Optimum Design and FEA of a Hybrid Parallel-deployable Structure-based 3-DOF Multi-gripper Translational Robot for Field Pot Seedlings Transplanting

摘要

Pot seedlings transplanting is an activity in the agricultural production industry. In its manual level, it is a time consuming, labour intensive, costly activity with low transplanting rate, uneven plant distribution and low degree of accuracy. So, in this paper, a novel partially decoupled 3-DOF multi-gripper pot seedlings transplanting robot is proposed to be used in the open agricultural field to increase the transplanting rate. The proposed robot is composed of two identical 2-DOF Diamond Delta robots, 1-DOF scissor mechanism and belt conveyor. Delta robot is a high speed parallel robot that is used to control the grippers in the X-Z plane while the scissor mechanism is a deployable structure that is worked in the multi-gripper and used to control the grippers in Y direction. Different kinematic and design aspects are considered; namely, the kinematic analysis and the optimum design as well as the finite element analysis in the most critical loading configuration are carried out. A unified frame work for the optimum dimensional synthesis for a prescribed workspace with force transmission and singularity avoidance constraints is developed for the optimal dimensions of the design parameters. The proposed robot is shown to have high transplanting rate and is safe in terms of stress and deformation.