Collaborative Handheld Robots Near the Limits of Human Dexterity—A Pilot Study

Jointly collaborating with a handheld robot could enable human users to exceed their freehand accuracy and speed. Handheld tool use builds on existing intuition and dexterity of hand use. While collaboration through the delegation of high-precision tasks to a large, grounded surgical robot has shown improved performance, joint collaboration is not widely studied in handheld robots. To further explore this topic, we evaluate the feasibility of a handheld robotic platform for studying joint human-robot collaboration in a trajectory tracking task that is impossible for either robot or human to complete alone: a precision constraint beyond human freehand precision in a workspace larger than the robot's reachable workspace. The handheld robot consists of a modified 2-DoF laser engraving module which compensates for human movement error and also semi-autonomously completes the portion of the task that is within the robot's reachable workspace. Motion data were collected for three users laser-marking a series of square shapes at varying distances apart on thermal paper. We observed a five-fold increase in the steering law Index of Performance (IP) [1] for joint collaboration over freehand lasering. This work provides evidence of feasibility for this platform and informs power analysis for future research.