Design And Implementation Of Servo System Of The Industrial Robot Based On FPGA

With the continuous development of the industrialization process,industrial robots were widely used in the manufacture and the six axis industrial robot was more common,which had more joints and flexible movement.The phenomenon that a servo driver controled a servo motor was more common at home and abroad,so that the production cost and the installation volume had increased,the synchronous flexibility of multiple servo motors was also restricted.In this paper,a servo system controls six AC PMSMs,which used FPGA as the main control chip and Nios II core for aided design to develop a set of integrated six axis industrial robot servo system.Firstly,a predictive control model was proposed based on the model of PMSM,which increased the position feedforward compensation control to improve the dynamic response speed of the servo drive,and increased the voltage feedforward decoupling control to reduce the coupling between the axis of the rotating coordinate system.At the same time there was comparison of models between before and after improvement with the Simulink tool,which was proved to be effective.And then due to the disadvantage that an AC servo motor controlled a servo driver,the control of the six AC servo motors was realized at the same time on the control board which was based on the FPGA chip.And the volume of the multi axis servo system was greatly reduced.The module that consumed more logical resources was used of the multi-channel multiplexing mode,which had saved the logical resources of FPGA.FPGA came with the ADC IP core samples phase current,which reduced the phase current sampling delay and extended the bandwidth of the current loop.A high speed absolute decoding method was proposed to ensure the current regulation rate of 20 k Hz.The improved T method of calculation speed was proposed to expande the speed regulation range of the servo system.In addition,the development of Nios II embedded system that used C language at Eclipse IDE made up of the speed of Verilog HDL in FPGA.At last,the function test and SI wave test were carried out on the hardware board,and the comprehensive report of the software compilation was analyzed.At the same time,the current loop,speed loop and position loop and other indicators of performance were tested with a four axis machine and two AC PMSMs combined with the matlab platform.The experimental results showed that the board layout was reasonable,the design of hardware was reliable and software w efficient at six axis industrial robot servo system based on FPGA.