Research And Application Of Start And Idle Station Control In Diesel Engine's Ectronic Control Unit

Diesel engine electronic control unit (ECU) is the core of the engine control. Start station and idle station are the most important conditions of engines. Studying on start and idle speed control method is very useful to increasing the diesel engine's power, discharge and economy. Therefore, study on start and idle speed control method has important practical significance.This paper studies the ECU control's key technology of start and idle. Start station provided enough starting torque to the engine crankshaft. The torque made the speed of the engine crankshaft into the starting speed and the engine became in the auto-running state. In this paper the start station was judged by the time scheduling approach. LMS method was used to amend the starting torque. The movement of the engine conditions was realized by the rotate speed. The results of the experiments showed that the starting speed got to the speed threshold rapidly in 0-3s, then the boot process completed successfully.ECU used the PID control of BP neural network closed-loop to control the idle speed of the torque. The speed in idle phase kept in 850r/min for a certain while. Selecting parameters and setting control word of Idle controller achieve the idle state controller functions.Then, in the calculation of the idle torque, the PID control of BP neural network controled better than the conventional PID control.It was more stable and faster to get the stable condition.The results of engine bench experiments proved that the control strategy and principle were correct and feasible.Compared with the old-fashioned mechanical control, the control strategy has improved the control precision and control flexibility. ECU using the start and idle speed control strategy is faster than the ECU using the original strategy when the engine gets the timing time, and has improved the performance of the PID control.