The Control Strategy And Calibration Of Cold Startability On The Electronic Controlled Engine

Since the cold start state contributes to the content of HC and CO in the emission, which accounts for almost 50% to 80% respectively of the total pollutant, the combustion control of cold start state is becoming significant. So the optimization and control of cold start combustion acts as one of the key technical proposals in the emission control on the automobile engines.There are two most important factors that result in the high emission in the cold start state. One is the bad mixture of fuel and air which is caused by the bad working condition and low temperature in the cylinder. Most of the fuel is unburned; the other is that the catalyst is not lighted up and the oxygen sensor can't get ready for the low temperature. We can decrease the emission through optimizing the combustion and increasing the exhaust temperature to light up the catalyst quickly.In the cold start state, as the engine works unsteadily, it may cause mistakes between signals and the engine real state. And at the same time, the catalyst has not been lighted up, thus the control is in the open loop during the cold start state. So it is vital to apply the control strategy and the calibration in order to get a good start ability.The EMS system includes Sensor, ECU and Actuator. Through the sensor the EMS can detect the engine state, and then the MAO of injection and the ignition time and duty ratio are calculated in the ECU.The control strategy is the key model and part of the EMS. The fuel consumption, torque, power and the driver ability are decided by the control strategy and the calibration. It has several most important modules such as Injection, Ignition and Idle Speed Control.At first, the normal state calibration and chassis dyno calibration must be accomplished. The calibration purpose is how to pass the emission regulation according to cold startability.After the calibration in the test center and chassis dyno, it is recommended to do the trip calibration in Hot and Altitude trip calibration to validate the calibration result. In Xinjiang the engine startability and the driverablity after the hot soak are to be checked. During the altitude trip calibration the facts caused by the ambient...