Design Of The Electronic Throttle Control System Based On Position Feedback

With the development of automotive industry,more request have been takento improve the security, stability and driveability by the passenger.Conventionalmechanism modulation and control method are difficult to optimize theperformance of automobile,so electronic control is the trend of steering device ofthe engine control system. Torque-based engine management system, which couldcoordinate torque demands of different modules and need better control of the inletairflow, is regarded as a promising way. Electronic throttle control system, whichcould control the inlet airflow based on the required torque of engine, isconsidered as a viable alternative to conventional air management systems.The electronic throttle control (ETC) system is a drive-by-wire system inwhich the mechanical linkages between the accelerator and the throttle arereplaced with pairs of sensors and actuators. The input signal of accelerator pedalis considered as the driver torque demand, all torque demands are coordinated andprioritized by the torque-based control architecture, and the final torque request isoutput. Also the required airflow is calculated by the engine management systemand corresponding control signal is output to the actuator, then the throttle reachesthe desired position. ETC systems have entered mass production abroad, while itcomes into use only in recent years at home and there is less research in this field.A set of electronic control system has been designed in this dissertation. Themain study include analyzing the structure and function of the electronic throttle,calibrating the output voltage characteristic of sensors, developing the hardwareand software of the control system, establishing the mathematical model of theelectronic throttle, investigating the non-linear characteristic of the throttle,thecausation of the difficult electronic throttle control have been found. Analyzingthe dynamic torque and static torque.Conventional PID and fuzzy PID aredesigned, analyzing the result of experiment.The key content in this paper is the choice of ETC strategy,the ETC strategyhas been designed through the experiment.The subroutine have been designed.Thesoftware, which is programmed with C language for micro-controller,accomplishes control function and serial communication function. The controlfunction achieves closed loop control of throttle plate position.The ETC system is a closed-loop control system and the position of thethrottle plate is precisely controlled through the DC motor. So the hardware has tomeet the required function of the system.In this thesis, a 16 bit micro-controllerXC167 produced by Simens is selected as main processor.Inlaid system circuit andsystem circuit that have two power supply have been designed.The A/D circuit ofthe throttle plate position sensor and the pedal position sensor have been designed.A semiconductor H-bridge MOTOROLA33886/D enables the motor to rotatebidirectionally.The interface of serial port communication system and the CANcommunication system have been exploited. The CAN communication function ofXC16X have been exploited.The CAN communication function betweenmicro-controller and PC and between micro-controller XC167 andmicro-controller XC164 are realized.The signal filter of TPS and PPS position hasbeen designed that used the function of PEC.Both step response and steady state tracking experiment have been done.Experiment results indicate that utilizing Fuzzy PID, the response time of the openup angle of throttle is fast, the overshoot is small, the hysteresis is unconspicuousand the transient tracking error is smaller than utilizing conventionalgain-scheduled PID,it is showed that the control effect with fuzzy PID method isobvious better than with Conventional PID.