Application of signal processing technique for the modification of a fruit sorting machine

Abstract

The objective of this study involves the optimise process of a sorting machine for spherical fruits, which are currently manually classified with a low level of efficiency in Iran. An instrumentation system is modelled and fabricated for the development of a fruit sorting machine. Mechanical components and control system are assembled on a chassis for fruit transferring and classifying. A gravity duct transfers the fruits toward six ejection points which is manipulated by pneumatic cylinders and magnetic valves. Peak signal to noise ratio (PSNR) criterion is employed to analyse the work quality of the mechatronic system. The PSNR experimental results specify that noise and vibration significantly affect the machine performance. To redesign the fabricated machine, the mechanical system of conveyor and actuators are separated from measuring and control unit. Field trials were conducted to modify the machine characteristics based on the minimum damage for the fruits. To avoid bruising in apple fruits, Golab variety, the duct slope was fixed at 0.02 which produces the maximum fruit velocity of 1 m/s. With no injury on apple fruit the sorting capacity of 130 kg/h is achieved for the machine.