Research On Pressure Control In High-pressure Common Rail Injection System Based On Embedded System

Increasingly rigorous emission legislation and severe energy shortage force diesel to be developed for the objects of lower pollution, lower fuel consume and high power per weigh. And diesel engine high-pressure common rail electronic control injection system is the most effective in emission reduction and engine performance improvement among all of the fuel injection system currently. Since common rail pressure directly refers to achievement of perfect injection rule, the study of common rail pressure control strategies have been one of current hotspots in high-pressure common rail system. This article introduces the way of implementing embedded real-time OS in high-pressure common rail electronic control system, which the function of pressure control have been added to. The main content is given as follows:1) On the base of widely research of relative paper, the development trend and the actuality of the foreign and domestic high pressure common-rail fuel injection system of diesel engine are studied, and the using of embedded OS in automobile industry in the foreign companies is also introduced.2) After study on pressure control technique of common rail system, a common rail model has been built in software Simulink according to principle of the components and the test data. This paper also developed a PID control strategy, and it's code has been generated automatically.3) The OSEK/VDX norm is introduced. Then based on research of the operation principle of a embedded real-time OSμC/OSⅡ, this paper improve and expand some functions ofμC/OSⅡkernel according to the definition of OSEK OS.4) A HIL (hardware-in-the-loop) system has been built. The author used the software LABVIEW to set up an interface which can watch and control the parameters. LABVIEW also run the common rail model code in the background, and sent the data from serial interface to the model. The DAQ export voltage to simulate the pressure sensor.μC/OSⅡhas a task for control which the pressure control strategy code is added to, and a task for serial communication.The simulation results of the hardware-in-the-loop system showμC/OSⅡcan control the pressure rapidly and accurately. Compared with the traditional method, this way of designing the software for control is more convenient.