Decision of impedance-based scaling factor for workspace mapping in teleoperation

In teleoperation, it is important to utilize the large workspace of a slave robot as well as to guarantee the execution accuracy in sophisticated work. However, the difference between the workspaces of the master device and the slave robot makes the teleoperational mission more difficult. To solve this problem, this study develops a new method for determining the scale factor of workspace mapping based on both 1) the impedance between the slave robot and object and 2) the moving distance of the master device. The object feature and information on the working environment collected from an RGB-D camera in the slave robot are used to set the scaling factor for collision avoidance. Furthermore, application of the movable distance of the master device into the determination of the scale factor helps to improve work efficiency. The fuzzy rule in this study plays a role in determining the scaling coefficient by considering two different pieces of information. Two experimental tests show the effectiveness of the proposed method in both work efficiency and execution accuracy.