The Study On Servo Control System Based On Network

As the development of science and technology, the performance of the servo system is getting better and better with a wider applied range, it becomes intelligent and networked. The development of the vector control makes permanent magnet synchronous motor play an important part in servo control, combined with digital control and intelligent control can reach good result. As the control system is more complicated and it has the need to remote control, it needs long and complex transmission lines using the traditional point to point control mode. It brings interference to the system and influence the control performance. Networked control system is a distributed feedback control system, network nodes exchange data though digital communication network. It can realize resource sharing, remote detection and control, reduce the connection and cost of the system, and improve the reliability of system, so it is a trend of servo control. At present, there are many network communication protocols for motion control. Industrial Ethernet has many advantages such as good compatibility, commonality and openness as well as deterministic and real-time, so it is widely used. EtherCAT is industrial Ethernet which has outstanding performance such as high real-time property, high reliability and speed, and down to I/O level, so it is ideal for servo control and high-speed data acquisition.Based on study of EtherCAT in detail, this paper proposed a position servo control and high-speed real-time data acquisition system based on EtherCAT taking wave maker as application background. Position servo control has the position control arithmetic realized at master station, and the master station sends speed command to slave station. The slave station takes dsPIC33FJ256MC710 as application controller, using its PWM module to produce pulse and direction signals to servo driver while at the same time send the position data acquired by orthogonal code module to the master station. Data acquisition function is to get the data of wave height sent from slave station to display and monitor at the master station. At slave station, the controller is MCU PIC24HJ256GP610, using it's twelve-bit A/D module to convert analog signals to digital signals with high speed, combined with DMA module improving working efficiency of CPU. Hardware connection and program design are realized in this paper. In the Matlab/simulink environment, build the simulation model of permanent magnet synchronous motor and model of network servo control system using TrueTime tool box, and get the simulation results. Design fuzzy PID controller and analyze the control performance to direct current servo motor though simulation. At last, test the system though experiment, the results demonstrate the system can achieve good performance to meet the demand of servo control and data acquisition. It testifies the feasibility of the system.