Design and modeling of an automatic colour separating and size grading machine for orange

Abstract

This research was aimed to develop and model an innovative and simple prototype of a size grading and colour separating machine for citrus fruits. Design feature included three major characteristics: a simple design and ease of use, parts locally available and ease of construction in addition to possibility sizing of most spherical fruits by changing some adjustments. The machine was adjusted to separate Valencia oranges into three colours and grading of the fruits into five categories based on their sizes. In case of colour separator, the fruit was separated with RGB (red, green and blue) colour method by using TCS3200 colour sensor and Arduino Uno Microcontroller to recognize RGB colours of oranges. The fruit was separated by the sensors based on its colour and the actuator, driven by servo motor, separated the citrus fruits based on their colour. The citrus fruit then fell into the place according to the fruit colour. While in the size grader section, the results revealed that the suggested design achieved high sizing efficiency by using the machine at an angle of inclination of the tilted flat (Af) that corresponded to the coefficient of static friction of fruit types graded. Also, the roller of the grading system must rotate against the fall of the fruit in order not to get stuck between the roller and the tilted flat.