Force-Estimation Based Interaction of Legged Robots through Whole-Body Dynamics.

External force estimation and adaptation is an assistive technology for legged robots. It enables the robot to accommodate to impacts or interferences and maintain its balance. This technology can also be used for the interaction between the robots and humans when the estimation of force is reliant. This paper presents this new interaction idea for the legged robots in the scenario of guiding visually impaired individuals. The external force is estimated through the whole-body dynamics without any extra force sensors, which enables the robot to handle the unexpected external disturbances or user manipulations in a same manner. We first demonstrate this force-estimation based interaction on a hexapod robot, using a rigid stick handler as the interface. This interaction technology not only has the advantage of being more adaptable to the environments, it also can help the robot to adjust its motions to follow the user's intention of movements.