Road Spectrum Reproduction And Suspension Control Based On Electro-hydraulic Servo System

In the past two decades,China's economy has been developing rapidly,and the automobile industry has been widely popularized.Cars have entered thousands of households,bringing great convenience to people's daily life.But at the same time,consumers have put forward more stringent requirements for the ride comfort of cars.However,the improvement of the ride comfort of cars has a direct relationship with the upgrading of suspension system.This is why The development and upgrading of suspension system should keep pace with the times.In the process of vehicle suspension design and development,with the development of Electro-hydraulic Technology,the electro-hydraulic servo system is often used as the main means of testing the suspension and its components.Therefore,the research of the electro-hydraulic servo system has been paid more and more attention in various fields,permeated in all walks of life and played an important role.In this paper,electro-hydraulic position servo system and 2-DOF 1/4 vehicle active suspension are selected as the research object.Firstly,it analyzes and models the electro-hydraulic position servo system and analyzes the stability of the system;establishes B,C,d three different road roughness models;establishes 2-DOF 1/4 vehicle active suspension model and analyzes its stability.The transfer function of the electro-hydraulic position servo system and the state space equation of 2-DOF 1/4 vehicle active suspension are derived.In this paper,fuzzy PID control theory and optimal control theory are used to design fuzzy PID controller and optimal controller respectively for electro-hydraulic position servo system and active suspension system.The fuzzy PID controller can not only realize the real-time output of the observation of the controlled object,but also adjust the parameters of the controller at the same time,so as to ensure the control speed and effect of the controller.The optimal control theory applies the minimum principle,and obtains the control method of the optimal control law by evaluating the minimum value of the performance index.In the MATLAB/Simulink software,the fuzzy PID controller,the optimal controller and the joint simulation model of the electro-hydraulic position servo system and the suspension system are built respectively.Finally,the simulation of each control system and the joint simulation system is carried out.The final simulation results show that the electro-hydraulic position servo system and the active suspension system based on the fuzzy PID control strategy can effectively restrain the vibration caused by the road roughness and improve the ride comfort of the vehicle.The joint fuzzy PID control is established for the electro-hydraulic servo system and the suspension system,and the joint optimal control of the electro-hydraulic servo system,the fuzzy PID control of the electro-hydraulic servo system and the fuzzy PID control of the active suspension are established.The simulation results show that the joint fuzzy PID control is better than the electro-hydraulic servo model in terms of the low,medium and high speed of 25km/h,65km/h and 105km/h respectively Fuzzy PID control and Active Suspension Fuzzy PID control greatly improve the ride comfort and ride comfort of the car.