The design and evaluation of a cooperative handheld robot

This paper concerns itself with a relatively unexplored type of personal robot that operates in the tool space. Handheld robots aim to cooperate with the user to solve tasks and improve what tools can offer enhanced by actuation, sensing, and importantly, task knowledge. To this end, we devised a new lightweight robotic platform that has 4 DoF and uses a cable driven continuum structure. Feedback from the robot to the user is provided in an intuitive, implicit manner by the robot end effector pointing towards the goal, avoiding pointing, and/or refusing to perform an action when it conflicts with the task specification. We evaluate two generic tasks involving aiming in space and picking/placing objects with a number of volunteers. Repeated measures ANOVA is used to analyse results to show in which conditions an increased level of automation in the handheld robot improves task performance or user perception of task load. The robot is offered as an open robotics platform[1] and the results indicate directions to improve on feedback and interaction mechanisms.