Research Of Distributed Control System For Multi-motor Based On CAN Bus

CAN bus is a bus-based serial communication network which can support distributed control or real-time control effectively.As one kind of industry fieldbus,it is very popular among industry circle because of its outstanding reliability,real time and flexibility.In this thesis,according to the general structure of distributed control system,a overall scenario for multi-motor distributed control system based on CAN bus is given;Taking DSP as main controller,the hardward of CAN intelligent node and adapter is designed to be the bottom hardware platform for the whole system; Following the performance features and the technical specifications of CAN bus,on the basis of soft model for the intelligent node, the application layer protocol of CAN bus is set down,including the assignment of message identifiers,the design of frame format,the method of data exchange and the mechanism of message filter, besides,some software interfaces are designed,such as message sending and receiving,motor control and so on;the main function flow charts for intelligent node and adapter are given and the software designed for intelligent node and adapter is completed;what's more,taking LabVIEW as platform, PC supervising software is designed to control each intelligent node and to monitor feedback datas from each intelligent node,such as speed and current values of motors,fault informations,the state of motor cooperation and so on.On the basis of hardware and software design,a multi-motor networking distributed control system based on CAN bus is constructed,taking brushless DC motor as controlled object,some tests have been done ,such as single motor test, motor cooperative test and fault test.The results proved that the system is stable and has good real-time performance, can realize not only CAN bus communication but also PC supervisory control , fundamentally meet the requirements of multi-motor distributed control system in industry.