Design Of Electronic Control System For Small Two-stroke Aviation Gasoline Engine

With the rapid development of modernization,drones,motorcycles,speedboats,and other motive devices are widely used,and a vast quantity of these devices are mainly powered by small two-stroke engines.Small two-stroke engines are simple in structure,lighter in weight,smaller in size,and have the advantages of low manufacturing costs and being easy to use and maintain.Due to the immaturity of core technology and other factors,the domestic long-term use of imported engines and electronic control systems or the use of traditional two-stroke carburetor fuel supply systems engines.Therefore,the development of a complete small two-stroke engine electronic control system has both application value and long-term strategic significance.The main research contents of this paper are as follows:(1)In this paper,the composition and structure of the engine’s electronic control system are analyzed.According to the working principle of the small two-stroke engine and the composition structure of the electronic control system,the overall design scheme of the engine’s electronic control system is determined.The fuel injection and ignition parameters of the engine are theoretically analyzed,and the specific control strategy of the electronic control system is proposed.Focused on the control of the basic injection pulse width and injection ignition signal of the engine,the basic injection MAP diagram was established to realize accurate control of the engine’s injection ignition.(2)In the hardware design of the engine electronic control system,a dual-chip approach to hardware circuit design is proposed in this paper.The S9KEAZ128 is chosen as the main control chip and the MC33814 as the driver chip,which greatly simplifies the design of complex driver circuits.The hardware design,including the power supply circuit,external clock circuit,debug interface circuit,sensor processing circuit,serial communication circuit,ignition drive circuit,etc.,was completed,and measures were taken for the anti-interference of the engine electronic control system.(3)On the basis of the hardware design of the engine electronic control system,the overall framework of the electronic control system software design is proposed,combined with the functional requirements of the engine electronic control system and the developed control strategy.The control program is designed in a modular way,and the detailed control strategy flow and method are given to complete the software design of the electronic engine control system.(4)The processing method of the MAP diagram of fuel injection is studied and analyzed.In this paper,a BP neural network algorithm is proposed for predictive processing of the injection MAP diagram,and it is ported to the ECU software program and successfully applied to the engine electronic control system.(5)In order to control the engine speed,a fuzzy RBF neural network PID control algorithm is proposed in this paper.According to the characteristics of neural networks,a fuzzy RBF neural network PID control system was designed by combining RBF neural networks,fuzzy control,and PID with each other,and simulations and results analysis were performed.The simulation results show that the engine speed under the fuzzy RBF neural network PID control algorithm has a short regulation time without overshoot and has a better control effect compared with the other two control algorithms.(6)In order to verify and test the basic functions of the engine’s electronic control system,a semi-physical simulation test platform was built.The semi-physical simulation tests show that the designed engine electronic control system can operate steadily and accurately control the engine injection and ignition signals,and the control strategy is effective and feasible.