Holding hands - guiding humanoid walking using sensorless force control

This paper presents a physical human-robot interaction (pHRI) interface, which enables the user to control a walking humanoid robot through physical contact. A human operator guides the robot in parent-child-like behavior by exerting force onto the hand of the robot. In contrast to a conventional approach of pHRI in which force/torque measurements are applied, the proposed solution is based on sensorless force control. Furthermore, we demonstrate an extension to the generic interface by implementing a number of gait control algorithms. This paper also evaluates user-acceptable robot responses while guiding a humanoid robot walking. User opinion on the presented control solution is evaluated through usability testing conducted among prospective users. The obtained results indicate that the developed interfaces present an effective solution to the problem of sensorless guidance of a walking robot.