Idle Speed Control Study Base On Engine Torque

On the base of the detailed analysis of domestic and overseas research statusand development tendency of the idle control of car engine, the paper summarize theadvantage and disadvantage of the main methods of idle control, and adds thecontrol strategy based on torque to the traditional PID control method. Theexperiment study on a B class car using the proposed method shows a good controleffect of the idle speed. The main conclusions are as follows:(1) The control strategy based on torque is made, Different functions areachieved by the torque control, and the torque requirements of every independentpower source and function can be satisfied. The torque needed is obtained bysuitable control measures.(2) The basic idle torque mainly includes engine resistance moment and torqueconsumed by engine accessories system, also includes idle self-learning torque,torque consumed by automatic gearbox, coefficient of rotate speed stability, controltorque of catalytic converter heating, and so on. The calculating method of basicidle torque is given.(3) The target idle speed includes static target and dynamic target, and differentcontrol strategies are given. Six idle control conditions and trigger conditions aredefined, the calculating methods of ignite torque adjust, air torque adjust andintegration torque adjust are given, the control strategies are given too.(4) The sample car using this control method is tested. The test results underwarming-up working condition and the condition from other speed back to idlespeed show a good stability of the target idle speed. Three kinds of idle torque andidle PID control torque tests all get the same effect as the control strategy model.The tests results show that the proposed engine idle speed control method based on torque gets good control effect.