Study On Timing Synchronization And Fuel Injection Control Of High Pressure Common Rail Diesel Engine

In order to control the fuel injection accurately, to save energy and decrease emission, to optimize the engine performance and to improve system operation stability, a kind of timing synchronization and fuel injection control of high pressure common rail diesel engine had been researched and realized in this paper, which were based on a large number of domestic and foreign relevant technical literature. On the basis of "Development on New Generation Energy-saving and Environment-protecting Efficient Internal Combustion Engine for Car" project, the relevant control strategy and methods had been developed and finally implemented in a embedded systems of MPC5634.According to the crankshaft and the camshaft sensor signal characteristics, a detailed signal coding-based design for timing synchronization was proposed, which was divided into three steps:(1) Checking camshaft and crankshaft sensor signal with Aba gradient an windows technique; (2) Generating control tables with the characteristics and the corresponding relations of the crankshaft and camshaft signal; (3) Realizing timing synchronization of engine with the segment pattern matching.Injection control timing based on the crankshaft timing signal was established on the basis of timing synchronization. The fuel injection energizing time and the start of energizing were calculated in the Pulse spectrum and environment correction. A six multiple-injection coordinate control model was built.To improve the Real-time and reliability of the system, a embedded operating systemμC/OS-Ⅱwas modified in accordance with OSEK/VDX specifications and actually used in the software.Through analyzing the control software's modules, software for the injection system was designed with the MPC5634's ETPU. Layered and modular design was adopted.The experiment was carried on many times on the bench test, the results showed that the timing synchronization could take place in 360℃A. The designed scheme could achieve the correct fuel injection in different conditions, and some key map date about injection was calibrated.It is concluded that the control strategy and software has achieved precise injection control and the desired goal, and they have laid a good foundation for developing high pressure common rail diesel engine control system with independent intellectual property, with a high practical value in the bench experiments.