Research on City-Bus Lamp Control System Based on SAE J1939
|School||Wuhan University of Technology|
|Course||Control Theory and Control Engineering|
|Keywords||CAN SAE J1939 City-Bus Lamp Networked Control|
With the improvement of society and the development of science and technology, there is increasing lots of demands asked by passengers for comfort, safe and economy of city-bus. At the same time, the government is strict with the environment pollution problem. So the main way to solving these problems is applying many ECUs (Electronic Control Units) in city-bus.At present, many ECUs and electric appliances in domestic city-bus are connected by point-to-point links and controlled independently, which causes lots of signal lines and sensors. To improve the service quality and the performance of city-bus, the time sequence and the correlative control among different ECUs are more and more important. But the traditional control method of city-bus can’t fulfill the demands of complex information communication and control. The in-vehicle network technology can implement the communication among different ECUs and produce uniform control information by judgment and ratiocination.In other words, it can implement city-bus networked control. As one of the basic equipments in city-bus body, the research and development of city-bus lamp networked control system provide a reference for city-bus networked control system.Firstly, the dissertation introduced typical network protocol and especially analyzed CAN (Controller Area Network) protocol. Based on autonomous region role, according to the module partition principle of closer position, similar function and same performance, the author constructed city-bus lamp control system with CAN bus.Secondly, the dissertation analyzed SAE J1939 protocol based on the ISO/OS (International Standardization Organization/Open Systems Interconnect) layered structure. For standardizing the information of city-bus lamp control system and providing base for lamp control, the author designed message format for city-bus lamp control system based on SAE J1939 protocol.For constructing the simulation test-bed of city-bus lamp control system, the author constructed switch module based on USBCAN interface card and designed lamp control module based on microcontroller, CAN controller, CAN transceiver, power driver chips and so on. With dynamic link library method, the dissertation implemented CAN parameter configuration, CAN message transmission and CAN message receiving. Based on the modularization program design method, the author divided lamp control module into different program units by function, which includes CAN initialization program unit, message transmission unit, message receiving unit and interrupt service program unit. This method can implement code reuse.Finally, the dissertation constructed the simulation test-bed of city-bus lamp control system based on software and hardware.