Design and implementation of a control IC for vertical articulated robot arm using SOPC technology

Abstract

A servo control IC for vertical articulated robot arm using SOPC (system-on-a-programmable-chip) technology is presented in this paper. The SOPC technology, developed by Altera Corporation, consists of a FPGA (field programmable gate array) and a Nios embedded processor. In this proposed servo control IC, there are two modules. One module performs the functions of the sequential control, the motion trajectory control and five-axis position control. The other module performs the functions of the five sets of PWM (pulse width modulation) generation and QEP (quadrature encoder pulse) capture. The former is implemented by software using Nios embedded processor due to the need of complicated control algorithm and low sampling frequency control (motion trajectory control & position control: less than 1 kHz). The latter is implemented by hardware using PLD (programmable logic device) in FPGA due to the need of high sampling frequency control (PWM circuit: 18 kHz, peripheral circuits: 4~8 MHz) but simple computation. As the result, the use of the SOPC technology can make the controller of the vertical articulated robot arm more compact, high performance and cost down.