Virtual radar: An obstacle information display system for teleoperation

During teleoperation, when the operator's attention is focused on controlling the end-effector's motion, it is very difficult to recognize the possible link collisions. Such collisions may damage the environment or the links seriously, because usually the links have no sensors. In this paper, we propose a so-called "virtual radar" which displays the collision information related to the motion of the whole manipulator at the end-effector level. The computer checks for unreachable areas due to the presence of obstacles and displays the appropriate information mapped on the task space using 3D graphics. This would enhance the reliability of the system. When applied to a 6-DOF manipulator, the possible collision space must also be a 6-dimensional. Hence it is difficult to be visualized and comprehended by the operator. To tackle this problem, the virtual radar displays the collision information by means of a deformable sphere and various patterns on it. The effectiveness of this method has been verified by experiments with a real telerobotic system.