A Robotic Arm for Sorting Metals and Non-metals Controlled by PLC and Microcontroller

This paper presents an automated robotic arm designed for sorting of objects into metals and non-metal base on their weight. The system is controlled by an FX3U-32M PLC and an Arduino Mega 2560 microcontroller. The robot arm utilizes an AC servo motor to drive its spindle, a linear slide rail for vertical movement, and a ball screw driven by a DC motor for horizontal arm motion. An inductive proximity sensor is used to differentiate metals. The object weight is determined using a load cell, which is compared with a specified reference weight entered via a keypad. This weight comparison is pre-processed by the microcontroller to interface with the PLC. The robot arm can move vertically up to 15 centimeters, horizontally up to 35 centimeters, rotate up to 180 degrees, and manipulate objects weighing up to 0.55 kg. Based on the experimental results, the robotic arm can accurately and precisely classify objects into metal and non-metal categories and by their weight and separate them in various pre-defined positions.