Vehicle Dynamics Simulation and Suspension System Design

The paper presents an integrated approach to suspension design with educational purposes. A dedicated design tool was created to instruct automotive engineering students in the whole process of suspension design across the various CAE tools involved, from early kinematics studies to CAD, vehicle dynamics simulations and FEM modelling. The tool has given birth to a proven design procedure that the authors would like to share in this paper with focus on the educational side, although suspension kinematics design is not certainly a novel subject in itself. The tool includes geometries like the widely used McPherson strut, complex five-link schemes for high-end road cars, and typical racing car geometries like the so-called push/pull rod systems used on Formula 1 and Le Mans racecars. It has been applied successfully to various projects developed by professionals as well as by students, including the latest three Formula SAE (FSAE) single-seaters of the University of Brescia (Brescia, Italy) team. The paper is structured as follows. The introduction describes the role student design competitions play in higher engineering education, and within the frame of the Automotive Engineering course at UniBS in particular. A selection of relevant bibliography on the topic is listed. The Educational scenario section deals with the specific case of the Automotive Engineering course at UniBS and the requirements posed by student competitions, also in the frame of the Dublin Descriptors, and shows how suspension design can play a pivot role in a FSAE project. The A tool for suspension kinematics: requirements, description, solution section presents the software tool in itself. The math underlying the user interface is outlined. Finally, the integration features towards other CAE tools are presented with the related advantages.

Suspension is one of the most important assemblies in modern automobile. The performance of suspension determines the whole vehicle performance, so the design and optimization of suspension system is an important part of automobile overall design. Under the background of the China University formula car race, this paper takes the suspension system of the University formula car designed by the team as the research object, and mainly carries out the following research work: 1, The type of suspension is determined by comparing the advantages and disadvantages of the structure; 2. Parameter design of the suspension, including the selection of wheel alignment parameters, suspension geometry drawing, various stiffness calculation, damping coefficient calculation, etc.; 3. According to the results of parameter design, the design and assembly of various parts of the suspension system are carried out; 4. Based on ADAMS / car simulation platform, The kinematics simulation model of the front and rear suspension is established, and the simulation analysis of the model is carried out to find out the variation range of parameters and find out the unreasonable performance parameters, which directly affects the handling stability and ride comfort of the racing car, so the reasonable design of the suspension system is of great significance to improve the performance of the formula racing car. To sum up, in order to improve the driving stability of formula racing car and make it have the appropriate ability of vibration attenuation, this paper designs the suspension system based on the third spring structure. This makes the structure of suspension linear stiffness and roll stiffness decoupled, so as to ease the contradiction between handling stability and ride comfort, so as to achieve the purpose that the third spring and lateral stabilizer bar manage the linear stiffness and roll stiffness respectively. Adams / car is used to simulate the dynamics of formula racing car. The results show that the third spring can increase the vertical stiffness and has little effect on the roll stiffness when the wheel jumps in the same direction. However, the influence on the body roll can be ignored in the process of acceleration and braking, but it can effectively inhibit the acceleration and braking. The simulation results show that the third spring can effectively improve the longitudinal performance of the vehicle. The method and experience can provide inspiration and method for the design of the suspension system of formula racing car.

Research and design of simulation and verification system of intelligent expressway based on ETC big data

The optimal control design of the ground-vehicle active suspension system is presented. The active suspension system is to improve the vehicle ride comfort by isolating vibrations induced by the road profile and vehicle velocity. The vehicle suspension system is approached by a quarter car model. Dynamic equations of the system are derived by applying Newton’s second law. The control law of the active suspension system is designed using linear quadratic regulator (LQR) method. Performance evaluation is done by benchmarking the active suspension system to a passive suspension system. Both suspension systems are simulated in computer. The simulation results show that the active suspension system significantly improves the vehicle ride comfort of the passive suspension system by reducing 50.37% RMS of vertical displacement, 45.29% RMS of vertical velocity, and 1.77% RMS of vertical acceleration.

Roadway rumble strips are used to reduce driving comfort and make drivers decelerate. While vehicle suspension systems are designed for passengers’ comfort by absorbing vibrations caused by bumping roadway surface, roadway rumble strips are implemented to alert motorists to reduce speed. An efficient and safe roadway rumble strips design depends on the understanding of the vehicles’ suspension system. Newer marked vehicles always have better suspension system that can absorb higher vibrations. This paper investigates the relationship between vehicle suspension system and roadway rumble strips design through TruckSim, a computer simulation model for trucks. The study analyzes the various shock-absorbing effect of current popular vehicle suspension systems on the roadway rumble strips designs in order to evaluate roadway rumble strips effectiveness in speed reduction. BACKGROUND There were 265,204 auto accidents in China in 2008. The direct financial cost of these crashes was more than 1.01 billion Yuan. 73,484 people were killed and 304,919 people injured. Speeding-related crashes account for over 10.17% of these auto accidents. 14.40% of killed people, 9.44% of injured people and 10.59% of the direct financial cost of these crashes (M.P.S., 2008). Speeding is thus a danger to all road users. When researchers do their best for the improvement of the road safety, many new methods and facilities are raised for application. Roadway rumble strips are a speed limit feature for road safety and have an extensive application on the freeway with sharp curves or long steep slopes. This article analyzes accelerations of seat surface when trucks with different suspension systems pass over different roadway rumble strips.

The stability of vehicles is influenced by the suspension system. At present, there are many studies on the suspension of traditional passenger vehicles, but few are related to agricultural mobile robots. There are structural differences between the suspension system of agricultural mobile robots and passenger vehicles, which requires structural simplification and modelling concerning suspension of agricultural mobile robots. This study investigates the optimal design for an agricultural mobile robot’s suspension system designed based on a double wishbone suspension structure. The dynamics of the quarter suspension system were modelled based on Lagrange’s equation. In our work, the non-dominated sorting genetic algorithm III (NSGA-III) was selected for conducting multi-objective optimization of the suspension design, combined with the Technique for Order Preference by Similarity to the Ideal Solution (TOPSIS) to choose the optimal combination of parameters in the non-dominated solution set obtained by NSGA-III. We compared the performance of NSGA-III with that of other multi-objective evolutionary algorithms (MOEAs). Compared with the second-scoring solution, the score of the optimal solution obtained by NSGA-III increased by 4.92%, indicating that NSGA-III has a significant advantage in terms of the solution quality and robustness for the optimal design of the suspension system. This was verified by simulation in Adams that our method, which utilizes multibody dynamics, NSGA-III and TOPSIS, is feasible to determine the optimal design of a suspension system for an agricultural mobile robot.

The vehicle suspension system serve a dual purpose – to provide passenger comfort and good road holding. In the design of a vehicle suspension system, these two contradictory criteria must be balanced out. Road irregularities are also a major source of anxiety amongst drivers and passengers alike. This research was undertaken to investigate the effect road irregularities will have on the vehicle structure especially the suspension system. In this study, the responses of different linear vehicle models are studied for step road input. The mathematical models considered are: a two degrees-of-freedom system (quarter car model) and a four degrees-of-freedom system (half car model). The equations of motion for both models were obtained using Newton’s method. These models are analysed using SIMULINK/Matlab. Different response parameters such as the acceleration of the vehicle body and the travel of the suspension are investigated for a passive suspension system. The responses of the vehicle suspension due to changes in parameters such as suspension stiffness and damping coefficients are investigated. The results show that road irregularities affect the vehicle structures and the response of the suspension system is dependent on the suspension parameters. Passive suspension systems do not satisfy road holding and passenger comfort at the same time.

The primary aim in the design of suspension systems using controlled d.c. electromagnets is to achieve an appropriate stability margin. When such a system is employed for suspension of passenger-carrying vehicles, however, a number of characteristics associated with vehicle dynamics will have to be considered in addition to the stability requirements. Some of these are suspension stiffness, damping and dynamic response and disturbance stability. A unified procedure to formulate the class of feedback control laws required for a single-magnet suspension system to obtain appropriate stability and ride characteristics corresponding to low-speed (up to 70 k.p.h.) urban transportation systems is presented in this paper.

This paper proposes a new type of a direct-drive valve (DDV) suspension system for vehicle controlled by the piezostack actuator associated with displacement amplifier. In order to achieve this goal, a new type of controllable piezostack DDV damper is designed and its performance evaluation of damping force is undertaken. Next, a full vehicle suspension system consisting of sprung mass, spring, tire and the piezostack DDV damper is constructed. After deriving the governing equations of the motion for the proposed the piezostack DDV suspension system, the skyhook controller is implemented for the realization of the full vehicle. Analytical model of the whole suspension system is then derived and performance characteristics are analyzed through numerical simulation. Finally, vibration control responses of the vehicle suspension system such as vertical acceleration are evaluated under both bump and sine road conditions.

Abstract: Suspension systems are integral to vehicle performance, playing a critical role in enhancing ride comfort, stability, and handling. By absorbing shocks and vibrations, suspension systems ensure a smoother ride for occupants, improve traction, and maintain optimal tire contact with the road. Effective suspension systems also contribute to overall vehicle safety by optimizing braking performance and manoeuvrability. In this research paper, we explore the design and analysis of electromagnetic suspension systems, focusing on their application in automotive engineering. The suspension system plays a critical role in providing passenger comfort, isolating occupants from road noise, bumps, and vibrations, and maintaining chassis stiffness. As vehicles evolve, the demand for sophisticated suspension systems that balance ride comfort, stability, and safety becomes increasingly important

Additive manufacturing (AM) technologies provide the possible method to manufacture the new suspension for ultra-weight green vehicles. In spite of traditional suspension system with a large amount of small components, Additive Manufacturing technologies allow the manufacturers to manufacture complicated mechanical structure in single piece which could efficiently decrease the number of components, the mass of new suspensions and the time for assembling. With the support of the modelling software, such as Creo® and AutoCAD®, the design concepts can be easily presented departments and made modifications when it is necessary. Finite element analysis software, such as ANSYS®, will provide the platform to do structural analysis by simulation without physically making the prototypes. Integrating these tools and technologies, time for products development will be dramatically reduced and ready-to-make products can be achieved. In this research, various concepts of the wishbones for the new suspension system will be designed based on the design constraints and the new designs will then be analysed by finite element analysis (FEA) in terms of stress distribution and total deformation of the model under a defined load. Creo® will be used to create the models of wishbones and ANSYS Workbench® will be employed for the structural analysis. Prototypes will also be built by Selective laser melting (SLM).Additive manufacturing (AM) technologies provide the possible method to manufacture the new suspension for ultra-weight green vehicles. In spite of traditional suspension system with a large amount of small components, Additive Manufacturing technologies allow the manufacturers to manufacture complicated mechanical structure in single piece which could efficiently decrease the number of components, the mass of new suspensions and the time for assembling. With the support of the modelling software, such as Creo® and AutoCAD®, the design concepts can be easily presented departments and made modifications when it is necessary. Finite element analysis software, such as ANSYS®, will provide the platform to do structural analysis by simulation without physically making the prototypes. Integrating these tools and technologies, time for products development will be dramatically reduced and ready-to-make products can be achieved. In this research, various concepts of the wishbones for the new suspension system wil...

Vehicle suspension system with hysteretic nonlinearity has obvious nonlinear characteristics, which directly cause the system to the possibility of existence of bifurcation and chaos. Two degrees of freedom for the 1/4 body suspension model is established and the behavior of the system under road multi-frequency excitations is analyzed. In the paper, it reveals the existence of chaos in the system with the Poincaré map, phase diagram, time history graph, and its chaotic behavior is controlled by nonlinear feedback. Numerical simulation shows the effectiveness and feasibility of the control method with improved ride comfort. The results may supply theoretical bases for the analysis and optimal design of the vehicle suspension system.

To create an energy efficient vehicle there are a number of aspects that need to be optimized, namely; the drive train of the vehicle and energy source, aerodynamics and weight. Focusing on weight reduction, while still maintaining the desired performance and structural strength, many manufacturers are turning to advanced composites due to their superior strength to weight characteristics. Solar car racing provides a research platform that drives this innovation through technology development and efficiency. A lightweight vehicle suspension system design is being presented, together with an introduction into future testing. A suspension system is made up of a number of critical components which are dynamically loaded during standard operation due to undulating forces imposed by the road surface. Unidirectional cross-wound carbon fiber tubing is used for suspension and steering arms. The tubing is interfaced with small steel inserts and pivoting arm tie rod ends. Concerns within the design are the adhesive bonding of the carbon tubing to the steel inserts, and what type of tensile loading the interface can withstand. Due to forces imposed on the system during cornering and shock loading the components are required to withstand a minimum of 1.2 times the weight of the overall vehicle, i.e. 258 kg. Tensile test results show that the mechanical properties of the adhesive joints rely somewhat on the surface characteristics and bond preparation. The target load of 258 kg was successfully obtained under static loading for two types of sample sets. The first based on the standard for describing the lap shear strength of adhesively bonded carbon fiber to aluminum, and the second based on the working component itself.

Upon the pedigree of technological advancement till our contemporary world, there has been an immense increment and improvement in the automotive industry like the development of vehicle suspension systems to suit the need of their customers whether it is soft (for comfort) or stiff (for good road holding capability for sports vehicle) or even a vehicle suspension system that can switch between these two modes. This research work focused on the effect and application of accelerometer in the design of an active suspension system using a microcontroller. It presents the control method implemented to keep the model vehicle leveled over pitching motions of the vehicle and the design of its component parts as well as the computer program to perform this action. The result showed that over different inclined surfaces the actuator was able to change the wheel–travel of both the rear and front wheels to keep the vehicle chassis leveled. These suggest possible adaptation of the design and improvement efforts which has capacity in addressing challenges of vehicles plying different road surfaces.

The Graduate Automotive Technology Education (GATE) Center at the University of Tennessee, Knoxville (UTK) offers courses addressing the simulation, modeling, and control system design of hybrid electric vehicles (HEV). In the Spring of 1999 such a course was conducted to support the UTK FutureCar Challenge entry for 1999. The vehicle modeled is a Dual-configuration Hybrid Electric Vehicle (DHEV) which uses a planetary power-split device similar to the Toyota Hybrid System used in the Toyota “Prius”. The goals of the course included the development of a real-time simulator that could incorporate actual vehicle control hardware in the simulator loop. This “control-hardware-in-the-loop” (CHIL) configuration was used for simulation, control system design, and troubleshooting. This approach allows the simulation of normal vehicle operating conditions as well as emergency fault handling situations in which it may not be desirable to subject the actual prototype vehicle to a given test condition. Additionally, it is possible to do a great deal of control system testing and development without an operating vehicle.