Inverse kinematics of planar redundant manipulators via virtual links with configuration index

Abstract

AbstractThis article presents a new method for generating inverse kinematic solutions for planar manipulators with large redundancy (hyper‐redundant manipulators). The proposed method starts by decomposing a planar redundant manipulator into a series of local planar arms that are either 2‐link or 3‐link manipulator modules, and connecting the conjunction points between them with virtual links. The manipulator then can be handled by a simple virtual link system, which may be conveniently divided into non‐singular and singular cases depending on its configuration. When the virtual link system is no longer effective due to a singular configuration, the displacement of the end‐effector is then allocated to virtual links according to a displacement distribution criterion. A dexterity index called the “configuration index” distinguishes the non‐singular and singular cases. The concept of virtual link is shown by computer simulations to be simple and effective for the inverse kinematics of a planar hyper‐redundant manipulator with a discrete model. In particular, it can be applied to solving the inverse kinematics of a SCARA‐type spatial redundant manipulator whose redundancy is included in its planar mechanism. © 1994 John Wiley & Sons, Inc.