focus sufficient attention on the visual channel, special attention must be given to the modeling and generation of auditory and haptic images and to the needs associated with integrating the different modalities in virtual environment systems.
In many ways, research issues in teleoperation are similar to those in virtual environments. Independent of the purpose for which a system is being designed (e.g., to train an operator, to remove hazardous waste) and independent of whether the relevant environment is real or virtual, both are concerned with the design, construction, and application of multimodal, immersive systems that enable the operator to interact usefully with some structured environment. Because of these similarities and the relatively long history of research in the teleoperation area, results in teleoperation can be usefully exploited in the virtual environment area. Concerns unique to teleoperator systems relate to the design and performance of the complex electromechanical systems referred to as telerobots and the unavoidable time delays that arise in communicating between the human-machine interface and the telerobot when these subsystems are separated by large distances. Such communication delays can result in degraded or unstable teleoperator performance.
Improved teleoperator systems require improved control algorithms and methods for constructing and using predictive displays and for realizing effective supervisory control techniques as strategies for combatting communication time delays. Hardware requirements include: (1) multiaxis, high-resolution tactile sensors to provide telerobots with an adequate sense of touch; (2) robot proximity sensors for local guidance prior to grasping, (3) multiaxis force sensors to measure net force and torque exerted on end effectors, (4) improved actuator and transmission designs for high-performance joints, and (5) real-time computational architectures. Also, since many new problems arise when a human is interfaced to a microtelerobot, research is needed to capitalize on the advances now being made in the field of microelectromechanics. Similarly, research is needed to explore possibilities and problems associated with the development and application of distributed telerobots (macro and micro).
Communication networks have the potential to transform virtual environments into shared worlds in which individuals, objects, and processes interact without regard to their location. In the future, such networks