Study On The Control Algorithm Of Traction Control System For Heavy-Duty Vehicle

The Traction Control System can improve the accelerating ability andcontrollability of the vehicle on icy, snowy, wet and slippery road or sand. Atpresent, traction control system has been equipped on vehicles and the patentshave come out. But in China the research on traction control system is at verybeginning and some vehicles equipped with traction control system have nointellectual property rights of their owns. So Jinlin University has doing someresearch work on strategy and algorithm of traction control system which isdepend on the Vital Science and Technology Project of Jilin Province. Theresearch project name is 'The Research and Development of ASR Control Systemfor Heavy-duty Vehicles'.The driving force of vehicle is defined by engine torque obtained by drivingwheel and adhesion friction between tire and road. The engine torque obtained bydriving wheel is confirmed by working character of engine and transmittingcharacter of power train, all those character have some disciplinarian accord withthe operation of driver. But the friction coefficient is an uncertainty variablerelated with tire structure, road condition, weather condition and vehicle velocity.The mass experiences demonstrate the director relationship between the frictioncoefficient and the wheel slip. When the wheel slip increase from 0 to , thisrange is also called 'steady range', the friction coefficient increase also, but whenthe wheel slip increase from to 1, this range is also called 'unsteady range',the friction coefficient decrease in verse. So driving wheel slip is tend to becontrolled in an area little than to exert the accelerating ability of drivingwheel with certain lateral stability. The traction control system control the drivingforce of the wheel to obtain the preferable longitudinal friction coefficient andlateral friction coefficient by means of judging the movement of wheels.S0S0S0The simulation model of vehicle TCS is made up. The control algorithm ofTCS is designed based on lucubrating control mechanism of TCS. The excessiveslip of driving wheel is prevented during vehicle accelerating and upgrading. Thecontrol principle of TCS is to let the wheel slip in a proper range so to exert theaccelerating ability of vehicle with good lateral friction coefficient.At first, the PID and reformative PID control algorithm are designed and thosealgorithms are validated by simulation model. The PID controller () has applying inseveral industry area with its advantages such as simple structure, easilyimplementing and good performance. The digital PID controller has goodpracticability because of it's easily amenability. The PID controller is based onsystem error and its control capability is depend on three control parameters andaccuracy of the mathematics model of the TCS.Secondly, the PID controlled with fixed parameters can not get idea effect indifferent control conditions and the parameters can not be easily tuned. So thegenetic algorithm and fuzzy controller for tuning the PID parameters arementioned in this thesis. The implement process of those methods are given andvalidated in this thesis.The design of controller is based on the accurate mathematic model, which isa common ground of the classical and modernistic control theoretic. But in realindustrial environment, the system is too complex to be described by accuratemathematic model. Under this condition, the applying of fuzzy control is verymeaningful because the fuzzy control needs not to establish mathematic model butonly need the output and input data of system and the experience of manipulator.This thesis has developed parameters self-adaptive PID algorithm, which canturning PID parameters real-time based on fuzzy rules. The initial numerical valuecan be set by experience, experiment or optimization results of genetic algorithm.The simulation results include two road condition are given in this thesis.The simulation can not replace the road test of vehicle because of somephenomenon can be simulated such as the vibration of the tire and so on. So theroad test of CA1140P1K2L7 has been implemented. The control algorithm hasbeen turned farther more and good test results have been gained. Limited with testfield and condition, only PID algorithm is tested in road test.The research results propose provide bases to the project of the Vital Science andTechnology Project of Jilin Province, 'The Research and Development of ASRControl System for Heavy-duty Vehicles', and have directive function to furtherresearch.