Study Of Electronic-controlled Engine Calibration System

In order to control the engine effectively and well under different working conditions, engine control unit must be calibrated to determine each control parameters. According to the different working conditions, the basic ignition angle and spray pulse width, etc, were calibrated on the MAP. Control commands were sent out to the control unit. According to the control strategy which was modified on-line and control data, the engine was controlled. The electronic calibration system is the highest control software in the electronic control system of engine.Based on the study of electronic-controlled engine Calibration System (ECS Calibration System) at home and abroad, and on the actual situation, the overall scheme of the Calibration System for electronic-controlled engine was proposed. Each module of calibration system was designed.Calibration system hardware was composed with the host (work-managing machine) and PCI2013 data acquisition card. It will collect, analyze and process data, communicate with control unit, send out control commands and modify on line. The signal processing circuits were designed, such as the crankshaft location signal, oxygen sensor signal, throttle position signal and temperature signals, etc. Based on the researches, drive circuit was improved. The hardware circuits were designed to enhance anti-interference performance.Based on the Windows environment, calibration system software was written by using Visual C++, SDI software architecture was established based on MFC software, Multi-threading and some advanced control (such as MSComm etc) are used to achieve ECU and calibration system transmission at the high speed of data. Host and control unit used a serial ports for data transmission so as to give the engine running condition effective monitoring.ECS use Visual C++mixed with MATLAB programming technology, by using third-party software MATCOM to realize the numerical computation and graphic image processing, the effect is very good and a good platform for the subsequent and more complex data post-processing was provided.The preliminary experimental research of calibration system in the NQ190N gas engine was conducted and the MAP of engine basic injection and basic ignition angle was finished. Experiments showed that this calibration system software had friendly interface, easy operation, strong commonality and function, can achieve more perfect online data acquisition, graphical display, data storage, on-line modification and so on, this calibration system had certain value and achieved the expected effect.