percentage, and web reinforcement all increase shear strength, while shear strength decreases as shear span-to-depth ratio increases.
3) The distribution and amount of vertical and horizontal web reinforcement also affects shear strength, but closely spaced stirrups do not necessarily enhance capacity or performance.
Role of voluntary teams of professional engineers in dissater management – ex...eSAT Publishing House
1) A team of 17 professional engineers from various disciplines called the "Griha Seva" team volunteered after the 2001 Gujarat earthquake to provide technical assistance.
2) The team conducted site visits, assessments, testing and recommended retrofitting strategies for damaged structures in Bhuj and Ahmedabad. They were able to fully assess and retrofit 20 buildings in Ahmedabad.
3) Factors observed that exacerbated the earthquake's impacts included unplanned construction, non-engineered buildings, improper prior retrofitting, and defective materials and workmanship. The professional engineers' technical expertise was crucial for effective post-disaster management.
This document discusses risk analysis and environmental hazard management. It begins by defining risk, hazard, and toxicity. It then outlines the steps involved in hazard identification, including HAZID, HAZOP, and HAZAN. The document presents a case study of a hypothetical gas collecting station, identifying potential accidents and hazards. It discusses quantitative and qualitative approaches to risk analysis, including calculating a fire and explosion index. The document concludes by discussing hazard management strategies like preventative measures, control measures, fire protection, relief operations, and the importance of training personnel on safety.
Review study on performance of seismically tested repaired shear wallseSAT Publishing House
This document summarizes research on the performance of reinforced concrete shear walls that have been repaired after damage. It begins with an introduction to shear walls and their failure modes. The literature review then discusses the behavior of original shear walls as well as different repair techniques tested by other researchers, including conventional repair with new concrete, jacketing with steel plates or concrete, and use of fiber reinforced polymers. The document focuses on evaluating the strength retention of shear walls after being repaired with various methods.
Monitoring and assessment of air quality with reference to dust particles (pm...eSAT Publishing House
This document summarizes a study on monitoring and assessing air quality with respect to dust particles (PM10 and PM2.5) in the urban environment of Visakhapatnam, India. Sampling was conducted in residential, commercial, and industrial areas from October 2013 to August 2014. The average PM2.5 and PM10 concentrations were within limits in residential areas but moderate to high in commercial and industrial areas. Exceedance factor levels indicated moderate pollution for residential areas and moderate to high pollution for commercial and industrial areas. There is a need for management measures like improved public transport and green spaces to combat particulate air pollution in the study areas.
Low cost wireless sensor networks and smartphone applications for disaster ma...eSAT Publishing House
This document describes a low-cost wireless sensor network and smartphone application system for disaster management. The system uses an Arduino-based wireless sensor network comprising nodes with various sensors to monitor the environment. The sensor data is transmitted to a central gateway and then to the cloud for analysis. A smartphone app connected to the cloud can detect disasters from the sensor data and send real-time alerts to users to help with early evacuation. The system aims to provide low-cost localized disaster detection and warnings to improve safety.
Coastal zones – seismic vulnerability an analysis from east coast of indiaeSAT Publishing House
This document summarizes an analysis of seismic vulnerability along the east coast of India. It discusses the geotectonic setting of the region as a passive continental margin and reports some moderate seismic activity from offshore in recent decades. While seismic stability cannot be assumed given events like the 2004 tsunami, no major earthquakes have been recorded along this coast historically. The document calls for further study of active faults, neotectonics, and implementation of improved seismic building codes to mitigate vulnerability.
Can fracture mechanics predict damage due disaster of structureseSAT Publishing House
This document discusses how fracture mechanics can be used to better predict damage and failure of structures. It notes that current design codes are based on small-scale laboratory tests and do not account for size effects, which can lead to more brittle failures in larger structures. The document outlines how fracture mechanics considers factors like size effect, ductility, and minimum reinforcement that influence the strength and failure behavior of structures. It provides examples of how fracture mechanics has been applied to problems like evaluating shear strength in deep beams and investigating a failure of an oil platform structure. The document argues that fracture mechanics provides a more scientific basis for structural design compared to existing empirical code provisions.
This document discusses the assessment of seismic susceptibility of reinforced concrete (RC) buildings. It begins with an introduction to earthquakes and the importance of vulnerability assessment in mitigating earthquake risks and losses. It then describes modeling the nonlinear behavior of RC building elements and performing pushover analysis to evaluate building performance. The document outlines modeling RC frames and developing moment-curvature relationships. It also summarizes the results of pushover analyses on sample 2D and 3D RC frames with and without shear walls. The conclusions emphasize that pushover analysis effectively assesses building properties but has limitations, and that capacity spectrum method provides appropriate results for evaluating building response and retrofitting impact.
Effect of hudhud cyclone on the development of visakhapatnam as smart and gre...eSAT Publishing House
This document discusses the effects of Cyclone Hudhud on the development of Visakhapatnam as a smart and green city through a case study and preliminary surveys. The surveys found that 31% of participants had experienced cyclones, 9% floods, and 59% landslides previously in Visakhapatnam. Awareness of disaster alarming systems increased from 14% before the 2004 tsunami to 85% during Cyclone Hudhud, while awareness of disaster management systems increased from 50% before the tsunami to 94% during Hudhud. The surveys indicate that initiatives after the tsunami improved awareness and preparedness. Developing Visakhapatnam as a smart, green city should consider governance
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Design and analysis of x y-q positioning stage based on
1. IJRET: International Journal of Research in Engineering and Technology eISSN: 2319-1163 | pISSN: 2321-7308
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Volume: 02 Issue: 09 | Sep-2013, Available @ http://www.ijret.org 371
DESIGN AND ANALYSIS OF X-Y-θθθθ POSITIONING STAGE BASED ON
REDUNDANT PARALLEL LINKAGE
U.Sudhakar1
, J.Srinivas2
1
Assistant Professor, Department of Mechanical Engg., GMRIT, Rajam, mr.u.sudhakar@gmail.com
2
Associate Professor, Department of Mechanical Engg., NIT Rourkela, 769008, Odisha, srin07@yahoo.co.in
Abstract
This paper presents the concept of a planar positioning stage based on a kinematically redundant parallel linkage. Basic kinematics
and workspace analysis of base redundant manipulator is initially explained and the procedure of static analysis to predict the
actuated joint torques is described. As there are six actuators in the linkage, the redundancy can be overcome by proper selection of
the base joint variables. Also it is assumed that the motion is at a constant speed. A numerical example is shown with a straight line
trajectory to illustrate the workspace and joint force calculation aspects of this linkage. The possible arrangement of the stage with
electrostatic actuation and sensing are finally highlighted.
Keywords: Kinematic redundancy, Parallel mechanism, Static analysis, and Workspace characteristics.
----------------------------------------------------------------------***------------------------------------------------------------------------
1. INTRODUCTION
In precision engineering, the positioning systems delivering
high strokes with compact sizes are essentially required. Most
of the positioning stages use parallel kinematic mechanisms,
which have a fixed base and movable end-effector connected
by multiple (at least two) independent kinematic chains in a
parallel scheme. The number of independent kinematic chains
is equal to the number of DOF of the end-effector. Spatial
positioning devices are often based on hexapods or tripods. A
typical example is the 6-DOF Stewart platform [1], in which
the platform is supported and driven by six struts (prismatic
joints). Another successful application is the Delta robot [2]
where a parallelogram is used to allow an output link to move
without changing its orientation with respect to an input link.
The three parallelograms completely prevent the platform
from rotating and make the Delta robot an XYZ stage. Other
examples include a tetrahedral tripod [3], which is a three-
cylindrical-prismatic-revolute XYZ translation stage. Three
prismatic joints are used to drive the platform by varying strut
lengths. This design is simple, singularity-free and efficient. It
provides a stiff and compact platform for machine tool
construction with high workspace-to-machine-volume ratio.
When it comes to the three degrees of freedom positioning,
commercially called x-y-theta positioning tables based on
serial linkages are used. In serial linkages, the first actuator
has to support the weight of other actuators resulting in a large
and sluggish device. For the last one decade, planar parallel
linkages have received considerable attention as positioning
devices.
Main disadvantage of parallel kinematic linkages is that end-
effector can only move within the intersection of the
workspaces of the kinematic chains. This can limit the
workspace of the stage. A direct result of the small workspace
is the poor dexterity and being constrained to the intersection
of the workspaces of several kinematic chains. The workspace
of a parallel manipulator generally contains loci of parallel or
type-2 singularities. In these singular configurations, the
manipulator cannot sustain certain wrench applied to its end-
effector. Redundancy is one of the means to reduce or
eliminate some of the limitations of parallel manipulators. In a
statically determinate system, equilibrium equations can be
used to determine the reaction forces at the constraints when
external forces are applied. Redundant parallel actuation can
also help-in improving damping, preload a structure in
addition to prevent the singular positions. There are two types
of redundancies in practice. First one is actuation redundancy,
which consists of either actuating normally passive joint or
adding additional actuated branches in an existing
manipulator. For sustaining a given wrench by the end-
effector, there are an infinite number of possible solutions for
the actuator torques. On the other hand, kinematic redundancy
consists of adding extra links and actuators. In this case, the
mobility of a manipulator is greater than the number of
degrees-of-freedom and there are an infinite number of
possible solutions for the inverse kinematic problem.
Several researchers illustrated the effectiveness of redundancy
in parallel kinematic linkages. Wang and Gosselin [4]
introduced one degree of kinematic redundancy in each leg of
a planar manipulator, a spherical manipulator and a spatial
manipulator. It was shown that the singularity configurations
were significantly reduced when compared to the non-
redundant manipulator. Mohamed and Gosselin [5] used
kinematic redundancy to reconfigure the platform of the
2. IJRET: International Journal of Research in Engineering and Technology eISSN: 2319-1163 | pISSN: 2321-7308
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Volume: 02 Issue: 09 | Sep-2013, Available @ http://www.ijret.org 372
parallel manipulators. Ebrahimi et al. [6] analyzed a 3-PRRR
manipulator and showed that kinematic redundancy enlarges
the workspace and can completely eliminate singularities
within it. Kotlarsky et al. [7] added one prismatic actuated
joint in one leg of a 3-RRR manipulator and used different
optimization strategies to avoid singularities and minimize the
pose errors. More recently, Boudreau and Nokleby [8]
presented a redundant parallel manipulator configuration for
resolving generalized forces during tracking of a trajectory.
Application of a parallel redundant configuration in a motion
system with the aim of minimizing the storage of elastic
energy in structure during acceleration is of recent concern.
More recent works aim at design of positioning stages using
mechanism redundancy. Ahn et al. [9] presented a micro
parallel positioning platform with two translational motions
and a rotational motion and employed it for simulation of
cutter path in laser-micromachining. Krishnan and Saggere
[10] proposed a compliant parallel redundant linkage for
micromanipulation tasks.
1.1 Objectives of Present Work
Based on the available literature, it is found that very few
works employed redundant parallel linkages in positioning
stages. In spite of their advantages, there may be
disadvantages like mechanical imperfection and friction due to
additional links and joints in a redundant linkage. Objectives
of present work are (i) illustrate the kinematics of 3-PRPR
linkage. (ii) Prediction of workspace and singularity
characteristics (iii) Perform static analysis during path tracking
application and (iv) Propose the stage for micro scale
application. Organization of the present paper is as follows:
Section-2 describes the kinematic analysis and workspace
determination. Section-3 deals with torque estimation
methodology. Results and discussions are presented in
section-4.
2. DESCRIPTION OF POSITIONING STAGE
A recently proposed 3-PRPR manipulator gives interesting
insights. Fig.1 shows this linkage. An actuated prismatic joint
fixed to the base (base prismatic joint) is added. It is followed
by a passive revolute joint, an actuated prismatic joint (distal
prismatic joint) and a passive revolute joint attached to the
mobile platform. The points O1, O2 and O3 and B1, B2 and
B3 are forming two equilateral triangles. The fixed reference
frame and the mobile frame attached to the end-effector are at
the geometric centers of triangles O1O2O3 and B1B2B3 with
origins at O and P, respectively.
Fig.1 Redundant 3-PRPR planar parallel platform
There are now six actuators and the length of the jth
actuator
(j=1, 2) of branch i (i=1, 2, 3) is represented by dij. The
coordinates of points Bi referring to fixed frame XOY is:
{OBi}={OP}+[R]{PB′i} (1)
Where [R] is the rotation matrix
φφ
φ−φ
cossin
sincos
, vector
OP=
y
x
and {PB′i} is vector from P to Bi expressed in
moving frame x-P-y.
Thus,
xBi =x+(PB′ix cosφ- PB′iy sinφ) (2a)
yBi =y+( PB′ix sinφ- PB′iy cosφ) (2b)
Also, the length of each actuator is given by:
di2
2
=(xBi - xAi)2
+(yBi - yAi)2
(3)
Here, (xAi, yAi) are the coordinates of the points Ai referred to
fixed coordinate frame XOY, which are nothing but the
displacements di1 of the extra actuators.
2.1 Workspace
The so-called constant-orientation workspace is the set of
positions attainable by the platform center for a fixed
orientation of the platform, given the actuator limits as inputs.
Referring to Fig.1, the workspace circles are given by:
2
12
22
11 d)}6/sin(ry{}d)6/cos(rx{ =π+φ−+−π+φ− (4)
{ }
{ } 2
22
2
21
2
211
d)3/sin(dsin)6/sin(ry
)3/cos(dt(cos)6/cos(rx
=π−φ+π+φ−+
π−−φ+π+φ−
l
l
(5)
A3
A2
A1
O3
O1 O2
B1
B2
B3
X
Y
O
xy
P
d11
d21
d31
d32
d12
d22
φ
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Volume: 02 Issue: 09 | Sep-2013, Available @ http://www.ijret.org 373
{ }2
312 )3/cos(dt()3/cos()6/cos(rx π−−π+φ+π+φ− l
2
32
2
313
d
)3/sin(dt(
)3/sin()6/sin(ry
=
π−−
π+φ+π+φ−
+
l
(6)
2.2 Jacobian Analysis
A Jacobian matrix is necessary in order to derive the dynamic
equation of manipulator. The Jacobian matrix is the relation of
small perturbation of input and the response of output. In order
to find Jacobian matrix, time-derivative of Eq.(3) yields:
)yy)(yy(2)xx)(xx(2dd2 AiBiAiBiAiBiAiBi2i2i −−+−−= &&&&&
(7)
Here,
φφ′+φ′−= &&& )cosBPsinBP(xx iyixBi
φφ′−φ′+= &&& )sinBPcosBP(yy iyixBi (8)
Substituting Eqs.(8) in Eq.(7) and dividing both sides by di2
we get:
x2inˆ)x1inˆ1id)cosiyBPsinixBP(x(2id &&&& −φφ′+φ′−=
y2inˆ)y1inˆ1id)siniyBPcosixBP(y( &&& −φφ′−φ′++ (9)
Where, x1inˆ and y1inˆ are the unit vectors of first prismatic
joint along global X and Y directions corresponding to the
limb i.
Similarly, x2inˆ =
2i
AiBi
d
)xx( −
and y2inˆ =
2i
AiBi
d
)yy( −
are the
components of unit vectors for distal prismatic joints along Ai
to Bi. Equation (9) gives the velocity of distal prismatic joints
in terms of Cartesian velocities ( φ&&& ,y,x ) and velocities of the
base prismatic joints 1id& . In Eq. (9), if all 1id& =0, then it reduces
to standard 3-RPR parallel manipulator Jacobian matrix [J]
which can be expressed as: }X{]J[}d{ 1 && −
= . Importance of
Jacobian matrix can also be found in estimating the singular
configurations in the workspace.
2.3 Joint Torques
Kinetostatics refers to the situation where the actuators move
at a constant speed and it does not cause the inertia forces to
vanish, since non-zero centripetal and Coriolis force arise
essentially out of accelerations of the links even when the
actuators do not accelerate. The most common applications of
such analysis is found in mechanism for machine tools, micro-
positioning, surgical robots etc. In this approach, the right side
term of Newton–Euler equations reduces to zero. Therefore,
there is no dependency on velocities and accelerations and the
entire workspace of a certain working mode can be analyzed.
The vector of distal joint torques {τ2} are obtained in terms of
the output wrench (forces at the mobile platform center) {F}
as {τ2}=[J]{F}. However, for base prismatic joints, the force
vector from geometry and vector mechanics is given as
follows: {τ1}= 1i2i nˆnˆ {τ2}, where 1inˆ is a unit vector from Oi
to Ai.
3. RESULTS AND DISCUSSION
Let l is side of mobile platform and r= 3/l is equivalent
radius of inscribed circle; t1=xO2, t2=xO3, t3=yO3 are the
coordinates of the base triangle with respect to inertial frame
of reference. Taking first time derivative on both sides and
simplifying, we get:
x1211 nˆ}d)6/sin(rx{ &&& −π+φφ+
12y12 dnˆ)}6/cos(ry{ &&& =π+φφ−+ (10)
x2221 nˆ))3/cos(dsin)6/sin(rx( π+φφ−π+φφ+ &&l&&
22y2221 dnˆ))3/sin(dcos)6/cos(ry( &&&l&& =π−φφ+π+φφ−+ (11)
x3231 nˆ))3/cos(d)3/sin()6/sin(rx( π+π+φφ−π+φφ+ &&l&&
)3/cos()6/cos(ry( π+φφ+π+φφ−+ &l&&
32y3231 dnˆ))3/sin(d && =π+ (12)
It is noticed that x1inˆ and y1inˆ in Eq.(9) are unit vector
components for each link-orientations derived as follows:
x12nˆ = }d)6/cos(rx{ 11−π+φ− /d12 (13)
y12nˆ = )}6/sin(ry{ π+φ− /d12 (14)
x22nˆ ={ })3/cos(dt(cos)6/cos(rx 211 π−−φ+π+φ− l /d22
(15)
y22nˆ ={ })3/sin(dsin)6/sin(ry 21 π−φ+π+φ− l /d22 (16)
x32nˆ =
{ })3/cos(dt()3/cos()6/cos(rx
d
1
312
32
π−−π+φ+π+φ− l
(17)
y32nˆ =
{ })3/sin(dt()3/sin()6/sin(ry 313 π−−π+φ+π+φ− l /d32
(18)
The dimensions chosen for the manipulator are O1O2= O2O3=
O3O1=0.3 m and B1B2= B2B3=B3B1=0.05 m. Computer
programs are developed in MATLAB for workspace analysis,
Jacobain and force analysis. Following input data is
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Volume: 02 Issue: 09 | Sep-2013, Available @ http://www.ijret.org 374
considered: The range limits on these prismatic joints are set
to 0.01 m to 0.29 m. Also φ∈[-180o
, 180o
]. The workspace of
non-redundant 3-RPR linkage is shown in Fig.2. It is
generated from inverse kinematics and by a method called
direct search approach. Here initially, we vary x, y and φ over
a range (in present case x,y∈[-0.4, 0.4]) and predict d2i values;
if (d2i)min <d2i <(d2i)max, the selected point falls into the
reachable workspace at that orientation.
Fig.2 Three-dimensional workspace of 3-RPR linkage
The workspace of redundant 3-PRPR manipulator for an
arbitrary values of d11=0.1613 m, d21=0.2900 m and
d31=0.1212 m is shown in Fig.3. It is seen that an increased
workspace is obtained due to additional prismatic joints in all
the orientations of the platform.
Fig.3 Workspace of 3-PRPR in constant arbitrary base posture
The velocity kinematics of manipulators is next studied with a
trajectory involving a straight-line path within the constant-
orientation workspace as shown in Fig.4. It may or may not
pass through the singular points.
Fig.4 Horizontal line trajectory within the workspace envelope
The platform is moving from the center A(0, 0) to B(0.2, 0) in
increments of 0.004 m. A constant force of 100 N is applied
on the platform in the direction opposite to the motion; thus
the force vector at the platform is [-100;0;0] N. Fig. 5 shows
the displacements at the joints during each time step as
obtained from Jacobian analysis.
Fig.5 Joint displacements corresponding to straight line track
The corresponding generalized forces required for the non-
redundant manipulator are shown in Fig.6.
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Volume: 02 Issue: 09 | Sep-2013, Available @ http://www.ijret.org 375
Fig.6 Joint forces for non-redundant configuration
It can be seen that the maximum forces occur at the starting
point of the trajectory, where it is touching the boundary of
workspace. This is a point of force (type-II) singularity. It is
assumed that the mobile platform is moving with constant
velocity in Cartesian plane. Further by adding additional
prismatic joints with the initial joint displacements: 0.16 m,
0.29m and 0.12m, the higher joint forces are not acting for
long duration as seen in Fig.7 for the same straight line
trajectory.
Fig.7. Joint actuation forces for redundant counterpart
Based on the advantages of this kinematically redundant
linkage, a prototype is planned to be fabricated. Here it is
assumed that the three actuated sliding joints are provided
with the electrostatic actuation using comb drives. The pivot
points (R) in the design are to be replaced by flexure hinges
[11] which allow in-plane rotation and the controlled prismatic
joints are to be implemented by linear comb actuators with
folded suspension springs to restore the joint to its original
position where the comb drives are de-energized. To
incorporate the effects of flexure hinge stiffness on the joint
motions, the resultant equations are to be slightly modified.
Fig.8 shows the screen shot of the table with one of leg of this
monolithic compliant parallel linkage developed in ANSYS
environment. The comb-drives will be provided beneath the
middle dyad link and platform as well as base slider is
respectively connected to this dyad using flexure joints. Base
prismatic joint is also actuated with electro-static actuation
with the help of a capacitor plate.
Fig.8 Surface model of the proposed positioning stage
The static analysis provides the approximate Jacobian matrix
in one of the postures of the linkage. Modal analysis gives an
estimation of natural frequencies of the stage.
CONCLUSIONS
A kinematically redundant planar parallel manipulator was
considered in this paper. Inverse kinematics and velocity
analysis of the linkage were mathematically explained. The
reachable workspaces were obtained and compared to that of
similar-sized non-redundant manipulator. It was shown that
the proposed manipulator’s workspaces were significantly
larger at all platform orientations. For a straight line trajectory,
the corresponding joint actuation forces have been computed
and it was shown that the mobile platform reaches the points
with little joint forces. In force-analysis, the arbitrarily
locations of base prismatic joints were initially selected.
However, in practical case it may be casted as an optimum
design problem where these locations are selected for either
maximizing stiffness or minimizing joint torques at each and
every point along the trajectory. Since, the manipulator is
kinematically redundant for every point inside the reachable
workspace, there are loci of solutions of the inverse
displacement problem for a given end effector pose.
Therefore, it is possible to choose sets of fixed solutions that
are singular-free.
ACKNOWLEDGEMENTS
The authors acknowledge Sri Chandra Sekharendra Viswa
Mahavidyalaya, Kancheepuram.
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REFERENCES
[1]. D. Stewart. ‘A platform with six degrees of freedom’,
Proc Inst Mech Eng., vol.180 (1), pp. 371–386, 1965.
[2]. Bonev, ‘Delta parallel robot’,
http://www.parallemic.org/Reviews/Review002.html.
[3]. B.S. El-Khasawneh, P.M. Ferreira, C.R. Boër, L.
Molinari-Tosatti and K.S. Smith (Eds.), ‘The
tetrahedral tripod, parallel-kinematic machines—
theoretical aspects and industrial requirements’,
Springer-Verlag pp. 419–430, 1999.
[4]. J. Wang and C.M. Gosselin, ‘Kinematic analysis and
design of kinematically redundant parallel
mechanisms’, ASME Journal of Mechanical Design,
vol.126 (1), pp.109–118, 2004.
[5]. M.G. Mohamed and C.M. Gosselin, ‘Design and
analysis of kinematically redundant parallel
manipulators with configurable platforms’, IEEE
Transactions on Robotics, vol.21 (3), pp.277–287,
2005.
[6]. I. Ebrahimi, J.A. Carretero and R. Boudreau, ‘3-PRRR
redundant planar parallel manipulator: inverse
displacement, workspace and singularity analyses’,
Mechanism and Machine Theory, vol. 42 (8), pp.1007–
1016, 2007.
[7]. J. Kotlarski, T.D. Thanh, B. Heimann and T. Ortmaier,
‘Optimization strategies for additional actuators of
kinematically redundant parallel kinematic machines’,
Proceedings of IEEE Conference on Robotics and
Automation, pp. 656–661, 2010.
[8]. R. Boudreau and S.Nokleby, ‘Force optimization of
kinematically-redundant planar parallel manipulators
following a desired trajectory’, Mechanisms and
Machine Theory, vol.56, pp.138-155, 2012.
[9]. C.Shn, T.Seo, J.Kim and T.W.Kim, ‘High-tilt parallel
positioning mechanism development and cutter path
simulation for laser micro-machining’, Computer-
Aided Design, vol.39, pp.218-228, 2007.
[10]. S.Krishnan and L.Saggere, ‘Design and Development
of a novel micro-clasp gripper for micromanipulation of
complex shaped objects’, Sensors and Actuators,
A:Physical, vol.176, pp.110-123, 2012.
[11]. D.Mukhopadhyay, J.Dong, E.Pengwang and P.Ferreira,
‘A SOI-MEMS-based 3-DOF planar parallel kinematics
nanopositioning stage’, Sensors and Actuators: A,
vol.147, pp.340-351, 2008.
BIOGRAPHIES
Er .U. Sudhakar is working as Assistant Professor at GMRIT-
Rajam. To his credit he published around 5 articles in national
conferences. His fields of interest include: manufacturing
techniques, parallel robots and MEMS.
Dr. J. Srinivas, a member of Institution of Engineers (India)
has around 15 years of research and teaching experience. He
has published around 70 research articles in various
conferences and journals. He authored 8 textbooks relating to
Mechanical Engineering. His topics of interest are dynamics
and control, micro positioning analysis and MEMS and
NEMS.