Research Of The Automotive Throttle Position Sensor

As people pay more and more attention to the driveability, economy and environment protection of the automobile, the sensor, source of electronic control system's signal, determines the performance of electronic control system engine. The throttle position sensor (TPS), one of the sensors in the system, is very important. It is the signal source of idle control system, fuel injection system, spark advance control system and other system.The throttle position is used in the poor environment, so the traditional contact—type throttle position sensor is vulnerable to oil pollution and dust,moist, high temperature, vibration and others, and the performance and life of TPS will be influenced, while the stability and controlling effect of electronic control system will be influenced. The contactless throttle position sensor can effectively avoid these influences.The throttle position, based on giant magnetoresistance effect (GMR), is discussed systemically and built in this paper, and the theoretical basis is provided for the designing of the GMR sensor. First the present development of TPS is introduced, and the characteristic of structure and the advantages and disadvantages of various TPS in market is also anslyzed. The development and theories of GMR is discussed, and the application and prospect development of the sensor based on GMR is also introduced. Then according to the requirements of the throttle position sensor and the principle about how GMR angle sensor works, we chose the GMR chip and magnetic, and we made a modification of chip structure. Then we analyse the magnetic field of magnet by using ANSYS software. Based on the traditional throttle position sensor structure, the sensor using GMR chip is designed, and the structure is designed by using UG and AUTOCAD software. The reasonable of GMR TPS and the advantage compared with the traditional TPS is analysed theoretically. Finally, according to the requirements of automotive electronic devices standard, we give a set of test programs about the GMR TPS to ensure that the sensor meets the requirements of the performance index.