Control Strategy Study For High Pressure Common Rail Diesel Engine

With increasing requirement of strict emission regulation, high pressue common railfuel system becomes an effective way to achieve this goal. It can achieve the control forinjection pressure, injection quantity, injection timing and injection laws. Besides themechanical parts and control unit performance, the most important way to improve engineperformance is to adapting new control strategy and control algorithem.In this paper, the structure of high pressure common rail fuel system and its workingtheory are introduced. Then based on this, a non-linear control model is built up with veryfew geometry parameters, which is based on the fuel pressure transference inside the fuelsystem. This model can meet differenct demand for building up modes and achieve theflexble control. The model is set up by Matlab/Simulink. The simulation results show thatthis model is basically correct and can be used for common rail fuel system calculation.High pressure common rail is a complex and time-based non-linear system. Thepressure control is the precondition for vectors optimization. Obviously traditional PIDcontrol can’t have a very satisfied control performance. Genetic algorithem (GA) is a newintelligent control methold and is widely studied in auto control field. The paper uses GAto optimize PID control parameters, and realize the tuning of parameters online. Forsolving the problem of astringency and maturation, the particle swarm optimization is used.The result shows the proposed algorithem is effective and applicable. The paper gives theprogram of how to realize this control method. The results show this control method has agood rail pressure control ability and real time operation performance.The high pressure common rail contol model and pressure control method, presentedin this paper, are very useful to the pratical study and application.