Research On Control Strategy Of Electric Control Suspension Based On Semi-physical Simulation Platform

Electrically controlled suspension can effectively improve the riding comfort and steering stability.This paper takes the electrically controlled suspension as the research object,analyzes its structure and working principle,to formulates controlled strategy.And Simulink is used to simulate the controlled strategy.The simulation experiment of the control strategy is carried out by the semi-physical simulation test bench to verify the feasibility of the controlled strategy.Firstly,the structure,characteristics and working principle of the air spring in the electronically controlled suspension are analyzed,and the relationship between the air spring stiffness and the height of the vehicle body is deduced.Secondly,based on the non-linear characteristics of charge-discharge of electronically controlled air suspension,a mathematical model of electronically controlled air suspension system is established,and the mathematical model is modeled by MATLAB/Simulink software.The mathematical model of the electronically controlled air suspension system includes the mathematical model of the air spring pressure,the mathematical model of the air flow of the electromagnetic valve and the dynamic model of the air suspension.Then according to the work process of filling and deflating air springs,a controlled strategy is formulated to control the height of the electrically controlled suspension body,the switch of the compressor of air and the damping value matching.And use Simulink to establish the model of controlled strategy.The body height controlled strategy applies the backstepping sliding mode controlled model to adjust the actualled height of the vehicle body to the targetted height and combine the backstepping sliding mode with the model of electronically controlled air suspension system in Simulink to simulate the backstepping sliding mode control the height of the body.Damping matching control divides the working condition into four gears and simulates the 1/4 vehicle model in four gears respectively.Matching the reasonable damping value to obtain the smallest value of body's vertical acceleration.And controlling the driving of automobile in different conditions with different damping value.Finally,in the semi-physical simulation platform,the model of controlled strategy will automatically generate code.Writing the code to the ECU.Combined with the actual sensors,air compressors and air springs in the semi-physical simulation platform of electronically controlled suspension,the semi-physical simulation experiments were carried out.Measuring and calibrating the parameters and verify the feasibility of the control strategy.