Research On The Software Development Technology And Signal Processing Method Of The Vehicle Control Unit

High complexity and reliability request of the in-vehicle ECU, as well as variations of working condition and running environment bring a lot of challenges to the software structure design and senser signal processing. In this dissertation, the design of in-vehicle software frames, processing of the sensor signals and vehicle information simulation technology are analyzed and discussed to empolder the reliable,reusable and transplantable softwares for in-vehicle ECU.In the second chapter, the common ECU software design problems such as task, alarm, interrupt, event, communication are proposed, and the solving methods in OSEK/VDX are analyzed which is the standard in-vehicle real-time operating system. Then, based on the instrument cluster software development application, the design problems from the software requirement, task analysis and realization, task assignment, interrupt management to communication technology are discussed, and the methods of partitioning the tasks, confirming the software structure to satisfy real-time demand and the realization technology are presented. Further more, the method of processing variables exclusively and message queue disposal in task communication are explained.The processing of sensor signal is another important issue of the in-vehicle ECU software development. Variation of the working condition, existence of the electromagnetic pollution as well as environmental variation makes the output of the sensor can't be applied directly, which couples true signal with noise and environment factors. In the third chapter, the method of senser signal processing based on model is dicussed in the oil tank level detecting application. By means of modeling fuel and Auto Leveling System, the influence of the suspension fluctuation oscillation on the fuel level and sensor of the ALS is discussed as well. The frequency characteristic of the sensor signal is analyzed, and the efficient filter used to process the output of ALS is designed. The simulation and experiment results show that the method is feasible and effective.A highly precise vehicle information simulation system could shorten the period of software development efficiently. In the forth chapter, a vehicle information simulation platform is implemented based on the rapid prototype and hard-ware-in-the-loop simulation technology, which can simulate the output of the steering-angle sensor, wheel speed sensor and vehicle running condition based on a precise vehicle dynamic model. This provides an external signal environment for the early software development.