Implementation of a wireless instrumented sphere for fruit processing

The aim of this study was to implement a wireless instrumented sphere to study the critical points in a citrus packing line by real-time measuring the impacts experienced by fruits. The noncommercial device was based on a MEMS (microelectro-mechanical system) sensor node with a sensing range from ±1 g to ±400 g (g = 9.8 m s-2), a ferroelectric RAM (FRAM) memory, a radio frequency (RF) transmitter, a microcontroller, and a 75 mAh lithium battery. The sensor node was placed inside an appropriate case with a total weight of 100 g to represent a 'Tardivo di Ciaculli' mandarin. An FR receiver allowed real-time transmission of the measured data. Total acceleration values, representing the stresses experienced by fruit, were studied. The results showed that total acceleration remained below 20 g in most of the measurements, but considerably higher values, up to 80 g, were obtained between the brushing and waxing machines.