Development An Electronic Control Unit Prototype For Natural Gas Engine

As global warming intensifies, countries are seeking for the low carbon,clean fuel to take the place of the traditional fossil fuels. As an ideal clean alternative fule,The natural gas has been attended extentively in the world.CNG engine will have extensive application for its high efficiency and low emission.The NQ120 diesel engine was designed to be a CNG (Compressed Natural Gas) engine, by the injection system modeling and simulation, as well as the ignition system control program design, and a new electric control system was designed match with the engine. Above all, building a mechanical model of the nozzle with some of the mechanical model of AMEsim software. The electric control model jet nozzle of the CNG engine has set up in different conditions by the SIMULINK software. The nozzle of the basic physical parameters was get. And the control strategy was verified in a variety of operating conditions air-fuel ratio, by the AMEsim / SIMULINK software co-simulation. CNG engine ignition systems in the mode of spark-ignited, and designed ignition control strategies matched with different operating conditions. To lay the foundation for the following of CNG engine control system hardware and software design .Secondly, Select the MC9S12XS128 (16-bit microcontroller) as the core processor . Designed the hardware circuit to meet the requirements of the system, including the minimum system microcontroller circuits, voltage regulator circuits, as well as driving the work of the nozzle and ignition coil driver circuit. Comprehensive consideration to the choice of components, printed circuit wiring, and interference. On the basis of this, mapping of the entire system hardware circuit schematic and PCB diagram by Protel, Using the CodeWarrior software to development the control system procedures for CNG engine.At Last, a serial communication module based on the LabVIEW software is used for ECU's (Electronic Control Unit) calibration and monition test. To debug the entire electronic control system hardware and software by the analog sensor signals of Engine Simulation, Bench Test results show that the designed ECU prototype could realize the accurate control for ignition timing and injection volume,after completed the ECU could be used in real application.