Vehicle Active Suspension with Four-Degrees of Freedom of Optimizing the Value of K Based on Genetic Algorithm

2011 ◽  
Vol 308-310 ◽  
pp. 1673-1678
Author(s):  
Yan Yan Zuo ◽  
Cai Bao Yan ◽  
Nan Yang

A vehicle active suspension model with 1 / 2 ,four-degrees of freedom is established and by combining genetic algorithm with optimal control theory,the author presents a new control method of active suspension that is to optimize the value of K controlled by LQG in default of road input based on genetic algorithm and makes a simulation in the environment of Matlab / Simulink. By simulation and analysis,the result indicates that,this method has an obvious effect on improving comprehensive performance of vehicles,such as ride comfort and operate stability and so on.

2011 ◽  
Vol 55-57 ◽  
pp. 1156-1161
Author(s):  
Jing Yue Wang ◽  
Hao Tian Wang ◽  
Li Min Zheng

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.


Symmetry ◽  
2022 ◽  
Vol 14 (1) ◽  
pp. 171
Author(s):  
Jiguang Hou ◽  
Xianteng Cao ◽  
Changshu Zhan

Suspension is an important part of intelligent and safe transportation; it is the balance point between the comfort and handling stability of a vehicle under intelligent traffic conditions. In this study, a control method of left-right symmetry of air suspension based on H∞ theory was proposed, which was verified under intelligent traffic conditions. First, the control stability caused by the active suspension control system running on uneven roads needs to be ensured. To address this issue, a 1/4 vehicle active suspension model was established, and the vertical acceleration of the vehicle body was applied as the main index of ride comfort. H∞ performance constraint output indicators of the controller contained the tire dynamic load, suspension dynamic stroke, and actuator control force limit. Based on the Lyapunov stability theory, an output feedback control law with H∞-guaranteed performance was proposed to constrain multiple targets. This way, the control problem was transformed into a solution to the Riccati equation. The simulation results showed that when dealing with general road disturbances, the proposed control strategy can reduce the vehicle body acceleration by about 20% and meet the requirements of an ultimate suspension dynamic deflection of 0.08 m and a dynamic tire load of 1500 N. Using this symmetrical control method can significantly improve the ride comfort and driving stability of a vehicle under intelligent traffic conditions.


Author(s):  
H. Saeidi ◽  
M. Heidari ◽  
M. Zahiri

In this study two approaches are proposed to improve the kinematic characteristics of the conventional crank-slider transmission mechanism. The investigation presented here deals with the motion control of a crank-slider mechanism rather than driving the input crank at a uniform speed. The purpose is to decrease the maximum value of the slider acceleration by applying an optimal control theory and a genetic algorithm (GA) to the crank speed. Results show a reduction of 43.68% and 42.23% of the peak acceleration value of the slider in optimal mechanisms analyzed by optimal control theory and genetic algorithm respectively in comparison with a constant angular speed driven crank. Examples are given to illustrate the design procedure.


2010 ◽  
Vol 44-47 ◽  
pp. 1492-1495 ◽  
Author(s):  
Rui Zhen Gao ◽  
Zhi Qiang Xu ◽  
Jing Jun Zhang

This paper establish a multi-body dynamic model of the Vehicle. The fuzzy logic controller was designed for the semi-active suspension based on improved genetic algorithm, then, the co-simulation were carried out based on Adams and Matlab/Simulink. The results demonstrate that this control method enhances the performance of the full car suspension system significantly.


2011 ◽  
Vol 467-469 ◽  
pp. 1066-1071
Author(s):  
Zhong Xin Li ◽  
Ji Wei Guo ◽  
Ming Hong Gao ◽  
Hong Jiang

Taking the full-vehicle eight-freedom dynamic model of a type of bus as the simulation object , a new optimal control method is introduced. This method is based on the genetic algorithm, and the full-vehicle optimal control model is built in the MatLab. The weight matrix of the optimal control is optimized through the genetic algorithm; then the outcome is compared with the artificially-set optimal control simulation, which shows that the genetic-algorithm based optimal control presents better performance, thereby creating a smoother ride and improving the steering stability of the vehicle.


2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
Zhi-Jun Fu ◽  
Bin Li ◽  
Xiao-Bin Ning ◽  
Wei-Dong Xie

In view of the performance requirements (e.g., ride comfort, road holding, and suspension space limitation) for vehicle suspension systems, this paper proposes an adaptive optimal control method for quarter-car active suspension system by using the approximate dynamic programming approach (ADP). Online optimal control law is obtained by using a single adaptive critic NN to approximate the solution of the Hamilton-Jacobi-Bellman (HJB) equation. Stability of the closed-loop system is proved by Lyapunov theory. Compared with the classic linear quadratic regulator (LQR) approach, the proposed ADP-based adaptive optimal control method demonstrates improved performance in the presence of parametric uncertainties (e.g., sprung mass) and unknown road displacement. Numerical simulation results of a sedan suspension system are presented to verify the effectiveness of the proposed control strategy.


Author(s):  
Yan-Jun Liang ◽  
You-Jun Lu ◽  
De-Xin Gao ◽  
Zhong-Sheng Wang

AbstractTechnique of approximate optimal vibration control and simulation for vehicle active suspension systems are developed. Considered the nonlinear damping of springs, mechanical model and a nonlinear dynamic system for a class of tracked vehicle suspension vibration control are established and the corresponding system of state space form is described. To prolong the working life of suspension system and improve ride comfort, based on the active suspension vibration control devices and using optimal control approach, an approximate optimal vibration controller is designed, and an algorithm is presented for the vibration controller. Numerical simulation results illustrate the effectiveness of the proposed technique.


Author(s):  
Amirhossein Kazemipour ◽  
Alireza B Novinzadeh

In this paper, a control system is designed for a vehicle active suspension system. In particular, a novel terminal sliding-mode-based fault-tolerant control strategy is presented for the control problem of a nonlinear quarter-car suspension model in the presence of model uncertainties, unknown external disturbances, and actuator failures. The adaptation algorithms are introduced to obviate the need for prior information of the bounds of faults in actuators and uncertainties in the model of the active suspension system. The finite-time convergence of the closed-loop system trajectories is proved by Lyapunov's stability theorem under the suggested control method. Finally, detailed simulations are presented to demonstrate the efficacy and implementation of the developed control strategy.


Author(s):  
Jialing Yao ◽  
Meng Wang ◽  
Yanan Bai

Automobile roll control aims to reduce or achieve a zero roll angle. However, the ability of this roll control to improve the handling stability of vehicles when turning is limited. This study proposes a direct tilt control methodology for automobiles based on active suspension. This tilt control leans the vehicle’s body toward the turning direction and therefore allows the roll moment generated by gravity to reduce or even offset the roll moment generated by the centrifugal force. This phenomenon will greatly improve the roll stability of the vehicle, as well as the ride comfort. A six-degrees-of-freedom vehicle dynamics model is established, and the desired tilt angle is determined through dynamic analysis. In addition, an H∞ robust controller that coordinates different performance demands to achieve the control objectives is designed. The occupant’s perceived lateral acceleration and the lateral load transfer ratio are used to evaluate and explain the main advantages of the proposed active tilt control. To account the difference between the proposed and traditional roll controls, a simulation analysis is performed to compare the proposed tilt H∞ robust control, a traditional H∞ robust control for zero roll angle, and a passive suspension system. The analysis of the time and frequency domains shows that the proposed controller greatly improves the handling stability and anti-rollover ability of vehicles during steering and maintains acceptable ride comfort.


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