The document describes the design of a slider-crank leg mechanism for a mobile hopping robotic platform. The mechanism uses a slider-crank mechanism to convert continuous motor rotation into piston motion, which impacts the ground to generate hopping locomotion. A mechanical clutch trigger mechanism was developed to control the impact timing and maintain a constant transmission angle for repeated hopping. Dynamic analysis was performed to determine the optimal position of the clutch trigger mechanism to maximize hopping height. Experimental validation was conducted, and future work on a two degree-of-freedom leg design is proposed.
PNEUMATIC VEHICLE ACTIVE SUSPENSION SYSTEM USING PID CONTROLLERTushar Tambe
The slide contains the simulation of pneumatic active suspension behavior on different road surface. These results shows the active suspension with controllers works effectively,if feedback loop is provided.
Improvement of vehicle ride comfort using geneticalgorithm optimization and p...ahmedgeweda
This document presents a study that aims to improve vehicle ride comfort using genetic algorithm optimization and a PI controller. The following key points are discussed:
1. A 7 degree-of-freedom full vehicle model is developed in MATLAB SIMULINK to study ride comfort.
2. A genetic algorithm is used to optimize the values of spring stiffness and damping coefficients for the front and rear passive suspension at different velocities.
3. A proportional-integral controller is also implemented to study its effect on ride comfort.
4. Comparisons of body acceleration and sprung mass displacement are made between the optimized suspension parameters, model with PI controller, and passive suspension system to evaluate ride performance improvements.
This document summarizes a research article that proposes two types of controllers for an active anti-roll bar system for passenger cars: a self-tuning fuzzy PI-PD controller and a PI-PD-type fuzzy controller. The performances of these controllers are evaluated in simulations and compared to a passive anti-roll bar and a conventional fuzzy PID controller. The PI-PD-type fuzzy controller is found to outperform the others by significantly improving the ride and handling of the simulated passenger car.
The optimal control system of the ship based on the linear quadratic regular ...IJECEIAES
In this paper, the authors propose an optimal controller for the ship motion. Firstly, the model and dynamic equations of the ship motion are presented. Basing on the motion equations of ship model, the authors build the linear quadratic regular algorithm-based control system of ship motion to minimize difference between the response coordinate and the setting-coordinate. The task of the controller is controlling the ship coordinate to coincide with the desired coordinate. The ship model and controller are built to investigate the system quality through Matlab-Simulink software. The results show the high quality of the control system. The coordinate of a ship always follows the desired coordinate with very small errors.
Research Inventy : International Journal of Engineering and Science is published by the group of young academic and industrial researchers with 12 Issues per year. It is an online as well as print version open access journal that provides rapid publication (monthly) of articles in all areas of the subject such as: civil, mechanical, chemical, electronic and computer engineering as well as production and information technology. The Journal welcomes the submission of manuscripts that meet the general criteria of significance and scientific excellence. Papers will be published by rapid process within 20 days after acceptance and peer review process takes only 7 days. All articles published in Research Inventy will be peer-reviewed.
This document describes a simulation of a quadcopter's dynamic system and interactive control system created by researchers at George Mason University. The simulation models the quadcopter's behavior in different environments based on parameters like payload, desired altitude, ascent/descent speeds and hover time. It includes equations of motion for the quadcopter in the z-axis and models forces like thrust, drag, weight. The simulation was able to follow user-specified altitude profiles within 1m of accuracy even with payloads over half the quadcopter's weight, demonstrating the potential for quadcopters as safe and effective delivery systems.
This document presents summaries of the dynamic models of three different vertical take-off and landing (VTOL) aircraft: the quad rotor, single tilting rotor VTOL, and single rotor VTOL. For the quad rotor, it describes its 6 degrees of freedom from 4 rotors and how pitch, roll, and yaw movements are achieved. For the single tilting rotor VTOL, it provides the rotational and translational dynamics equations and simplifies the model. For the single rotor VTOL, it gives the simplified model equations after neglecting various torques.
The document describes the design of a slider-crank leg mechanism for a mobile hopping robotic platform. The mechanism uses a slider-crank mechanism to convert continuous motor rotation into piston motion, which impacts the ground to generate hopping locomotion. A mechanical clutch trigger mechanism was developed to control the impact timing and maintain a constant transmission angle for repeated hopping. Dynamic analysis was performed to determine the optimal position of the clutch trigger mechanism to maximize hopping height. Experimental validation was conducted, and future work on a two degree-of-freedom leg design is proposed.
PNEUMATIC VEHICLE ACTIVE SUSPENSION SYSTEM USING PID CONTROLLERTushar Tambe
The slide contains the simulation of pneumatic active suspension behavior on different road surface. These results shows the active suspension with controllers works effectively,if feedback loop is provided.
Improvement of vehicle ride comfort using geneticalgorithm optimization and p...ahmedgeweda
This document presents a study that aims to improve vehicle ride comfort using genetic algorithm optimization and a PI controller. The following key points are discussed:
1. A 7 degree-of-freedom full vehicle model is developed in MATLAB SIMULINK to study ride comfort.
2. A genetic algorithm is used to optimize the values of spring stiffness and damping coefficients for the front and rear passive suspension at different velocities.
3. A proportional-integral controller is also implemented to study its effect on ride comfort.
4. Comparisons of body acceleration and sprung mass displacement are made between the optimized suspension parameters, model with PI controller, and passive suspension system to evaluate ride performance improvements.
This document summarizes a research article that proposes two types of controllers for an active anti-roll bar system for passenger cars: a self-tuning fuzzy PI-PD controller and a PI-PD-type fuzzy controller. The performances of these controllers are evaluated in simulations and compared to a passive anti-roll bar and a conventional fuzzy PID controller. The PI-PD-type fuzzy controller is found to outperform the others by significantly improving the ride and handling of the simulated passenger car.
The optimal control system of the ship based on the linear quadratic regular ...IJECEIAES
In this paper, the authors propose an optimal controller for the ship motion. Firstly, the model and dynamic equations of the ship motion are presented. Basing on the motion equations of ship model, the authors build the linear quadratic regular algorithm-based control system of ship motion to minimize difference between the response coordinate and the setting-coordinate. The task of the controller is controlling the ship coordinate to coincide with the desired coordinate. The ship model and controller are built to investigate the system quality through Matlab-Simulink software. The results show the high quality of the control system. The coordinate of a ship always follows the desired coordinate with very small errors.
Research Inventy : International Journal of Engineering and Science is published by the group of young academic and industrial researchers with 12 Issues per year. It is an online as well as print version open access journal that provides rapid publication (monthly) of articles in all areas of the subject such as: civil, mechanical, chemical, electronic and computer engineering as well as production and information technology. The Journal welcomes the submission of manuscripts that meet the general criteria of significance and scientific excellence. Papers will be published by rapid process within 20 days after acceptance and peer review process takes only 7 days. All articles published in Research Inventy will be peer-reviewed.
This document describes a simulation of a quadcopter's dynamic system and interactive control system created by researchers at George Mason University. The simulation models the quadcopter's behavior in different environments based on parameters like payload, desired altitude, ascent/descent speeds and hover time. It includes equations of motion for the quadcopter in the z-axis and models forces like thrust, drag, weight. The simulation was able to follow user-specified altitude profiles within 1m of accuracy even with payloads over half the quadcopter's weight, demonstrating the potential for quadcopters as safe and effective delivery systems.
This document presents summaries of the dynamic models of three different vertical take-off and landing (VTOL) aircraft: the quad rotor, single tilting rotor VTOL, and single rotor VTOL. For the quad rotor, it describes its 6 degrees of freedom from 4 rotors and how pitch, roll, and yaw movements are achieved. For the single tilting rotor VTOL, it provides the rotational and translational dynamics equations and simplifies the model. For the single rotor VTOL, it gives the simplified model equations after neglecting various torques.
PID vs LQR controller for tilt rotor airplane IJECEIAES
This document summarizes and compares PID and LQR control strategies for controlling the maneuvers of a tilt rotor airplane. Multiple attitude and altitude PID controllers were used to control a simplified linear model, but this did not account for all coupling between degrees of freedom. An LQR controller was also adopted to provide a more feasible solution for complex maneuvering, though both controllers require linearization of the model. The mathematical modeling section describes the rigid body equations of motion for the tri-tilt rotor configuration in body and earth frames using Newton-Euler formalism. Control of attitudes, positions and transitions between helicopter and airplane modes are discussed.
Simulation of an Active Suspension Using PID ControlSuzana Avila
The document simulates an active vehicle suspension using PID control. It builds a quarter car model and analyzes the controllability and observability. Numerical simulations show the active suspension with PID controller improves performance over the passive suspension by reducing displacement peaks and settling times for step, harmonic, and noise road profiles. The active suspension improves comfort but has higher manufacturing costs than passive suspensions.
Research Inventy : International Journal of Engineering and Science is published by the group of young academic and industrial researchers with 12 Issues per year. It is an online as well as print version open access journal that provides rapid publication (monthly) of articles in all areas of the subject such as: civil, mechanical, chemical, electronic and computer engineering as well as production and information technology. The Journal welcomes the submission of manuscripts that meet the general criteria of significance and scientific excellence. Papers will be published by rapid process within 20 days after acceptance and peer review process takes only 7 days. All articles published in Research Inventy will be peer-reviewed.
DESIGN AND OPTIMIZATION OF “KLANN MECHANISM” USING OCTO-POD ROBOTNikhil Koli
This project highlights the reduction in jerk-imparted to the robot by improving the root gait profile of "KLANN Mechanism" used for locomotion in robot.
Stabilized controller of a two wheels robotjournalBEEI
The Segway Human Transport (HT) robot, it is dynamical self-balancing robot type. The stability control is an important thing for the Segway robot. It is an indisputable fact that Segway robot is a natural instability framework robot. The case study of the Segway robot focuses on running balance control systems. The roll, pitch, and yaw balance of this robot are obtained by estimating the Kalman Filter with a combination of the pole placement and the Linear Quadratic Regulator (LQR) control method. In our system configuration, the mathematical model of the robot will be proved by Matlab Simulink by modelling of the stabilizing control system of all state variable input. Furthermore, the implementation of this system modelled to the real-time test of the Segway robot. The expected result is by substitute the known parameters from Gyro, Accelero and both rotary encoder to initial stabilize control function, the system will respond to the zero input curve. The coordinate units of displacement response and inclination response pictures are the same. As our expected, the response of the system can reach the zero point position.
Car Dynamics using Quarter Model and Passive Suspension, Part VI: Sprung-mass...IOSR Journals
1) The document investigates the step response of a 2 DOF quarter-car model with passive suspension using MATLAB.
2) It derives the mathematical models for the sprung-mass displacement and acceleration in response to a 100mm step road disturbance.
3) The simulations show that increasing the suspension damping coefficient decreases the overshoot and settling time of the sprung-mass displacement response, but increases the maximum acceleration. Suspension stiffness has little effect on the maximum acceleration.
This document summarizes a study on developing a wheel slip control system for an electric vehicle to improve traction and energy efficiency during acceleration. The study proposes a sliding mode controller and vehicle velocity estimator. Simulations using CarSim software and experiments on a test electric vehicle equipped with in-wheel motors validate that the control system enhances traction performance and reduces energy consumption compared to uncontrolled acceleration. The robust wheel slip controller and practical vehicle velocity estimation approach make use of the advantages of electric vehicle drivetrains for improved acceleration control.
IRJET- Design & Development of Two-Wheeled Self Balancing RobotIRJET Journal
This document describes the design and development of a two-wheeled self-balancing robot. An inertial measurement unit (IMU) containing an accelerometer and gyroscope is used to measure the robot's tilt angle. A PID controller applies motor speed adjustments to correct any error between the desired setpoint and actual tilt angle, balancing the robot. The PID controller is able to balance the robot with some limitations. Simulation results are compared to the hardware performance. PID tuning is also performed to improve balancing. Key components include an Arduino, motor driver, motors, IMU, and Bluetooth module. The system architecture integrates these components to enable self-balancing.
Maglev trains use magnetic levitation to move along guideways without touching the ground. This reduces friction and allows for higher speeds. The fastest commercial train is the Shanghai Maglev, which reaches 430 km/h. Maglev trains move more smoothly than wheeled trains and are less affected by weather. While more expensive to build initially, maglev systems have lower maintenance costs than conventional trains. Only a few commercial maglev lines have been built, but many countries are researching the technology further.
This document describes a method for online cylinder fault diagnosis in internal combustion engines. The method involves recording engine speed fluctuations at the flywheel and front end of the engine over one combustion cycle. From the speed fluctuations, the cylinder-to-cylinder variations in net engine torque are computed. A drop in computed torque for an individual cylinder indicates a performance deterioration, allowing faults to be detected and located during normal engine operation without interrupting operation or requiring physical contact with the engine. The diagnostics hardware consists of a digital speed data acquisition system and controller suited for in-vehicle installation.
Nonlinear integral control for dc motor speed control with unknown and variab...Saif al-din ali
This document discusses nonlinear integral control for DC motor speed control with unknown and variable external torque. It begins with an introduction to DC motors and common speed control techniques. It then provides the basic model of a DC motor and derives the transfer function. It discusses nonlinear control systems and elements like saturation, deadband, and friction. It describes methods for solving nonlinear transient responses, nonlinear system stability, and provides a Simulink model example comparing PI and P controller performance for speed and error. References for DC motor speed control and optimization of PI controllers are also provided.
Zarzirbird Project: Modeling RPAS Dynamics for Load StabilityAndreia Rossi
This project presents a new mathematical modeling approach as the core of a RPAS physical control system, specifically considering a hexacopter. This work is a first step towards the definition of a RPAS system for load stability analysis integrated with a communication system control, which is the main objective of the ongoing ZarzirBird Project. The mathematical approach builds on quaternions applied to mechanical structure design, which allows more accurate results in spatial orientation than traditional models. The control system exploits the gyroscope characteristics, which allows a better stability of the flight directions in navigation. The model has been validated both in nominal flight conditions, and considering the occurrence of both internal and external events like wind variation, propeller damage limits, different environment conditions. The proposed control system is based on SIMO (Single Input, Multiple Outputs) system type, which is extended to include the features for improving flight safety and enabling flight-to-ground communication. The output of the control system, which manipulates one variable only, consists of yaw, pitch and roll rotation. Linearization of nonlinear mathematical models, stability criteria, system analysis in time and frequency domains are some of the techniques used in the modeling approach. The mathematical approach is compliance with certification standards (NATO). Next steps within the ZarzirBird Project will concern the communication analysis for integration in a non-segregated airspace, which will be based on the structural mechanical system. In this perspective, we will apply different techniques as trajectory estimated method, angle variation by interference vibration, and movement accuracy.
Design and analysis of spider robot used as agricultural sprayerYuvraj Pather
8-legged walking spider robot based on klann mechanism capable of walking on uneven terrain. The robot is mounted with a mini sprayer which can be used for agricultural spraying.
This project thesis is made by a group of mechanical engineering students as a final semester project.The project thesis data is collected by referring many other project work data and research papers which are easily available online some of them we also mention in the reference chapter.
***We are uploading this thesis as a refrence to other students and interested personnel's so it will be helpful for them. We don't have any intention of provoking any one.***
We work very hard for completing this thesis and will be very happy if anyone wants to continue on this project and make it more advanced.
Contact details are provided at the end of the thesis feel free to ask related to the project. Peace
The document discusses magnetic levitation (Maglev) trains. It begins by defining Maglev as using magnetic levitation to suspend, guide, and propel trains using magnets. It then explains the basic principles of levitation, propulsion, and lateral guidance that Maglev trains use to operate at high speeds. This includes using magnets to levitate the train 10 cm above the track and linear motors in the guideway to propel the train electromagnetically. The document also discusses the technologies, merits, and demographics of existing and planned Maglev systems around the world.
Computational Aeroacoustic Investigation of Co-rotating rotors for Urban Air Mobility.
The presentation is split into different slides (for pdf format) corresponding to different animations.
Master of Science in Aerospace Engineering, specializing in Aerodynamics, Aeroacoustics, and Wind Energy at TU Delft, the Netherlands.
1) A novel gearshift system is introduced comprising a 2 degree-of-freedom electromagnetic actuator to simplify structure, increase efficiency, and improve shift quality of automated manual transmissions.
2) The gearshift process is divided into non-synchronization and synchronization phases, with different control algorithms designed for each. Extended state observer based inverse system method is used for non-synchronization, while active disturbance rejection controller is used for synchronization.
3) Comparative simulations and experiments demonstrate the effectiveness of the proposed control method in achieving good gearshift performance for the novel system. The control strategy provides a new solution for automated manual transmission applications.
The document summarizes a master's thesis that analyzes and develops controllers for a quadcopter. It presents the dynamic equations of the quadcopter and linearizes them. Two backstepping controllers are developed - a simpler one that cannot absorb disturbances, and a more advanced one that can handle disturbances like changes in mass. Both controllers separate attitude from horizontal/vertical position control. The controllers are simulated and compared to evaluate their performance.
mechanical spider robot by klann mechanismNeel Shah
The document describes a mechanical spider robot project that uses a Klann mechanism for locomotion. The Klann mechanism converts rotational motion to linear foot movement similar to animal walking. It allows the robot to access rough terrain unlike wheeled robots. The project aims to create an 8-legged robot to test new walking algorithms that could be useful for the robotics community. The robot design is loosely based on spiders and their advanced octopedal locomotion.
This document discusses magnetic levitation trains (Maglev trains). It describes two main types of Maglev trains: electromagnetic suspension (EMS) and electrodynamic suspension (EDS). EMS uses electromagnets to attract the train to the track for levitation and propulsion, while EDS uses superconducting magnets and repulsion for levitation. The document outlines the basic principles, pros and cons of each system and concludes that Maglev trains offer a more efficient transportation alternative with advantages like very high speeds and less environmental impact.
Projet ESMO - European Students Moon Orbiter - CLES-FACIL 2007CLES-FACIL
This document outlines the workplan for the reaction wheel subsystem for a student moon orbiter project. It discusses the current reaction wheel design using Dynacon Micro Wheel 1000 reaction wheels. The workplan includes updating models, selecting electronic components, developing simulations in MATLAB/Simulink to validate that the wheel design can maintain spacecraft attitude under expected disturbance torques for at least 24 hours before needing to offload momentum using thrusters. The workplan objectives are divided into tasks to further develop requirements, models, simulations, and validate the reaction wheel subsystem design.
This document discusses different mechanisms for generating electricity from vehicles passing over speed breakers, including gear, roller, and rack and pinion mechanisms. It describes the basic principles of converting kinetic and potential energy from vehicles into electrical energy. The rack and pinion mechanism is presented as having higher efficiency around 70% compared to the roller mechanism at 50%. Construction details and the working procedure of the rack and pinion system are provided. The document concludes that this is a low-cost way to generate electricity without fuel by capturing wasted vehicle energy.
This document discusses generating electricity from speed breakers using vehicles' kinetic and potential energy. It describes two mechanisms - roller and rack/pinion mechanisms. The rack/pinion is more efficient (70% vs 50%) and easier to design for, converting the linear motion of the speed breaker into rotational motion to power a generator. Charts show voltage increasing with vehicle speed and electrical load. In conclusion, this method generates pollution-free power from vehicles at low cost, providing a solution to energy shortages.
PID vs LQR controller for tilt rotor airplane IJECEIAES
This document summarizes and compares PID and LQR control strategies for controlling the maneuvers of a tilt rotor airplane. Multiple attitude and altitude PID controllers were used to control a simplified linear model, but this did not account for all coupling between degrees of freedom. An LQR controller was also adopted to provide a more feasible solution for complex maneuvering, though both controllers require linearization of the model. The mathematical modeling section describes the rigid body equations of motion for the tri-tilt rotor configuration in body and earth frames using Newton-Euler formalism. Control of attitudes, positions and transitions between helicopter and airplane modes are discussed.
Simulation of an Active Suspension Using PID ControlSuzana Avila
The document simulates an active vehicle suspension using PID control. It builds a quarter car model and analyzes the controllability and observability. Numerical simulations show the active suspension with PID controller improves performance over the passive suspension by reducing displacement peaks and settling times for step, harmonic, and noise road profiles. The active suspension improves comfort but has higher manufacturing costs than passive suspensions.
Research Inventy : International Journal of Engineering and Science is published by the group of young academic and industrial researchers with 12 Issues per year. It is an online as well as print version open access journal that provides rapid publication (monthly) of articles in all areas of the subject such as: civil, mechanical, chemical, electronic and computer engineering as well as production and information technology. The Journal welcomes the submission of manuscripts that meet the general criteria of significance and scientific excellence. Papers will be published by rapid process within 20 days after acceptance and peer review process takes only 7 days. All articles published in Research Inventy will be peer-reviewed.
DESIGN AND OPTIMIZATION OF “KLANN MECHANISM” USING OCTO-POD ROBOTNikhil Koli
This project highlights the reduction in jerk-imparted to the robot by improving the root gait profile of "KLANN Mechanism" used for locomotion in robot.
Stabilized controller of a two wheels robotjournalBEEI
The Segway Human Transport (HT) robot, it is dynamical self-balancing robot type. The stability control is an important thing for the Segway robot. It is an indisputable fact that Segway robot is a natural instability framework robot. The case study of the Segway robot focuses on running balance control systems. The roll, pitch, and yaw balance of this robot are obtained by estimating the Kalman Filter with a combination of the pole placement and the Linear Quadratic Regulator (LQR) control method. In our system configuration, the mathematical model of the robot will be proved by Matlab Simulink by modelling of the stabilizing control system of all state variable input. Furthermore, the implementation of this system modelled to the real-time test of the Segway robot. The expected result is by substitute the known parameters from Gyro, Accelero and both rotary encoder to initial stabilize control function, the system will respond to the zero input curve. The coordinate units of displacement response and inclination response pictures are the same. As our expected, the response of the system can reach the zero point position.
Car Dynamics using Quarter Model and Passive Suspension, Part VI: Sprung-mass...IOSR Journals
1) The document investigates the step response of a 2 DOF quarter-car model with passive suspension using MATLAB.
2) It derives the mathematical models for the sprung-mass displacement and acceleration in response to a 100mm step road disturbance.
3) The simulations show that increasing the suspension damping coefficient decreases the overshoot and settling time of the sprung-mass displacement response, but increases the maximum acceleration. Suspension stiffness has little effect on the maximum acceleration.
This document summarizes a study on developing a wheel slip control system for an electric vehicle to improve traction and energy efficiency during acceleration. The study proposes a sliding mode controller and vehicle velocity estimator. Simulations using CarSim software and experiments on a test electric vehicle equipped with in-wheel motors validate that the control system enhances traction performance and reduces energy consumption compared to uncontrolled acceleration. The robust wheel slip controller and practical vehicle velocity estimation approach make use of the advantages of electric vehicle drivetrains for improved acceleration control.
IRJET- Design & Development of Two-Wheeled Self Balancing RobotIRJET Journal
This document describes the design and development of a two-wheeled self-balancing robot. An inertial measurement unit (IMU) containing an accelerometer and gyroscope is used to measure the robot's tilt angle. A PID controller applies motor speed adjustments to correct any error between the desired setpoint and actual tilt angle, balancing the robot. The PID controller is able to balance the robot with some limitations. Simulation results are compared to the hardware performance. PID tuning is also performed to improve balancing. Key components include an Arduino, motor driver, motors, IMU, and Bluetooth module. The system architecture integrates these components to enable self-balancing.
Maglev trains use magnetic levitation to move along guideways without touching the ground. This reduces friction and allows for higher speeds. The fastest commercial train is the Shanghai Maglev, which reaches 430 km/h. Maglev trains move more smoothly than wheeled trains and are less affected by weather. While more expensive to build initially, maglev systems have lower maintenance costs than conventional trains. Only a few commercial maglev lines have been built, but many countries are researching the technology further.
This document describes a method for online cylinder fault diagnosis in internal combustion engines. The method involves recording engine speed fluctuations at the flywheel and front end of the engine over one combustion cycle. From the speed fluctuations, the cylinder-to-cylinder variations in net engine torque are computed. A drop in computed torque for an individual cylinder indicates a performance deterioration, allowing faults to be detected and located during normal engine operation without interrupting operation or requiring physical contact with the engine. The diagnostics hardware consists of a digital speed data acquisition system and controller suited for in-vehicle installation.
Nonlinear integral control for dc motor speed control with unknown and variab...Saif al-din ali
This document discusses nonlinear integral control for DC motor speed control with unknown and variable external torque. It begins with an introduction to DC motors and common speed control techniques. It then provides the basic model of a DC motor and derives the transfer function. It discusses nonlinear control systems and elements like saturation, deadband, and friction. It describes methods for solving nonlinear transient responses, nonlinear system stability, and provides a Simulink model example comparing PI and P controller performance for speed and error. References for DC motor speed control and optimization of PI controllers are also provided.
Zarzirbird Project: Modeling RPAS Dynamics for Load StabilityAndreia Rossi
This project presents a new mathematical modeling approach as the core of a RPAS physical control system, specifically considering a hexacopter. This work is a first step towards the definition of a RPAS system for load stability analysis integrated with a communication system control, which is the main objective of the ongoing ZarzirBird Project. The mathematical approach builds on quaternions applied to mechanical structure design, which allows more accurate results in spatial orientation than traditional models. The control system exploits the gyroscope characteristics, which allows a better stability of the flight directions in navigation. The model has been validated both in nominal flight conditions, and considering the occurrence of both internal and external events like wind variation, propeller damage limits, different environment conditions. The proposed control system is based on SIMO (Single Input, Multiple Outputs) system type, which is extended to include the features for improving flight safety and enabling flight-to-ground communication. The output of the control system, which manipulates one variable only, consists of yaw, pitch and roll rotation. Linearization of nonlinear mathematical models, stability criteria, system analysis in time and frequency domains are some of the techniques used in the modeling approach. The mathematical approach is compliance with certification standards (NATO). Next steps within the ZarzirBird Project will concern the communication analysis for integration in a non-segregated airspace, which will be based on the structural mechanical system. In this perspective, we will apply different techniques as trajectory estimated method, angle variation by interference vibration, and movement accuracy.
Design and analysis of spider robot used as agricultural sprayerYuvraj Pather
8-legged walking spider robot based on klann mechanism capable of walking on uneven terrain. The robot is mounted with a mini sprayer which can be used for agricultural spraying.
This project thesis is made by a group of mechanical engineering students as a final semester project.The project thesis data is collected by referring many other project work data and research papers which are easily available online some of them we also mention in the reference chapter.
***We are uploading this thesis as a refrence to other students and interested personnel's so it will be helpful for them. We don't have any intention of provoking any one.***
We work very hard for completing this thesis and will be very happy if anyone wants to continue on this project and make it more advanced.
Contact details are provided at the end of the thesis feel free to ask related to the project. Peace
The document discusses magnetic levitation (Maglev) trains. It begins by defining Maglev as using magnetic levitation to suspend, guide, and propel trains using magnets. It then explains the basic principles of levitation, propulsion, and lateral guidance that Maglev trains use to operate at high speeds. This includes using magnets to levitate the train 10 cm above the track and linear motors in the guideway to propel the train electromagnetically. The document also discusses the technologies, merits, and demographics of existing and planned Maglev systems around the world.
Computational Aeroacoustic Investigation of Co-rotating rotors for Urban Air Mobility.
The presentation is split into different slides (for pdf format) corresponding to different animations.
Master of Science in Aerospace Engineering, specializing in Aerodynamics, Aeroacoustics, and Wind Energy at TU Delft, the Netherlands.
1) A novel gearshift system is introduced comprising a 2 degree-of-freedom electromagnetic actuator to simplify structure, increase efficiency, and improve shift quality of automated manual transmissions.
2) The gearshift process is divided into non-synchronization and synchronization phases, with different control algorithms designed for each. Extended state observer based inverse system method is used for non-synchronization, while active disturbance rejection controller is used for synchronization.
3) Comparative simulations and experiments demonstrate the effectiveness of the proposed control method in achieving good gearshift performance for the novel system. The control strategy provides a new solution for automated manual transmission applications.
The document summarizes a master's thesis that analyzes and develops controllers for a quadcopter. It presents the dynamic equations of the quadcopter and linearizes them. Two backstepping controllers are developed - a simpler one that cannot absorb disturbances, and a more advanced one that can handle disturbances like changes in mass. Both controllers separate attitude from horizontal/vertical position control. The controllers are simulated and compared to evaluate their performance.
mechanical spider robot by klann mechanismNeel Shah
The document describes a mechanical spider robot project that uses a Klann mechanism for locomotion. The Klann mechanism converts rotational motion to linear foot movement similar to animal walking. It allows the robot to access rough terrain unlike wheeled robots. The project aims to create an 8-legged robot to test new walking algorithms that could be useful for the robotics community. The robot design is loosely based on spiders and their advanced octopedal locomotion.
This document discusses magnetic levitation trains (Maglev trains). It describes two main types of Maglev trains: electromagnetic suspension (EMS) and electrodynamic suspension (EDS). EMS uses electromagnets to attract the train to the track for levitation and propulsion, while EDS uses superconducting magnets and repulsion for levitation. The document outlines the basic principles, pros and cons of each system and concludes that Maglev trains offer a more efficient transportation alternative with advantages like very high speeds and less environmental impact.
Projet ESMO - European Students Moon Orbiter - CLES-FACIL 2007CLES-FACIL
This document outlines the workplan for the reaction wheel subsystem for a student moon orbiter project. It discusses the current reaction wheel design using Dynacon Micro Wheel 1000 reaction wheels. The workplan includes updating models, selecting electronic components, developing simulations in MATLAB/Simulink to validate that the wheel design can maintain spacecraft attitude under expected disturbance torques for at least 24 hours before needing to offload momentum using thrusters. The workplan objectives are divided into tasks to further develop requirements, models, simulations, and validate the reaction wheel subsystem design.
This document discusses different mechanisms for generating electricity from vehicles passing over speed breakers, including gear, roller, and rack and pinion mechanisms. It describes the basic principles of converting kinetic and potential energy from vehicles into electrical energy. The rack and pinion mechanism is presented as having higher efficiency around 70% compared to the roller mechanism at 50%. Construction details and the working procedure of the rack and pinion system are provided. The document concludes that this is a low-cost way to generate electricity without fuel by capturing wasted vehicle energy.
This document discusses generating electricity from speed breakers using vehicles' kinetic and potential energy. It describes two mechanisms - roller and rack/pinion mechanisms. The rack/pinion is more efficient (70% vs 50%) and easier to design for, converting the linear motion of the speed breaker into rotational motion to power a generator. Charts show voltage increasing with vehicle speed and electrical load. In conclusion, this method generates pollution-free power from vehicles at low cost, providing a solution to energy shortages.
Electricity Generation using Treadmill TricycleIRJET Journal
1. Students at the Sree Narayana Institute of Technology designed a treadmill tricycle that allows people to exercise and generate electricity at the same time.
2. The tricycle replaces the pedals with a treadmill. As the user exercises on the treadmill, it drives the rear wheels of the tricycle via a chain drive, allowing the user to travel while exercising.
3. Small generators are attached to rotating parts of the tricycle. As the parts rotate due to the user's exercise, the generators produce electrical energy that can be stored in a battery. This stored energy can then be used to power devices during emergencies or power outages.
This document summarizes a student project to modify a go-kart gearbox to allow for full hand control operation for physically impaired drivers. The project objectives were to research available human motions, determine the optimal motion for controls, generate concept ideas, and 3D model the final design. Various control concepts were analyzed and a final concept using a thumb throttle, motorcycle brake levers for braking and clutching, and electronic push buttons for gear changing was developed. Future work could include optimizing the design, clarifying regulations, prototyping, and testing.
DESIGN & FABRICATION OF FOUR WHEEL STEERED MULTI- UTILITY VEHICLEDelwin CK
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Walking on uneven terrain is always a benchmark problem for autonomous guided vehicles. In the present work, the same issue is dealt with the help of a legged mobile robot. Various comparisons are made among two, four, and sixlegged walking machine and a four-legged walking machine is selected based on the suitability criterion. In this paper, the emphasis is given for minimization of the design and controlling complexities for the four-legged walking machine. A prototype devised to test various gaits. For the walking and turning, an improved gait is presented. The legs are designed with one degree of freedom each. The actuation is tested on normal DC geared motors as well as DC servo motors. A comparison is made between the two actuators. For proper walking, a control scheme is prepared and real time tests are performed by implementing it on the Arduino microcontroller. The present work is helpful to analyze the performance of a legged autonomous walking machine on unstructured environment.
Keywords: Walking Machining, Legged AGV, Mobile Robotics, Servo Motor Control
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This chapter discusses different types of actuators used to control movement in robots. It describes pneumatic, hydraulic, and electrical motor systems. Pneumatic systems use compressed air and are low-cost but have limitations from air compressibility. Hydraulic systems provide greater speed and strength but require more space. Electrical motor systems like DC, AC, servo, and stepper motors offer more accuracy and repeatability than hydraulic systems. The chapter compares advantages and disadvantages of pneumatic and hydraulic actuators and describes various linear and rotary configurations for each system.
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Slides used in PhD Thesis Defence: Lalit Patnaik 2015, Indian Institute of Science
1. Dynamics and Control of a
Rimless Wheel based 2D Dynamic Walker
using Pulsed Torque Actuation
Lalit Patnaik
Research Advisor: Prof. L Umanand
Department of Electronic Systems Engineering
Indian Institute of Science
April 17, 2015
3. Introduction
Terrestrial Locomotion Alternatives
Energetics of Locomotion
Models of Walking
Thesis Scope
Dynamics and Torque Regimes
Analytical Solution for Dynamics
Torque Regimes
Experimental Results
Analysis of Operating Point Space
Physical Constraints
Optimal Walker
Hardware Design and Control Topology
Mechanical Hardware
Electrical Hardware
System Integration
Control Scheme
Conclusion
4. Dynamics and Control of Rimless Wheel using Pulsed Torque
Introduction
Terrestrial Locomotion Alternatives
Wheeled locomotion: efficiency
I Fast
I Energy efficient
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5. Dynamics and Control of Rimless Wheel using Pulsed Torque
Introduction
Terrestrial Locomotion Alternatives
Wheeled locomotion: efficiency
I Fast
I Energy efficient
I Continuous ground contact
I Need prepared surface: hard AND even
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6. Dynamics and Control of Rimless Wheel using Pulsed Torque
Introduction
Terrestrial Locomotion Alternatives
Wheeled locomotion: efficiency
I Fast
I Energy efficient
I Continuous ground contact
I Need prepared surface: hard AND even
Pair of surfaces Coefficient of rolling resistance
µr = (drag force)/(normal reaction)
Steel wheels on steel rails ∼0.001
Car tyre on tar/asphalt road ∼0.01
Car tyre on loose sand ∼0.1
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7. Dynamics and Control of Rimless Wheel using Pulsed Torque
Introduction
Terrestrial Locomotion Alternatives
Legged locomotion: versatility
I No need of prepared surface
I Can traverse diverse terrain
5 / 76
8. Dynamics and Control of Rimless Wheel using Pulsed Torque
Introduction
Terrestrial Locomotion Alternatives
Legged locomotion: versatility
I No need of prepared surface
I Can traverse diverse terrain
I Intermittent ground contact
I Can be lossy: braking and ground impacts
5 / 76
9. Dynamics and Control of Rimless Wheel using Pulsed Torque
Introduction
Terrestrial Locomotion Alternatives
Legged locomotion gaits
Gaits
Walking Running
Static Zero Moment Point
(ZMP) based
Dynamic
t
slow fast
Never air-borne
t
Sometimes air-borne
in phase
out of phase
slow fast
t = Kinetic Energy
= Potential Energy
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10. Dynamics and Control of Rimless Wheel using Pulsed Torque
Introduction
Terrestrial Locomotion Alternatives
Static walking: Jansen mechanism
−1 0 1 2 3 4 5 6 7 8
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Link−0
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Node−0
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Node−2
Node−3
Node−4
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CC
Link-1
L
in
k
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L
i
n
k
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L
in
k-
0
L
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n
k
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Link-4
L
in
k
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L
in
k
-6
Link-7
L
in
k
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Link-10
Node-0
Node-1
Node-2
Node-3
Node-4
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CC Pin
−1 0 1 2 3 4 5 6 7
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0
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Link−3
Link−8
Node−3
Node−4
Node−2
Pin
CC
Node−5
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11. Dynamics and Control of Rimless Wheel using Pulsed Torque
Introduction
Terrestrial Locomotion Alternatives
Static walking: Jansen mechanism
−1 0 1 2 3 4 5 6 7 8
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0
1
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Link−10
Node−0
Node−1
Node−2
Node−3
Node−4
Node−5
Pin
CC
Link-1
L
in
k
-9
L
i
n
k
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2
L
in
k-
0
L
i
n
k
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3
Link-4
L
in
k
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L
in
k
-6
Link-7
L
in
k
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Link-10
Node-0
Node-1
Node-2
Node-3
Node-4
Node-5
CC Pin
−1 0 1 2 3 4 5 6 7
−6
−5
−4
−3
−2
−1
0
1
2
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Link−1
Link−2
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Node−1
Node−0
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Link−6
Link−5
Link−7
Link−4
Link−3
Link−8
Node−3
Node−4
Node−2
Pin
CC
Node−5
I Kinematics: [Jansen Mechanism Animation]
7 / 76
12. Dynamics and Control of Rimless Wheel using Pulsed Torque
Introduction
Terrestrial Locomotion Alternatives
Bond graph model of Jansen mechanism
Bond Graph Model of Jansen Mechanism
0
Sf : ω
35
36
1
R
:
R
1
C : C1
1
1
L
:
I
0
2
S
e
:
3
7
3
78
mTF
M1
4
5
mTF
M8
79
80
0
10
1
R : R2
9
C : C2 8
0
13
1
R : R3
12
C : C3
11
0
85
1
R : R4
84
C : C4 83
0
88
1
R : R5
87
C : C5
86
6
7
81
82
mTF
M2
14
16
15
mTF
M9
89
91
90
1
1
1
1
1
1
17
18
19
92
93
94
L
:
m
1
20
L
:
m
1
21
S
e
:
38
L
:
I
1
22
L
:
m
6
95
L
:
m
6
96
S
e
:
97
L
:
I
6
98
mTF
M3
23
24
mTF
M10
100
101
0
29
1
R : R6
28
C : C6 27
0
32
1
R : R7
31
C : C7
30
0
106
1
R : R8
105
C : C8 104
0
109
1
R : R9
108
C : C9
107
25
26
102
103
mTF
M4
mTF
M11
33
1
48
L
:
I
2
34
S
e
:
39
110
1
113
L
:
I
8
11
1
S
e
:
11
2
mTF
M5
49
50
mTF
M12
114
115
0
55
1
R : R10
54
C : C10 53
0
58
1
R : R11
57
C : C11
56
0
120
1
R : R12
119
C : C12 118
0
123
1
R : R13
122
C : C13
121
51
52
116
117
mTF
M6
59
61
60
mTF
M13
124
126
125
1
1
1
1
1
1
62
63
64
L
:
m
3
65
L
:
m
3
66
S
e
:
67
L
:
I
3
68
L
:
m
4
13
0
S
e
:
13
7
L
:
m
4
13
1
S
e
:
13
2
L
:
I
4
13
3
S
e
:
13
4
mTF
M7
70
7
1
mTF
M14
127
128
129
0
0
135
1
3
6
77
1
C
:
C
1
4
7
5
R
:
R
1
4
7
6
74
1
C
:
C
1
5
7
2
R
:
R
1
5
7
3
LINK-0
LINK-1
LINK-6
LINK-2-9-10
LINK-8
LINK-3
LINK-4-5-7
MOTOR
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13. Dynamics and Control of Rimless Wheel using Pulsed Torque
Introduction
Terrestrial Locomotion Alternatives
Legged locomotion gaits
Static ZMP-based Dynamic
Stability high low intermediate
Posture sprawling upright upright
bent knees extended knees
No. of legs 4 or more 2 2 and 4
Energy high high low
Terrain uneven even intermediate
Foot type point flat any
Appearance natural unnatural natural
Natural hardly any damped utilized
dynamics
9 / 76
14. Dynamics and Control of Rimless Wheel using Pulsed Torque
Introduction
Energetics of Locomotion
Energy budget
10 / 76
15. Dynamics and Control of Rimless Wheel using Pulsed Torque
Introduction
Energetics of Locomotion
Energy budget
10 / 76
16. Dynamics and Control of Rimless Wheel using Pulsed Torque
Introduction
Energetics of Locomotion
Energy budget
10 / 76
17. Dynamics and Control of Rimless Wheel using Pulsed Torque
Introduction
Energetics of Locomotion
Energy budget
Once per lifetime
10 / 76
18. Dynamics and Control of Rimless Wheel using Pulsed Torque
Introduction
Energetics of Locomotion
Energy budget
Once per lifetime
Once per walk
10 / 76
19. Dynamics and Control of Rimless Wheel using Pulsed Torque
Introduction
Energetics of Locomotion
Energy budget
Once per lifetime
Once per walk Continuous
10 / 76
20. Dynamics and Control of Rimless Wheel using Pulsed Torque
Introduction
Energetics of Locomotion
Energy flow
Actuator Mechanical
Load
Mechanical
Energy
Metabolic / Electrical
Energy
Muscle / Motor
11 / 76
21. Dynamics and Control of Rimless Wheel using Pulsed Torque
Introduction
Energetics of Locomotion
Energy flow
Actuator Mechanical
Load
Mechanical
Energy
Metabolic / Electrical
Energy
Muscle / Motor
dynamics
losses
11 / 76
22. Dynamics and Control of Rimless Wheel using Pulsed Torque
Introduction
Energetics of Locomotion
Energy flow
Actuator Mechanical
Load
Mechanical
Energy
Metabolic / Electrical
Energy
Muscle / Motor
speed
efficiency
dynamics
losses
11 / 76
23. Dynamics and Control of Rimless Wheel using Pulsed Torque
Introduction
Energetics of Locomotion
Energy flow
Actuator Mechanical
Load
Mechanical
Energy
Metabolic / Electrical
Energy
Muscle / Motor
speed
efficiency
dynamics
losses
I Biological systems
I minimize metabolic energy[1]
for given actuator (muscle)
[1] Minetti and Alexander, “A Theory of Metabolic Costs for Bipedal Gaits,” J. Theor. Biol. (1997)
11 / 76
24. Dynamics and Control of Rimless Wheel using Pulsed Torque
Introduction
Energetics of Locomotion
Energy flow
Actuator Mechanical
Load
Mechanical
Energy
Metabolic / Electrical
Energy
Muscle / Motor
speed
efficiency
dynamics
losses
I Biological systems
I minimize metabolic energy[1]
for given actuator (muscle)
I Engineered systems
I minimize mechanical energy, then design actuator
[1] Minetti and Alexander, “A Theory of Metabolic Costs for Bipedal Gaits,” J. Theor. Biol. (1997)
11 / 76
25. Dynamics and Control of Rimless Wheel using Pulsed Torque
Introduction
Terminology
Human walking[2]
Right
heel-
strike
Left
toe-
off
Right
mid-
stance
Left
heel-
strike
Right
toe-
off
Left
mid-
stance
Right
heel-
strike
Left
toe-
off
0 % 50 % 100 %
Time, percent of cycle
Double
support Right single support
Double
support Left single support
Double
support
Right stance phase
Left stance phase
Right swing phase
Left swing phase
Cycle (stride) duration
[2] Inman et al, Human walking (1981)
12 / 76
26. Dynamics and Control of Rimless Wheel using Pulsed Torque
Introduction
Models of Walking
Models of walking
a b c
d e f g
[3] Alexander, “Mechanics of Bipedal Locomotion,” Perspectives in Experimental Biology (1976)
[4] Margaria, Biomechanics and Energetics of Muscular Exercise (1976)
[5] Alexander, “Simple models of human movement,” ASME Appl. Mech. Rev. (1995)
13 / 76
27. Dynamics and Control of Rimless Wheel using Pulsed Torque
Introduction
Models of Walking
Models of walking
a b c
d e f g
[3] Alexander, “Mechanics of Bipedal Locomotion,” Perspectives in Experimental Biology (1976)
[4] Margaria, Biomechanics and Energetics of Muscular Exercise (1976)
[5] Alexander, “Simple models of human movement,” ASME Appl. Mech. Rev. (1995)
13 / 76
28. Dynamics and Control of Rimless Wheel using Pulsed Torque
Introduction
Models of Walking
Ideal inverted pendulum walker
mid-stance velocity
14 / 76
29. Dynamics and Control of Rimless Wheel using Pulsed Torque
Introduction
Models of Walking
Ideal inverted pendulum walker
step angle
14 / 76
30. Dynamics and Control of Rimless Wheel using Pulsed Torque
Introduction
Models of Walking
Ideal inverted pendulum walker
impact
14 / 76
31. Dynamics and Control of Rimless Wheel using Pulsed Torque
Introduction
Models of Walking
Ideal inverted pendulum walker
14 / 76
32. Dynamics and Control of Rimless Wheel using Pulsed Torque
Introduction
Models of Walking
Practical inverted pendulum walker
15 / 76
33. Dynamics and Control of Rimless Wheel using Pulsed Torque
Introduction
Models of Walking
Loss mechanisms
Braking loss
I Muscles performing negative work[6]
[6] Cavagna et al, “The role of gravity in human walking: penduluar energy exchange, external work and optimal 16 / 76
34. Dynamics and Control of Rimless Wheel using Pulsed Torque
Introduction
Models of Walking
Loss mechanisms
Braking loss
I Muscles performing negative work[6]
I Coulomb friction in rotary joints
[6] Cavagna et al, “The role of gravity in human walking: penduluar energy exchange, external work and optimal 16 / 76
35. Dynamics and Control of Rimless Wheel using Pulsed Torque
Introduction
Models of Walking
Loss mechanisms
Braking loss
I Muscles performing negative work[6]
I Coulomb friction in rotary joints
I Rolling resistance for walking
[6] Cavagna et al, “The role of gravity in human walking: penduluar energy exchange, external work and optimal 16 / 76
36. Dynamics and Control of Rimless Wheel using Pulsed Torque
Introduction
Models of Walking
Loss mechanisms
Impact loss: instantaneous loss of kinetic energy
0 20 40 60
0
0.2
0.4
0.6
0.8
1
φm
(degree)
v
m
’/v
m
[7] Alexander, Principles of animal locomotion (2003)
[8] McGeer, “Passive dynamic walking,” Int. J. Robot. Res. (1990)
17 / 76
37. Dynamics and Control of Rimless Wheel using Pulsed Torque
Introduction
Models of Walking
Achieving a sustained walk
Passive dynamic walker on downward incline
18 / 76
38. Dynamics and Control of Rimless Wheel using Pulsed Torque
Introduction
Models of Walking
Achieving a sustained walk
Passive dynamic walker on downward incline
I Biped
I Without knees[8]
I With knees[9]
[8] McGeer, “Passive dynamic walking,” Int. J. Robot. Res. (1990)
[9] McGeer, “Passive Walking with Knees,” IEEE ICRA (1990)
18 / 76
39. Dynamics and Control of Rimless Wheel using Pulsed Torque
Introduction
Models of Walking
Achieving a sustained walk
Passive dynamic walker on downward incline
I Biped
I Without knees[8]
I With knees[9]
I Rimless wheel
I Point foot[10]
I Flat foot[11]
[8] McGeer, “Passive dynamic walking,” Int. J. Robot. Res. (1990)
[9] McGeer, “Passive Walking with Knees,” IEEE ICRA (1990)
[10] Coleman et al, “Motions of a Rimless Spoked Wheel: a Simple 3D System with Impacts,”
Dynam. Stabil. Syst. (1997)
[11] Nirukawa et al, “Design and Stability Analysis of a 3D Rimless Wheel with Flat Feet and Ankle Springs,”
J. Sys. Design & Dyn. (2009)
18 / 76
40. Dynamics and Control of Rimless Wheel using Pulsed Torque
Introduction
Models of Walking
Achieving a sustained walk
Add actuator
19 / 76
41. Dynamics and Control of Rimless Wheel using Pulsed Torque
Introduction
Models of Walking
Achieving a sustained walk
Add actuator
[12] Collins et al, ”A 3D Passive-Dynamic Walking Robot with Two Legs and Knees,” Int. J. Robot. Res. (2001)
[13] Dertien, Realisation of an energy-efficient walking robot (2005)
19 / 76
42. Dynamics and Control of Rimless Wheel using Pulsed Torque
Introduction
Thesis Scope
Thesis scope
Motor
Controller Load
1 2
3
20 / 76
43. Dynamics and Control of Rimless Wheel using Pulsed Torque
Introduction
Thesis Scope
Thesis scope
Motor
Controller Load
1 2
3
1. Load dynamics, energetics and torque regimes
Achieving sustained forward motion with pulsed torque
20 / 76
44. Dynamics and Control of Rimless Wheel using Pulsed Torque
Introduction
Thesis Scope
Thesis scope
Motor
Controller Load
1 2
3
1. Load dynamics, energetics and torque regimes
Achieving sustained forward motion with pulsed torque
2. Physical constraints on choice of operating points
Locating optimal operating points
20 / 76
45. Dynamics and Control of Rimless Wheel using Pulsed Torque
Introduction
Thesis Scope
Thesis scope
Motor
Controller Load
1 2
3
1. Load dynamics, energetics and torque regimes
Achieving sustained forward motion with pulsed torque
2. Physical constraints on choice of operating points
Locating optimal operating points
3. Control topology for pulsed torque actuation of two
synchronized brushless DC (BLDC) motors
20 / 76
46. Introduction
Terrestrial Locomotion Alternatives
Energetics of Locomotion
Models of Walking
Thesis Scope
Dynamics and Torque Regimes
Analytical Solution for Dynamics
Torque Regimes
Experimental Results
Analysis of Operating Point Space
Physical Constraints
Optimal Walker
Hardware Design and Control Topology
Mechanical Hardware
Electrical Hardware
System Integration
Control Scheme
Conclusion
47. Dynamics and Control of Rimless Wheel using Pulsed Torque
Dynamics and Torque Regimes
Analytical Solution for Dynamics
Closed form solution missing
I "Surprisingly, the inverted pendulum model of walking does
not appear to have been solved analytically before." [14]
I Taylor’s analytical solution uses elliptic integrals
(not closed form)
[14] Graham Taylor and Adrian Thomas, Evolutionary Biomechanics (2014)
22 / 76
48. Dynamics and Control of Rimless Wheel using Pulsed Torque
Dynamics and Torque Regimes
Analytical Solution for Dynamics
Torque sources
sin
23 / 76
49. Dynamics and Control of Rimless Wheel using Pulsed Torque
Dynamics and Torque Regimes
Analytical Solution for Dynamics
Closed-form analytical solution
φ(t) =
vi
vn
sinh (ωnt) + (φc + φi) cosh(ωnt) − φc
v(t) =
dφ
dt
l = vi cosh (ωnt) + (φc + φi) · vn · sinh (ωnt)
where
vn =
p
gl
ωn =
r
g
l
φc = sin φa − sin φb
24 / 76
50. Dynamics and Control of Rimless Wheel using Pulsed Torque
Dynamics and Torque Regimes
Analytical Solution for Dynamics
0 0.5 1
−40
−20
0
20
40
t (s)
φ
(degree)
t (s)
v
(m/s)
0 0.5 1
0.5
1
1.5
2
numerical
analytical
numerical
analytical
Parameter values: m = 50 kg, l = 1 m, φb = 5◦, φa = 15◦
Initial conditions: φi = −25◦, vi = 1 m/s
Final condition: φf = 25◦
Error < 6% (for step angle < 25◦)
25 / 76
63. Dynamics and Control of Rimless Wheel using Pulsed Torque
Dynamics and Torque Regimes
Experimental Results
Chatur: Rimless Wheel based 2D Dynamic Walker
I Sustained forward motion using pulsed torque
I All four proposed torque regimes achieved
I Oscilloscope mounted on mobile platform
31 / 76
64. Dynamics and Control of Rimless Wheel using Pulsed Torque
Dynamics and Torque Regimes
Experimental Results
Chatur: Rimless Wheel based 2D Dynamic Walker
I Sustained forward motion using pulsed torque
I All four proposed torque regimes achieved
I Oscilloscope mounted on mobile platform
I [Chatur Video]
31 / 76
65. Dynamics and Control of Rimless Wheel using Pulsed Torque
Dynamics and Torque Regimes
Experimental Results
Regime 1
1
2
3
4
1
2
3
4
Time scale 250 ms/div, dis = 3/8
(1) Accelerometer output (2 V/div)
(2) Motor-1 sector number
(3) Motor-1 phase current Ia1 (10 A/div)
(4) Torque reference (1 V/div)
32 / 76
66. Dynamics and Control of Rimless Wheel using Pulsed Torque
Dynamics and Torque Regimes
Experimental Results
Regime 2
1
2
3
4
1
2
3
4
Time scale 250 ms/div, dis = 4/8
(1) Accelerometer output (2 V/div)
(2) Motor-1 sector number
(3) Motor-1 phase current Ia1 (10 A/div)
(4) Torque reference (2 V/div)
33 / 76
67. Dynamics and Control of Rimless Wheel using Pulsed Torque
Dynamics and Torque Regimes
Experimental Results
Regime 3
1
2
3
4
1
2
3
4
Time scale 250 ms/div, dis = 5/8
(1) Accelerometer output (2 V/div)
(2) Motor-1 sector number
(3) Motor-1 phase current Ia1 (10 A/div)
(4) Torque reference (2 V/div)
34 / 76
68. Dynamics and Control of Rimless Wheel using Pulsed Torque
Dynamics and Torque Regimes
Experimental Results
Regime 4
1
2
3
4
1
2
3
4
Time scale 250 ms/div, dis = 1
(1) Accelerometer output (2 V/div)
(2) Motor-1 sector number
(3) Motor-1 phase current Ia1 (5 A/div)
(4) Torque reference (1 V/div)
35 / 76
69. Dynamics and Control of Rimless Wheel using Pulsed Torque
Dynamics and Torque Regimes
Experimental Results
Average power vs average speed
Pavg = 2 · τavg · ωavg
0 0.2 0.4 0.6 0.8
0
2
4
6
8
10
vx,avg
(m/s)
P
avg
(W)
R1
R2
R3
R4
36 / 76
70. Dynamics and Control of Rimless Wheel using Pulsed Torque
Dynamics and Torque Regimes
Experimental Results
Mechanical cost of transport vs normalized speed
Mechanical COT = Pavg/mgvx,avg
0 0.1 0.2 0.3 0.4
0
0.01
0.02
0.03
0.04
Normalized vx,avg
Mechanical
CoT
R1
R2
R3
R4
37 / 76
71. Introduction
Terrestrial Locomotion Alternatives
Energetics of Locomotion
Models of Walking
Thesis Scope
Dynamics and Torque Regimes
Analytical Solution for Dynamics
Torque Regimes
Experimental Results
Analysis of Operating Point Space
Physical Constraints
Optimal Walker
Hardware Design and Control Topology
Mechanical Hardware
Electrical Hardware
System Integration
Control Scheme
Conclusion
72. Dynamics and Control of Rimless Wheel using Pulsed Torque
Analysis of Operating Point Space
Physical Constraints
Take-off constraint
0 1 2 3 4
0
10
20
30
40
50
v0
(m/s)
φ
m
(degree)
v2
0 = gl(3 cos φm + 2φm sin φb − 2)
[15] Usherwood, “Why not walk faster?,” Biol. Lett. (2005)
39 / 76
73. Dynamics and Control of Rimless Wheel using Pulsed Torque
Analysis of Operating Point Space
Physical Constraints
Take-off constraint
0 1 2 3 4
0
10
20
30
40
50
v0
(m/s)
φ
m
(degree)
1
.
0
m
0
.
8
m
0
.
6
m
0
.
4
m
v2
0 = gl(3 cos φm + 2φm sin φb − 2)
[15] Usherwood, “Why not walk faster?,” Biol. Lett. (2005)
39 / 76
74. Dynamics and Control of Rimless Wheel using Pulsed Torque
Analysis of Operating Point Space
Physical Constraints
Sliding constraint
0 1 2 3 4
0
10
20
30
40
50
v0
(m/s)
φ
m
(degree)
40 / 76
75. Dynamics and Control of Rimless Wheel using Pulsed Torque
Analysis of Operating Point Space
Physical Constraints
Constant speed region
0 1 2 3 4
0
10
20
30
40
50
v0
(m/s)
φ
m
(degree)
1%
41 / 76
76. Dynamics and Control of Rimless Wheel using Pulsed Torque
Analysis of Operating Point Space
Physical Constraints
Constant speed region
0 1 2 3 4
0
10
20
30
40
50
v0
(m/s)
φ
m
(degree)
0.1%
1%
41 / 76
77. Dynamics and Control of Rimless Wheel using Pulsed Torque
Analysis of Operating Point Space
Physical Constraints
Fall-back constraint
0 1 2 3 4
0
10
20
30
40
50
v0
(m/s)
φ
m
(degree)
42 / 76
78. Dynamics and Control of Rimless Wheel using Pulsed Torque
Analysis of Operating Point Space
Physical Constraints
Fall-back constraint
0 1 2 3 4
0
10
20
30
40
50
v0
(m/s)
φ
m
(degree)
42 / 76
79. Dynamics and Control of Rimless Wheel using Pulsed Torque
Analysis of Operating Point Space
Physical Constraints
Steady-state constraint
0 1 2 3 4
0
10
20
30
40
50
v0
(m/s)
φ
m
(degree)
43 / 76
80. Dynamics and Control of Rimless Wheel using Pulsed Torque
Analysis of Operating Point Space
Physical Constraints
Region of operation
0 1 2 3 4
0
10
20
30
40
50
v0
(m/s)
φ
m
(degree)
take-off
sliding
fall-back
constant-speed
steady-state
region
of
operation
44 / 76
81. Dynamics and Control of Rimless Wheel using Pulsed Torque
Analysis of Operating Point Space
Physical Constraints
Region of operation : l = 1 m, φb = 1◦
0 1 2 3 4
0
10
20
30
40
50
v0
(m/s)
φ
m
(degree)
45 / 76
82. Dynamics and Control of Rimless Wheel using Pulsed Torque
Analysis of Operating Point Space
Physical Constraints
Region of operation : l = 1 m, φb = 1◦
0 1 2 3 4
0
10
20
30
40
50
v0
(m/s)
φ
m
(degree)
0 1 2 3 4
0
10
20
30
40
50
v0
(m/s)
φ
m
(degree)
45 / 76
83. Dynamics and Control of Rimless Wheel using Pulsed Torque
Analysis of Operating Point Space
Optimal Walker
Average velocity: vx,avg = f2(v0, φm)
v0
(m/s)
φ
m
(degree)
1 2 3
10
15
20
25
0
.4
m
/s
1.2
m/s
0.
8
m
/s
1.6
m/s
2.
0
m
/s
Parameters: m = 65 kg, l = 1 m, φa = 10◦, φb = 1◦
46 / 76
84. Dynamics and Control of Rimless Wheel using Pulsed Torque
Analysis of Operating Point Space
Optimal Walker
Average power: Pavg = f1(v0, φm)
v0
(m/s)
φ
m
(degree)
1 2 3
10
15
20
25
1
0
W
2
0
W
3
0
W
4
0
W
Parameters: m = 65 kg, l = 1 m, φa = 10◦, φb = 1◦
47 / 76
85. Dynamics and Control of Rimless Wheel using Pulsed Torque
Analysis of Operating Point Space
Optimal Walker
Optimal operating point for a given speed
v0
(m/s)
φ
m
(degree)
1 2 3
10
15
20
25
0.4 m
/s
5
0
W
7
0
W
90
W
Parameters: m = 65 kg, l = 1 m, φa = 10◦, φb = 1◦
48 / 76
86. Dynamics and Control of Rimless Wheel using Pulsed Torque
Analysis of Operating Point Space
Optimal Walker
Locus of optimal operating points
v0
(m/s)
φ
m
(degree)
1 2 3
10
15
20
25
Parameters: m = 65 kg, l = 1 m, φa = 10◦, φb = 1◦
49 / 76
87. Dynamics and Control of Rimless Wheel using Pulsed Torque
Analysis of Operating Point Space
Optimal Walker
Optimal locii for various leg lengths
0 0.5 1
5
10
15
20
25
30
Normalized v0
φ
m
(degree)
Parameters: m = 65 kg, g = 9.81 m/s2
, φa = 10◦ and φb = 1◦
50 / 76
88. Dynamics and Control of Rimless Wheel using Pulsed Torque
Analysis of Operating Point Space
Optimal Walker
Power vs speed
0 1 2 3
0
100
200
300
vx,avg
(m/s)
P
avg
(degree)
Parameters: m = 65 kg, g = 9.81 m/s2
, φa = 10◦ and φb = 1◦
51 / 76
89. Dynamics and Control of Rimless Wheel using Pulsed Torque
Analysis of Operating Point Space
Optimal Walker
Mechanical COT vs speed
vx,avg
(m/s)
Mechanical
COT
0 1 2 3
0
0.05
0.1
0.15
0.2
0.25
Parameters: m = 65 kg, g = 9.81 m/s2
, φa = 10◦ and φb = 1◦
52 / 76
90. Introduction
Terrestrial Locomotion Alternatives
Energetics of Locomotion
Models of Walking
Thesis Scope
Dynamics and Torque Regimes
Analytical Solution for Dynamics
Torque Regimes
Experimental Results
Analysis of Operating Point Space
Physical Constraints
Optimal Walker
Hardware Design and Control Topology
Mechanical Hardware
Electrical Hardware
System Integration
Control Scheme
Conclusion
91. Dynamics and Control of Rimless Wheel using Pulsed Torque
Hardware Design and Control Topology
Mechanical Hardware
Version-1: Mild steel slotted angle frame
I Rimless wheel = hub motor + annular disc + 18 spokes
54 / 76
92. Dynamics and Control of Rimless Wheel using Pulsed Torque
Hardware Design and Control Topology
Mechanical Hardware
Version-1: Mild steel slotted angle frame
I Rimless wheel = hub motor + annular disc + 18 spokes
I Two wheels take care of lateral stability
54 / 76
93. Dynamics and Control of Rimless Wheel using Pulsed Torque
Hardware Design and Control Topology
Mechanical Hardware
Version-1: Mild steel slotted angle frame
I Rimless wheel = hub motor + annular disc + 18 spokes
I Two wheels take care of lateral stability
I ‘Tail’ with castor wheel to resist counter torque on frame
54 / 76
94. Dynamics and Control of Rimless Wheel using Pulsed Torque
Hardware Design and Control Topology
Mechanical Hardware
Version-1: Mild steel slotted angle frame
I Rimless wheel = hub motor + annular disc + 18 spokes
I Two wheels take care of lateral stability
I ‘Tail’ with castor wheel to resist counter torque on frame
I Problems: wheel alignment, assembly issues
54 / 76
95. Dynamics and Control of Rimless Wheel using Pulsed Torque
Hardware Design and Control Topology
Mechanical Hardware
Version-2: Welded mild steel frame
TOP VIEW
SIDE VIEW
FRONT VIEW
SOUTH-EAST
ISOMETRIC VIEW
55 / 76
96. Dynamics and Control of Rimless Wheel using Pulsed Torque
Hardware Design and Control Topology
Mechanical Hardware
Version-2: Welded mild steel frame
56 / 76
97. Dynamics and Control of Rimless Wheel using Pulsed Torque
Hardware Design and Control Topology
Mechanical Hardware
Electronics enclosure design
TOP VIEW ISOMETRIC VIEW
FRONT VIEW SIDE VIEW
Chatur
board
controller
CIPOS
boards
inverter
Heat sinks
57 / 76
98. Dynamics and Control of Rimless Wheel using Pulsed Torque
Hardware Design and Control Topology
Electrical Hardware
Electrical hardware
I Energy source: Lead acid batteries
58 / 76
99. Dynamics and Control of Rimless Wheel using Pulsed Torque
Hardware Design and Control Topology
Electrical Hardware
Electrical hardware
I Energy source: Lead acid batteries
I Motor drive: Infineon CIPOS based 3-phase inverter
58 / 76
100. Dynamics and Control of Rimless Wheel using Pulsed Torque
Hardware Design and Control Topology
Electrical Hardware
Electrical hardware
I Energy source: Lead acid batteries
I Motor drive: Infineon CIPOS based 3-phase inverter
I Actuator: Brushless DC (BLDC) hub motor
58 / 76
101. Dynamics and Control of Rimless Wheel using Pulsed Torque
Hardware Design and Control Topology
Electrical Hardware
Electrical hardware
I Energy source: Lead acid batteries
I Motor drive: Infineon CIPOS based 3-phase inverter
I Actuator: Brushless DC (BLDC) hub motor
I Controller: Cypress PSoC5 based controller card
58 / 76
102. Dynamics and Control of Rimless Wheel using Pulsed Torque
Hardware Design and Control Topology
Electrical Hardware
Electrical hardware
I Energy source: Lead acid batteries
I Motor drive: Infineon CIPOS based 3-phase inverter
I Actuator: Brushless DC (BLDC) hub motor
I Controller: Cypress PSoC5 based controller card
I Sensors: Motor currents, battery voltages, rotor-position,
3-axis accelerometer
58 / 76
103. Dynamics and Control of Rimless Wheel using Pulsed Torque
Hardware Design and Control Topology
Electrical Hardware
Electrical hardware
I Energy source: Lead acid batteries
I Motor drive: Infineon CIPOS based 3-phase inverter
I Actuator: Brushless DC (BLDC) hub motor
I Controller: Cypress PSoC5 based controller card
I Sensors: Motor currents, battery voltages, rotor-position,
3-axis accelerometer
I Communication: Radio frequency link to operator
58 / 76
104. Dynamics and Control of Rimless Wheel using Pulsed Torque
Hardware Design and Control Topology
System Integration
Full system after integration
Parameters for Chatur
I mass: m = 50 kg
I leg/spoke length:
l = 0.57 m
I step angle:
φm = 10◦
I Torque constant:
Kt = 0.6 Nm/A
59 / 76
105. Dynamics and Control of Rimless Wheel using Pulsed Torque
Hardware Design and Control Topology
System Integration
Electrical system block diagram
1
CIPOS
Inverter 1
CIPOS
Inverter 2
BLDC motor1
PWM
V sense
Fault
I sense
Rotor position
JTAG
RS232
DACs
Sensed quantities
Oscilloscope
Chatur Controller Board
RF link
BLDC motor2
Batteries
Personal Computer
60 / 76
106. Dynamics and Control of Rimless Wheel using Pulsed Torque
Hardware Design and Control Topology
System Integration
Load and actuator torque profiles
φ (degree)
Torque
(Nm
)
−10 −5 0 5 10
−50
0
50
−50 0 50
−200
−100
0
100
200
Torque
(Nm
)
φ (degree)
τl = Opposing load torque
τa = Actuator torque
Pattern repeats 18 times per mechanical revolution
61 / 76
107. Dynamics and Control of Rimless Wheel using Pulsed Torque
Hardware Design and Control Topology
Control Scheme
Inner loop: Torque control
PI Controller Limiter PWM
Logic-2
Logic-1
gate pulses
to inverter
rotor position
motor currents
d
+
-
62 / 76
108. Dynamics and Control of Rimless Wheel using Pulsed Torque
Hardware Design and Control Topology
Control Scheme
Non-commutating current feedback
sector
number
5 4 6 2 3 1 sector
number
5
4
6
2
3 1
Reconstructing torque feedback (Ifb) from motor phase currents
63 / 76
109. Dynamics and Control of Rimless Wheel using Pulsed Torque
Hardware Design and Control Topology
Control Scheme
Full control scheme
Scaling
EMA
Filter
Torque
Controller
Logic
gate pulses
(to inverter)
rotor position
motor currents
+
-
Scaling impacts
(from accelerometer)
+
Mux
+
sector change count
sector change count
of other motor
ref
(from operator)
wheel sync
term
lag
0
select
64 / 76
110. Dynamics and Control of Rimless Wheel using Pulsed Torque
Hardware Design and Control Topology
Control Scheme
Experimental results: Torque control
1
2
4
3
Time scale: 100 ms/div
(1) Accelerometer output: 2 V/div
(2) Motor phase current: 10 A/div
(3) Torque reference: 0.5 V/div
(4) Torque feedback: 0.5 V/div
65 / 76
111. Dynamics and Control of Rimless Wheel using Pulsed Torque
Hardware Design and Control Topology
Control Scheme
Experimental results: Wheel synchronization
1
2
3
4
double impact
dip in torque
reference
Time scale: 250 ms/div
(1) Accelerometer output: 2 V/div
(2) Motor-1 sector number
(3) Motor-1 phase current Ia1: 10 A/div
(4) Torque reference: 1 V/div
66 / 76
112. Introduction
Terrestrial Locomotion Alternatives
Energetics of Locomotion
Models of Walking
Thesis Scope
Dynamics and Torque Regimes
Analytical Solution for Dynamics
Torque Regimes
Experimental Results
Analysis of Operating Point Space
Physical Constraints
Optimal Walker
Hardware Design and Control Topology
Mechanical Hardware
Electrical Hardware
System Integration
Control Scheme
Conclusion
113. Dynamics and Control of Rimless Wheel using Pulsed Torque
Conclusion
Summary of Contributions
1. Four torque regimes in a rimless wheel based dynamic
walker using pulsed torque actuation
68 / 76
114. Dynamics and Control of Rimless Wheel using Pulsed Torque
Conclusion
Summary of Contributions
1. Four torque regimes in a rimless wheel based dynamic
walker using pulsed torque actuation
I Regimes are defined by ratio of energy losses (Eloss) to
available actuator torque (τa)
68 / 76
115. Dynamics and Control of Rimless Wheel using Pulsed Torque
Conclusion
Summary of Contributions
1. Four torque regimes in a rimless wheel based dynamic
walker using pulsed torque actuation
I Regimes are defined by ratio of energy losses (Eloss) to
available actuator torque (τa)
I For sustained forward motion: Eloss ↑⇒ pulse duty ratio ↑
68 / 76
116. Dynamics and Control of Rimless Wheel using Pulsed Torque
Conclusion
Summary of Contributions
1. Four torque regimes in a rimless wheel based dynamic
walker using pulsed torque actuation
I Regimes are defined by ratio of energy losses (Eloss) to
available actuator torque (τa)
I For sustained forward motion: Eloss ↑⇒ pulse duty ratio ↑
I 4 types of sub-phases (unactuated rise, unactuated fall,
actuated rise, actuated fall) are concatenated in 4 different
ways to form repeating cycles yielding the 4 regimes
68 / 76
117. Dynamics and Control of Rimless Wheel using Pulsed Torque
Conclusion
Summary of Contributions
1. Four torque regimes in a rimless wheel based dynamic
walker using pulsed torque actuation
I Regimes are defined by ratio of energy losses (Eloss) to
available actuator torque (τa)
I For sustained forward motion: Eloss ↑⇒ pulse duty ratio ↑
I 4 types of sub-phases (unactuated rise, unactuated fall,
actuated rise, actuated fall) are concatenated in 4 different
ways to form repeating cycles yielding the 4 regimes
I Proposed regimes holds for all walkers – engineered or
biological (actuation is present only for a portion of the
stance phase)
68 / 76
118. Dynamics and Control of Rimless Wheel using Pulsed Torque
Conclusion
Summary of Contributions
2. Closed-form analytical solution for stance phase
dynamics of 2D inverted pendulum walking using
hyperbolic functions
69 / 76
119. Dynamics and Control of Rimless Wheel using Pulsed Torque
Conclusion
Summary of Contributions
2. Closed-form analytical solution for stance phase
dynamics of 2D inverted pendulum walking using
hyperbolic functions
I Parametric expression for constant actuation and braking
torques (τa and τb)
69 / 76
120. Dynamics and Control of Rimless Wheel using Pulsed Torque
Conclusion
Summary of Contributions
2. Closed-form analytical solution for stance phase
dynamics of 2D inverted pendulum walking using
hyperbolic functions
I Parametric expression for constant actuation and braking
torques (τa and τb)
I Error in solution within 6% (for step angle < 25◦
)
69 / 76
121. Dynamics and Control of Rimless Wheel using Pulsed Torque
Conclusion
Summary of Contributions
2. Closed-form analytical solution for stance phase
dynamics of 2D inverted pendulum walking using
hyperbolic functions
I Parametric expression for constant actuation and braking
torques (τa and τb)
I Error in solution within 6% (for step angle < 25◦
)
I Useful tool for investigating effect of various
parameters/variables on dynamics
69 / 76
122. Dynamics and Control of Rimless Wheel using Pulsed Torque
Conclusion
Summary of Contributions
3. Framework of physical constraints on the choice of
operating points for a generic inverted pendulum walker
70 / 76
123. Dynamics and Control of Rimless Wheel using Pulsed Torque
Conclusion
Summary of Contributions
3. Framework of physical constraints on the choice of
operating points for a generic inverted pendulum walker
I Not all operating points (v0,φm) lead to realizable
steady-state gait
70 / 76
124. Dynamics and Control of Rimless Wheel using Pulsed Torque
Conclusion
Summary of Contributions
3. Framework of physical constraints on the choice of
operating points for a generic inverted pendulum walker
I Not all operating points (v0,φm) lead to realizable
steady-state gait
I Constraint lines delimit valid region of operation of walker
(fundamental limits on walking like an inverted pendulum)
70 / 76
125. Dynamics and Control of Rimless Wheel using Pulsed Torque
Conclusion
Summary of Contributions
3. Framework of physical constraints on the choice of
operating points for a generic inverted pendulum walker
I Not all operating points (v0,φm) lead to realizable
steady-state gait
I Constraint lines delimit valid region of operation of walker
(fundamental limits on walking like an inverted pendulum)
I Sub-regions that result in various regimes of walking are
identified
70 / 76
126. Dynamics and Control of Rimless Wheel using Pulsed Torque
Conclusion
Summary of Contributions
4. Optimal operating points in inverted pendulum walking
71 / 76
127. Dynamics and Control of Rimless Wheel using Pulsed Torque
Conclusion
Summary of Contributions
4. Optimal operating points in inverted pendulum walking
I Operating point with minimum Pmech for given speed is
located based on tangency of power and velocity contours
71 / 76
128. Dynamics and Control of Rimless Wheel using Pulsed Torque
Conclusion
Summary of Contributions
4. Optimal operating points in inverted pendulum walking
I Operating point with minimum Pmech for given speed is
located based on tangency of power and velocity contours
I Repeating for different speeds, optimal locus of operating
points is obtained
71 / 76
129. Dynamics and Control of Rimless Wheel using Pulsed Torque
Conclusion
Summary of Contributions
4. Optimal operating points in inverted pendulum walking
I Operating point with minimum Pmech for given speed is
located based on tangency of power and velocity contours
I Repeating for different speeds, optimal locus of operating
points is obtained
I Shape and location of optimal locus is sensitive to loss and
internal energy models
71 / 76
130. Dynamics and Control of Rimless Wheel using Pulsed Torque
Conclusion
Summary of Contributions
4. Optimal operating points in inverted pendulum walking
I Operating point with minimum Pmech for given speed is
located based on tangency of power and velocity contours
I Repeating for different speeds, optimal locus of operating
points is obtained
I Shape and location of optimal locus is sensitive to loss and
internal energy models
I Using a suitable constant step angle over a broad range of
speeds could lead to an inverted pendulum walker that is
close to optimal
71 / 76
131. Dynamics and Control of Rimless Wheel using Pulsed Torque
Conclusion
Summary of Contributions
5. Hardware design and control topology for pulsed torque
actuation of a synchronized dual BLDC motor driven
platform
72 / 76
132. Dynamics and Control of Rimless Wheel using Pulsed Torque
Conclusion
Summary of Contributions
5. Hardware design and control topology for pulsed torque
actuation of a synchronized dual BLDC motor driven
platform
I Complete design for mechanical and electrical hardware of
hub-actuated dual rimless wheel 2D dynamic walker
(Chatur)
72 / 76
133. Dynamics and Control of Rimless Wheel using Pulsed Torque
Conclusion
Summary of Contributions
5. Hardware design and control topology for pulsed torque
actuation of a synchronized dual BLDC motor driven
platform
I Complete design for mechanical and electrical hardware of
hub-actuated dual rimless wheel 2D dynamic walker
(Chatur)
I Method for wheel synchronization: increment torque of
lagging motor
72 / 76
134. Dynamics and Control of Rimless Wheel using Pulsed Torque
Conclusion
Summary of Contributions
5. Hardware design and control topology for pulsed torque
actuation of a synchronized dual BLDC motor driven
platform
I Complete design for mechanical and electrical hardware of
hub-actuated dual rimless wheel 2D dynamic walker
(Chatur)
I Method for wheel synchronization: increment torque of
lagging motor
I BLDC drive with non-commutating current feedback
reduces current spikes during sector transitions.
72 / 76
135. Dynamics and Control of Rimless Wheel using Pulsed Torque
Conclusion
Summary of Contributions
5. Hardware design and control topology for pulsed torque
actuation of a synchronized dual BLDC motor driven
platform
I Complete design for mechanical and electrical hardware of
hub-actuated dual rimless wheel 2D dynamic walker
(Chatur)
I Method for wheel synchronization: increment torque of
lagging motor
I BLDC drive with non-commutating current feedback
reduces current spikes during sector transitions.
I Control scheme can be used in any synchronized dual
motor system with pulsed actuation
72 / 76
136. Dynamics and Control of Rimless Wheel using Pulsed Torque
Conclusion
Scope for Further Work
1. Improvements in mathematical model
73 / 76
137. Dynamics and Control of Rimless Wheel using Pulsed Torque
Conclusion
Scope for Further Work
1. Improvements in mathematical model
I Unified model for walking and rolling
73 / 76
138. Dynamics and Control of Rimless Wheel using Pulsed Torque
Conclusion
Scope for Further Work
1. Improvements in mathematical model
I Unified model for walking and rolling
I Effect of distributed mass on dynamics
73 / 76
139. Dynamics and Control of Rimless Wheel using Pulsed Torque
Conclusion
Scope for Further Work
1. Improvements in mathematical model
I Unified model for walking and rolling
I Effect of distributed mass on dynamics
2. Reduce losses in experimental prototype
73 / 76
140. Dynamics and Control of Rimless Wheel using Pulsed Torque
Conclusion
Scope for Further Work
1. Improvements in mathematical model
I Unified model for walking and rolling
I Effect of distributed mass on dynamics
2. Reduce losses in experimental prototype
I Compliance
73 / 76
141. Dynamics and Control of Rimless Wheel using Pulsed Torque
Conclusion
Scope for Further Work
1. Improvements in mathematical model
I Unified model for walking and rolling
I Effect of distributed mass on dynamics
2. Reduce losses in experimental prototype
I Compliance
I Better wheel alignment
73 / 76
142. Dynamics and Control of Rimless Wheel using Pulsed Torque
Conclusion
Scope for Further Work
1. Improvements in mathematical model
I Unified model for walking and rolling
I Effect of distributed mass on dynamics
2. Reduce losses in experimental prototype
I Compliance
I Better wheel alignment
I Lower detent torque
73 / 76
143. Dynamics and Control of Rimless Wheel using Pulsed Torque
Conclusion
Scope for Further Work
1. Improvements in mathematical model
I Unified model for walking and rolling
I Effect of distributed mass on dynamics
2. Reduce losses in experimental prototype
I Compliance
I Better wheel alignment
I Lower detent torque
I Actuators with high efficiency at low speed
73 / 76
144. Dynamics and Control of Rimless Wheel using Pulsed Torque
Conclusion
Scope for Further Work
3. Ability to start from standstill.
74 / 76
145. Dynamics and Control of Rimless Wheel using Pulsed Torque
Conclusion
Scope for Further Work
3. Ability to start from standstill.
I High torque actuator
74 / 76
146. Dynamics and Control of Rimless Wheel using Pulsed Torque
Conclusion
Scope for Further Work
3. Ability to start from standstill.
I High torque actuator
I Introduce mechanical advantage: actuated feet, variable
length spokes?
74 / 76
147. Dynamics and Control of Rimless Wheel using Pulsed Torque
Conclusion
Scope for Further Work
3. Ability to start from standstill.
I High torque actuator
I Introduce mechanical advantage: actuated feet, variable
length spokes?
4. Avoid undesirable effects of castor wheel, tail piece
74 / 76
148. Dynamics and Control of Rimless Wheel using Pulsed Torque
Conclusion
Scope for Further Work
3. Ability to start from standstill.
I High torque actuator
I Introduce mechanical advantage: actuated feet, variable
length spokes?
4. Avoid undesirable effects of castor wheel, tail piece
I Reduce system weight
74 / 76
149. Dynamics and Control of Rimless Wheel using Pulsed Torque
Conclusion
Scope for Further Work
3. Ability to start from standstill.
I High torque actuator
I Introduce mechanical advantage: actuated feet, variable
length spokes?
4. Avoid undesirable effects of castor wheel, tail piece
I Reduce system weight
I Use counterweight on stator
74 / 76
150. Dynamics and Control of Rimless Wheel using Pulsed Torque
Conclusion
Scope for Further Work
3. Ability to start from standstill.
I High torque actuator
I Introduce mechanical advantage: actuated feet, variable
length spokes?
4. Avoid undesirable effects of castor wheel, tail piece
I Reduce system weight
I Use counterweight on stator
I Ability to walk backward
74 / 76
151. Dynamics and Control of Rimless Wheel using Pulsed Torque
Conclusion
Scope for Further Work
5. Phase displaced rimless wheels
75 / 76
152. Dynamics and Control of Rimless Wheel using Pulsed Torque
Conclusion
Scope for Further Work
5. Phase displaced rimless wheels
I Alternating ground impacts for spokes of left and right
wheels
75 / 76
153. Dynamics and Control of Rimless Wheel using Pulsed Torque
Conclusion
Scope for Further Work
5. Phase displaced rimless wheels
I Alternating ground impacts for spokes of left and right
wheels
I Minimize lateral dynamics: reduce distance between
wheels
75 / 76
154. Dynamics and Control of Rimless Wheel using Pulsed Torque
Conclusion
Scope for Further Work
5. Phase displaced rimless wheels
I Alternating ground impacts for spokes of left and right
wheels
I Minimize lateral dynamics: reduce distance between
wheels
6. Dynamics and energetics of turning
75 / 76
155. Dynamics and Control of Rimless Wheel using Pulsed Torque
Conclusion
Scope for Further Work
5. Phase displaced rimless wheels
I Alternating ground impacts for spokes of left and right
wheels
I Minimize lateral dynamics: reduce distance between
wheels
6. Dynamics and energetics of turning
I Large reflected torque on the actuators
75 / 76
156. Dynamics and Control of Rimless Wheel using Pulsed Torque
Conclusion
Scope for Further Work
5. Phase displaced rimless wheels
I Alternating ground impacts for spokes of left and right
wheels
I Minimize lateral dynamics: reduce distance between
wheels
6. Dynamics and energetics of turning
I Large reflected torque on the actuators
I How to minimize energy spent for turning?
75 / 76
157. Dynamics and Control of Rimless Wheel using Pulsed Torque
Conclusion
Thank you!
Questions?
Lalit Patnaik
plalit@dese.iisc.ernet.in
76 / 76
167. Specifications of Chatur
Parameter Value
Leg length, l 0.57 m
Step angle, φm 10◦
Step length, ls = 2l sin φm 0.2 m
CoM height variation, 9 mm
∆h = l(1 − cos φm)
Mass, m rimless wheels, 2 × 12 kg
frame, 7 kg
batteries, 15 kg
others, 4 kg
total, 50 kg
Motor torque constant, Kt 0.6 Nm/A
Maximum actuator torque parameter, 3◦
φa,max (at Imax = 12 A)
Braking torque parameter, φb ∼1◦
168. Specifications of BLDC hub motor
Parameter Value
Power 300 W
Voltage 24 V
Current 12 A
Pole pairs 25
Torque constant (Kt ) 0.6 Nm/A
Phase resistance (Rph) 0.35 Ω
Phase inductance (Lph) 0.12 mH
Mass 5.2 kg
Block rotor test
169. Commutation sequence of BLDC motor (CCW rotation)
Sector no. Motor current Inverter state*
direction A B C
(101)2 = 5 A+B− sw 0 x
(100)2 = 4 A+C− sw x 0
(110)2 = 6 B+C− x sw 0
(010)2 = 2 B+A− 0 sw x
(011)2 = 3 C+A− 0 x sw
(001)2 = 1 C+B− x 0 sw
*sw = switching, 0 = clamped to 0, x = both switches OFF
A
B C
B A
C A
A C
B C
C B
A B
+ -
+ -
+ -
+ -
+ -
+ -
170. BLDC circuit schematic & stator mmf orientations
A
B
C
A B
+ -
B A
+ - C A
+ -
A C
+ -
B C
+ - C B
+ -
North pole
5
4
6
2
3
1
171. PWM schemes for BLDC
A
B
C
Va
Vb
Vab
Va
Vb
Vab
Tsa=Tsb
Ts
PWM scheme with
both legs switching:
Tsa=Tsb=2Ts
PWM scheme with
one leg switching and
other leg clamped:
Tsa=Ts
Tsa
Ts
174. CIPOSTMinverter board specifications
Inputs (1) 24 V dc link, 12 A
(2) Power supply for gate drive (15 V)
and fault detection circuit (5 V)
(3) Six PWM control signals for the IGBTs
Outputs (1) Three pole voltages of the inverter
(2) Fault indication to controller
Dimensions 87 mm × 37 mm × 1.6 mm
175. Chatur controller board specifications
Inputs (1) Power
(a) 24 V, 0.6 A power supply (for flyback)
(b) 5 V aux. power supply (unused)
(2) Sensing
(a) Motor currents (Ia1, Ib1, Ia2 and Ib2)
(b) Battery voltages (Vdc1 and Vdc2)
(c) Rotor positions (3-bit digital output)
(3) Others
(a) JTAG program/debug interface
(b) Remote control signal from RF TX
(c) Fault indication from inverters
Outputs Six PWM control signals for each inverter
Dimensions 190.5 mm × 146.9 mm × 1.6 mm
176. Specifications of flyback power supply
Input 23–27 V, 0.6 A
Outputs (1) 5V, 0.3A (circuits on control side)
(2) 5V, 0.3 A (low voltage circuits on power side)
(3) 15V, 0.3A (CIPOSTMgate drive)
Switching 100 kHz
frequency
177. Electrical wiring diagram
CONN1
(JTAG)
10
Battery-1
Battery-2
Battery-3
Battery-4
Battery-5
Battery-6
Terminal Block
CIPOS
Inverter
Board-2
HS Fan-1
HS Fan-2
Motor-1
Motor-2
Chatur Controller Board
24 V
12 V
0 V
24 V
12 V
0 V
24 V
0 V
Vdc1
Vdc2
15
V
5
V
0
V
A
B
C
A
B
C
PWM
PWM
7 7
5 5
Position
Position
CONN401
(PBT)
CONN403
(PBT)
CONN7-8
(RMC)
CONN201-202
(RMC)
CONN301-302
(RMC)
CONN303-310
(FTs)
J25
(PBT)
CIPOS
Inverter
Board-1
J25
(PBT)
J24
(RMC)
J24
(RMC)
J26,30
(FT)
J26,30
(FT)
J27-29
(FTs)
J27-29
(FTs)
Note: RMC = Relimate Connector; PBT = PCB Terminal Block; FTs = Faston Tabs; HS = Heat Sink
CONN4
(RMC)
9
IDACs
178. Acquiring motor currents (once per PWM cycle)
ADC
Mux
channel
select
(chan)
start-of-conversion
DMA
soc
(soc)
chan
179. Time scales of various events/processes
Description Time
ADC conversion time 10 µs
PWM cycle time 61.2 µs
Software loop time 100 µs
Motor L/R time constant 350 µs
Sector dwell time 30–120 ms
Double impact blindfold window 300 ms
Step duration 350–900 ms