Wheell Speed Measurement & Electronic Throttle Control For Traction Control System

With the development of technology and the improvement of living standard,more and more concern is focused on the security of automotive. The securityincludes two parts: active safety and passive safety. Active safety works bydecreasing or avoiding traffic accident. Passive safety works by protectingpassenger while the accident happens. With the development of micro-electronictechnique and control technology, more and more electronic device are applied tothe automotive, have improved active safety greatly.As an active safety technology, traction control improves the traction anddirectional control during acceleration by controlling the slip rate of driving wheel.Traction Control System (TCS) is an active safety device which was developed inthe middle of 1980's. In China, TCS is applied on vehicle more and more widely.However, the research about TCS is at very beginning in our country. So, studyingabout TCS has important realistic meaning and wide application prospect.This thesis is organized roughly in the order of developing traction controlsystem. Based on the aboard achievement in this field, the following issues arediscussed: the measuring of sensor signal; control of actuator; the design of controllogic. There are five chapters in this thesis.In Chapter One, the developing history and the function of traction controlsystem are introduced. And the developing history and developing trend of sensorand actuator for TCS are introduced in detail. The content of this thesis are listed.In Chapter Two, the research about sensor signal of TCS is carried on. As theonly sensor device of traction control system, wheel speed sensor is important andthe accuracy of measuring result of wheel speed sensor signal is significant fordeveloping traction control system. Aiming at the goal, a test rig is set up and thewheel rotation speed measuring system is developed using the test rig. The systemmainly includes two parts: the circuit used to process the wheel speed sensor signaland the algorithm used to measure the wheel rotation speed. The circuit transformsthe wheel speed sensor signal to standard square wave at same frequency. Thealgorithm calculates the wheel rotation speed by measuring the cycle of squarewave. It is proved that the system works with a wide range of speed and the resultis accurate through experiment. Based on the system, the research about developingtraction control system can go foreword. As a actuator of TCS, the electronic throttle has influence on design and resultof control logic. In Chapter Three, the structure and the principle are introduced. Atest rig used to study Electronic Throttle Control (ETC) is set up and the ETCalgorithm is developed using the test rig. The test result shows that the ETC systemcan meet requirements in dynamic response and tracking error. Then, amathematics model about ETC system is built in the way of system identificationbased on the test result. Based on the model, the system characteristic of dynamicresponse is analyzed and the result proves in theory that the control algorithm isaccurate. The model of ETC system provides a proper tool considering thethrottle's characteristic for traction control simulation. In Chapter Four, a vehicle model for traction control system is built based onVehicle Component Platform (Ve-Com). Then, the traction control algorithm usingPI controller based on driving wheel slip rate is developed. To study the validity ofcontrol logic, the simulation of startup on low-μroad surface is carried usingMatlab/ Simulink software. The simulating result proves that control algorithm...