High-precision task-space sensing and guidance for autonomous robot localization

This paper addresses the accurate positioning (localization) of a robotic end-effector, undertaking high-precision tasks, by introducing a novel proximity sensing-based point-to-point motion guidance algorithm. The proposed task-space sensing system is only employed at the final stages of motion after the long-range positioning of the end-effector fails to move it to its desired location. Three identical sub-systems that are spatially placed are incorporated into the sensing system, each consisting of a laser emitter, a galvanometer, and a corresponding PSD (position sensitive diode) that is placed directly on the end-effector. The three-step guidance algorithm uses the laser beams and the offsets they produce along the PSDs to guide the end-effector from its actual pose (position and orientation) to its desired pose. The proposed system (sensing and guidance algorithm) was successfully tested via simulation on a three degree-of-freedom (dof) planar parallel manipulator.