The Injection Rate Research Of Vehicle Diesel Engine High Pressure Common Rail System

The performance of the high-pressure common-rail diesel engine， such as powerperformance,fuel economy performance and emissions performance,depends largely on thecombustion process. By adjusting the fuel injection rate of the high-pressure common-rail dieselengine，the combustion process can be improved, thereby, the performance of the engine isimproved.This paper briefly introduces the main factors affecting the emission performance of highpressure common rail electronically controlled fuel injection system, such as injection timing,injection pressure and injection rate,as well as elaberates how to optimize the fuel injection ratecontrol strategy and the development of the injection rate optimized ECU in detail.ECUhardware part consists of32-bit the PD70F3239micro-controller, the power supply circuit ofthe electronically controlled injection system, the main sensor circuit and injector solenoid valveand high pressure oil pump solenoid valve circuit, etc.In the software part,real-time multi-taskingoperating method is adapted, by setting and distribution the MCU internal resources andprogramming,to realise the main injection&pre-injection process.Fanally, through the use of MATLAB∕Simulink software, simulation comparative analysisto fuzzy PID control and PID control was done. Simulation results show that the injection ratedynamic response characteristics of the fuzzy PID control algorithm are more stable than thetraditional PID control.