Design And Control Research On Active Passive Compoundg Suspension Of The Three-axle Heavy Vehicle

In order to improve the dynamic response speed and control accuracy of active suspension actuator based on electro-hydraulic servo control.This paper relies on the national key research and development program “Research on the special chassis and suspension key technology of high-mobility emergency rescue vehicles(including firefighting vehicles)”(Project No.2016YFC0802902).The design of actuator,hydraulic system and control strategy of active suspension system is studied for the purpose of improving vehicle ride comfort and steering stability.In this paper,the composite suspension system based on oil-gas suspension and electrohydraulic servo control active suspension modified by the oil-gas suspension system is studied.The active suspension system and the oil-gas suspension system can be switched according to the driving conditions of vehicle.Since the suspension actuator is an actuator shared by the active suspension and the passive suspension,it is of great practical value to study dynamic response characteristics and control strategy of the suspension actuator.The main contents of this paper include:A oil-gas spring model of oil-gas suspension,a single-actuator dynamic model of active suspension,and a random road surface input model are established.According to technical requirements of suspension system,the mechanical structure of suspension system is designed and finite element analysis of main components is carried out.The hydraulic system of suspension system is designed,and the selection of main hydraulic components is completed.Two controllers based on ceiling and LQR control strategy are designed respectively.The control model of active suspension system based on the above two control strategies is established in MATLAB/Simulink.According to the simulation results of two control strategies,the effects of active suspension and oil-gas suspension on ride comfort and steering stability of vehicle are compared and analyzed.In order to verify effectiveness of the designed suspension actuator performance and contruol strategy,a single actuator test bench with electro-hydraulic servo control is designed,and the response test of a single actuator under sinusoidal following signals of different frequencies and amplitudes under rated load force is carried out.The test results show that the designed actuator performance and control strategy basically meet the design requirements.