Automated Color-Based Object Sorting System: Design and Implementation Using Arduino

Abstract

The ability to effectively categorize and segregate objects based on visual characteristics is one of the key preconditions of quality control, food processing, and logistics in the rapidly changing environment of modern industrial automation. Although manual sorting remains traditional, it is labor-intensive and time-consuming, and is also prone to human error. Consequently, there is a high demand to invent intelligent, automated versions of the practice. The current paper describes the process of developing, manufacturing, and implementing a low-cost, automated color-sorting device, especially tailored to confectionery products in the form of spheres, using the medium of Skittles. This project aims to recreate the capabilities of large-scale industrial optical sorters by applying the concepts of mechatronics, sensor fusion, and embedded system control into a small desktop system.
The architecture of the system is built around the Arduino Nano microcontroller, which is the main processing unit. A TCS34725 RGB sensor is used to detect the colour precisely because it has an infrared (IR) blocking filter and an I2C interface communication, which significantly reduces spectral noise generated by ambient light. Mechanical actuation is achieved by a two-servo system, including a continuous-rotation servo to rotate a slotted Geneva-like wheel to isolate and convey items and a standard positional servo to drive a directional chute. In order to achieve the stability of their operation, the power distribution network is divided into two logical and power rails through lever-nut connectors in order to isolate the sensitive sensor data of the motors and the electrical noise produced by them.
The control software adopts a state-machine algorithm that includes self-calibration procedures, real-time RGB thresholding, and error-handling routines aimed at overcoming mechanical jams. The kind of accuracy of sorting is about 90 per cent according to the experimental validation when the lighting conditions are controlled. In turn, this project shows how robotics and computer programming can be used practically in automation, and proves that the complex industrial tasks can be successfully modeled with the help of the available and inexpensive hardware.