Immersive virtual environment (WE) technology has great promise as a tool for basic experimental research in psychology. NE technology gives participants the experience of being surrounded by the computer-synthesized environment. We begin with a discussion of the various devices needed to im-plement immersive virtual environments, including object manipulation and social interaction. We re-view the benefits and drawbacks associated with virtual environment technology, in comparison with more conventional ways of doing basic experimental research. We then consider a variety of examples of research using IVE technology in the areas of perception, spatial cognition, and social interaction. Human history records a progression of artifacts for representing and recreating aspects of external reality, ranging from language, drawings, and sculpture in earlier times to the more modern artifacts of photographs, movies, television, and audio recordings. Relatively recently, the digital computer and its associated technologies, includ-ing three-dimensional (3-D) graphics, have given rise to increasingly realistic artifacts that blur the distinction be-

The field of view (FOV) in most head-mounted displays (HMDs) is no more than 60 degrees wide -- far narrower than our normal FOV of about 200 wide. This mismatch arises mostly from the difficulty and expense of building wide-FOV HMDs. Restricting a person's FOV, however, has been shown in real environments to affect people's behavior and degrade task performance. Previous work in virtual reality too has shown that restricting FOV to 50 or less in an HMD can degrade performance. I conducted experiments with a custom, wide-FOV HMD and found that performance is degraded even at the relatively high FOV of 112, and further at 48. The experiments used a prototype tiled wide-FOV HMD to measure performance in VR at up to 176 total horizontal FOV, and a custom large-area tracking system to establish new findings on performance while walking about a large virtua...

Human users of virtual environments (VE) are disturbed by system latency

Eight subjects ’ abilities to detect changes in system latency during voluntary lateral hand movement of virtual objects were studied in an immersing virtual environment. A two-alternative forced choice procedure was used in which discrimination of latency was studied with respect to three reference latencies: 27, 94, and 194 msec. Results show that subjects are able to reliably detect changes definitely less than 33 msec and probably less than 16.7 msec. Strikingly, for the short latencies we examined, subjects ’ ability to detect latency changes does not depend upon the base latency we used as a reference. Thus, the discrimination we studied does not appear to follow Weber’s law and may provide evidence for quick adaptation to the reference latencies used.

This paper describes experimental studies conducted using a pneumatically driven haptic interface (PHI) system. The PHI is a unilateral exoskeletal device that tracks the motion of the shoulder and elbow. The study was carried out to evaluate the impact of an exoskeletal haptic interface on human perceptional capabilities. A population of twenty subjects participated in a set of experiments that were tailored to assess force sensation, shape perception, and effect of force feedback in task performance. Using Weber fractions, we contrasted the outcome of our force sensation experiments against results reported by psychophysical researchers. The results indicated that the perception of weight (or force magnitude) through the haptic interface was significantly affected for relatively low reference force levels (4.44 N, Weber fraction 5 0.5). The effect progressively diminished as the force level was increased, and almost matched the natural human capabilities for a reference force level of 18 N (Weber fraction 5 0.06). The haptic shape identification experiments showed that the subjects were able to identify various shapes using the PHI system (1 5 0.3 m reference length, with Weber fraction 5 0.38). This identification, however, was adversely affected by the lack of tactile sensation in the haptic device. The outcome of the force-feedback experiments demonstrated mixed results, an observation that was consistent with experimental studies of other researchers. While force feedback did not affect the time needed to complete the task, the subjects' performance was significantly improved when the experiments involved controlling the thickness of a curve drawn on a pressure-sensitive tablet. 1

Exploratory Studies on the Sense of Presence as a Function of Visual and Auditory Display Parameters in Virtual Environments by Claudia Mary Hendrix Chairperson of the Supervisory Committee: Professor Woodrow Barfield Department of Industrial Engineering The focus of this research was to develop subjective measures of presence in order to relate the amount of presence experienced within a virtual environment to visual and auditory display parameters. Furthermore, the research examined the relationship between presence and performance in spatial judgments. To accomplish this goal three experiments were performed; the first two experiments investigated virtual presence as a function of auditory and visual display parameters used to design virtual environments while the third study investigated presence as a function of performance measures and visual display parameters. The first experiment investigated the sense of presence within virtual environments as a function of visual display parameters while the second investigated the effect of auditory display parameters. The variables for the first experiment included the presence or absence of head tracking, the presence or absence of stereoscopic cues, and the geometric field of view (GFOV) used to design the visual display. The variables for the second experiment included the presence or absence of spatialized sound to a stereoscopic virtual environment display and the addition of spatialized versus non-spatialized sound to a stereoscopic virtual environment display. Subjects were required to navigate a virtual environment and to complete a questionnaire designed to ascertain the level of presence experienced by the participant within the virtual world. The results indicated that the reported level of presence was significa...

Application by

Abstract. The COTESYS cluster of excellence a investigates cognition for technical systems such as vehicles, robots, and factories. Cognitive technical systems (CTS) are information processing systems equipped with artificial sensors and actuators, integrated and embedded into physical systems, and acting in a physical world. They differ from other technical systems as they perform cognitive control and have cognitive capabilities. Cognitive control orchestrates reflexive and habitual behavior in accord with longterm intentions. Cognitive capabilities such as perception, reasoning, learning, and planning turn technical systems into systems that “know what they are doing”. The cognitive capabilities will result in systems of higher reliability, flexibility, adaptivity, and better performance. They will be easier to interact and cooperate with.

Tracking has proven a difficult problem to solve accurately without limiting the user or the application. Vision-based systems have shown promise, but are limited by occlusion of the landmarks. We introduce a new approach to vision-based tracking using structured light to generate landmarks. The novel aspect of this approach is the system need not know the 3D locations of landmarks. This implies that motion within the field of view of the camera does not disturb tracking as long as landmarks are reflected off any surface into the camera. This dissertation specifies an algorithm which tracks a camera using structured light. A simulator demonstrates excellent performance on user motion data from an application currently limited by inaccurate tracking. Further analysis reveals directions for implementation of the system, theoretical limitations, and potential extensions to the algorithm. The term augmented reality (AR) has been given to applications that merge computer graphics with ima...

Note: the formatting of this document is different from the manuscript and from the book. Final draft end May 2000