Ignition Advance Angle Optimizer Design And Test Of CNG/Gasoline Engine

Because automobile industry is an important pillar industry of national economy, it plays an important role in the national economy and shoulder the important responsibility to promote social development. But with the growing of consumer demand for cars, the attendant environmental pollution and energy security and other issues are getting worse. In order to solve the problem of automobile emissions and energy, the development of new energy vehicles was strongly support from Chinese government,which contributed to the rapid development of CNG vehicle. Considering the different of physical and chemical properties between oil and gas, ignition advance angle optimizer of CNG/gasoline engine need to be redesign to improve the engine performance. Based on the analysis of the current ignition advance angle control method, ignition advance angle optimizer design and test of CNG / gasoline engine was proposed.First of all, we need to determine the control functions of ignition advance angle optimizer, then design its control procedures; at the same time, we need to design the hardware circuit of ignition advance angle optimizer. By the simulation test and real tests of ignition advance angle optimizer, the control effects of the ignition advance angle optimizer were analyzed. The following research was done mainly in this topic to solve these problems:(1) Design the hardware circuit of ignition advance angle optimizer. It mainly includes the calculation module circuit of ignition advance angle and the adjustment module circuit of crank signal. The calculation module circuit of ignition advance angle includes an IG(ignition signal) processing circuit, a power supply circuit, a crank signal processing circuit,a LCD display circuit and one PIC microcontroller and minimum system. The adjustment module circuit of crank signal includes two PIC microcontroller and minimum system.(2) Design the control procedures of ignition advance angle optimizer. It mainly includes the control procedures of calculation module and the control procedures of cranksignal adjustment module.The main functions of calculation module are determining the rotational speed N, The throttle opening ?, the ideal ignition advance angle ? and the actual ignition advance angle?0. According to the difference between ?0 and ?, the deviation signal ? is determined, and then this deviation signal ? is delivered to the adjustment module of crank signal.Design the control procedures of crank signal adjustment module. The main functions of crank signal adjustment module are receiving the deviation signal ? and advancing the crank signal according to this deviation signal ?.(3)Test the ignition advance angle optimizer. The test include simulation test and real test and emission test. The simulation test mainly test the crankshaft speed and ignition advance angle results of optimizer in order to confirm that whether the optimizer meets the design requirements; If the simulation test results is ideal, the real tests is conducted; then the simulation test results and the real test results are analyzed to determine the accuracy and feasibility of ignition timing optimizer. If the real test results is ideal, the emission test is conducted to determine the emission behavior.