Software Design For Electronic Controlled Injection System Of High Pressure Common Rail Diesel

With increasingly strict emission regulation and development of electronic controlled diesel-fuel injection technology, high pressure common rail (CR) engines have become the trend of vehicle diesel engines. Research on hardware and software design of ECU for CR engines is an important issue in advancement and self-exploitation ability of inland motor industry. This thesis presents the research results achieved by the author on the area in software design for electronic controlled injection system of CR diesel engine. Based on ECD-U2 CR system and ECU developed independently, this thesis has accomplished software design on injection control and engine management, as well as elementary calibration and experiment on test bed. Injection control is mainly based on modules of MC68376. Processing of digital signal and converting of analog signal from sensor have been achieved. And according to analysis on driving principle of injector solenoid valve and supply pump PCV, precise pilot, main and multi injections have been realized, as well as flexible injection timing and duration, adjustable supply timing. Engine management adopts the control mode based on fuel quantity. According to various conditions of diesel engine, detailed control strategy enables steady rail pressure, precise fuel quantity and injection timing, as well as the performance of rapid starting and stable running. Data structures of MAP and message protocol provide online calibration and reliable and effective communication. Functions of trouble diagnosis and fault tolerant ensure safety of engines. Experiments on test bed finish the MAP calibration about sensor signal, primary control and compensate. The test results verify the precision, feasibility and reliability of software design, and anticipated control effect was achieved.