Study On Matching And Calibration Of Electronic Engine Control For 491QE Gasoline Engine

Electronic Engine Control is an important method to reduce the engine emissions and improve power and economic performance. It is necessary to match the Electronic Control System with the engine and to optimize and calibrate the control parameters in order to meet the China Emission Standard and get better power and economic performance. Local optimization integrated with global optimization, on-line calibration, automatic calibration and transient state calibration are promising methods for calibration and optimization of the Electronic Control System for automotive engine.This paper takes the popular used 491QE gasoline engine as research object. Firstly, the restriction of matching and calibration is analyzed. The basic purpose of engine matching and calibration is to improve economic performance and to obtain good power performance and drivability based on meeting the China Emission Standard. Secondly, the control strategy of Electronic Control System is analyzed, including fuel-air ratio control and ignition advance angle control. Speed-density method is applied to fuel fix quantity and the fuel-air ratio control includes open-loop control and close-loop control. The control of ignition advance angle is mostly open-loop control and the control data is obtained from experiment. Close-loop control method is applied to avoid engine knock. Finally, a procedure of matching and calibration for 491QE gasoline engine is made on the basis of analysis above.An integrated development environment of Electronic Engine Control is established during the test trip, including engine operation controlling, sensor signals collecting, emission performance testing, ECU control parameters collecting, data analyzing and other subsystems. It is easy to accomplish the on-line and automatic calibration of electronic control system by communicating and sharing the data between the ECU and the Up-PC.The calibration of steady state for 419QE gasoline engine is finished firstlyduring the test trip. Aiming on X close-loop control, by completing the state points plotted before, the map of base fuel inject pulse width and base ignition advance angle are obtained. The modification coefficient of fuel inject pulse width and ignition advance angle caused by intake air temperature, coolant temperature and storage battery voltage are obtained by changing test environment. The adjustments of exhaust gas oxygen sensor voltage threshold value and fuel-air ratio during the X close-loop control process are introduced as well.Based on steady state calibration, the cold start and warm up operation, idle speed, acceleration and deceleration, power enrichment and other transient states are analyzed. The control way is introduced and the control parameters are obtained. The final results show that the system performed very well.