Study On Electronic Control Technology Of High Pressure Common Rail Diesel

Even though diesel engine will play a more and more important position in the future motor power, however, with increasingly stringent emissions regulations or standards are promulgated and executed, diesel engine will face many questions. In order to improve power and fuel economy, reduce pollutant emissions and noise, diesel engine itself must be researched and improved, and application of electronic control systems also has become an essential. High pressure common rail electronic-controlled fuel injection technology is a new fuel injection technology based on direct injection technology, pre-injection technology and electronic control technology. Because the high pressure common rail injection system has a high pressure at all speed range, it can precise control injection pressure and injector pulse width, and achieve the purpose of reducing noise, lower emissions of pollutants and high output power. High pressure common rail injection system has become an important direction of diesel vehicles in the future.Electronic controlled unit (ECU) is the high pressure common rail diesel engine fuel injection system's core components, and its fuel injection control strategy is very important to impact the engine performance. In order to control and manage the high pressure common rail diesel engine fuel injection, this dissertation used NEC's V850 series production of 32-bit microprocessor uPD70F3239 as the main chip to design ECU.At the hardware system, through the design of a variety of sensor signal conditioning circuit for shaping, filtering and amplification the input signals, these signals were convert into the standard signal which can be received by the electronic control unit; Through the design of output driver circuits, fuel injection solenoid valve and common rail pressure control valve can be precisely controlled; Through the design of communications circuits, it can not only to communicate with the host computer, but also to facilitate debugging.At the software systems, the software platform which is based on the embedded RTOS of RX850 was detailed introduction. In accordance with the actual work of high pressure common rail diesel engine, the software division of ways and system of resource allocation methods are made. According to these principles, this paper completed division of tasks, design of programming and design of task scheduling strategy, and the requirement of real-time performance and reliability of electronic controlled unit has been met finally.Rational allocation of hardware system and software system can effective to improve the system efficiency and performance. Program debugging was executed to verify the reliability of electronic control unit, and the experimental results were satisfactory.