Design And Implementation Of The Monitoring System Of Gasoline Engine ECU

That automobile engine electronic control unit (ECU) is adopted greatly improve engineeconomic, dynamical and emission performance of the car, and the stability and reliabilityalso become the important standard for measuring ECU performance. In order to ensure thatcar can steadily and reliably work, it need to monitor some key work processes of carECU.Therefore, it is very important to research and design a monitoring system of gasolineengine ECU.On the basis of digesting and absorbing a large number of literature and analysis ofcharacteristics of automobile engine ECU, according to the characteristics of the engine ECUand its monitoring requirements, in accordance with the ECU system with the core of theMPC5634processor of Freescale company, the monitoring system of ECU was designed andimplemented In order to monitor working process of engine ECU system and process ofanalog signal sampling, mainly work have done as follows:(1) According to the analysis of characteristics of monitoring system and everymicroprocessor, hardware circuit design of the monitoring system of ECU with the core of theSTM8S processor of Stmicroelectronics Company.has been completed.(2) The structure and work principle of SPI module of the MPC5634processor and theSTM8S processor were analyzed, through the configuration of internal registers and softwareprogramming, SPI comunication has been realized.(3) According to the characteristics of the engine ECU work, exception condition of theengine ECU work condition was dealed with. Through SPI communication mode, fixed datain fixed time intervals was sent to STM8S processor from MPC5634, MPC5634normallywork or not can be sured according to whether the correct data in fixed time was received. If itwas in abnormal situation, a reset signal will be sent to MPC5634from STM8S through theSTM8S GPIO pin, and MPC5634’s restoration was made immediately.(4) The structure and work principle of A/DC module of the STM8S processor wereanalyzed, analog-to-digital conversion of external analog signal was realized through the configuration of STM8S’s internal registers and software programming.(5) Through analysis of the sensor characteristics and hardware circuit, The value of theanalog signal meet specific relation. the collected data from A/DC module were moved andhandled, the handling result with the special relationship value was compared to judgewhether the data was right, actuator was controlled to stop work through STM8S GPIO pin Ifthe process of analog signal sampling was abnormal.Test results show that each function of monitoring system run correctly, monitoringsystem can complete work on monitoring task of ECU key process and achieve the expectedpurpose,it has the high practical value.