Design And Experimental Research Of Fuel Injection And Ignition Control System For Electronically Controlled Gasoline Engine

It has become a trend for the automobile to adopt electronic control technology as the emissions regulation is getting increasingly strict and the energy source is getting increasingly deficient in the world. Electronically controlled engines have replaced conventional fuel supply and ignition system engines, which can't meet power, fuel economy and exhaust emissions of engines.According to the present situation of automotive engine in our country and chief task of reducing exhaust pollutions by analysing data about electronically controlled system for gasoline engine in domestic and abroad, and combining with our practical situation, the electronically controlled systems of gasoline engine are studied based 465Q engine produced Shanxi Huaihai Mechanical Factory. The dissertation develops a set of electric systems, which realizes control for fuel injection and ignition system of gasoline engine. On account of the problems self-adaptability and control precision of conventional PID control, we explore new control theoretics such as fuzzy fontrol and neural network that are applied in idle speed, ignition and fuel injection of gasoline engine.The dissertation analyze the ECU technologies and control principles of fuel injection and ignition system for 465Q engine .The electronically controlled system of 465Q engine adopts engine management system (EMS) of Delphi. This system uses grouping synchronous multi-point fuel injection and the distributorless ignition system with two cylinders ignited synchronously, and measures the engine process parameters through some sensors such as MAP (Manifold Absolute Pressure sensor), CPS (Crankshaft rotatory speed and Position Sensor), CTS (Coolant Temperature Sensor), IAT (Intake Air Temperature Sensor), and TPS (Throttle Position Sensor), oxygen sensor, etc. The ECU (Electronic Control Unit) chooses and processes the information, computes optimum fuel injection time and ignition advance angle of the engine through MAP diagrams that have attained through engine bench test, and drives actuators such as injector and ignition system, so as to realize optimum control of A/F ratio and ignition advance angle for gasoline engine.According to characteristics under different operation conditions of engine, the dissertation analyzes control demands of air fuel mixture and control essential factors of ignition system, and establishes fuel injection and ignition control strategies corresponding different operation conditions including start, warm-up, idle speed, part load, full load, acceleration, deceleration, stop injection, etc.The dissertation determines the type of microprocessor through analysing data in domestic and abroad, and does research using 16 bit 80C196KB microprocessor produced Intel Company, and designs a fuel injection and ignition control system for electronically controlled gasoline engine under making possible use of original sensors. Hardware circuit designs include expanding circuit of program memory and data memory, input signal process circuits, drive circuits of actuators such as injector and ignition system, etc. Because control signals are output through High Speed Output (HSO) system of 80C196KB microprocessor, and aren't intervened by CPU, control signals possess feature of rapid response. Software designs include injection program designs under different working conditions, ignition program, signal measuring and analyzing program. For improving the reliability and stability of ECU, The dissertation makes the anti-interference design to its hardware and software.According to engine control parameter MAP attained through off-line type, control system realizes optimum control of A/F ratio and ignition advance angle. The system is called as static predetermined optimum control type. When engine works, sensors measure working condition information, ECU consult predetermined control parameter of MAP, and drives actuators so as to realize optimum control of A/F ratio and ignition advance angle. The dissertation designs MAP experimental system, and measures three-dimension MAP of fuel injection and ignition control by using PCHud software of Delphi engine electronic control system, and provide learn samples for training of neural network.By taking into account nonlinearity, time variation and unsteadiness of idling process in engines, the dissertation studies the application of fuzzy control theory in the idling speed control, and designs a fuzzy control system so as to control the idle speed of gasoline engine. The control parameters are determined by using simulink simulation tool of MATLAB.Using advantages of self-adaptability, self-learning, self-association, highly nonlinear ability, tolerance, and storing information in distribution way, BP neural network is applied for gasoline engine control. The dissertation develops the new control strategy of fuel injection and ignition timing for highly nonlinear system of engine.Through the research on electronic control technologies, the dissertation realizes optimum control of fuel injection and ignition system for electronically controlled gasoline engine. At the same time, it also provides the some references for studying the engine management system and realizing national electronic control engine industrialization, and possesses important signification for promoting development of electronic control technologies.