Collision-Free Inverse Kinematics of Redundant Manipulator For Agricultural Applications Through Optimization Techniques

This article presents an optimization-based technique for solving the inverse kinematics (ik) of spatially redundant manipulators in agricultural environments (workspaces). a kinematic configuration of 9 degrees of freedom (dof) manipulator with eight revolute and one prismatic joint has been modelled to improve the accessibility in complex workspaces. the proposed manipulator has been simulated for harvesting fruits and vegetables. to perform the desired task in the working environment, the ik solution of the robot needs to be determined. the ik problem has been formulated as a constrained optimization problem with the objective of minimizing the positional and orientational errors by avoiding obstacles. a 3d cad environment with different fruits and vegetable plants has been modelled in solidworks. a target location in this environment has been chosen to pluck the fruit/vegetables. the trunk, branches, and leaves are considered as obstructions. the collision avoidance technique was implemented using a bounding box approach by including a collision detection algorithm. ik simulations of the spatial redundant manipulator in a cluttered environment were performed and results are reported. the joint trajectories of the robot while reaching desired task-space location has been depicted using simscape multibody. the results demonstrate that the end-effector of the robot has been reached desired task location successfully with an accurate ik solution. the approach is adaptable in a wide range of working environments based on the simulation results of the ik solution of robots.