【作者】 张艳；

【导师】 李国岫；

【作者基本信息】 北京交通大学 ， 动力机械及工程， 2007， 硕士

【摘要】 随着排放法规的日益严格和柴油机电控技术的不断进步,高压共轨燃油喷射系统作为一种高度柔性控制的燃油喷射系统,以其显著的优越性,已成为现代车用柴油机技术发展的趋势之一。研究高压共轨柴油机电控系统的软硬件技术,对于我国汽车行业的技术进步和自主研发能力的提高,具有重要的现实意义。本文在深入分析电控系统控制原理的前提下,确定了高压共轨柴油机电控系统的总体设计方案,进行了高压共轨柴油机电控单元的硬件开发设计,主控芯片采用美国MOTOROLA公司的16位微控制器MC9S12DP512,并选定了电控系统中的传感器与执行器。结合电子控制理论,经过对系统控制方案的设计,最终获得喷油量、喷油定时和共轨压力等主要控制变量的控制策略。喷油量和喷油定时通过查MAP图计算来实现,共轨压力则主要采用闭环PID控制。最后,对于整个电控系统,采用基于油量的控制策略,划分了高压共轨柴油机的运行状态,实现了稳定控制共轨压力和精确控制喷油量、喷油定时的目标,同时满足柴油机快速起动和平稳运转的要求。根据分层设计和模块化思想,进行了电控系统的软件开发,控制软件包括初始化模块、信号采集模块、逻辑控制模块、驱动控制模块、串行通信模块以及监控模块在内的六大功能模块。以上各模块在电控系统中既相对独立又相互联系,实现了完整的电控系统的控制任务。最后,进行了电控单元的调试试验及喷油泵台架试验。试验结果表明:所开发的电控单元能够完成信号采集、驱动控制、串行通讯的基本控制以及基本的喷油控制和共轨压力的闭环控制。更多还原

【Abstract】 With the increasingly strict emission regulation and the development of diesel engine electronic control technology, as a high flexible fuel injection system,the high pressure common rail (CR) injection system has become a trend of the diesel engines technology for its remarkable advantages. Research on hardware and software design of electronic control system for CR diesel engines is very important for improving independent development ability of domestic automobile industry.Based on the control principle of electronic control system, a total design scheme of the electronic control system for CR diesel engines has been made out. The hardware of electronic control unit (ECU) for CR engines is designed and developed. Motorola’s MC9S12DP512 micro controller unit is used as the electronic control unit. The sensors and actuators are also selected.On the basis of the electronic control theory, the stable control strategy of injection quantity, injection timing and rail pressure have been designed after designing of system’s control project. The injection quantity and the injection timing are controlled on the basis of the MAP, and the rail pressure is mainly controlled by using PID of closed loop. Finally, the whole control system adopts the control strategy based on the injection quantity. According to various conditions of the diesel engine, detailed control strategy achieves the steady rail pressure, precise injection quantity and injection timing, as well as the performance of rapid starting and stable running.According to the idea of hierarchical and modular design, the development of controlled software is divided into six functional modules, including initialization module, signal acquiring module, logic control module, driver module, serial communication module and monitor module. All above modules are independent, but interrelated to each other, and they can achieve the control objects of electronic control system together.The test of ECU has been carried out and the results show that the basal functions of ECU are achieved. It can acquire signals from sensors、communicate with PC and drive actuators. Then the ECU has been installed on the fuel injection pump test bed and the elementary bench experiment is made. The experiment results show that basic control of fuel injection can be achieved, and the rail pressure control is achieved by using PID of closed loop.更多还原