A Prototyping of 2-DOF Robot Arm Using Feedback Control System

Robotic technology is rapidly developed. One type of robots commonly used in industry scale is a robotic manipulator or a robot arm. In this paper, a prototype of 2-DOF robot arm is designed by using Solidworks and built. The joints are driven by permanent magnet DC motor coupled with encoders. The prototype is controlled by feedback control system with PID controller that was obtained by parameter estimation and PID tuning and has been tested by the RAPCON platform with MATLAB-Simulink. The tracking results are the responses at different reference input. First, at 60 and 90 degree reference input, both motors respond over the reference input with maximum overshoot less than 21 degree of maximum overshoots, rise time does not exceed 2 second and steady-state errors range from 14% to 21%. Second at 15 or 30 degree reference input, both motors were unable to reach the reference input and had steady-state errors range from 20% to 25%. The error occurs because of the friction of worm gearbox and the control of armature voltage.