Research On Key Technologies Of Car Information Centralized Control System

There are many kinds of Electronic Control Units (ECUs), which are mostly independent in a modern car. However, there frequently exist correlative and time sequence control requirements between them. How to centrally control these ECUs in an effective, orderly, safe and convenient way and how to synthetically use their information have already become theoretical and applied problems that must be solved urgently in the course of applying electronic technologies to cars and development of the car's technologies.This dissertation is supported by several projects, especially technically supported by Laboratoire Lorrain de Recherche en Informatique et ses Applications (LORIA). In order to improve the holistic performances of a car, aiming at solving the existing problems of the ECUs, based on central transmission and control correlative information from various independent car ECUs, adopting advanced in-vehicle network, the author of this dissertation researches the Car Information Central Control System (CICCS) and its key technologies.After researching the definition, features and forming rules of CICCS, the author builds the whole structure of CICCS and the structure of its nodes. By compare, gateway model of CICCS is determined.Rule-based control method and hierarchically control method of CICCS are put forward. To CICCS with a car information central controller, both methods could be used. To CICCS without a car information central controller, only hierarchically control method could be adopted.Based on the classification of a car's outer factors in the course of driving and classification of traffic environment, hiberarchy of control rules in CICCS is built. After division of braking process, safe braking distances during drive beeline, decline and ascent are calculated. Control rules of collision and fire are brought forward. Steering round a cross-road and steering round a traffic circle as examples, control rules during steering are researched. Thus produce process and main ways of control rules in CICCS are demonstrated.On the basis of the analysis of CICCS real-time, combined with universal working load characteristic table for different level network communication developed by Bosch, information need to be transmitred under some condition in CICCS is designed. Adopting Rate Monotonic (RM) and Deadline Monotonic (DM)scheduling to assign information priorities, worst-case response time in CICCS are calculated. The results show, when the bit rate of high-speed CAN reaches 500Kbit/s and the speed of low-speed Controller Area Network (CAN) is 100Kbit/s, all the messages meet their timing constraints under both RM and DM.Adopting dependability of distributed real time system, fault classes and dependability requirements in CICCS are analyzed, dependability system is presented and its reliability is deduced.Choosing Kvaser Navigator as the simulation flat of CICCS performance analysis, event oriented, real time and dependability simulations of CICCS are conducted. The results validate its availability, real time and dependability. The author compares the safe braking distance while a car brakes by driver during decline with the value when a car brakes through CICCS. The results show that under the same conditions, brake performance of the car by CICCS could be improved remarkably.