The Hardware Design Research Of The Electronic Fuel Injection System

Though the auto engines of the medium-to-high grade cars made by the big automobile manufactures almost have adopted the electronic fuel injection technology in our country, the home automobile manufactures depend on importing foreign product line of EFI system or fitting the foreign ECU system directly supplied by the foreign manufacturers.The paper has discussed its current development situation of the EFI system, it also has carried out relevant careful research and analyzed to the composition structure and the operation principle of the ECU and the sensors including the control principle and control strategy about the EFI system. It has analyzed the means of control to the fuel injection, the feedback control demands of the perfect burning rate of atmosphere to fuel, the theory of injecting fuel, ignition timing and the ignition ahead angel demand of various operation status of the auto engine.This paper has carried out the study of the EFI system mainly dividing into three parts: the hardware circuit of the ECU, the whole structure and function module of the software, the anti-jamming problem of the EFI system.In the designing of ECU hardware part, it has introduced the function characteristic of MC9S12DT128 and the designing of peripherally circuit, including the clock circuit, the reset circuit, the processing circuit of sensors' signal, the driving circuit of the injecting fuel and ignition signal.In the software part, it has discussed the throughway and realization method of the software, including the account of rotate speed of engine, the control of injecting fuel signal and ignition signal. Moreover, it has introduced the development environment simply.Finally, gave some methods of anti-jamming to the ECU system.