Optimization Of Wheel Drive Electric Vehicle Semi-active Suspension And Control Research

With the increasing number of cars,environmental pollution caused by car exhaust emissions has attracted more and more attention from all over the world.The electric car has the characteristics of pollution-free,renewable energy and low noise,and are popularized by countries all over the world.Among them,wheel-driven electric vehicles have become an important research direction of modern new energy vehicles due to their high integration of braking,driving and transmission systems,and simple chassis structure.However,because the drive motor of wheel-driven electric vehicles is located inside the hub,The unsprung mass of a car is much larger than that of a fuel car.Nowadays,most electric vehicles still use the suspension system of traditional fuel vehicles,and have not improved the suspension according to the characteristics of wheel-driven electric vehicles.Therefore,it is very important to optimize the suspension according to the characteristics of wheel-driven electric vehicles.of.This paper studies the control strategy of semi-active suspension,adopts intelligent control to the suspension system,so that it can have different performances according to different road conditions,so as to optimize driving comfort and handling stability,and use Adams\Car simulation software to find the wheels The relationship between the positioning parameters and the driving comfort of the car,the position of the hard point is modified through the sensitivity relationship,and the wheel positioning parameters are optimized to achieve the purpose of optimizing the driving comfort and handling stability of the vehicle.The main research contents of this paper include:(1)A half vehicle semi-active suspension model with higher accuracy was established,and a simulation model was established in Simulink;In order to accurately express the road excitation received by the vehicle,the road excitation was modeled and analyzed based on filtering white noise method.(2)In order to enable the controllable damping in the semi-active suspension to adjust its numerical value in real time and accurately,the fuzzy control rules are formulated through the fuzzy control theory,the fuzzy PID controller is designed,and the controller parameters are optimized by particle swarm optimization algorithm.(3)A two-degree-of-freedom model of four-wheel steering system was established to analyze its dynamic characteristics.A four-wheel steering control system was designed based on yaw velocity feedback information and fuzzy control.The yaw velocity and sideslip Angle of the center of mass were used as evaluation indexes,and compared with front wheel steering system and yaw velocity feedback steering system.(4)The multi-body dynamics simulation software Adams/CAR was used to build a virtual prototype model of the suspension,and the two-wheel runout experiment was carried out;Based on the sensitivity analysis of the hard point position of the suspension,the coordinates of the hard point position were optimized according to the analysis results.The optimized suspension was simulated and compared with the wheel positioning parameters of the front and rear suspension after optimization.