Research On Sliding Mode Control Of Vehicle Active Suspension System Based On Neural Network Algorithm

The development of science and technology in the 21st century is in full swing,and the development of the automobile industry is also changing with each passing day.By December 2019,China’s vehicle population had reached 348 million,an increase of 25.78 million over the end of 2018.The number of motor vehicle drivers reached 435 million,an increase of 28 million from the end of 2018.With the continuous increase of car ownership,people’s requirements on the performance of cars are gradually improved,from the initial safety and economic development to the driving comfort and handling stability.In intelligent vehicles,suspension system is the main component that affects the above performance.Suspension system is the vehicle frame(or bearing body)and the axle(or wheel)between the transmission device general name,to improve the performance and safety of the vehicle has a very important impact.With the continuous development of suspension technology,the suspension system has gradually developed from the original passive suspension to the direction of adjustable parameters,thus giving birth to semi-active suspension and active suspension with better performance.Active suspension is the addition of a controllable force generator on top of the passive suspension to generate the required control force to reduce vibration.The research content of this paper is mainly divided into the following aspects:(1)Model building.Firstly,according to the nonlinear characteristics of the suspension system,the dynamic model of the suspension system is selected and established,and then the mathematical model of the active suspension is established according to the vehicle dynamic model.This paper analyzes several road conditions that will be encountered when the vehicle system is running,and establishes a simulation model for several common road excitation.According to the performance of the suspension system,the vehicle smoothness and handling stability are analyzed to obtain the evaluation index of the suspension performance.(2)Research on sliding mode control strategy.In the design of active suspension system,the choice of control strategy is very important.Taking a simple sliding mode control strategy as an example,the motion of sliding mode control and the basic conditions of sliding mode control are studied.The design problems of switching control quantity and equivalent control quantity,four kinds of sliding mode approach law and invariability of sliding mode control are studied and analyzed respectively.Finally,the simple sliding mode control strategy of active suspension system is designed.In order to improve the robustness of sliding mode control,inverse method and sliding mode control are combined to design the equivalent control quantity in sliding mode control.(3)The active suspension model based on sliding mode control strategy(SMC)and the active suspension model based on RBF-SMC control strategy inversion algorithm were established in Matlab/Simulink,and a comparative simulation analysis was conducted.The results show that both RBF-SMC control strategy and SMC control strategy can suppress body vibration,and the control effect of RBF-SMC controller is better than THAT of SMC controller.Compared with the passive suspension system,the evaluation index performance is good,which proves that the control strategy designed in this paper can effectively improve the comfort and safety of the vehicle during operation.