Design Of Software For GDI Engine’s Electronic Control Unit Based On TC1782

Compared with the conventional port fuel injection (PFI) gasoline engines, gasoline direct injection (GDI) engines can enhance the vehicle’s power output, drive ability and fuel economy drastically, and the emission performance is excellent especially. In the face of tigher emission regulations and increasingly fierce market competition, GDI engines win the domestic and foreign manufacturers’s favour. With the strengthing of the GDI engine’s control functions, thus the scale and complexity of ECU software is increasing, the traditional software architecture based on foreground and background pattern can not meet the engine’s control requirement of multitasking and high real-time again. At the same time, in order to ensure the safety of the engine’s operating and to avoid the damage of components, fault diagnosis and potection have beame a fundamental part of the control software, and accout for more than 60% of the whole software. Perfect the ECU software based on the early developed ECU hardware and drive software for GDI engines, whose core is Infineon’s TC1782 microprocessor, refered to the mature embedded system software architecture standards. The main research of the article is as follows.(1) Fault diagnosis and protection research on some sensors of the engine control system. The strategies were built from the aspects of sensor signal range check and plausible diagnosis, and took the coolant temperature sensor, throttle position sensor, accelerator pedal position sensor and rail pressure sensor for example. Determined the proper threshold according to the characteristic of sensors, and took corresponding measures to protect the fault sensor. The fault diagnosis software based on C language was wroted, and the software was verified in fault state.(2) The transplantation of embedded real-time operating system based on TC1782.The embedded real-time operating system was introduced and the open layered software architecture was established. Functions related to the kernel of TC1782 such as context switch, critical area to enter and exit, stacks were wroted, and the FreeRTOS was tranplanted into the ECU based on Infineon TC1782 microprocessor. Combined with the needs of the project, in order to realize the reasonable scheduling of the operating system, the ECU software tasks system was divided according to the priority, and the reuseability and portability of the ECU software was ensured.(3) The study of electronic throttle’s control with fuzzy PID. With the problem of high control accuracy requirement for throttle at small open degree and thottle jitter due to flow shock, the fuzzy PID control algorithm was adopted to improve the robustness of the control. On the basis of incremental PID, the fuzzy controller used the error e and error rate ec calculated by the target position and actual position, and corresponding rules of the fuzzy control was made, and the self-regulation of the PID parameters was realized. The control precision and stability of the electronic throttle was enhanced tremendously than previously.