Servo Motor Controller using PID and Graphical User Interface on Raspberry Pi for Robotic Arm

Abstract

The usage of the robotic arm in industries has been growing as the robotic arm can provide many advantages to the industries. However, the usage of the robotic arm has many challenges faced by the industries. One of the problems is the error of the angle position caused by the movement of the robotic arm’s joint which affects the precision of the desired position of the end-effector. Therefore, this paper aims to study the solution of the PID controller to increase the accuracy of the position of the end-effector in the X-Y plane using forward kinematic. It describes the mechanical system, design concept, and the prototype of a 6 DOF robotic arm. Initially, the angle error of the joint for 2D plane movement is captured manually using the trigonometric calculation. Then, to reduce this error, the coefficient of the PID controller, k p , k i , and k d are tuned automatically using Simulink and MATLAB. Then, the controller is programmed on a Raspberry Pi with a servo driver, PCA9685. There are six servo motors used as the joints of the robotic arm, namely MG996R. Each servo motor can be controlled by using a Graphical User Interface (GUI) scripted in Python Programming Language. The end position of the end-effector will be displayed on this GUI. It is found that the angle position error of the 6 DOF robotic arm for X-Y plane movement is reduced from 4.7° to 0° by using the PID controller.