Research And Simulation Analysis Of Four-wheel Drive Vehicle Acceleration Slip Regulation Control Algorithm

Acceleration Slip Regulation(ASR)can make full use of the ground to provide the wheel adhesion and improve the stability of vehicle performance by controlling the driving wheels of the vehicle to prevent the driving wheels when car is staring,accelerating or climbing a hill.On ASR system,foreign research started earlier and the technology has been mature already;but in our country,the ASR research started late and relies on the import of foreign products mainly at present.So it has very important significance to master the independent intellectual property rights and break the foreign technology monopoly by researching in this area.In this paper,I analyze the main factors that influencing the car drive torque in the first place and established engine model,the braking system model,the transmission system model,tire model,vehicle model and so on.Secondly I analyze the basic method and principle of drive torque control system.I understood the influence of tire-road friction coefficient,the wheel slip rate and road conditions for drive torque.Then I estimate adhesion coefficient of road surface and the best car skidding of the wheels turn rate method based on fuzzy theory,I designed the controller based on PID and fuzzy PID,and select engine output torque and braking torque as the control parameter of the system.I use the powerful Simulink software to establish each subsystem model,through connection,operation and complete vehicle ASR control system in three common roads.I aimed at the characteristics of nonlinear,time-varying in the process of driving,I adopted the robustness better PID control and fuzzy PID control method,established fuzzy PID controller and PID controller based on control principle of the two methods in the MATLAB/Simulink platform,I use the powerful Simulink software to analyze through connection,operation and complete vehicle ASR control system in three common roads.The results showed that:(1)The ASR control system based on fuzzy theory of road identification can keep wheel slip ratio in the optimum slip ratio,inhibition drive wheel slip to improve the power and directional stability.(2)Two control algorithms are able to get good ASR control effects,but relative to the PID,the fuzzy PID has better adaptability and robustness.