Design Of Four Axis Servo Control System Based On FPGA

With the rapid development of the global advanced manufacturing, the servodrives with high-performance is increasing. Currently, in the system of high-speed,multi-axis servo applications synchronous linkage, the high-speed fieldbus is widelyused to achieve, and a drive is equipped for each axis, the program not only to dealwith the complicated bus protocol synchronous clock distribution operations, and thecost is higher and synchronization is not accuracy. In response to these problems, thepaper designed axis servo control system based on FPGA.Based on the physical structure of a permanent magnet synchronous motor,operating principle, the principle of coordinate transformation, the paper derive fluxequations, voltage equation, torque equation and motion equation of the permanentmagnet synchronous motor in the synchronous rotating coordinate system. The paperfocus on the permanent magnet synchronous motor vector control algorithm, andselects the appropriate control strategies; analyze the digital method of the spacevector pulse width modulation (SVPWM) and the algorithm principle of coordinaterotation digital computer (CORDIC), to provide a theoretical basis for the properimplementation for the system.The various simulation models of the system is built in the Matlab platform,including sectors judgment module, the basic voltage vector action time calculationmodule, inverter module selection time, pulse output module, and make simulation.Verilog hardware description language is used to design the FPGA software,including decoding module, CLARK transformation module, PARK transformationmodule, inverse transform module PARK, PI regulator module, judging modulesector, the role of the basic voltage vector time calculation module, the triangularwave generator module, serial communication module, SPI communication moduleand a control module, and writing test code for each module, functional and timingof each sub-module simulation by Modelsim, and provides experimental data for design implementation.Finally, using Altera’s EP4C115F29C7to design FPGA circuit control board andusing TI’s DRV8301to design power board circuit, building a complete hardware testplatform. Download system software for the sum tests and analyze test results,demonstration of the correctness of the design.The design used the four vector algorithms with a modular fashion to achieve inthe FPGA, design of control module is responsible for parsing the PC command andcoordination four vector control algorithm module, thus avoiding the complicatedbus protocol and improving the system of synchronization accuracy, saving systemcost, and vector control algorithm improves the performance of permanent magnetsynchronous motor control, to meet the requirements for advanced manufacturing ofhigh-performance, low-cost servo drive.