Harvesting machine for soft fruits - optically detects ripe fruit and uses vacuum for plucking and holding fruit during transport to bin

摘要

The device is for harvesting soft fruits, such as raspberries and strawberries. A scanning optical sensor detects fruit of the required colouring by filtering incoming light which is passed to a photosensor. The intensity of incident light is measured by an electronic circuit and if the required threshold of intensity is reached an electric signal stops the scanning motors. An ultrasonic telemetry system measures the distance to the fruit by measuring the time for a pulse of ultrasound to go and return. Several wavelengths may be emitted to improve accuracy. The picking device is a tube ending in a soft material and is oriented by electric motors so that it points towards the fruit. A vacuum pump creates a vacuum in the tube, holding the fruit to the end of the tube. The tube is then withdrawn, breaking off the fruit and the vacuum is released when the tube has moved so its end is over a collecting bin.