Pressure Control Of The High-Pressure Common-Rail Electronic Control System Based On HCS12

As general energy crisis become more and more serious and increasinglyrigorous emission legislation, it is necessary for diesel to be developed with lowerpollution, lower fuel consumption and high power per weigh. As a high flexible fuelinjection system, the high pressure common rail (CR) injection system has become atrend of the diesel engines technology for its remarkable advantages. Research onhardware and software design of ECU for CR engines is an important issue inadvancement and self-exploitation ability of inland motor industry.According to the idea of hierarchical and modular design, the development ofcontrolled software is divided into six functional modules, including initializationmodule, signal acquiring module, logic control module, driver module, serialcommunication module and monitor module. All above modules are independent, butinterrelated to each other, and they can achieve the control objects of electroniccontrol system together.With the analysis of system's structure and control principle, pressure controlstrategy research has been done. After that a study on the technologie of hardware andsoftware for ECU development has been done.The precise pressure control is the premises for many other parameters'soptimal control, at starting condition, it requests establishment of rail pressure speedly;after starting, it should adapt to the changes of working conditions, and maintainstability. In order to control pressure better, the MC9S12DP256B is adopted to meetthe function requirements of ECU. The schematic diagram and PCB is designed. Toevery part, the schematic diagrams and the detailed introductions of the chips used inthat part are given. At last, the thesis introduces the system testing programme. The results showedthat the control software and hardware were rational, and accomplished good controlfunction.