基于TC1796的高压共轨电控柴油机判缸控制策略研究

【作者】 杨骐菲；

【导师】 申立中；

【作者基本信息】 昆明理工大学 ， 动力机械及工程， 2012， 硕士

【摘要】 与传统的机械控制柴油机喷射系统相比,高压共轨柴油机更好的适应了越来越严格的排放标准,降低了燃油消耗率,并且改善了发动机运转情况。但是柱塞式、分配式等机械控制柴油机的燃油喷射正时由正时齿轮决定,而高压共轨柴油机中喷射系统的执行器和曲轴是没有机械连接的,是依靠电子控制单元(ECU)对曲轴位置传感器信号和凸轮轴位置传感器信号进行处理,决定喷油时刻。ECU快速精准的获取一缸压缩上止点(TDC1),确定柴油机各个时刻运行的角度相位,与高压共轨柴油机精确控制喷油密不可分,决定着柴油机运行和排放性能的优劣。因此,柴油判缸控制策略及实现的研究非常必要。判缸控制策略所要实现的是快速准确地确定发动机一缸压缩上止点(TDC1)的位置,然后获得发动机各个时刻的运行角度相位,并且利用曲轴位置传感器信号完整精确地计算出发动机的瞬时转速和平均转速。主要工作是ECU采集并且处理两位置传感器信号,获取它们与一缸压缩上止点(TDC1)之间尽可能多的相关位置信息和发动机各个时刻运行的角度相位,再反馈给ECU进行计算,决定喷油系统中的执行单元的动作。课题以云内动力股份有限公司的YN30CR高压共轨柴油机柴油机为研究对象,设计一种判缸控制策略。高级车用单片机TC1796采集由硬件电路处理过的曲轴方波信号和凸轮轴方波信号,检测两方波信号的动态合理性,然后利用曲轴方波信号计算发动机的各种转速,确定曲轴方波信号的缺齿处和凸轮轴信号的多齿处,以缺齿和多齿与TDC1的固定角度关系,确定发动机的角度相位,这是正常判缸模式。但是由于发动机工作环境恶劣,可能出现获得的信号已经发生了错误和失真,这时候,需要多种判缸模式来应对所出现的错误情况。如果在动态合理性检测中,凸轮轴传感器发生故障,启动后备1模式(单曲轴判缸模式)判缸,以假设的发动机相位来确定喷油,喷油后检测发动机的转速来获得TDC1位置。如果动态合理性检测中,曲轴传感器发生故障,启动后备2模式(单凸轮轴判缸模式)判缸,以凸轮轴多齿和TDC1之间的固定信号关系获取TDC1位置。后面两种判缸模式,是故障状态的判缸,不适合发动机长期运行。判缸控制策略主要实现这三种模式下的判缸,以柴油机构造学、C语言程序设计和单片机原理为理论工具,以英飞凌公司(Infineon)的高端车用单片机TC1796为硬件基础,以英飞凌公司的DAvE (Digital Application VirtualEngineer,数字应用虚拟工程师)DAvE、Tasking EDE(Embedded Development Environment)嵌入式系统集成开发环境为软件平台,实现信号倍频,转速计算,确定发动机运行相位等工作,完成判缸工作任务。论文首先就国内外研究判缸的技术方法和当前用于动力方面设计的主流车用单片机进行了介绍,在全面分析判缸所要实现的任务后,列出三种能实现判缸的控制模式,并进一步具体说明信号倍频、信号合理性检测、三种判缸模式的实现过程和获得的程序结果。最终在对获得的实验结果进行数据分析后提出了后续可能实现的工作展望。更多还原

【Abstract】 Compare to traditional mechanical controlled diesel fuel injection system, High pressure common rail diesel engine can better adjust to the increasing rigorous emission regulation with lower fuel consumption as well as improved engine operating performance. Unlike some mechanical controlled dieselengines, such as the plunger engine or the distribution engine, the timing of high pressure common rail diesel engine is decided upon ECU to processing the position signal of crankshaft and camshaft,instead of the timing gear, since no mechanical connection exist between injection actuator and crankshaft. The accuracy of TDC1, which can be used to infer the angel phase at different moment, is strongly interconnected with the inject precision of high pressure common rail diesel engine which in turn have a direct influence on the performance of engine operating and emission.The main task of engine position determination control policy is to know the position of TDC1, then the instant and average rotational speed can be calculated from the angel phase of different moment in the engine and position signal from sensoron crankshaft. The main task is to use ECU to acquire and process the position signal from crankshaft and camshaft, so position information between them and TDC1as well as the phase angel of engine at different moment can be maximally retrieved. Then all these data is the input of ECU to guide the actuator in the injection system.This paper used YN30CR high pressure common rail diesel engine as research target to devise acontrol policy. The usual approach is use advanced vehicle MCU TC1796to verify the reasonableness of rectangle signal from crankshaft aswell as camshaft first, then combined with rotational speed of engineto know the angel phase of engine, finally, the phase angel of engine can be calculated from fixed angel difference between TDC1and miss tooth and add tooth, which were decided by miss tooth in crankshaft and add tooth in camshaft. Due to the poor working environment of engine, the acquired signal might have error or distortion, where several control mode are needed. If the camshaft break down in dynamic reasonableness detection, backup mode#1(single crankshaft cylinder Detection mode)will be used to assume the injection phase, which in turn can be used to know the TDC1position of engine after the fuel injection. By the same token, backup mode #2(camshaft Cylinder Detection mode) will be used if crankshaft break down to know the TDC1position from the fixed angel difference between camshaft and TDC1. These two modes are used during fault status, not suitable for long timeoperation.The main content of cylinder detection policy is to implement these three mode of cylinder detection.The implementation is based on diesel engine tectonics,C program design and MCU principle, in combine with advanced vehicleMCU TC1796as well as DAvE(Digital Application Virtual Engineer), Tasking EDE(Embedded Development Environment) software development environment, to determine the operating phase through frequency multiplying and rotational speed calculation, finally achieve the goal of cylinder detection.This paper first introduced the technical approaches and main vehicle MCU adopted in and out of china, after complete analyses all the tasks the cylinder detection should implement, three applicable control mode of cylinder detection, then frequency multiplying signal, single reasonableness, implementation of threecylinder detection mode and program output are explained in details.Finally, the analyses base on experiment results were conducted,future effort needed is also proposed.更多还原