Testing of an assistive robot system for haptic exploration of objects.

INTRODUCTION: When children with physical impairments cannot perform hand movements for haptic exploration, they may miss opportunities to learn the properties of objects. Assistive robots may enable them to make manipulation actions.

OBJECTIVE: To examine the differences between using a robotic teleoperation system with haptic feedback and manual exploration when making perceptual comparisons about object properties. Accuracy and exploratory procedures (EP) using the system were compared to those in manual exploration.

METHOD: Twenty adults without physical disabilities and ten typically developing children manipulated four pairs of objects and chose one based on size, roughness, hardness and shape. All participants completed the task with the robotic system (Tech) and manual exploration (No Tech), with the order counterbalanced.

RESULTS AND CONCLUSION: Participants performed a previously unidentified EP, "tapping", in the Tech condition. Enclosure was not possible with the robot end effector, but tapping afforded the required perceptual information. Adults' perceptual comparisons were always accurate and they predominantly performed the optimum EP in both conditions. Even when children performed the optimum EP with the system, their answers were less accurate than with manual exploration. Most gave the correct answer, except for hardness, which was likely due to mechanical flexibility in the robotic system.