Redundancy resolution under hard joint constraints: a generalized approach to rank updates

Abstract

The increasing interest in autonomous robots with a high number of degrees of freedom for industrial applications and service robotics have also increased the demand for efficient control algorithms. The unstructured environment these robots operate in often impose constraints on the joint motion, an important type being the joint limits of the robot itself. These circumstances demand control algorithms to handle multiple tasks as well as constraints efficiently. This paper shows that both kinematic and torque control of redundant robots under hard joint constraints can be formulated in a single framework as a constrained optimization problem. To solve said problem, a generalization of the Fast-SNS algorithm to weighted pseudoinverses is proposed, which fulfills our demand of efficiently and reliably handling joint constraints.