Bilateral Control Method Based on Transformation Matrix Relating Motion Features and Tool Coordinates

Abstract

Conventional bilateral controllers have been designed on the basis of a tool coordinate system. However, from the viewpoint of versatility, a transformation technique based on physical features of an operator is advantageous. Therefore, this paper proposes a bilateral control technique that can be used to operate slave robots; the technique is based on motion features of an operator and facilitates intuitive operation. Here, motion features imply displacement ratios of joints. A coordinate transformation matrix containing the motion features of the operator is obtained by principal component analyses. The transformation matrix can be used to abstract the motion features, while other transformation matrices require symmetric motion or symmetric sensor placement. The validity of the proposed bilateral control method is experimentally verified. In an experiment, the proposed method is applied to a wearable robot hand and a forceps robot. A grasping motion extracted by the wearable robot hand is transmitted to the forceps robot on the basis of the obtained coordinate transformation matrix.