Electromagnetic Sensing for Non-Destructive Real-Time Fruit Ripeness Detection: Case-Study for Automated Strawberry Picking

Abstract

Rapid non-destructive measurement or prediction of ripeness, quality and fungal infection in various fruits is a challenge currently affecting automation of fruit harvesting and gathering. This is especially true for delicate and difficult to store fruit such as strawberries, which are traditionally delivered directly to the customer from the farm. However, transportation of the product, often overseas, means that fruits’ condition at the time of gathering should be precisely planned. This paper reports on the initial trials of using non-invasive athermal microwave spectroscopy as a tool to assist in real-time fruit ripeness detection. The trials were conducted during June 2018 and have illustrated that the proposed method can distinguish between strawberries at different stages in ripening (R2 = 0.788, p = 0.0283). The findings support further development of the technique, which aims for integration with the Thorvald II agricultural robotic system.