Development of Robotic Strawberry Harvester to Approach Target Fruit from Hanging Bench Side

Abstract

To reduce the labor involved in strawberry production, we have developed a strawberry harvesting robot that can operate on a hanging bench culture. In the hanging bench culture, a plant is grown on a bench that has been hung from a beam of the greenhouse. The bench is set at a height of approximately 1.0 m from the floor. In general, mature fruits are located behind immature fruits as viewed from the aisle side. In such a case, a conventional robotic harvester tends to fail in approaching the target fruit because of obstacles such as neighboring immature fruits. As viewed from the hanging bench side, mature fruits are located in front of the immature fruits. Considering this case, our robot has a unique feature that it approaches the target fruit from the hanging bench side and positions itself right below the hanging bench. We have developed a traveling platform for the robot to traverse on and accomplish complete harvesting tasks in a 2D area in a greenhouse. The traveling platform has a gantry structure that moves on a set of three rails. The performance of the traveling platform has been tested, and basic stable movements have been observed in the transverse and the path direction. A negative longitudinal slippage has been observed when a weight of 200 kg was loaded. Basic performance tests of the robotic harvester have confirmed that the robot can successfully harvest mature fruits.