Well known collision avoiding approaches used in automatic robot path planning are also applied in teleoperation systems when moving in hazardous environments. In such cases, it is very useful to define forbidden zones in order to avoid dangerous situations for both the equipment and the operator. An efficient collision detection algorithm, based on the generation of virtual forces, which avoids dangerous situations in teleoperated robots, is presented. Whenever the operator moves the robot to a predefined forbidden zone, the algorithm will generate a virtual force on the human operator arm in real time, not allowing the operator to keep further with the movement. The algorithm has been successfully applied to a robot system for live-line maintenance (ROBTET) substituting the time consuming operation of the placement of insulated covers by a software protection. By this approach, short-cuts and any unwanted collision are immediately avoided.

Outage-free maintenance of electrical power lines has been conducted throughout the years in order to fulfil the increasing demand of uninterrupted power supply. In these techniques care regarding electric shock and falls must be exercised while the work is performed on or near energized elements. In order to increase the safety and comfort of the workers as well as the overall efficiency, a teleoperated system for live-line maintenance, called ROBTET, has been developed for the electrical utility IBERDROLA. ROBTET is described in detail in the paper. It has two hydraulic-driven master-slave teleoperated manipulators on top of an insulated boom over a truck. The operator commands the manipulators from a cabin on the truck via a pair of master arms, while he receives visual feedback through a vision system. Multimedia display, voice commands, stereo vision and force-feedback are some of the new features implemented in order to achieve the required telepresence of the operator and hence increase the performance of the system.