MIDDLESEX, United Kingdom—Scientists from the National Physical Laboratory (NPL) have developed a novel imaging technology that can identify the ripeness of strawberries before they are picked. The “robotic strawberry picker" technology also may one day help to reduce food waste and improve productivity.
The team has completed a series of tests on strawberries and other crops successfully. The software is built on the logic of learning from past experiences. The technology uses radio frequencies, microwaves, terahertz and the far-infra red. These four parts of the electromagnetic spectrum all have potential to safely penetrate the crop layers and identify whether the crop meets the pre-designed criteria for ripeness, for a relatively low cost. NPL developed the technology, and the requisite software, for crop identification and selection.
Researchers began by modifying microwave measurement systems to measure the structure of various crops. A series of measurements made on real crops in the laboratory and field enabled a statistical range of measurements for precise size and ripeness identification. The data was then designed into an algorithm which allows the technology to provide the relevant information from a single measurement.
NPL’s Richard Dudley, who proved the original concept in 2009, said: "The focus now is strawberries. This is a fairly easy fruit to measure as it has high water content and dry leaves, and microwave imaging is particularly useful for identifying water levels. Strawberries are also a high value fruit which are very time-consuming to pick, so there is a stronger business case to implement automated picking technology for strawberries than with some other crops."
He said the agriculture industry does not have access to equipment or the skills required to operate in these parts of the electromagnetic spectrum. But having effective ways of identifying ripeness is going to be important in improving efficiency and reducing waste.
“It is also a vital part of the move to automation, which is a big issue for the agricultural industry right now as it could dramatically improve global harvesting productivity and ultimately benefit consumers through cheaper food in supermarkets," he said.
