Study On On-Board Control System Of Electric Locomotive Based On CAN Bus

In recent years, electric locomotive control technologies are being innovated and optimized unceasingly and the newest control skills with the core of microcomputer come into being gradually with the quick development of microelectronics and computer applications techniques. Because of the quick development of microprocessor and all kinds of field-buses, distributed control skills applied in microcomputer on-board are becoming possible in order to collect local signals and to drive local objects, at the same time lots of signal wires can be reduced in order to simplify the internal circuits. Logic control unit based on computer technologies is able to better the control performances of locomotive and improve its reliability dramatically, compared with traditional relay control system.The development of system on-board is introduced and distributed logic control unit based on field-bus is used to renovate the control system of SS3B locomotive, summarizing the characteristics of all kinds of on-board systems. Then, techniques of train-bus and control area net which are being widely used are recommended emphasizing the CAN bus and its performances and criterion. The functions of message filter and frame format of CAN are described in detailed. Ethernet, ControlNet and CAN, the three control bus, which are in common use, are analyzed. By comparing their characteristics of function of the MAC sub-layer and considering the requirements of control systems on-board, CAN bus has been chosen in the communication system built in locomotive. Communication module based on CAN bus has been designed and completed in order to realize the communication among all the modules in the system. According to the need of control system, the reliability of system has been canvassed, and considering the system studied in this paper dual system prepared online have been projected. Failure estimation methods of module in system are proposed; especially, failure estimation methods of microprocessor based on distributed system have been put forward and proved correctly too, further more their switch modes are also completed.