Task Compatibility of Manipulator Postures

TLDR

Humans instinctively choose arm postures that best exploit motion and strength for manipulation tasks. The study aims to emulate this human posture selection in robots to fully exploit manipulator capabilities. An index is introduced that quantifies posture–task compatibility by modeling the manipulator as a mechanical transformer linking joint‑space and task‑space velocities and forces, and optimizing this index to match transmission characteristics to task requirements, with implications for redundancy use and workspace design.

Abstract

In performing a manipulation task, humans tend to adopt arm postures that most effectively utilize the motion and strength capabilities of the arm. Selecting arm postures that are compatible with the task requirements has become almost instinctive to humans. By mimicking this approach in robotic manipulation, we can exploit the full capability of a manipu lator in performing a task. An index is proposed for measur ing the compatibility of manipulator postures with respect to a generalized task description. The manipulator is viewed as a mechanical transformer, with joint space velocity and force as input and task space velocity and force as output. Optimi zation of the index corresponds to matching the velocity and force transmission characteristics to the task requirements. The applications of this index to manipulator redundancy utilization and workspace design are also discussed.