Monitoring of a pseudo contact point for fine manipulation

Monitoring of a contact state is an important technique to achieve tasks in which an end-effector should be in contact with an object. This paper introduces a pseudo contact point that is useful for precise tasks including contact processes. When the position of a point contact between the end-effector and the object moves to another position, the pseudo contact point denotes the present contact point. The pseudo contact point is defined as the foot of the perpendicular from the previous contact point to the line on which the external force vector lies. Experimental results suggest the applicability of our method