ECU Study Of Gasoline Engine Electronic Fuel Injection System

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.