The design and finite element analysis of the mushroom picking flexible robotic arm

This article presents a robotic arm designed for mushroom picking in a greenhouse environment, taking into consideration the specific characteristics of Agaricus bisporus. The robotic arm was equipped with self-lifting and self-stretching functions, allowing it to move effectively within the restricted space of the greenhouse, while picking and placing Agaricus bisporus without causing any damage. The mechanical arm and flexible gripper were designed according to the growth environment and size of Agaricus bisporus. A finite element analysis was carried out on the flexible gripper, with the use of ABAQUS to construct a simulation model. The Yeoh model and the Mooney-Rivlin model are used as the research models, and tetrahedral linear elements C3D4H were used for meshing. By changing the positive and negative pressure of the gas inside the flexible gripper's airbag to simulate gripping and releasing actions, it was demonstrated that the deformation of the flexible gripper meets the requirements for picking actions under both the Yeoh model and the Mooney-Rivlin model. It was shown that a shear force greater than 3.2N is needed for the gripping and twisting of Agaricus bisporus within the flexible gripper to successfully complete the picking action. Finally, the experimental verification was carried out, proving the stability and feasibility of the mushroom picking robotic arm. And the design of flexible gripper control system, through the distributed computing and I/O structure, CANopen communication protocol, etc. makes the flexible gripper can perform accurate gripping tasks in complex environments, with high efficiency, reliable, flexible control performance, adaptable, and easy to expand and optimize.