A Study On An Electronic Control Unit For Spark Ignition Engine Fueled With Various Components Coal Bed Methane

Energy crisis and Air pollution have been the most important topics in resent years. With the increasing concerns on health and environment, countries all over the world bring forward increasingly stringent emission regulations. As a solution, clean fuels become more and more important. This paper introduced a new alternative and a new electronic control unit.Due to the special problem "with varying component Methane the Air-Fuel ratio has to be efficiently controlled", the paper introduces a new electronic control unit (ECU). The ECU consists of two P1C16F877 micro-controllers, sensor processing circuit, driving circuit. First the required operating parameters are registered by sensors and converted into numerical signals, and then the theoretical air-fuel ratio is acquired according to the MAP, finally the two valves positions are adjusted by the air-fuel ratio. Redundancy design and module circuit design have been used, and completely think over the adaptability to environment, self-protection and heat release.The control software is compiled with ASM language, the software includes the air-fuel ratio control program under different situations, monitor program and signal processing program. In order to improve the software extension and modification, the software is made with sub-program and layer structure model. The idea of a layer-based architecture is that lower layers offer all the services needed by the higher layers.Through the modulation of hardware circuit and software, the ECU is feasible. The ECU can perform three tasks: to display the measured data received from the sensors, to calculate the air-fuel ratio, to control the two valves position.