Design of real-time ethernet motion controller based on FPGA

Abstract

In order to meet the high precision and real-time demand of master-slave robot, the motion controller of it is designed with field programmable gate array (FPGA) as the core chip. The controller firstly implements real-time Ethernet Powerlink instead of the traditional field bus to transfer location information between master-slave hands, then PID closed-loop control algorithm calculates an pulse width modulation (PWM) duty cycle based on the deviation from the location information of master-slave hands, PWM generation module generates corresponding square wave signal to drive the motor rotates. To feedback actual location information and ensure the security of system, encoder acquisition module and motor enable module are designed with logical hardware in FPGA. Finally the motor position control is realized. The results of experiments show that the motion controller based on FPGA, which is compared with the traditional motion controller realized by digital signal processor (DSP) and FPGA, can greatly improve the precision and real-time performance of master-slave robot.