Study On Electronic Control Unit For Engine Based On Real Time Operation System

With the automobile industry rapid development, the automobile in the control, the correspondence and the network aspect request is more and more complex. The new generation Electronic Control Unit (ECU) which character as the embedded real-time operating system and be loaded 32 bit microcontroller are becoming the main stream of automobile electronic application. Recently the automobile industry spontaneously uses real-time operating system as the key system of ECU which standized by OSEK.The OSEK/VDX project whick initiated by Germany's Karlsruhe university early supports re-useful and re-transplantble of software in many projects,saved the massive cost of developing and re-developing software of ECU. I did a lot of work to study ECU software witch based on embedded real-time system.In this paper, I analyzed the standard OSEC/VDX which used in the embedded operating system of car, based on this, to select the open-source real-time operating systemμC/OS-Ⅱas an operation system that will be translated in the control chip. Particularly I analyzed the kernel structure of theμC/OS-Ⅱ, and modified the kernel of the system in accordance with OSEK/VDX standards in order to in line with the international standards. when I working, then translated theμC/OS-Ⅱsystem to the ARM7 chip and run it successfully, it was the foundation for the application development.Since The successful of transplanting real-time operating system, it is possible to divide the old-timey complex engine control foundation to single task. After divided to single task, then design them, including set the priority of task, the work flow design and the using of semaphore flag etc. Finally to work for overall control system software design based on the finish of above work, and to get the basic control function.The software architecture's establishment above avoided being redundant the sampling in the identical control period that led to waste the CPU time, and in the control period, it is only once to complete the detecting of control signal, after transforming them to normal data then carried on the control algorithm again resolving. These process has guaranteed the consistency between output and input value. When fluctuates the system function only need adjust the corresponding module, it is advantageous to complete the complex control and satisfy engine's control request.Based on the real-time multi-tasking operating system design, it is possible to make process management mechanisms to replace the traditional single-mandate mechanisms, and allowing the system to have higher real-time ability, reliability and flexibility.