Advanced Teleoperation Technology

The capability to remotely, robotically perform space assembly, inspection, servicing, and science functions would rapidly expand our presence in space, and the cost efficiency of being there. There is thus considerable interest in developing "telerobotic" technologies, which also have comparably important terrestrial applications to health care, underwater salvage, nuclear waste remediation and other. Such tasks, both space and terrestrial, require both a robot and operator interface that is highly flexible and adaptive, i.e., capable of efficiently working in changing and often casually structured environments. One systems approach to this requirement is to augment traditional teleoperation with computer assists -advanced teleoperation. We have spent a number of years pursuing this approach, and highlight some key technology developments and their potential commercial impact. This paper is an illustrative summary rather than self-contained presentation; for completeness, we include representative technical references to our work which will allow the reader to follow up items of particular interest. A BRIEF TECHNICAL OVERVIEW Telerobotics technology development [ 1] is motivated by a desire to remotely perform complex physical tasks under human supervisory control. To date, robotic systems that have embodied significant supervisory (autonomous) control of their manipulation functions have been limited to highly structured tasks that were performed under favorable and certain conditions -by definition not complex tasks, and not adaptive performance. This has fostered the widespread use of teleoperation, which at the other extreme from automation, is a characteristically laborious manual control procedure, historically applied to hazardous environments such as nuclear materials handling, underseas recovery, and recently, space shuttle operations. Virtual environments and virtual reality (VR) engineering are related and currently popular areas of technology development, wherein the human operator directly manipulates or experiences a modeled, rather than physical reality via computer-synthesis and appropiate input/output devices (e.g., master control gloves/stereo-immersive displays). There exists an important technical intersection of VR technology with telerobotics, most specifically with teleoperation: Virtual environments are useful tools for simulation and design, including task analysis, training, and on-line task preview and prediction. Thus, if VR can be efficiently integrated and physically calibrated with teleoperation systems, it has promise to assist the operator's on-line perception, planning, and control functions. With regard to space applications, teleoperation systems could have important near-term roles in remote platform servicing, telescience, and lunar exploration, as already illustrated in Shuttle STS-RMS operations. However, the physical and logistical demands of space telemanipulation, particularly in less structured environments, will be high. Tasks can be physically complex and time-consuming, and the operator's manual dexterity and hand-to-eye motion calibration must be good. Further, the work will often be conducted under degraded observational conditions and thus be tedious and fatiguing. Operational uncertainties include obstructed viewing and manipulation, as well as the very disorienting effects of possible time-delay between the operator inputs and robot actions (a major obstacle to achieving desirable ground versus on-orbit operations). In the face of these cdllective challenges (which have their metaphors in other applications areas such as minimally invasive medical robotics and deep sea teleoperations), we have been trying to "computer-enhance" the performance of traditional teleoperation, and have made progress in the technical areas of redundant telemanipulator control, viewing s'ystems, real-time graphics-based task simulation and predictive control, integrated operator interface design, systems-scale ground laboratory experiments and accompanying human factors data collection & analysis. The laboratory photographs of the next page give a sense of our system implementation; we comment below on our specific enabling technical advances (with supporting citations). For the reader seeking a detailed engineering overview of this work through end-1991, see reference [2]