Research On CAN Bus Technology Application To Motor Control System

As the development of computer network technology and chip technology, and also theimprovement of control chip performance, control network technology occupies anindispensable position as the representative of field bus in the industrial control. CAN bus isvery popular as one of several fieldbuses in recent years. It has been widely used in manyindustrial fields. In terms of motor control, control methods and the species of the chip arevaried. The combination of digital signal processor and the motor control has become amainstream trend in control field. This binding mode which has become one of the hottestresearch field implements the digital control of motor.Aiming at the industrial fields which need to control multiple motors, a multi-motorcontrol system based on CAN bus was designed and implemented by this thesis. The full textstarted with two aspects, including hardware and software, which analysed and designed thewhole system. First, through the analysis of the general structure of the CAN bus, the systemdiagram of the overall design was given, and also hardware circuits of USB-CAN adapter andCAN nodes were designed. The digital signal processor(DSP)as the motor control chip wasused in lower computer. Its model was TMS320F2812. The enhanced CAN module and DSPperipheral circuit were researched.In terms of software, the appropriate message frame types and packet filtering mechanismwere determineed on the basis of CAN2.0B CAN bus protocol. A CAN bus application layerprotocol was developed. The definition of the main functions of the PC and message sendingand receiving process were given. By analyzing the sampling process of ADC module, ADCmodule setting for the system was designed. This thesis gave a method used to calculate theangle of rotation in vector control. In the end, Delphi software was selected to design PCinteractive interface, whose operation panel contained the speed setting and the motorsampling data. The delay starting design for the problem of excessive electric current causedby multiple motors starting simultaneously was a major feature.To verify the feasibility of the design system facilitately, this thesis used three permanentmagnet synchronous motors as the controlled objects. Under the existing conditions of thelaboratory, single motor test and multi-machine test were measured separately. On the one hand it can control the motor speed, while allowing the motor to accelerate and decelerate,forward or reverse operation, on the other hand it can collect the operating parameters of themotor. Delayed start function is simple and suitable for large-scale industrial control sites.