Towards Safe Real-Time Robot Teleoperation: Automatic Whole-Sensitive Arm Collision Avoidance Frees the Operator for Global Control

In traditional teleoperation systems, the operator is saddled with two distinct tasks: 1) move the robot arm to its desired position, and 2) avoid obstacles that can obstruct the robot arm manipulator. To accomplish these tasks, an area of current teleoperation research is involved with providing the operator with as much input information about the task site as possible using, for example, stereo vision and feedback of contact forces. These methods presume that humans operators are capable of planning the motion for the entire body of a robot arm operating in a cluttered environment. However, studies have shown that the operators, first, cannot address both tasks in realtime, and second, are not good at generating collision-free motion. Recent results in sensor-based motion planning suggest that the collision avoidance task can be handled automatically, thus freeing the operator for global control. We propose to use for this purpose whole-sensitive arm manipulators whose whole bodies are covered with a sensitive skin sensor to detect nearby objects. The data from the sensitive skin is used along with the sensor data processing and motion planning algorithms, to avoid collisions for the entire robot arm body in an unknown or time-varying environment. The result is a highly efficient, safe and robust hybrid system in which the shift of motion control between the operator and the automatic system is done transparently and in realtime. The motion of the master arm is either executed faithfully, or, to avoid collisions, is used as general guidance for the slave arm.