Robot perception of environment impedance

This paper proposes a novel identification technique of constraint condition that the environment imposes on the robot's end-effector, based on position and force sensing during arbitrary manipulation. In the proposed method, the impedance that constrains the motion of the end-effector is estimated on-line; the uncertainties of the estimates are evaluated; and discontinuous changes of the impedance are detected. This method can be installed to robots as human-like perception of impedance, and can be used for monitoring human demonstration. Results of preliminary experiments are presented.