CNG/汽油两用燃料发动机ECU设计

Design of Alternative Fuel Engine ECU

针对某品牌四缸两用燃料发动机,完成了基于Motorola 16位单片机MC9S12DP256的汽油机ECU和CNG发动机ECU硬件设计.完成汽油机ECU硬件电路的开发和调试,包括PCB图双层板设计、PCB板制作与焊接,硬件调试,模拟信号测试与波形观察.测试结果表明:基于曲轴信号和凸轮轴信号的控制逻辑能很好地满足发动机工作的时序要求,实现分组同步点火、喷油等模块的控制.喷油时间控制准确度达到0.01ms,误差小于5%;点火提前角最小分辨率为0.01°,误差小于5%.

Enormous natural gas reserves in our country and more complete CNG filling stations in urban city provided a larger space for the development of CNG vehicles.Thus,the use of natural gas and gasoline-fueled dual-fuel engine control system is of great practical significance and dedicated to improving the current dual-fuel vehicle technology in the engine management level,being the driving force to enhance engine performance,minimizing emissions reduction,and making full use of China＇s natural gas resources.Based on the Motorola 16-bit MCU MC9S12DP256,the gasoline engine and the CNG engine ECU hardware were design.Base on the embedded C language with CodeWarrior IDE,software was design and debugged,and the control stratagy was made according to the data acquisition and data analysis.Through the MAP,with the engine speed and intake manifold absolute pressure signal values,the basic fuel injection pulse width was founded by interpolation method.According to other working condition parameters,the closed-loop feedback control and air-fuel ratio control were modified and realized the fuel injection control.