Telecommunication and remote-controlled operations are common in our daily lives. While performing these operations, users want to have a feeling of being present on site and directly performing jobs that they would like to do, instead of controlling them remotely. However, the present commercially available telecommunication systems and/or telepresence systems do not provide the sensation of self-presence or self-existence, and hence, users do not get the feeling of being present or existing in remote places. Moreover, these systems do not provide haptic sensation, which is necessary for the direct manipulation of remote operations, resulting in not only the lack of reality, but also difficulty in performing tasks.

Prof. Tachi and his team have been working on telexistence, in which the aim is to enable a human user to have the sensation of being present on site, and to perform tasks as if he is directly performing them there. By using a telexistence master-slave system, the human user can have a feeling of being present in a remote environment or have a sensation of self-existence or self-presence in the remote environment, and would be able to perform tasks directly as though he is present there. The telexistence master–slave system is a virtual exoskeleton human amplifier, by which a human user would be able to operate a remote avatar robot as if it is his or her own body; he or she can have the feeling of being inside the robot or wearing it as a garment.

The concept of telexistence was invented by Dr. Susumu Tachi in 1980, and it was the fundamental principle of the eight-year Japanese national large-scale "Advanced Robot Technology in Hazardous Environment" project, which began in 1983, together with the concept of third generation robotics. Theoretical considerations and the systematic design procedure for telexistence systems were established through the project. Since that time, experimental hardware for the telexistence systems have been developed, and the feasibility of the concept has been demonstrated.

Two important problems that remained to be solved are mutual telexistence and haptic telexistence. Mutual telexistence is a telexistence system that can provide the sensations of both self-presence and their presence, and is used mainly for communication purposes, while haptic telexistence adds haptic sensation to the visual and auditory sensations of self-presence, and is used mainly for remote operations of real tasks.

Recent advancements in telexistence have partly solved the above problems. TELESAR II (telexistence surrogate anthropomorphic robot version II) is the first system that provided the sensations of both self-presence and their presence for communication purpose using RPT (retroreflective projection technology). For remote operation purposes, Prof. Tachi and his team have developed a telexistence master-slave system named TELESAR V, which can transmit not only visual and auditory sensations, but also haptic sensation. Haptic sensation is displayed based on the principle of haptic primary colors.


(Revised from Susumu Tachi,"Telexistence: Enabling humans to be virtually ubiquitous," Computer Graphics and Applications, vol. 36, No.1, pp.8-14, 2016.)