M any people have longed to project themselves to a remote environment—one where they have the sensation of existing in a different place—while actually remaining where they are. Another dream involves amplifying human muscle power and sensing capabil- ities with machines while reserving human dexterity through a sensation of direct operation. In the late 1960s, General Electric proposed a research and development program to develop a pow- ered exoskeleton that a person would wear like a gar- ment, called Hardiman. The concept was to wear the Hardiman exoskeleton and command a set of mechan- ical muscles that would multiply human strength by a factor of 25. In this union of human and machine, the subject would feel objects and forces almost as if in direct contact with them. However, the project failed for a cou- ple of reasons. First was the potentially dangerous effects of wearing a powered exoskeleton should it mal- function. Second, space inside the machine was needed to store computers, controllers, actuators, and the ener- gy source, which eliminated the space for a human operator. Thus, the design proved impractical in its orig- inal form. With the advent of science and technology, however, the realization of these dreams again becomes possible with a different concept. Telexistence The concept of projecting ourselves using robots, computers, and a cybernetic human interface is called telexistence (tele-existence). This concept expands to include projection in a remote real world or telexisting in a computer-generated virtual environment. Figure 1 illustrates the concept. The telexistence concept I proposed in the 1980s played the principal role in the eight-year Japanese National Large-Scale Project “Advanced Robot Technology in a Hazardous Environment.” That project started in 1983, along with the concept of third- generation robotics, and ultimately established sys- tematic design procedures for telexistence systems. As part of the project, experimental hardware telexis- tence systems have developed and their conceptual fea- sibility demonstrated. I participated in the project at the Mechanical Engineering Laboratory (MEL) in Tsukuba Susumu Tachi University of Tokyo 0272-1716/98/$10.00 © 1998 IEEE Real-time Remote Robotics— Toward Networked Telexistence ______________________ Editors: Lawrence J. Rosenblum and Michael R. Macedonia 6 November/ December 1998 Sensory information Sensory information Control information Control information Realistic display • Visual, auditory, tactile, palatal, olfactory • Kinesthetic To another telexistence syst em To another telexistence syst em Real environment Surrogate robot Interaction Interaction Real-virtual matching Virtual human Sensor fusion Estimation of human intent Computer Virtual environment Measurement of human status • Motion • Voice • EEG • ECG • EMG • Blood pressure • Pulse • Perspiration • Respiration • Head • Eyeballs • Upper limbs • Lower limbs • Trunk External Internal Another virtual human Another robot 1 Diagram of a telexistence system. Projects in VR .