Research On Control Strategy And Simulation Of The Wheeled Engineering Vehicles' Anti-slip Differential System By Brake Interfering

Automatic anti-slip differential system has been widely used, which can prevent the driving wheel from excessive slipping and promote safety and stability of the automobile on low-μroad. At present one of the most common methods of automatic anti-slip differential system is to control the output torque of engine and the brake torque to driving-wheels,and the electronic throttle control apparatus is the actuator which can control the output torque of engine by activating the stepping motor and the electromagnetic clutch.This paper based on the analysis in automatic anti-slip differential control system's control methods and the principles of wheeled engineering vehicles,has conducted the research and simulation analysis to the differential control system's control method as well as vehicles'brake interfering control method.Because it is more difficult to set up the mathematical model for electronic throttle and braking devices, classical control theory or modern control theory can not meet the static and dynamic requirements. In this paper, based on the nonlinear characteristics of electronic throttle control system, a Fuzzy-PID controller is designed. And a Fuzzy controller is designed to adjust the brake torque to driving-wheels. All the controllers including PID controller,Fuzzy controller, and GA-Fuzzy controller are set up by Matlab/Simulink,Fuzzy control toolbox. The correct choice of membership function in fuzzy control is the key to fuzzy controller' s design, the dynamic performance and static performance and control effect in fuzzy control system are decided by membership function.To the lack of the traditional method of getting membership function,the Genetic Algorithms is introduced to optimize the membership function, the optimized membership function is better than the traditional one.The layout scheme of anti-slip differential system is set up.The dynamic equations of rear wheel driving(RWD) of vehicle and simulink models are established.The mathematical models include diesel engine model,transmission model,tire model,7 freedom full vehicle model,vertical load model alculation model,velocity calculation model and engine speed calculation model. The control algorithm of driving torque distribution system is researched by using the relative slip rate and velocity difference of rear driving wheels.The control algorithm of engine throttle control system is also researched by respectively using target slip rate and target speed.The power performance of rear wheel driving engineering vehicle is simulating researched on split-μroad. The simulation results are compared and analyzed, the research results shows that the fuzzy controller with optimized membership function is improved on controller' s quality.