Research On Fuel Injection Control Strategy Of A Small Two-Stroke Gasoline Engine

The paper is based on a small two-stroke gasoline engine of Hirth3203 made in Germany. The engine is tested on the dynometer using the software that can monitor the ECU(Electronic Control Unit) internal dataflow. And the electronic control fuel injection system parameters (e.g. position of throttle valve, engine speed, air temperature, engine temperature, duration of injection) are acquired at many different working conditions of engine. Finally, the fuel injection base MAP and a series of correction curves are obtained via analysing the data of test result acquired by theECU monitoring software. The ECU fuel injection control strategy which can be applied to this type of engine is developed.The contents of the research are outline as follow:1. Researching on the features of electronic control fuel injection system of the Hirth 3203 engine, layout the steps of this development.2. Researching on the serial communication protocol between ECU and external equipment. The LabVIEW has been utilized for building a virtual instrument software to test the ECU internal dynamic dataflow. This software can be used for acquiring and saving data, monioring the engine state at real-time.3. Comparing two different engines tested on the dynometer: the Hirth2706 equips carburetor system and charge as piston valve, and the Hirth3203 equips electronic control fuel injection system and charge as reed valve.4. Analysing the data of test result acquiring by the ECU monitoring software, the fuel injection base MAP and related correction curves are roughly delivered, the fuel injection control strategy for this type of engine is developed, and the flow chart of ECU control program for fuel injection control is also designed.The research on fuel injection control strategy in this paper is mainly based on the original ECU control strategy of Hirth3203 engine. And the work is also based on the experience of many people who succeeded in developing the fuel injection control system. This work can established the foundation for developing the electronic control fuel injection technology of gasoline engine in the future.