Design And Implement Of Vessel Electromechanical Devices Monitoring System Based On CAN Bus

With the development of computer technology and automation technology, the automation level of electromechanical equipments which are core parts in a ship gains the ceaseless progress. Currently among automatic marine electromechanical equipments, the vast majority is foreign products. In order to improve the level of domestic ship automation and bring our great country from a shipbuilding large country into shipbuilding strong country, it is necessary to carry out independent research on ship automation. This essay will focus on ship electrical and mechanical control techniques, and the design and development of ship electromechanical control system, based on small laboratory-type marine electric propulsion pod control experimental platform in the ship laboratory of advanced control technology which is supported by Ministry of Transport.Ship monitoring system is generally composed of three networks, and they are management layer, ship control layer and field equipment layer. The monitoring system of field equipment layer is studied in this paper, and an electromechanical monitoring system based on CAN bus is completed as well. The main tasks are as follows:(1) The design of Monitoring Node. The microcontroller AT89S52 is applied in Monitoring Node, to achieve field collecting of operational parameters, data processing, local displaying and alarming about the electromechanical equipments on ship, as well as receiving control signals from host computer, and performing the appropriate action. Four PCBs that achieve 16 analog and 32 digital data acquisition and processing is completed and each of them is debugged successfully.(2) The establishment of CAN bus network structure. To ensure security and stability of data transmission, a fully redundant mode is applied in the network. The bus controller is electrical isolated from transceiver by high-speed optical coupler, meanwhile, anti-lightning diode and capacitance are connected between the output of bus and GND to enhance anti-jamming ability of the bus nodes. CAN application protocol layer is based on the standard of CAN2.0B, using the extended frame format, on 29 for the identifier to plan, facilitating the expansion of the network nodes. Six nodes in the bus network have been tested and, the data are sampled in real time and accurately. (3) Finally, the system is verified through a serial port tool and a test software on host computer. The results indicate that the entire system is stable, reliable with data transmission.