Patent ID: 8396594

Claim:
A robot comprising: a multi-joint robot arm; an external force detection unit that is installed in the multi-joint robot arm, and detects an external force; a joint movable-state calculation unit that (i) calculates a movable state of a joint of the multi-joint robot arm, the joint being located at any position within a movable range, and (ii) determines whether or not the external force is a force applied to the multi-joint robot arm that tries to move the joint in a direction from inside the movable range to outside the movable range; an external force conversion unit which, based on the movable state of the joint calculated by the joint movable-state calculation unit, converts the external force detected by the external force detection unit to a converted external force; and a control unit that controls the multi-joint robot arm so as to be operation-regulated in accordance with the movable state of the joint of the multi-joint robot arm by carrying out impedance control using the converted external force when the joint movable-state calculation unit determines that the external force is the force applied to the multi-joint robot arm that tries to move the joint in the direction from inside the movable range to outside the movable range, wherein the external force conversion unit converts the external force detected by the external force detection unit to the converted external force such that the converted external force is an orthogonal projection onto a tangential plane of a constraint curved surface in which a hand of the multi-joint robot arm is allowed to move when the joint of the multi-joint robot arm is fixed.