Robot Manipulator Redundancy Resolution

Chapter 8QP Based Manipulator State Adjustment

8.1 Introduction

A manipulator is said to be redundant when more DOF are available than necessary for a given end-effector path-tracking task. This implies that redundancy can be established simply with respect to some particular tasks [62]. For non-redundant manipulators, the joint motion is uniquely determined by a prescribed end-effector primary task, and thus there are no redundant freedoms left for executing some secondary tasks, such as handling joint physical limits, environmental constraints, and configuration singularities. In contrast, redundant manipulators have wider operational space and meet more functional constraints, because an infinite number of feasible joint configurations can be available. They have thus been widely applied, for example, in cleanup and remediation of nuclear and hazardous materials, and in space or sea exploration [62, 77, 78, 94, 100, 157–165]. Therefore, a lot of research into redundant manipulators has been carried out, and much attention has been paid by the research community to motion planning and control of robot manipulators [15, 62, 76–78, 94, 100, 150, 157–167].

A redundancy-resolution scheme is a method or an algorithm that selects one joint-space solution from an infinite number of possible solutions, given the end-effector primary task of following a desired workspace trajectory. This kind of selection is usually used to accomplish some secondary tasks for robot manipulators or ...