Research And Implementation Of The Control Strategies Of Start To Idle Speed For Gasoline Engine

The work conditions from start to idle speed are the most work conditions of theengine. It has a close connection with the engine emissions and fuel consumption. Startingcondition is transient operating condition. And under this condition the successful start-upof the engine should be ensured as well as the smooth transition from starting condition towarm-up condition or idle condition. This requires lower fuel consumption and emissionsof HC and CO. As unstable working condition, warm-up condition is transition fromstarting to idle condition. It requires short time. With the increasing of coolant temperature,engine speed decreases gradually. When coolant temperature turn to normal, smoothswitches of engine speed to idle condition will be required. As stable working condition,idle condition runs with regulated speed. During the idle condition, the load ofair-conditioning compressor, power steering gear and automatic transmission changedsuddenly, and these external disturbance factors make the working-engine speedfluctuating, instability or even flame-out. In order to meet the demand of the strict emissionregulation, it is especially important to control the idle spend and keep it stable.In this paper, the control strategies of start to idle speed were proposed. The start toidle speed for gasoline engine was implemented by the control system. The performancewas verified by engine dynamometer test. The details are as follows:(1)Control strategies of start to idle speed were proposed for the479QE engine.Thecontrol strategies included: starting control strategy, warm-up strategy, and idle controlstrategy.(2)The platform of electronic control system was designed, which included hardwareand software design. The design of hardware included: microprocessor determination,sensor signal processing circuit, actuator driving circuit and monitoring circuit base on CAN bus. The design of software follows ideas of modularization design. The modulesconsisted of58X signal control logic, speed calculation, spark ignition control, fuelinjection control, date of sensor processing stepper motor control and monitoring systembase on CAN bus.(3)The control strategies were converted into program and were tested by enginedynamometer test using479QE engine. Firstly, simulation test platform is configured todebug the electronic control system by using simulation signal generator. After thereliability and feasibility were verified, the second engine dynamometer test was done. Andthen adjust and verify the control strategies by engine dynamometer test with479QEengine.