Real-time environmental mode extraction of contact points described in 3 dimensional location and direction using quaternion for bilateral control

In this paper, real-time environmental recognition method is proposed. With this method, location of the contact points are described in three dimensions and directions of the forces are also described in three dimensions. At first, modes of the contact points are divided into two modes; ldquoforce moderdquo and ldquomoment moderdquo. After that, ldquoexternal moderdquo and ldquointernal moderdquo are extracted from each modes by DFT matrix. Finally, environmental modes are achieved from external mode. In this way, hierarchy of the modes is given. This hierarchy is essential for the three dimensional extraction. After the extraction, each of the matrices is normalized to assure the continuity of the transformation. The validity of the proposed method is confirmed by a experiment.