Design of Alternative Fuel Engine ECU

With the increasing strictness of emissions regulations, continuously high requirements of market on automotive performance and energy-saving, the technology of engine electronic control is more and more extensive and deeper. 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. Foreign ECU hardware technology, such as microcontroller, microprocessor, sensor, actuator, and special-purpose integrated circuit, has been very mature [12]. In China, only some universities and a few companies[5-7] focus on this field. Generally, there is a considerable gap between domestic technology and the foreign. 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 stratagem 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.