Development Of Electronic Control Ignition System For GDI Engine Based On LabVIEW

Electronic control technology adopted in gasoline engine has become an indispensable technique to reduce fuel consumption and emission. Electric control technology could achieve integration and optimum control to I.C.E. For adjusting and optimizing spark advance angle of SI engine and improving power density and fuel economy and reducing exhaust emission, an electronic control ignition system applied to GDI engine was developed in this paper.DAQ and LabVIEW which is a platform for software exploitation made by American NI Corporation are adopted in this system, by collecting rotate speed signal and camshaft position signal and using control strategy to control ignition timing of engine. The programs for manual adjustment and automatic adjustment according to rotate speed spark advance angle are developed. Curve fitting program is developed according to least square method using LabVIEW, and the relationship between spark advance and rotate speed are fitted, and then the optimal spark advance for different rotate speed is determined.Main design of electronic control system includes software and hardware design. Hardware design includes: choice of DAQ and sensors, designs of sensors input signal circuit, ignition actuating circuit and power supply circuit. Software design includes: writing programs of rotate speed computing module, ignition timing computing module and ignition control module and curve fitting.On front panel of control system, ignition parameters which engine operation need according to experiment demands can be recomposed (spark advance angle and charging interval can be modified on line and spark advance, charging interval, rotate speed et al can be displayed). This control system is a humanized design. At the same time, for ensuring the reliability and stability of system operation, anti-interference mode is designed.Finally, function of software and hardware of electronic control system are tested. After adjusting software and hardware with signal generator and oscilloscope, analog simulation experiment is done. According to the experiment result, this electronic control system has the characteristics of accuracy ignition and reliability, all function have been achieved expectant standard and satisfied ignition need of engine. Good preparations are made for further optimization of electronic control system.