Assessment of the Functional Rotational Workspace of Different Grasp Type Handles for the lambda.6 Haptic Device

Orientational misalignment between the master and slave devices in teleoperation leads to decreased task performance. Such a misalignment occurs for example when indexing is applied to rotational degrees of freedom of the master device. In this context, the handle of the telemanipulator on the master side seems to play a crucial role and should be designed in a way that allows users to reach the rotational workspace necessary for the task at hand. Therefore, in this study we investigated the reachable rotational workspace for and the usability of different grasp type handles mounted to a lambda.6 device. We could show a clear difference in the functional rotational workspace that nine naive participants could reach with nine different grasp type handles. For example, the biggest pitch / yaw workspace was reached with the fixed hook and quadpod grasp handles. The differences between the handles were robust despite a high interpersonal variability for both the functional pitch / yaw and roll workspaces for many grasp type handles. According to these results, telemanipulator handles must be chosen carefully with respect to the target application.