Kenji Hiyoshi

Basic Study on Strawberry Harvesting Robot (Part II)

Abstract These papers describe a strawberry harvesting robot where by robot vision and a 4 DOF’s Cartesian coordinate manipulator were used. This first part presents the development of a robot vision system and the algorithm for locating and feature extracting of strawberry fruits. The robot vision system employs the use of two color CCD cameras. The first camera is used to capture the whole area image under focus within the harvesting range, and the second camera captures only the image of the strawberry fruit to be plucked. The algorithm converts the captured images from RGB to L*a*b and extracts recognized position, orientation and shape of strawberry from a gray image of the L*a*b color model. Experimental results show that the robot vision system can extract position, orientation and shape of various strawberries in ordinary lighting condition. The Part II presents the design and development of the robot frame, the plucking hand, 4 DOF’s Cartesian coordinate manipulator and the Control System.

Basic Study on Strawberry Harvesting Robot (Part II): Design and Development of Harvesting Mechanism

Abstract The aim of the study was to develop an automatic harvesting robot for strawberry. The algorithm for recognition of fruit and its location, and the design concept of the robot vision system were reported in Part I of this study. This part describes the design and development of the robot frame, the plucking hand, 4 DOF’s Cartesian coordinate manipulator and the control system. The plucking hand and its position geometry are very important for any harvesting robot. The developed plucking hand is a non-touch fruit type as it specifically grips the stem to be cut. The experiment results show that the optimum air pressure supplied to the harvesting hand was from 0.09 to 0.17 MPa during the plucking process, and more than 0.23 MPa during the cutting off process. A high harvest accuracy of nearly 100 % was confirmed. And since the plucking process is a method accomplished by grasping the stem of the strawberry, it was demonstrated that strawberry can be harvested without touching the delicate fruits.