Automobile Engine Centralized Control System Base On CAN_bus

With the development of social, people provided the higher demands in performances and environment protection of automobile. The conventional mechanical devices have already not soluted some problems involved with automobile function demands, so will be replaced by the electric technologies and electric control technologies of automobile. The electric control technologies are extensively used in every inspects, it can not only improve the motivity, the economic, the security of automobile, polish up the steady and comfort in running, impulse the development of automobile industry, but also exploit wide market for electric products. Thus, developing automobile electric control technique of modern times, speed up automobile electronic is a important means of startup and brace up automobile industry.Though the auto engines of the medium-to-high grade cars made by the big auto mobile 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,Then put forward a task that automobile engine centralized control system base on CAN bus.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 communications problem of the CAN system.In the designing of ECU hardware part, it has introduced the function characteristic of MC9S12DG128 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, ignition signal and the designing of CAN node based on msCAN.In the software part, it has discussed the throughway and realization method of the software, including based on module idea, designed intact marshal control system, realized the effect management of in-out and soft-hardware, settled the base of whole machine control arithmetic development and matching. analyzed logic arrangement and attemper timing of whole machine oil managing; studied oil control policy of different state, and arithmetic of twinkling process modifying and fume limit modifying.Then used Visusal C++ to designe charged software that running in PC. Moreover, it has introduced the development environment Metrowerks Codewarrior.