汽油机电控燃油喷射系统ECU技术研究

河北工业大学

硕士学位论文

汽油机电控燃油喷射系统ECU技术研究

姓名：胡新强

申请学位级别：硕士

专业：车辆工程

指导教师：石维佳

20071101

河北工业大学硕士学位论文

汽油机电控燃油喷射系统ECU技术研究

摘 要

随着排放法规的日益加严和市场对汽车性能、节能等要求的不断提高，发动机电控技术得到越来越广泛和深入地发展。作为汽车电子核心技术之一，发动机电控系统软硬件技术及其自主创新研究和开发，对于我国汽车工业的发展具有非常重要的现实意义。

本文以四缸汽油机电控燃油喷射系统为研究对象，结合对燃油喷射系统组成与控制策略的全面分析，基于英飞凌16位单片机XC167CI，采用嵌入式C语言，完成了多点燃油顺序喷射系统ECU的软件设计与调试，并进行了初步的实验研究。

在对电控多点燃油喷射系统原理与控制进行分析的基础上，本文通过磁电式曲轴位置传感器（CAS）和具有58X-2齿形结构的曲轴信号轮，结合霍尔式凸轮轴位置传感器（CPS）实现了对曲轴转角、转速的测量，以及发动机的判缸与喷油量、喷油正时控制。

本文对发动机起动工况、运行工况及过渡工况（加减速工况）的控制策略做了全面分析。对起动工况喷油采用了预喷、起动喷射和起动后加浓的控制方式。对运行工况喷油采用了速度－密度法，通过发动机速度和进气歧管绝对压力，对基本喷油脉宽查表插值，并根据其他工况参数进行修正控制及空燃比闭环反馈控制，实现了对运行工况燃油喷射的综合控制。同时，以节气门开度变化率为参考，实现了加减速的判断与喷油控制。

基于英飞凌（Infineon）16位单片机XC167CI的捕捉比较（CAPCAM）单元、ADC单元及定时器单元等丰富的硬件资源，结合相应的控制策略，采用了嵌入式C语言，完成了多点燃油顺序喷射系统ECU的软件设计与调试，并对系统进行了初步的实验研究。系统经调试运行，能基本实现发动机的喷油控制功能，并为今后对发动机ECU的深入与扩展研究建立一个良好的软硬件平台。

关键词：发动机电控，汽油机，电控单元ECU，多点燃油顺序喷射

i

汽油机电控燃油喷射系统ECU技术研究

ii

ECU STUDY OF GASOLINE ENGINE ELECTRONIC

FUEL INJECTION SYSTEM

ABSTRACT

With the increasingly rigorous emission regulation and more requirements in automotive

performance and energy-saving, engine electronic control technologies have been developed more and more extensively and intensively. As a core technology of automotive electronics, hardware and software of engine electronic control system and its independent innovation has a profound and realistic significance to the development of automotive industry in our country.

In the thesis, gasoline engine EFI system with 4 cylinders is the research subject. There is a rounded analysis to the composition and control strategy of EFI system. And the software of system is designed and debugged in embedded C programming language based on Infineon 16bit MCU XC167CI. Then primary experiment study is carried out.

According to the principle and characteristic of sequential multi-point EFI system, we select magnetoelectric crankshaft angle sensor (CAS) , crankshaft signal wheel with 58X-2 structure, and hall camshaft position sensor (CPS). Through them, these functions can be carried out, such as crankshaft angle and speed measure, engine cylinder identification, injection timing and pulse width controls.

The engine control strategies include crank mode, run mode and transient mode (acceleration and deceleration) in the thesis. In crank mode, injection control includes primary, crank injection and thick correction after crank. In run mode, speed-density method is adopted, so basic injection pulse width is got by look-up table and interpolation. The table is composed of engine speed and manifold absolute pressure. Injection control is finished by the combination of basic pulse width and its corrections including A/F close-loop control. Moreover, identification and injection of acceleration and deceleration modes are controlled by the change rate of throttle position.

The software design and debugging of multi-point sequential EFI system is accomplished on the base of Infineon 16bit MCU XC167CI, relevant control strategies and embedded C language. Some functions of XC167CI MCU are used, which include its ADC unit, GPT unit and CAPCAM unit etc. Finally, the system is validated through some primary experiment. They prove that the injecting control function can be carried out right. The system will be a helpful hardware and software basement to more extensive and intensive study of engine ECU.

KEY WORDS: engine electronic control, gasoline, electronic control unit (ECU), multi-point sequential fuel injection