The Design And Research Of Engine Electronic Control Unit Hardware System Based On MPC5634M

Gasoline direct injection engine (GDI) has greater advantages and potential in fueleconomy, power and exhaust emissions, and it has become a key-point of developmentand research in the engine field. The GDI engines have two different operation modes,namely, homogeneous charge and stratified charge, the essential differences of thesetwo modes are injection timing, throttles position and mixture composition, whereas anelectronic control unit (ECU) being able to control effectively the various parameters isthe basic guarantee of carrying out experiments research on GDI engines.The design of hardware and underlying driver software is the foundation of ECUdevelopment work, relates to matching of the sensors, actuators, hardware interface withthe Microcontroller Abstraction Layer software and the ECU Abstraction Layersoftware. According to functional requirements of the GDI engine electronic controlunit for the bench tests, the hardware system of an ECU was designed based onMPC5634M microcontroller, and some of the drivers were developed. The main studycontents are as follows:(1)Aimed to the sensors and actuators configuration, the overall structure scheme ofthe ECU was proposed. In terms of the sensor input signal types and characteristics, andactuator drive requirements, chips selection and configuration were conducted.(2) Design and analysis of sensor signal conditioning circuits. According to theelectric characteristics of the sensor and the anti-disturbance requirements of themeasured signal filtering, based on the signal conditioning circuit model, the circuitsimulation software was adopted for the circuit function design and parameter design toprovide a theoretical basis for the sensor and the ECU input circuit hardware matching.In the schematic design phase, the basic structure and parameters of the circuit weredetermined through validation of the circuit functions. Meanwhile, using the analogsignal generator provided by the simulation software, to simulate the sensor outputsignal with interference at different frequencies and amplitudes, the filtering effectswere verified and then the filter parameters were determined.(3) Design of actuator driver circuits. According to the requirements of the actuatordriver capability, driving circuit modules were designed, including solenoid valves,ignition coils, injectors, electronic throttle, and oxygen sensors heating etc. Through theuse of application specific integrated circuits (ASIC), the feedback information of theASIC can be read by the MPC5634M microcontroller, and the status information such as current and voltage of the driver circuits were obtained to provide fundamental basisfor the diagnosis of hardware circuit.(4) Design of main underlying driver. According to the requirements of theapplication layer, combined with actual situation of the hardware connection, driverssoftware were designed, including the clock driver, timing task drivers, analog signalacquisition driver, frequency signal acquisition driver, discrete signal acquisition driver,injector driver, ignition driver, electronic throttle driver, solenoid drivers, and CANcommunication driver etc.Through the debugging for the actuators and CAN driver, the function of the ECUhardware and driver software were verified, and this laid a solid foundation forfollow-up design of Services Layer and Complex Device Driver software and forachievement of more control functions in the ECU.