Research On Design And Control Strategy Of RT-flex High Pressure Common Rail Diesel Engine Electronic Control System

The diesel engine is still the main power on present commercial ships, but the traditional diesel engine camshaft cannot meet human’s requirements of flexible control and pollution emission control, so the electronically controlled high pressure common rail diesel engine has become the developing mainstream of current marine diesel engines. The control system is the core of the electronic control diesel engine unit. However, due to various reasons, the gap between diesel engine development levels at home and abroad is relatively big, especially the design ability of diesel engine control system is insufficient, and there is still no domestic product of electronic control unit (ECU).This paper takes RT-flex diesel engine as the research object, analyzes the high pressure common rail diesel engine control system, main engine remote control system, electronic governor system, main engine security system, and the logical relationship between monitoring alarm system and the electronic control unit (ECU), and introduces the bus system communicated between each subsystem. The article carries out a key design to electronic control unit (ECU), including the selection of MC9SXEP100 microprocessor, the design of microprocessor peripheral auxiliary circuit like reset circuit and clock circuit, the digital and analog input signal acquisition circuit. In order to meet the sensitivity requirements of fuel injector high-speed solenoid valve, the paper designs the booster circuit and electromagnetic valve dual pressure control circuit. As for the communication module, based on microprocessor MC9SXEP100 function foundation, the paper designs the CAN bus circuit, Mod bus circuit and SSI bus circuit which is dedicated collect crank angles. In the production of printing circuit boards, the paper considers and adopts the anti-jamming design, which improves the system stability and the ability to adapt to bad working environment.On the basis of hardware circuit design, the paper makes a study and design to the control strategy of the control system, including the common rail fuel pressure control strategy, control strategy of fuel injection quantity, injection timing control strategies and fuel injection rate control strategy.In order to verify the control strategy, the paper introduces the mathematical modeling of the high pressure common rail system, and makes a simulation by using the Simulink tools of Matlab software, and simulation verification to the control of common rail fuel pressure tube. The simulation results show that the common rail pipe pressure is relatively stable, and the fuel common rail pressure control strategy designed in this paper can meet the control requirements of fuel pressure by high pressure common rail system.