Flight Telerobotic Servicer: Teleoperations in Microgravity

Abstract

The Flight Telerobotic Servicer (FTS) is a dual-arm robot which will perform operations in space through manual teleoperation or autonomous control. The FTS is being designed and built by Martin Marietta Astronautics Group for NASA and will be used for aiding astronauts in assembling, servicing, maintaining, and inspecting Space Station Freedom (SSF). Robots will be an important part of SSF operations in order to limit hazardous astronaut EVA time. Some typical tasks the FTS is being designed to perform include installation/removal of structural truss elements, changeout of modular electronics packages, mate/demate of connectors, and performance of inspection tasks. FTS control stations will be located on board both the Shuttle and SSF. These workstations consist of controls/displays, video from telerobot cameras, force reflecting hand controllers, and operator restraints. Special problems which have been encountered by the ongoing human factors effort include the design of a restraint system to accommodate 5th to 95th percentile astronauts, maximizing hand controller operational envelopes in limited space, noncongruent operator, display, and teleoperation coordinate systems, and design of a human-computer interface which minimizes the amount of time the operator must release hand controllers to perform other workstation functions. Test flights for FTS have been planned for 1991 and 1993 and will allow evaluation of such issues as the biomechanics of a restrained operator using force reflecting hand controllers in microgravity, assessing effects on operator performance of various control modes, use of different translational, rotational, and force reflection gains, degrees of shared control (active compliance), and operator fatigue.