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At the request of a consortium of federal government agencies, the Committee on Virtual Reality Research and Development was established to provide guidance and direction on the allocation of resources for a coordinated federal program in the area of virtual reality. In responding to this charge, the committee has included both virtual environments and teleoperation in its assessment of the field.
This report includes recommendations and extensive background material concerning systems popularly referred to by such terms as virtual reality,1 cyberspace, virtual environments, teleoperation, telerobotics, augmented reality, and synthetic environments. In all such systems, the basic components are a human operator, a machine, and a human-machine interface linking the human operator to the machine.
In a teleoperator system, the machine is an electromechanical tool containing sensors and actuators (i.e., a telerobot) that effectively extend the operator's sensorimotor system and thereby allow him or her to sense and manipulate the real environment in new ways. In a virtual environment (VE) system, the machine is an appropriately programmed computer
At the request of a consortium of federal government agencies, the Committee on Virtual Reality Research and Development was established to provide guidance and direction on the allocation of resources for a coordinated federal program in the area of virtual reality. In responding to this charge, the committee has included both virtual environments and teleoperation in its assessment of the field. Such an extension is required not only for logical and scientific reasons, but also because many of the examples cited in the charge feature the use of teleoperator systems
In a synthetic environment (SE) system, the human operator is transported into a new interactive environment by means of devices that display signals to the operator's sense organs and devices that sense various actions of the operator. In teleoperator systems, the human operator is connected by means of such displays and controls to a telerobot that can sense, travel through, and manipulate the real world. In virtual reality (VR) or virtual environment (VE) systems, the human operator is connected to a computer that can simulate a wide variety of worlds, both real and imaginary. Simple remote manipulators are an example of the first type of system; video games of the second type
Teleoperator systems effectively provide the operator with a transformed sensorimotor system that enables him or her to perform new types of actions in the real world. Virtual environment systems effectively provide the operator with controllable methods for generating new types of experiences. Using both teleoperator and virtual environment systems, one can (or will be able to) explore the ocean floor and outer space, visit Samarkand while staying in Elmira, try out products not yet manufactured, dig up a 10-ton container of hazardous waste, take a canoe trip through the human circulatory system, and have one's hair trimmed by a barber in Seville.
Scope Of The Synthetic Environment Field
The research and development required to realize the potential of SE systems is extremely challenging. The systems are complicated because they involve both complex artificial devices and a complex biological system (the human operator). There is a crucial need for cooperation among many disciplines, including computer science, electrical and mechanical engineering, sensorimotor psychophysics, cognitive psychology, and human factors. Also, the range of possible applications is exceedingly broad. Overall, the committee believes that the SE field has great potential, that the research and development required to realize this potential is just beginning, and that work in this area should be vigorously pursued by a wide variety of specialists in a wide variety of institutions
agenda, could give Japan a major competitive advantage in SE. The extent to which this advantage is actually realized will depend, at least in part, on the extent to which Japan can become a leader in the relevant computer software areas
This overview begins by presenting some basic concepts and terminology that are important in talking about virtual environments and teleoperator systems. We then present some visions of where we think the technology may be leading. The visions section differs from the rest of this report in the speculative nature of the material and in the incorporation of societal issues into the scenarios. The overview then goes on to summarize the current state of the synthetic environment (SE) field, covering application domains, knowledge about human behavior and performance, technology issues, and evaluation issues. The committee's assessment of needs and priorities completes the overview. In making these recommendations, we include consideration of the extent to which various research goals are likely to be realized without special government funding efforts or are likely to require such efforts. Similarly, we consider issues related to the infrastructure required to carry out various research and development programs
Basic Concepts And Terminology
There are currently no precise and generally accepted definitions of the terms being used in our area of interest. This is due in part, as already discussed, to the interdisciplinary nature of the field and to public relations matters. It is also due to fundamental problems of the type usually encountered in efforts to create language that faithfully reflects the structures and processes to which the language refers. For example, whereas language is fundamentally discrete, the evolutionary process by which virtual environment systems have developed from antecedent systems (such as desktop computing systems, simulators, teleoperator systems, etc.) is effectively continuous. Thus, either the definition of virtual environment systems must remain rather fuzzy, or one must set arbitrary thresholds on the complex, continuous evolutionary process
Here, we outline some of the principal defining ideas and indicate how the terms virtual environment, teleoperator, and augmented reality are related to each other and to other closely related terms such as simulator, telerobot, and robot. Our purpose is to provide background on the meaning of the terms we use in order to permit readers to understand later sections of the report. The process of creating and defining terms in this area will of course continue for many years.
A teleoperator system consists of a human operator, a human-machine interface, and a telerobot (Figure 1). Environmental signals are sensed by
sensors (cameras, microphones, etc.) located in the telerobot, transmitted to the human-machine interface, and presented to the human by means of display devices (e.g., cathode ray tubes, earphones) in the interface. Human responses, usually motor actions, are sensed by the interface and used to control the actions of the telerobot. Thus, a teleoperator system can be viewed as a system for extending the sensorimotor system of the human organism. The purpose of such a system is to facilitate the human operator's ability to sense, maneuver in, and manipulate the environment. Teleoperator systems vary along many dimensions, including the structure of the human-machine interface and the telerobot and the nature of the control algorithms.
Teleoperator systems have been used to conduct work in outer space and under the ocean; to perform a variety of tasks in connection with security, firefighting, nuclear plants, and hazardous waste removal; to assist in various types of military operations; to perform microsurgery; and to aid in the rehabilitation of individuals with severe physical disabilities. In some teleoperator systems, the human operator has direct and detailed control of all the telerobot's actions. In other systems, the human's control occurs only at a supervisory level and many of the telerobot's detailed actions are controlled locally and automatically. In the extreme, there is no human control, all actions of the telerobot are automatic and autonomous, and the telerobot is called simply a robot.
A virtual environment system (also illustrated in Figure 1) consists of a human operator, a human-machine interface, and a computer. The computer and the displays and controls in the interface are configured to immerse the operator in an environment containing three-dimensional objects with three-dimensional locations and orientations in three-dimensional space. Each virtual object has a location and orientation in the surrounding space that is independent of the operator's viewpoint, and the operator can interact with these objects in real time using a variety of motor output channels to manipulate them. The extent to which a virtual environment is designed to simulate a real environment depends on the specific application in mind.
As illustrated in Figure 1, teleoperator and virtual environment systems are similar in that they both involve human operators and elaborate human-machine interfaces. They differ however, with respect to what takes place on the nonhuman side of the interface. Whereas in a teleoperator system the interface is connected to a telerobot that operates in a master-slave or supervisory control mode in a real-world environment, in a VE system the interface is connected to a computer
Consistent with this difference in structure is the difference in purpose between the two types of systems: whereas the purpose of a teleoperator system is to sense, manipulate, and transform the state of the
Cuevadefuego
demonstrates the potential for photo-realistic visualization of a spacious
geological structure within a synthetic environment. Its bubbling lava, swinging
pendulum and burning torches illustrate the real-time application of effects
such as animation, lighting models, and reflection that commonly are only
possible in frame-by-frame rendering.
This world was developed in conjunction with the German National Research Center
for Information Technology, Sankt Augustin, Germany. It was part of their "Caveland
on Cyberstage" showcase at the CEBIT '97 Festival in Germany.
Cuevadefuego represents approximately 500 hours of labor. It was designed and
built using MultiGen II, Performer libraries, Audio Works, and Photoshop. The
18.1 megabyte database is comprised of 131,647 triangles and 46 level of detail
nodes. It is accompanied by 16.6 megabytes of textures and 13.8 megabytes of
sound. Because of this, a Silicon Graphics Power Onyx is required to obtain
desirable frame rates.
The Virtual Reality Application Center (VRAC) is an interdisciplinary research center administered by the Institute for Physical Research and Technology at Iowa State University. Our focus is the rapidly expanding interface between humans and computers.
Our research centers around developing computer interfaces that integrate virtual environments, wireless networking, pervasive computing and third generation user interface devices to amplify the creativity and productivity of people.
VRAC Fast Facts:
· Home to about $10 million in ongoing contract research for industry and government agencies.
· Research support for more than 30 faculty and over 130 graduate and undergraduate students and post docs.
· Research addresses a diverse range of challenging problems, including:
· Human computer interaction.
· Virtual prototyping.
· Real time simulations.
· Computational fluid dynamics (CFD).
To pursue this vision, VRAC and its research sponsors have made substantial investments in personnel and infrastructure. Current VRAC resources include:
· More than twenty Silicon Graphics computers.
· Five Sun graphics workstations.
· Two linux-based compute clusters totalling over 30 1GHz processors.
· The C6, the world's first fully immersive six-sided SE device with wireless tracking and navigation.
· The C4, a reconfigurable, four-sided immersive SE device with wireless tracking and navigation.
· A Barco Baron stereo workbench equipped with three-dimensional spacial tracking.
· Head mounted displays (HMDs).
Access to a 244
seat auditorium equipped for real-time passive stereo-projection of
two side-by-side simulated environments on a 29 foot wide screen.