3-Axis Robot Arm Using Micro-Stepping with Closed-Loop Control

Abstract

Robot arm is one of the most buzzing words in industrial automation. The challenge of designing a robot arm is anticipating and controlling its system dynamics. This paper focuses on developing of robot arm with 3 degrees of freedom (DoF) with high speed and precision. The position of the robotic arm is determined from the accelerometer using closed-loop feedback system. The stepper motor in the arm of the robot decides the direction; the desired movements will be controlled by PWM pulses through the controller, as per the requirement of the user. A4988 stepper motor driver is used instead of rotary encoder to control the movements of robotic arm by stepper motor. The step angle of the arm is controlled by micro-stepping using 200 steps to 3200 steps resolution which provides a smooth movement and precision degree of accuracy. A graphical user interface is designed using LabVIEW to display and control the position of arm. Finally, 3-axis robot arm with micro-stepping is developed by integrating the electronic circuitry and mechanical parts.