Direct Teaching Algorithm for a Manipulator in a Constraint Condition using the Teaching Force Shaping Method

This paper proposes a direct teaching algorithm to teach a manipulator in a constraint condition by the teaching force and moment of an operator. Most of the previous research supposes that an operator's teaching motion is always right while under the direct teaching process. However, the operator's teaching motion is not precise enough to directly teach the manipulator in a constraint condition with small contact force. For this reason, the novel idea of modifying the operator's original teaching force into the adequate teaching force considering the contact situation is proposed in this paper. It is termed the 'teaching force shaping method'. The direct teaching algorithm using the 'teaching force shaping method' is also proposed. As a result, with the proposed direct teaching algorithm, the reference trajectory of a manipulator can be directly taught even when the manipulator comes into contact with the workpiece and the contact has to be maintained with small contact force while under the teaching process. Verification of the proposed control scheme is demonstrated through experimental results. (C) Koninklijke Brill NV, Leiden and The Robotics Society of Japan, 2010