Electronically Controlled High Pressure Common Rail Diesel Engine Start And Idle Speed Control System Research And Development

With the emission control regulations more and more stringent, the emission control of starting and idle in diesel engine becomes a prominent problem. This message introduces starting and idle research and development of diesel engine. It determines starting and idle control strategy and basic data through analyzing the control strategy of traditional control diesel engine and High Pressure Common-Rail Diesel Engine Control System. Designs and develops the electric control systems of starting and idle in diesel engine by using the software-ASCET of ETAS.After many starting torque experiments with different input torques, it finds that: when the environment temperature is low, starting torque should be suitably increased. That is because the temperature and pressure of gas at the end of compressing rock is low and not easy on fire. At this time, we should suitably increase the starting torque to make the combustible mixture gas combust. Accordingly, with the high temperature, it should be decreased. Due to the high emissions at starting phases, we should start engine as quickly as possible. So, we should use large starting torque when engine speed low, and when the speed increasing, the starting torque should be decreased in order to avoid the high fuel consumption, high emission and vibration effects to engine.It uses the variable parameters-PID controllers to control the idle stability. Control rules: With small offset, use the large K_P and K_I value in order to respond the offset quickly. Contrarily, use small K_P and K_I value to make speed transform to the idle speed smoothly. This control rules can make the idle speed control without overshoot and oscillation. Variable parameters-PID controllers achieve the targets that self-tuning online, more adaptability to external conditions, better idle stability, faster response and no oscillation phenomena.