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Telepresence is a sophisticated form of robotic remote control in which a human operator has a sense of being on location so that the experience resembles virtual reality (VR). The remotely-controlled robot (or telechir) and the human operator can be located at a great distance from each other. Control and feedback are done by telemetry over wires, optical fibers, wireless links or the Internet.
In a telepresence system, the telechir is often a humanoid robot, also known as an android. The control station can consist of a full body suit that the user wears. Sensors detect, and transducers reproduce, sensations of vision and sound. In some systems, tactile sensing is also possible (this is called haptics). The user wears headgear with a display and headphones that reproduce scenes and sounds as they appear at the site of the telechir. Binocular machine vision allows a sense of depth. Binaural machine hearing facilitates the perception of sounds with a sense of loudness and direction. The telechir may have one or two arms with end effectors (grippers) resembling human hands. In haptic systems, the user wears data gloves.
Applications of telepresence include working in extreme heat or cold, high or low pressure, and in other conditions hazardous to human life. Telepresence might be used to disarm bombs, handle toxic materials, and conduct dangerous military missions. Telepresence has been suggested as a method of performing surgery by remote control, and as a method of performing nanoscale operations by scaling down the telechir by a factor of thousands or millions.
One serious problem with long-distance telepresence is the fact that data and control signals cannot travel faster than the speed of light in free space. This limits the practical distance over which telepresence can be maintained without excessive latency. Another problem is posed by the level of precision with which detection and perception take place. Exceptional image resolution, sound perception and haptics require large amounts of bandwidth for signal transmission.