Design Of Embedded Gateway And The System's Simulation In City Bus Information Integrated Controlling System

With the fast development of city bus' technologies and increasing social requirements for city bus' functions, electronic technology has been gradually applied in the field of city bus. There are various kinds of ECUs (Electronic Control Units), which coexist and are independent in the city bus. How to centrally control these ECUs in an effective and safe way has already become an urgent problem that must be solved in the course of developing the city bus' technologies. CBIICS (City Bus Information Integrated Control System) is a distributed real-time control system that interconnects the separated ECUs by in-vehicle network controlling technologies used in city bus for specifically control function. This system makes use of vehicle electronic controlling technologies, in-vehicle network technologies and intelligent controlling technologies synthetically to share the messages with each ECUs and implement associated real-time control functions. It intents to improve the security and comfort of the bus, lessen the lean upon the drivers.This dissertation has divided CBIICS into two sub-systems, one is the vehicle body controlling system and another is driving controlling system, it needs a gateway to transfer data from one network to another, so the gateway is the backbone of the system. Based on the analysis of the function of the gateway in CBIICS', this dissertation has designed the gateway's hardware and software according to the embedded gateway's anti-jamming, stability and reliability.According to the criterion of CAN(Controller Area Network) protocol, this dissertation has founded the CBIICS' network simulation model includes CAN physical layer model, CAN MAC(Media Access Control) layer model, CAN LLC(Logical Link Control) layer model and CAN application layer model with the simulation tool of OPNET Modeler, and has analyzed the network's key performance by comparing the simulation value with theoretic value. At last, this dissertation has founded the experiment platform of the body lights controlling system of city bus. Comparing the experimental data with the simulation results, it can conclude that this simulation model validates the feasibility and dependability.This dissertation provides basic technologies for the researching and application of CBIICS and it's significative to the development of electronic technology of city bus.