A UK company, Martin Lishman, has developed a range of fruit- and vegetable-shaped sensing devices designed to monitor and log the conditions experienced by fresh produce during handling and transport.
Another company, the produce-handling specialist, Brillopak, has used Lishman’s “electronic apple” to redesign its systems to minimise potential damage to fruit, and to cut packing wastage and costs.
Lishman’s ImpacTrack products mimic the shape, size and densities of various fruits and vegetables, including carrots, strawberries, avocados and kiwi fruit. They are intended to measure and log shocks and temperatures experienced by the produce during processing and to transmit this data via Bluetooth to an app running on a smart device. From this, users can identify causes of damage and thus help to cut food waste and improve quality control.
Brillopak has been using the electronic apples to measure the G forces experienced by fruit during crate packing and robotic handling, and to redesign its machines to minimise damage to delicate fruit.
For example, it inserted the dummy fruit in place of a real apple in a flow-wrapped pack and found that the automated reject system that it had been using – which pushed the apples off a conveyor belt at right-angles – was subjecting the fruit to forces of up to 26 G, bruising some of them and making them impossible to repack.
The company therefore designed an alternative reject system that uses a tangential force to guide rejected packs off a belt at a shallow angle using a flexible polyurethane band mounted on a servomotor-controlled pusher. This mechanism keeps the forces below 6G, allowing many more apples to be repacked.
“The electronic apple allowed us to pinpoint where the maximum force was,” explains Brillopak’s technical director, Peter Newman. “Armed with that knowledge, we were able to redesign the system to reduce that force below the damage threshold. This is a major benefit to fresh produce packers, for whom waste as a result of bruising is a considerable – and largely avoidable – cost.”
Brillopak has also used the dummy fruit to monitor its delta-robot-based pick-and-place systems – a potential hotspot for damage, with some robots dropping fruit from heights of 250mm. The company has developed a robot control system that optimises acceleration and deceleration to minimise this risk.
“When lifting a pack of apples, the robot arm accelerates strongly upwards into a curve, then decelerates down into the crate, so the pack is tightly controlled as it reaches the bottom of the crate,” Newman says. “What sets us apart is our ability to perform this task at high speed without bruising the product.”