Optimization of vehicle suspension system using genetic algorithmIAEME Publication
Modeling the suspension of an automobile is of interest for many automotive and vibration engineers. Of importance for these engineers is the ride quality of the vehicle traversing over broken roads and control of body motion. When traveling over rough terrain, the vehicle exhibits bounce (up and down), pitch (rotation about the center of gravity along the vehicle's length) and roll (rotation about the center of gravity along the vehicle's width) motions.
SIMULTANEOUS OPTIMIZATION OF SEMIACTIVE QUARTER CAR SUSPENSION PARAMETERS USI...ijmech
In present paper, a methodology is presented related to the optimization of semi-active quarter car model
suspension parameters having three degrees of freedom, subjected to bump type of road excitation.
Influence of primary suspension stiffness, primary suspension damping, secondary suspension stiffness and
secondary suspension damping are studied on the passenger ride comfort, taking root mean square (RMS)
values of passenger seat displacement and settling time into account. Semi-active quarter car model
assembled with magneto-rheological (MR) shock absorber is selected for optimization of suspension
parameters using Taguchi method in combination with Grey relational analysis. Confirmatory results with
simulation run indicates that the optimized results of suspension parameters are helpful in achieving the
best ride comfort to travelling passengers in terms of minimization of passenger seat displacement and
settling time values.
CFD Simulation for Flow over Passenger Car Using Tail Plates for Aerodynamic ...IOSR Journals
This work proposes an effective numerical model based on the Computational Fluid Dynamics
(CFD) approach to obtain the flow structure around a passenger car with Tail Plates. The experimental work of
the test vehicle and grid system is constructed by ANSYS-14.0. FLUENT which is the CFD solver & employed in
the present work. In this study, numerical iterations are completed, then after aerodynamic data and detailed
complicated flow structure are visualized.
In the present work, model of generic passenger car has been developed in solid works-10 and
generated the wind tunnel and applied the boundary conditions in ANSYS workbench 14.0 platform then after
testing and simulation has been performed for the evaluation of drag coefficient for passenger car. In another
case, the aerodynamics of the most suitable design of tail plate is introduced and analysedfor the evaluation of
drag coefficient for passenger car. The addition of tail plates results in a reduction of the drag-coefficient
3.87% and lift coefficient 16.62% in head-on wind. Rounding the edges partially reduces drag in head-on wind
but does not bring about the significant improvements in the aerodynamic efficiency of the passenger car with
tail plates, it can be obtained. Hence, the drag force can be reduced by using add on devices on vehicle and fuel
economy, stability of a passenger car can be improved.
Comparison Of Multibody Dynamic Analysis Of Double Wishbone Suspension Using ...IJRES Journal
This paper presents the multibody dynamic analysis of wishbone suspension for automotive cars. Modeling and analysis of suspension is carried out using MATLAB SimMechanics toolbox. Rigid dynamic analysis of suspension is also carried out using ANSYS software. Results of both the analysis are compared and it is observed that results of both the analysis are similar.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
Aerodynamic Drag Reduction for A Generic Sport Utility Vehicle Using Rear Suc...IJERA Editor
The high demand for new and improved aerodynamic drag reduction devices has led to the invention of flow control mechanisms and continuous suction is a promising strategy that does not have major impact on vehicle geometry. The implementation of this technique on sport utility vehicles (SUV) requires adequate choice of the size and location of the opening as well as the magnitude of the boundary suction velocity. In this paper we introduce a new methodology to identifying these parameters for maximum reduction in aerodynamic drag. The technique combines automatic modeling of the suction slit, computational fluid dynamics (CFD) and a global search method using orthogonal arrays. It is shown that a properly designed suction mechanism can reduce drag by up to 9%.
Optimization of vehicle suspension system using genetic algorithmIAEME Publication
Modeling the suspension of an automobile is of interest for many automotive and vibration engineers. Of importance for these engineers is the ride quality of the vehicle traversing over broken roads and control of body motion. When traveling over rough terrain, the vehicle exhibits bounce (up and down), pitch (rotation about the center of gravity along the vehicle's length) and roll (rotation about the center of gravity along the vehicle's width) motions.
SIMULTANEOUS OPTIMIZATION OF SEMIACTIVE QUARTER CAR SUSPENSION PARAMETERS USI...ijmech
In present paper, a methodology is presented related to the optimization of semi-active quarter car model
suspension parameters having three degrees of freedom, subjected to bump type of road excitation.
Influence of primary suspension stiffness, primary suspension damping, secondary suspension stiffness and
secondary suspension damping are studied on the passenger ride comfort, taking root mean square (RMS)
values of passenger seat displacement and settling time into account. Semi-active quarter car model
assembled with magneto-rheological (MR) shock absorber is selected for optimization of suspension
parameters using Taguchi method in combination with Grey relational analysis. Confirmatory results with
simulation run indicates that the optimized results of suspension parameters are helpful in achieving the
best ride comfort to travelling passengers in terms of minimization of passenger seat displacement and
settling time values.
CFD Simulation for Flow over Passenger Car Using Tail Plates for Aerodynamic ...IOSR Journals
This work proposes an effective numerical model based on the Computational Fluid Dynamics
(CFD) approach to obtain the flow structure around a passenger car with Tail Plates. The experimental work of
the test vehicle and grid system is constructed by ANSYS-14.0. FLUENT which is the CFD solver & employed in
the present work. In this study, numerical iterations are completed, then after aerodynamic data and detailed
complicated flow structure are visualized.
In the present work, model of generic passenger car has been developed in solid works-10 and
generated the wind tunnel and applied the boundary conditions in ANSYS workbench 14.0 platform then after
testing and simulation has been performed for the evaluation of drag coefficient for passenger car. In another
case, the aerodynamics of the most suitable design of tail plate is introduced and analysedfor the evaluation of
drag coefficient for passenger car. The addition of tail plates results in a reduction of the drag-coefficient
3.87% and lift coefficient 16.62% in head-on wind. Rounding the edges partially reduces drag in head-on wind
but does not bring about the significant improvements in the aerodynamic efficiency of the passenger car with
tail plates, it can be obtained. Hence, the drag force can be reduced by using add on devices on vehicle and fuel
economy, stability of a passenger car can be improved.
Comparison Of Multibody Dynamic Analysis Of Double Wishbone Suspension Using ...IJRES Journal
This paper presents the multibody dynamic analysis of wishbone suspension for automotive cars. Modeling and analysis of suspension is carried out using MATLAB SimMechanics toolbox. Rigid dynamic analysis of suspension is also carried out using ANSYS software. Results of both the analysis are compared and it is observed that results of both the analysis are similar.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
Aerodynamic Drag Reduction for A Generic Sport Utility Vehicle Using Rear Suc...IJERA Editor
The high demand for new and improved aerodynamic drag reduction devices has led to the invention of flow control mechanisms and continuous suction is a promising strategy that does not have major impact on vehicle geometry. The implementation of this technique on sport utility vehicles (SUV) requires adequate choice of the size and location of the opening as well as the magnitude of the boundary suction velocity. In this paper we introduce a new methodology to identifying these parameters for maximum reduction in aerodynamic drag. The technique combines automatic modeling of the suction slit, computational fluid dynamics (CFD) and a global search method using orthogonal arrays. It is shown that a properly designed suction mechanism can reduce drag by up to 9%.
Multi link structure for rear independent suspension of heavy vehicleIAEME Publication
Automobile systems today is going through major changes and as concert to comfort the suspension system and it’s working is very important. The study of four link suspension system and dynamic analysis are discussed in this paper. This paper discusses the design problem of vehicles using four-link suspension systems with the aim of totally optimizing vehicle handling and stability.
Optimization of a Passive Vehicle Suspension System for Ride Comfort Enhancem...IDES Editor
This paper reports on an investigation to determine
the spring and damper settings that will ensure optimal ride
comfort of vehicle in different speeds using Design of
Experiment Method (DOE). The extent to which the ride
comfort optimal suspension settings vary for roads of different
roughness and varying speeds and the levels of ride comfort
that can be achieved, are addressed. Optimization is performed
with the DOE method with 7 DOF modeled for speeds ranging
from 60 to 90 km/h. Results indicate that optimization of
suspension settings using different road rouphness and
specified range of speed improve the ride comfort. It was found
that ride comfort is most sensitive to a change in rear spring
stiffness.
Deep neural network for lateral control of self-driving cars in urban environ...IAESIJAI
The exponential growth of the automotive industry clearly indicates that self-driving cars are the future of transportation. However, their biggest challenge lies in lateral control, particularly in urban bottlenecking environments, where disturbances and obstacles are abundant. In these situations, the ego vehicle has to follow its own trajectory while rapidly correcting deviation errors without colliding with other nearby vehicles. Various research efforts have focused on developing lateral control approaches, but these methods remain limited in terms of response speed and control accuracy. This paper presents a control strategy using a deep neural network (DNN) controller to effectively keep the car on the centerline of its trajectory and adapt to disturbances arising from deviations or trajectory curvature. The controller focuses on minimizing deviation errors. The Matlab/Simulink software is used for designing and training the DNN. Finally, simulation results confirm that the suggested controller has several advantages in terms of precision, with lateral deviation remaining below 0.65 meters, and rapidity, with a response time of 0.7 seconds, compared to traditional controllers in solving lateral control.
Modeling, simulation and optimization analysis of steering knuckle component ...eSAT Journals
Abstract Light weight and low fuel consumption are the two main demands for a vehicle, particularly for a race car. Steering knuckle, as one of the critical components of a race car, is the main subject in the present study. A light weight and optimized design of steering knuckle is proposed to be used for an EIMARace race car; a small high-performance formula-style car, with suitable material selection as well as valid finite element analysis and optimization studies. First part of this study involves modeling of steering knuckles and analysis of the stresses and displacement under actual load conditions. A CAD and FEA software; SolidWorks, is applied for modeling as well as for static analysis studies. Shape optimization is the second part of this study, utilizing solid Thinking software from Altair Engineering packages. The improved design obtained had achieved 45.8% reduction of mass while meeting the strength requirement. Keywords: Steering knuckle, FEA, Optimization, Race car.
Fuzzy rules incorporated skyhook theory based vehicular suspension design for...IJERA Editor
The vehicle suspension system supports and isolate the vehicle body and payload from road vibrations due to surface roughness by maintaining a controllable damping traction force between tires and road surface. In modern luxury vehicles semi active suspension system are offering both the reliability and accuracy that has enhanced the passenger ride comfort with less power demand. In this paper we have proposed the design of a hybrid control system having a combination of skyhook theory with fuzzy logic control and applied on a semi-active vehicle suspension system for its ride comfort enhancement. A two degree of freedom dynamic model is simulated using Matlab/Simulink for a vehicle equipped with semi-active suspension system with focused on the passenger‟s ride comfort performance.
Presentation on advance traffic engineering.pptxEtahEneji1
This presentation was done to fulfil the course requirement for the pursuit of my M. ENG on the course title: Advanced traffic engineering Course code : (CIV 8331).
Course Lecturer : ENGR. PROF H. M. AlHASSAN
Design of Multi Link Structure for Rear Suspenion of a Heavy Vehicletheijes
Automobile systems today is going through major changes and as concert to comfort the suspension system and it’s working is very important. The study of four link suspension system and dynamic analysis are discussed in this paper. This paper discusses the design problem of vehicles using four-link suspension systems with the aim of totally optimizing vehicle handling and stability. Since this problem includes many evaluation items, and Four-link suspension system has interconnected behaviour, the optimization is so complicated. An efficient and computable model is indispensable for compromising the total optimization. This paper investigates a structure of objectives, introduces appropriate simulation models for respective items; we apply multi body dynamic analysis to plot the varies terms such as wheel travel, camber angle, caster angle, toe-in, toe-out etc. The result of optimization calculation shows the validity of the optimization model
Newly Developed Nonlinear Vehicle Model for an Active Anti-roll Bar SystemjournalBEEI
This paper presents the development of a newly developed nonlinear vehicle model is used in the validation process of the vehicle model. The parameters chosen in a newly developed vehicle model is developed based on CARSIM vehicle model by using non-dominated sorting genetic algorithm version II (NSGA-II) optimization method. The ride comfort and handling performances have been one of the main objective to fulfil the expectation of customers in the vehicle development. Full nonlinear vehicle model which consists of ride, handling and Magic tyre subsystems has been derived and developed in MATLAB/Simulink. Then, optimum values of the full nonlinear vehicle parameters are investigated by using NSGA-II. The two objective functions are established based on RMS error between simulation and benchmark system. A stiffer suspension provides good stability and handling during manoeuvres while softer suspension gives better ride quality. The final results indicated that the newly developed nonlinear vehicle model is behaving accurately with input ride and manoeuvre. The outputs trend are successfully replicated.
Drag Reduction of Front Wing of an F1 Car using Adjoint Optimisationyasirmaliq
The Project Poster summarizes the aims and objectives of the Final Year Dissertation. The project starts with a detailed study on the parameters that tend to affect the performance of front wings of an F1 car and goes through designing the front wings(3) with endplates and wheel, meshing it, solving/analysing the flow and finally optimising the selected geometry using Fluent Adjoint Solver for efficient performance.
Adjoint optimisation technique is used to achieve optimal performance from the front wings. It's the most successful shape optimisation method as it's independent of the number of design variables exponentially reducing computational time and cost. The emphasis has been put on optimising the shape of the front wings using the Adjoint method as it’s the most efficient and computationally inexpensive method for design optimisation. The approach towards shape optimisation is downforce constrained drag minimization as it would result in keeping a constraint on downforce and reducing the drag at the same time, thus producing optima for a given downforce/drag value.
INTEGRATED INERTER DESIGN AND APPLICATION TO OPTIMAL VEHICLE SUSPENSION SYSTEMijcax
The formula cars need high tire grip on racing challenge by reducing rolling displacement at corner or double change lands. In this case study, the paper clarifies some issues related to suspension system with inerter to reduce displacement and rolling angle under impact from road disturbance on Formula SAE Car. We propose some new designs, which have an advance for suspension system by improving dynamics.
We optimize design of model based on the minimization of cost functions for roll dynamics, by reducing the displacement transfer and the energy consumed by the inerter. Base on a passive suspension model that we carried out quarter-car and half-car model for different parameters which show the benefit of the inerter. The important advantage of the proposed solution is its integration a new mechanism, the inerter, this system can increase advance in development and have effects on the vehicle dynamics in stability vehicle.
INTEGRATED INERTER DESIGN AND APPLICATION TO OPTIMAL VEHICLE SUSPENSION SYSTEMijcax
The formula cars need high tire grip on racing challenge by reducing rolling displacement at corner or double change lands. In this case study, the paper clarifies some issues related to suspension system with inerter to reduce displacement and rolling angle under impact from road disturbance on Formula SAE Car. We propose some new designs, which have an advance for suspension system by improving dynamics.
We optimize design of model based on the minimization of cost functions for roll dynamics, by reducing the displacement transfer and the energy consumed by the inerter. Base on a passive suspension model that we carried out quarter-car and half-car model for different parameters which show the benefit of the inerter. The important advantage of the proposed solution is its integration a new mechanism, the inerter, this system can increase advance in development and have effects on the vehicle dynamics in stability vehicle.
With Microsoft prePress, you can access just-written content from upcoming
books. The chapters come straight from our respected authors, before they’re
fully polished and debugged—for critical insights now, when you need them.
This document contains one or more portions of a preliminary version of a Microsoft Press title and is provided
“as is.” The content may be changed substantially upon final publication. In addition, this document may make
reference to pre-released versions of software products that may be changed substantially prior to final
commercial release. Microsoft reserves the right to not publish this title or any versions thereof (including
future prePress ebooks). This document is provided for informational purposes only. MICROSOFT MAKES NO
WARRANTIES, EITHER EXPRESS OR IMPLIED, IN THIS DOCUMENT. Information and views expressed in this
document, including URL and other Internet website references may be subject to change without notice. You
bear the risk of using it.
En principio, para entender con facilidad esta obra es recomendable estar familiarizado
con los conceptos básicos de programación orientada a objetos, en particular con los
lenguajes de programación C++ o Java de los que C# deriva.
Sin embargo, estos no son requisitos fundamentales para entenderla ya que cada vez que
en ella se introduce algún elemento del lenguaje se definen y explican los conceptos
básicos que permiten entenderlo. Aún así, sigue siendo recomendable disponer de los
requisitos antes mencionados para poder moverse con mayor soltura por el libro y
aprovecharlo al máximo.
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Multi link structure for rear independent suspension of heavy vehicleIAEME Publication
Automobile systems today is going through major changes and as concert to comfort the suspension system and it’s working is very important. The study of four link suspension system and dynamic analysis are discussed in this paper. This paper discusses the design problem of vehicles using four-link suspension systems with the aim of totally optimizing vehicle handling and stability.
Optimization of a Passive Vehicle Suspension System for Ride Comfort Enhancem...IDES Editor
This paper reports on an investigation to determine
the spring and damper settings that will ensure optimal ride
comfort of vehicle in different speeds using Design of
Experiment Method (DOE). The extent to which the ride
comfort optimal suspension settings vary for roads of different
roughness and varying speeds and the levels of ride comfort
that can be achieved, are addressed. Optimization is performed
with the DOE method with 7 DOF modeled for speeds ranging
from 60 to 90 km/h. Results indicate that optimization of
suspension settings using different road rouphness and
specified range of speed improve the ride comfort. It was found
that ride comfort is most sensitive to a change in rear spring
stiffness.
Deep neural network for lateral control of self-driving cars in urban environ...IAESIJAI
The exponential growth of the automotive industry clearly indicates that self-driving cars are the future of transportation. However, their biggest challenge lies in lateral control, particularly in urban bottlenecking environments, where disturbances and obstacles are abundant. In these situations, the ego vehicle has to follow its own trajectory while rapidly correcting deviation errors without colliding with other nearby vehicles. Various research efforts have focused on developing lateral control approaches, but these methods remain limited in terms of response speed and control accuracy. This paper presents a control strategy using a deep neural network (DNN) controller to effectively keep the car on the centerline of its trajectory and adapt to disturbances arising from deviations or trajectory curvature. The controller focuses on minimizing deviation errors. The Matlab/Simulink software is used for designing and training the DNN. Finally, simulation results confirm that the suggested controller has several advantages in terms of precision, with lateral deviation remaining below 0.65 meters, and rapidity, with a response time of 0.7 seconds, compared to traditional controllers in solving lateral control.
Modeling, simulation and optimization analysis of steering knuckle component ...eSAT Journals
Abstract Light weight and low fuel consumption are the two main demands for a vehicle, particularly for a race car. Steering knuckle, as one of the critical components of a race car, is the main subject in the present study. A light weight and optimized design of steering knuckle is proposed to be used for an EIMARace race car; a small high-performance formula-style car, with suitable material selection as well as valid finite element analysis and optimization studies. First part of this study involves modeling of steering knuckles and analysis of the stresses and displacement under actual load conditions. A CAD and FEA software; SolidWorks, is applied for modeling as well as for static analysis studies. Shape optimization is the second part of this study, utilizing solid Thinking software from Altair Engineering packages. The improved design obtained had achieved 45.8% reduction of mass while meeting the strength requirement. Keywords: Steering knuckle, FEA, Optimization, Race car.
Fuzzy rules incorporated skyhook theory based vehicular suspension design for...IJERA Editor
The vehicle suspension system supports and isolate the vehicle body and payload from road vibrations due to surface roughness by maintaining a controllable damping traction force between tires and road surface. In modern luxury vehicles semi active suspension system are offering both the reliability and accuracy that has enhanced the passenger ride comfort with less power demand. In this paper we have proposed the design of a hybrid control system having a combination of skyhook theory with fuzzy logic control and applied on a semi-active vehicle suspension system for its ride comfort enhancement. A two degree of freedom dynamic model is simulated using Matlab/Simulink for a vehicle equipped with semi-active suspension system with focused on the passenger‟s ride comfort performance.
Presentation on advance traffic engineering.pptxEtahEneji1
This presentation was done to fulfil the course requirement for the pursuit of my M. ENG on the course title: Advanced traffic engineering Course code : (CIV 8331).
Course Lecturer : ENGR. PROF H. M. AlHASSAN
Design of Multi Link Structure for Rear Suspenion of a Heavy Vehicletheijes
Automobile systems today is going through major changes and as concert to comfort the suspension system and it’s working is very important. The study of four link suspension system and dynamic analysis are discussed in this paper. This paper discusses the design problem of vehicles using four-link suspension systems with the aim of totally optimizing vehicle handling and stability. Since this problem includes many evaluation items, and Four-link suspension system has interconnected behaviour, the optimization is so complicated. An efficient and computable model is indispensable for compromising the total optimization. This paper investigates a structure of objectives, introduces appropriate simulation models for respective items; we apply multi body dynamic analysis to plot the varies terms such as wheel travel, camber angle, caster angle, toe-in, toe-out etc. The result of optimization calculation shows the validity of the optimization model
Newly Developed Nonlinear Vehicle Model for an Active Anti-roll Bar SystemjournalBEEI
This paper presents the development of a newly developed nonlinear vehicle model is used in the validation process of the vehicle model. The parameters chosen in a newly developed vehicle model is developed based on CARSIM vehicle model by using non-dominated sorting genetic algorithm version II (NSGA-II) optimization method. The ride comfort and handling performances have been one of the main objective to fulfil the expectation of customers in the vehicle development. Full nonlinear vehicle model which consists of ride, handling and Magic tyre subsystems has been derived and developed in MATLAB/Simulink. Then, optimum values of the full nonlinear vehicle parameters are investigated by using NSGA-II. The two objective functions are established based on RMS error between simulation and benchmark system. A stiffer suspension provides good stability and handling during manoeuvres while softer suspension gives better ride quality. The final results indicated that the newly developed nonlinear vehicle model is behaving accurately with input ride and manoeuvre. The outputs trend are successfully replicated.
Drag Reduction of Front Wing of an F1 Car using Adjoint Optimisationyasirmaliq
The Project Poster summarizes the aims and objectives of the Final Year Dissertation. The project starts with a detailed study on the parameters that tend to affect the performance of front wings of an F1 car and goes through designing the front wings(3) with endplates and wheel, meshing it, solving/analysing the flow and finally optimising the selected geometry using Fluent Adjoint Solver for efficient performance.
Adjoint optimisation technique is used to achieve optimal performance from the front wings. It's the most successful shape optimisation method as it's independent of the number of design variables exponentially reducing computational time and cost. The emphasis has been put on optimising the shape of the front wings using the Adjoint method as it’s the most efficient and computationally inexpensive method for design optimisation. The approach towards shape optimisation is downforce constrained drag minimization as it would result in keeping a constraint on downforce and reducing the drag at the same time, thus producing optima for a given downforce/drag value.
INTEGRATED INERTER DESIGN AND APPLICATION TO OPTIMAL VEHICLE SUSPENSION SYSTEMijcax
The formula cars need high tire grip on racing challenge by reducing rolling displacement at corner or double change lands. In this case study, the paper clarifies some issues related to suspension system with inerter to reduce displacement and rolling angle under impact from road disturbance on Formula SAE Car. We propose some new designs, which have an advance for suspension system by improving dynamics.
We optimize design of model based on the minimization of cost functions for roll dynamics, by reducing the displacement transfer and the energy consumed by the inerter. Base on a passive suspension model that we carried out quarter-car and half-car model for different parameters which show the benefit of the inerter. The important advantage of the proposed solution is its integration a new mechanism, the inerter, this system can increase advance in development and have effects on the vehicle dynamics in stability vehicle.
INTEGRATED INERTER DESIGN AND APPLICATION TO OPTIMAL VEHICLE SUSPENSION SYSTEMijcax
The formula cars need high tire grip on racing challenge by reducing rolling displacement at corner or double change lands. In this case study, the paper clarifies some issues related to suspension system with inerter to reduce displacement and rolling angle under impact from road disturbance on Formula SAE Car. We propose some new designs, which have an advance for suspension system by improving dynamics.
We optimize design of model based on the minimization of cost functions for roll dynamics, by reducing the displacement transfer and the energy consumed by the inerter. Base on a passive suspension model that we carried out quarter-car and half-car model for different parameters which show the benefit of the inerter. The important advantage of the proposed solution is its integration a new mechanism, the inerter, this system can increase advance in development and have effects on the vehicle dynamics in stability vehicle.
With Microsoft prePress, you can access just-written content from upcoming
books. The chapters come straight from our respected authors, before they’re
fully polished and debugged—for critical insights now, when you need them.
This document contains one or more portions of a preliminary version of a Microsoft Press title and is provided
“as is.” The content may be changed substantially upon final publication. In addition, this document may make
reference to pre-released versions of software products that may be changed substantially prior to final
commercial release. Microsoft reserves the right to not publish this title or any versions thereof (including
future prePress ebooks). This document is provided for informational purposes only. MICROSOFT MAKES NO
WARRANTIES, EITHER EXPRESS OR IMPLIED, IN THIS DOCUMENT. Information and views expressed in this
document, including URL and other Internet website references may be subject to change without notice. You
bear the risk of using it.
En principio, para entender con facilidad esta obra es recomendable estar familiarizado
con los conceptos básicos de programación orientada a objetos, en particular con los
lenguajes de programación C++ o Java de los que C# deriva.
Sin embargo, estos no son requisitos fundamentales para entenderla ya que cada vez que
en ella se introduce algún elemento del lenguaje se definen y explican los conceptos
básicos que permiten entenderlo. Aún así, sigue siendo recomendable disponer de los
requisitos antes mencionados para poder moverse con mayor soltura por el libro y
aprovecharlo al máximo.
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Como su nombre lo indica, la Investigación de Operaciones (IO), o
Investigación Operativa, es la investigación de las operaciones a realizar para el logro
óptimo de los objetivos de un sistema o la mejora del mismo. Esta disciplina brinda y
utiliza la metodología científica en la búsqueda de soluciones óptimas, como apoyo
en los procesos de decisión, en cuanto a lo que se refiere a la toma de decisiones
óptimas y en sistemas que se originan en la vida real.
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In 2015, I used to write extensions for Joomla, WordPress, phpBB3, etc and I ...Juraj Vysvader
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In this presentation we will share our experiences around getting started with the Globus Compute multi-user endpoint. Working with the Pharmacology group at the University of Auckland, we have previously written an application using Globus Compute that can offload computationally expensive steps in the researcher's workflows, which they wish to manage from their familiar Windows environments, onto the NeSI (New Zealand eScience Infrastructure) cluster. Some of the challenges we have encountered were that each researcher had to set up and manage their own single-user globus compute endpoint and that the workloads had varying resource requirements (CPUs, memory and wall time) between different runs. We hope that the multi-user endpoint will help to address these challenges and share an update on our progress here.
We describe the deployment and use of Globus Compute for remote computation. This content is aimed at researchers who wish to compute on remote resources using a unified programming interface, as well as system administrators who will deploy and operate Globus Compute services on their research computing infrastructure.
A Comprehensive Look at Generative AI in Retail App Testing.pdfkalichargn70th171
Traditional software testing methods are being challenged in retail, where customer expectations and technological advancements continually shape the landscape. Enter generative AI—a transformative subset of artificial intelligence technologies poised to revolutionize software testing.
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Navigating the Metaverse: A Journey into Virtual Evolution"Donna Lenk
Join us for an exploration of the Metaverse's evolution, where innovation meets imagination. Discover new dimensions of virtual events, engage with thought-provoking discussions, and witness the transformative power of digital realms."
In software engineering, the right architecture is essential for robust, scalable platforms. Wix has undergone a pivotal shift from event sourcing to a CRUD-based model for its microservices. This talk will chart the course of this pivotal journey.
Event sourcing, which records state changes as immutable events, provided robust auditing and "time travel" debugging for Wix Stores' microservices. Despite its benefits, the complexity it introduced in state management slowed development. Wix responded by adopting a simpler, unified CRUD model. This talk will explore the challenges of event sourcing and the advantages of Wix's new "CRUD on steroids" approach, which streamlines API integration and domain event management while preserving data integrity and system resilience.
Participants will gain valuable insights into Wix's strategies for ensuring atomicity in database updates and event production, as well as caching, materialization, and performance optimization techniques within a distributed system.
Join us to discover how Wix has mastered the art of balancing simplicity and extensibility, and learn how the re-adoption of the modest CRUD has turbocharged their development velocity, resilience, and scalability in a high-growth environment.
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As part of the DOE Integrated Research Infrastructure (IRI) program, NERSC at Lawrence Berkeley National Lab and ALCF at Argonne National Lab are working closely with General Atomics on accelerating the computing requirements of the DIII-D experiment. As part of the work the team is investigating ways to speedup the time to solution for many different parts of the DIII-D workflow including how they run jobs on HPC systems. One of these routes is looking at Globus Compute as a way to replace the current method for managing tasks and we describe a brief proof of concept showing how Globus Compute could help to schedule jobs and be a tool to connect compute at different facilities.
OpenFOAM solver for Helmholtz equation, helmholtzFoam / helmholtzBubbleFoamtakuyayamamoto1800
In this slide, we show the simulation example and the way to compile this solver.
In this solver, the Helmholtz equation can be solved by helmholtzFoam. Also, the Helmholtz equation with uniformly dispersed bubbles can be simulated by helmholtzBubbleFoam.
Listen to the keynote address and hear about the latest developments from Rachana Ananthakrishnan and Ian Foster who review the updates to the Globus Platform and Service, and the relevance of Globus to the scientific community as an automation platform to accelerate scientific discovery.
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(4) AI Ebook Suite Review: https://sumonreview.com/ai-ebook-suite-review
Accelerate Enterprise Software Engineering with PlatformlessWSO2
Key takeaways:
Challenges of building platforms and the benefits of platformless.
Key principles of platformless, including API-first, cloud-native middleware, platform engineering, and developer experience.
How Choreo enables the platformless experience.
How key concepts like application architecture, domain-driven design, zero trust, and cell-based architecture are inherently a part of Choreo.
Demo of an end-to-end app built and deployed on Choreo.
2. movement. Although the quarter car model is simple and widely used for dynamic
performance analysis, it fails to capture the more realistic results of actual behaviour of the
vehicle. Thus, in this work we analysed HCM because captures important characteristics of
full car model. Although the passive suspension systems have some inherent constraints we
consider them in our analysis due to their provided trade-off between the ride comfort level
and vehicle stability at low cost. The passive systems consists in elastic (spring) and
dissipative (damper) elements, their dynamic behaviour being described by the
characteristics of the items referred. To have a good performance of handling and stability
at different driving conditions (load, road profile, speed), the spring stiffness of suspension
system should be very high, which determines the passenger to experience uncomfortable
driving feeling. Conversely, if we expect that the suspension system to ensure a high level
of ride quality protecting the vehicle and driver from harmful stresses, the spring stiffness
should be decreased, which will determine the instability of vehicle when is drove.
This work can be seen also as a useful learning tool for students of Industrial
(Mechanical) Engineering specializations that successfully combines in their training
knowledge from different scientific fields such as: Computer Science (Artificial
Intelligence, Programming Languages, and Distributed Computing), Mathematics
(Differential Equations), Transportation Engineering (Vehicle Design), Mechanical
Engineering (Vibrations) to solve a real problem, even critical in Romania, characterized by
a developing infrastructure and poor quality roads.
The organization of the rest of this paper is as follows. In section 2 we review some
related work solutions applied in suspensions optimization, whereas section 3 describes the
dynamic suspension system in order to software implement. Section 4 presents the
mathematical model, provides programming details on solving the system of differential
equations by “Runge-Kutta” method, exhibits the application GUI and illustrates simulation
results. Finally, section 5 suggests directions for future work and concludes the paper.
2 Related work
In [1] the authors investigate the vibration and ride features of a passive HCM model with 5
DOF vehicle suspension system excited by a sinusoidal surface. Their model parameters are
kept fixed and made simulations in Simulink and Matlab for determining the amplitude of
vibrations. The main differences between their work and this paper consist in the software
vision of optimization methods that we performed (C# implementation of NSGA-II
algorithm), the number of degrees of freedom and the random road profile that we tested.
In [2] the authors present the mathematical model of QCM suspension’s system from
OPEL cars and in [3] the authors apply multi-objective optimization techniques for
designing the quarter car model on random and sinusoidal road profiles. Unlike these two
previous works, in this paper we changed the model of suspension (analysing HCM) and
also we have added two more degrees of freedom that expanded the differential equations
system of order two.
Studying the vibrations induced by surface irregularities in road pavements in [4] the
authors make some Matlab tests where they have shown that the road profile is a
combination of a large number of longer and shorter holes of different amplitudes. Based
on their equations we implemented the random road profiles in C#.
In [5] the authors present an optimization of a QCM 4-DOF vehicle’s human with seat
suspension system using weighted sum genetic algorithms (with fixed weights) to
determine suspension parameters. Unlike their work we apply on HCM 4-DOF Pareto
multi-objective optimization algorithms.
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3. 3 The Half-Car suspension system
The Half-Car model is a basic model used to simulate the vehicle’s suspension system
performance by investigating the dynamic response of cars when running on different
surfaces. HCM includes an independent Front and Rear vertical suspension (see Figure 1).
The HCM name is due to the fact that total vehicle mass is divided equally on two and
might be seen as combination of two quarter car models. The spring has significant role in
establishing the suspension function of the system, while the damper is used to dissipate
kinetic energy of spring and supply a damping function. We consider that there is no effect
of eccentricity of driver seat when located on the centre of gravity and the tires are always
touching the ground.
Fig. 1. The analytical model of half-car suspension system
We made the following notations:
x m1, m2, ms: (in the following order) mass of the Front tire wheel, Rear tire wheel and the
vehicle body (sprung mass).
x T : pitching motion angle of car body.
x Ix: pitch moment of inertia.
x a: lateral distance between the body centroid and Front tire wheel.
x b: lateral distance between the body centroid and Rear tire wheel.
x c1, c2: Damping coefficient of the Front suspension and Rear suspension.
x k1, k2: Vertical spring stiffness of the Front tire, Rear tire.
x k3, k4: Vertical spring stiffness of the sprung body Front suspension and Rear
suspension.
x Z1, Z2, Zs: (in the following order) bounce motion of the Front tire wheel, Rear tire
wheel and the vehicle body.
The four degree of freedom considered in this work are the three displacements: of car
body, Front and Rear tire respectively, and the pitching angle of car body.
4 Modelling and software implementation of the suspension
system
4.1 The mathematical model
In this section we described the mathematical model followed by C# software
implementation of the half-car suspension model with four degrees-of-freedom (4-DOF)
tested on a generic car. The purpose of modelling is to obtain a state space representation of
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4. the vehicle model. The mathematical model used for describing and studying of the
suspension is provided by a system of four differential equations of order 2.
∙ ̈ + ∙ ̇ + ∙ = ∙ (1)
In equation (1) M, C and K respectively, are mass matrix, damping matrix and stiffness
matrix. The forces that are transmitted from the running unevenness surface are exhibited
through Forces matrix (F).
Besides the aforementioned matrixes the system has as input the road excitation matrix
Q, where = ( )
(the height of potholes on front and rear wheel) and as outputs
the generalized displacement vector Z, where = ( )
.
=
0
0
0 0
0 0
0 0
0 0
0
0
; =
0 − −
0 −
− − + −
− −
+
;
(2)
=
+ 0 − −
0 + −
− − + −
− −
+
; =
0
0
0
0
0
0
The governing equations are:
⎩
⎪
⎪
⎨
⎪
⎪
⎧
∙
̈ + ∙ (
̇ − ̇ − ∙ ̇) + ∙ + ∙ ( − − ∙ ) = ∙
∙
̈ + ∙ #
̇ − ̇ + ∙ ̇$ + ∙ + ∙ ( − + ∙ ) = ∙
∙ ̈ + ∙ #̇ −
̇ + ∙ ̇$ + ∙ #̇ −
̇ − ∙ ̇$ + ∙ ( − + ∙ ) +
(3)
+ ∙ ( − − ∙ ) = 0
∙ ̈ + ∙ #̇ −
̇ + ∙ ̇$ ∙ − ∙ #̇ −
̇ − ∙ ̇$ ∙ + + ∙ ( − + ∙ ) ∙ −
− ∙ ( − − ∙ ) ∙ = 0
First two equations from system (2) describe the bounce motion of Front tire wheel and
Rear tire wheel, respectively. The third equation illustrates the bounce motion of body
vehicle while the last one shows the pitch motion of car. The system (2) will be transformed
into 8 differential equations of first order by introducing new unknown functions. The next
step aims solving the 8 kinematic equations of motion using C# DotNumerics.ODE [6]
package (see section 4.2) by “Runge-Kutta” numerical time integration method.
4.2 The software design
The developed software application was implemented in Microsoft Visual Studio 2015
(C#), .NET Framework 4.5, using DotNumerics a numerical library for .NET [6, 7]. The
class diagram of the project’s solution is presented in Figure 2.
The class that contains the evaluation of the vehicle input variables and uses the “Runge
Kutta” method [6] to solve the differential equations system in order to get the output
variables of the system is the SuspensionModelEvaluation class. The principal method here
is the Evaluate method, which receives as input parameters a SuspensionDesignSolution
object and a RandomRoadGenerator object. First we briefly described these two classes
and then we explain how Evaluate method works. Finally, it sets the displacement of the
Front tire wheel, the displacement of Rear tire wheel and the body mass acceleration.
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5. ¾ SuspensionDesignSolution class contains the properties that characterize a solution:
x The design variables that we wanted to optimize (vertical stiffness of Front suspension
(k3), vertical stiffness of Rear suspension (k4), vertical spring stiffness of the Front tire
(k1) and Rear tire (k2), vertical damping coefficient of the Front suspension (c1), vertical
coefficient damping of Rear suspension (c2)) as an array of type DesignVariable.
x The output variables that we want to optimize, such as
DisplacementSprungMassFrontTire (Z1), DisplacementSprungMassRearTire (Z2),
bodyMassAcceleration and their root mean square (RMS) version:
RmsDisplacementSprungMassFrontTire, RmsDisplacementSprungMassRearTire and
RmsBodyAcceleration.
x The front number (from all Pareto fronts) in which a solution is places, after evaluation
of the results within NSGA-II algorithm.
x The crowding distance that is specific to the solution, also needed in NSGA-II.
Fig. 2. The application classes
¾ RandomRoadGenerator is a class used for generating a random road signal on a specific
length and with a certain velocity. The constructor gets a few parameters: the length of
the road, the signal rate (step), the degree of roughness, the minimal and the maximal
wavelength and the velocity.
x The method GenerateSignal calculates the road signal and returns an array of double
values that represent the heights of the road on the specified length.
x Method GenerateRoadSignalAtTime is very important because it returns the road signal
at a specific time. It is very useful when calculating the displacements and accelerations
of vehicle model elements at a certain moment.
x Using ZedGraph functions package we realized 2D graphical representation of
generated artificial road profiles. The GenerateGraphic method from principal
MainForm class has the following parameters: a ZedGraphControl object, the title of
the graphic, the X axis string, the Y axis string, the signal and the signal step.
¾ In the Evaluate method of the SuspensionModelEvaluation class we instantiate an
OdeExplicitRungeKutta45 object from DotNumerics library [6], establish the initial
values of time (t0) and signal (y0), set the sampling interval of time array (t) and then
with the method Solve(y0,t) we get as result a matrix that has the number of rows equal
to the number of sampling values. In each row, there is an array of values that
correspond to the outputs of the system that was solved with “Runge Kutta” method.
The displacements and acceleration that we have interest in are saved in arrays and after
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6. iterating through all the samples, we calculate the RMS values of the outputs, which are
saved in the RmsDisplacementSprungMassFrontTire, RmsDisplacementSprungMassRearTire
and RmsBodyAcceleration properties of the solution of type SuspensionDesignSolution.
¾ The method ComputeMathematicalModelResult is used in the solving of differential
equations system and it contains the real differential equations. It is sent as a parameter
to OdeExplicitRungeKutta45 method.
4.2.1 Multi-objective optimization. Implementation of NSGA-II algorithm
Modified non-dominated sorting genetic algorithm (NSGA-II) [8] has been used for multi-
objective optimization of a 4-DOF vehicle model which excited with random road profile.
The conflicting objective functions considered were vertical acceleration of sprung mass,
relative displacement between body mass and Front tire wheel and relative displacement
between body mass and Rear tire wheel. NSGA-II is one of the most used algorithms in
experiments due to its capacity of generating good solutions regardless of the problem [3].
Because the pseudo-code of NSGA-II algorithm is presented in [3, 8] here we are limiting
to briefly describe how the main algorithm works:
x We have a parent population P0 of chromosomes (design solutions) that is randomly
initialized. The algorithm applies genetic operators (Binary tournament selection,
crossover, and mutation operators) in order to create a child population Q0 of size N.
The old and new populations are combined together, then a sorting is done using non-
dominance as criteria. Each solution is assigned a fitness equal to its rank (non-
domination level where 1 is the best level). Thus, minimization of fitness is assumed. A
combined population Rt = Pt ‰ Qt is formed, where t is the generation number. The
population Rt will be of size 2N. Then, the population Rt is sorted according to non-
domination. The new parent population Pt+1 is formed by adding solutions from the first
fronts till the size exceeds N. The ranks and crowding distance (density of individuals
surrounding a particular one) are used to guide the selection. An individual is better, if it
has a smaller rank, or in case of equality, the one with the bigger crowding distance.
x In order to sort a population of size N according to the level of non-domination, each
solution must be compared with every other solution in the population to find if it is
dominated. This process is continued to find the members of the first non-dominated
class for all population members. At this stage, all individuals in the first non-dominated
front are found. In order to find the individuals in the next front, the solutions of the first
front are temporarily discounted and the above procedure is repeated.
x First, for each solution we calculate two entities: (i) ni, the number of solutions which
dominate the i solution and (ii) Si, a set of solutions which the i solution dominates. We
identify all those points which have ni = 0 and put them in a list. We call F1 the current
front.
x Then, for each solution in the current front we visit each member (j) in its set and reduce
its nj value by one. In doing so, if for any member the count becomes zero, we put it in a
separate list H. When all members of the current front have been checked, we declare
the members in the list F1 as members of the first front. We then continue this process
using the newly identified front H as our current front.
x To get an estimate of the density of solutions surrounding a particular point in the
population we take the average distance of the two points on either side of this point
along each of the objectives. This quantity distance serves as an estimate of the size of
the largest cuboid enclosing the point without including any other point in the
population (the crowding distance).
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7. The implementation of the algorithm was done in NSGAII class. In the constructor we
pass some parameters which are: the maximum number of generations of genetic algorithm,
the population size, the road signal, the car parameters (as object of CarModel class) and
the relative and absolute tolerance used in the evaluation of a solution. The most important
method of NSGAII class is the ProcessAlgorithm method. It contains the main loop of the
algorithm. The GenerateInitialPopulation method randomly initialized the first parent
population. Then, each possible solution from the current parent population is evaluated to
get the objective functions in method SetObjectivesForSolutionSet, which gets as input
parameter the list of SuspensionDesignSolution. After this evaluation comes a while loop in
which at each iteration from the current population is generated a new population, till the
maximum number of iterations is reached. In this loop, the following actions are made:
• A new offspring population is generated from the parent population. They have the
same size. Pairs of two parents are selected by the binary tournament selection
mechanism (from BinaryTournamentSelection class, in which in the Execute method is
done the random selection of two solutions from population, then these solutions are
compared by their values of objective functions and crowding distance and the best
solution is returned). Then, recombination with one crossover point is done in Execute
method of CrossoverOperator class. After this, mutation is applied to both offspring
resulted from crossover. In method Execute from MutationOperator class is done the
mutation by randomly changing the value of one design variable.
• Offspring population is evaluated from the perspective of the 3 objective functions.
• A new population is generated by combining together the parent and children
populations. This one has twice the size of the parent / children population.
• The new population is split in Pareto fronts. Fronts are obtained mainly by getting for
each solution the number of solutions which dominate it and the set of solutions which
the solution dominates. The implementation is made in the constructor of the
ParetoFronts class.
• Each front is taken into consideration iteratively, from the first to the last one. Solutions
from the fronts are copied in a new population one by one, front by front, till the new
population has the size of the initial parent population. Each solution of the fronts that is
added to the population is assigned a crowding distance in this moment.
• Best solutions from the resulting population (the ones from the first front) are saved in a
list of solutions, which will be returned by the Process method.
4.3 The user guide and some simulation results
To run the optimization algorithm, a few steps are needed before to initialize the
random road profile and the car model parameters:
x In the interface, the parameters for road profile can be selected and a graphic of the road
is generated when pressing the “Show road” button.
x Then, the car model parameters must be set. The body mass, the Front wheel mass, the
Rear wheel mass, the Front tire stiffness and the Rear tire stiffness can be edited from
the interface. Others are hardcoded: pitch moment of inertia, distance between the body
centroid and Front tire and distance between the body centroid and Rear tire.
It is possible to evaluate a single solution pushing the “Process this solution” button (see
Figure 3) by editing also the specific design variables: vertical spring stiffness of the sprung
body Front suspension and Rear suspension, damping coefficient of the Front suspension
and Rear suspension.
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8. Fig. 3. Application’s GUI: Random road profile parameters and simulation results
These values along with the car model parameters and random road signal are passed to
the Evaluate method of SuspensionModelEvaluation class, and the graphics of the
evolution of objective functions in time can be seen in the right part of the interface. Then,
to apply NSGAII algorithm, the number of generations and the population size must be set
and “Evaluate” button pressed. The results are written in a text file (see Figure 4). In this
text file the best solutions from each generation are showed in this way: in the first row the
values of the three objective functions and on the second row are written the values of the
design variables that generated those results.
Fig. 4. NSGA-II simulation results
5 Conclusions and further work
This paper accomplished two-fold objectives: first, describe in details some C# functions
useful for non-IT specialists to develop (custom) optimization methods of suspension
systems and second, is concerned to improve 4-DOF HCM suspension’s system by
optimizing the stiffness and damping coefficients with the help of multi-objective methods
(NSGA-II) in order to increase the ride comfort. Our preliminary results have shown that
increasing generation number of genetic algorithm lead to obtaining better solutions.
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