Simulation Study Of Semi-active Suspension’s Control Stategy Based On Carsim Software

Suspension system is an important part of modern vehicles,plays a decisive role in the vehicle riding comfort and handling stability.In order to improve the riding comfort and handling stability of the vehicle,semi-active suspension has become the hot spot of research.It can be real-time to get the road and vehicle attitude changes in data through the sensor to control the variable damping shock absorber to change the damping characteristics,control the vibration of the vehicle.Based on the 27-DOF vehicle model established in the Carsim software,the semi-active suspension control strategy based on vehicle is studied,and the joint simulation model of Carsim and Simulink is constructed.The control effect of the control strategy on the vertical,pitching,roll vibration of the vehicle and suspension dynamic deflection and the dynamic load performance of the wheel are analyzed.Firstly,the research status of semi-active suspension at home and abroad is summarized.The characteristics of road structure and its irregularity expressing methods and the characteristics of Carsim road documents are studied.A three-dimensional model of 3D pavement model reconstruction based on Simulink and Carsim is designed,and a three-dimensional model of B-class random pavement and trapezoidal deceleration zone is established in this way.Then,the theoretical analysis of an electronically controlled variable damping shock absorber is carried out to establish its mathematical model.And the evaluation index of the performance of the vehicle suspension is determined.Set parameters for Carsim,a joint simulation platform for simulating simulations of Carsim modules and Simulink control modules for semi-active suspension vehicles was established.And the simulation experiments based on the passive suspension are carried out through the B-class random road and the deceleration zone road.Finally,aiming at the characteristics of vehicle semi-active suspension control,the vertical vibration fuzzy controller,the pitch vibration fuzzy controller and the roll vibration fuzzy controller are designed respectively.A modular vehicle semi-active suspension damping control system with three vertical controllers,vertical vibration,pitching vibration and rollvibration is designed.Based on the joint simulation platform,the semi-active suspension vehicle with modular fuzzy control system is simulated on the B-class random road surface and the ladder-type deceleration zone road.And the simulation results are compared with the vertical,pitching,roll vibration,suspension dynamic deflection,and the wheel dynamic response of the vehicle of passive suspension.It is found that the modular fuzzy control system can improve the vibration performance of the vehicle effectively.