This paper describes a new algorithm for estimating the position and orientation of objects. The problem is formulated as an optimization problem using dual number quaternious. The advantage of using this representation is that the method solves for the location estimate by minimizing a single cost function associated with the sum of the orientation and position errors and thus is expected to have a better performance on the estimation, both in accuracy and in speed. Several forms of sensory information can be used by the algorithm. That is, the measured data can be a combination of measured points on an object's surfaces and measured unit direction vectors located on the object. Simulations have been carried out on a Compaq 386/20 computer and the SiIIIUkItiOU reSUltS are analyzed.

Exact algorithms for detecting all rotational and involutional symmetries in point sets, polygons and polyhedra are described. The time complexities of the algorithms are shown to be O(n) for polygons and O(nlogn) for two-and three-dimensional point sets. O(n logn) time is also required for general polyhedra, but for polyhedra with connected, planar surface graphs O(n) time canbe achieved. All algorithms are optimal in time complexity, within constants.

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We present a haptic feedback technique that combines feedback from a portable force-feedback glove with feedback from direct contact with rigid passive objects. This approach is a haptic analogue of visual mixed reality, since it can be used to haptically combine real and virtual elements in a single display. We discuss device limitations that motivated this combined approach and summarize technological challenges encountered. We present three experiments to evaluate the approach for interactions with buttons and sliders on a virtual control panel. In our first experiment, this approach resulted in better task performance and better subjective ratings than the use of only a force-feedback glove. In our second experiment, visual feedback was degraded and the combined approach resulted in better performance than the glove-only approach and in better ratings of slider interactions than both glove-only and passive-only approaches. A third experiment allowed subjective comparison of approaches and provided additional evidence that the combined approach provides the best experience.

There is a growing need for humans to perform complex remote operations and to extend the intelligence and experience of experts to distant applications. A blending of human intelligence, modern information technology, remote control, and intelligent autonomous systems is required, and the authors have coined the term teleautonomous technology, or teleautomation, for methods for producing intelligent action at a distance. Teleautomation goes beyond autonomous control in that it blends in human intelligenge and action as appropriate. I t goes beyond teleoperation in that it incorporates as much autonomy as i s possible or reasonable. A new approach for solving one of the fundamental problems facing teleautonomous systems is discussed in detail: the need to overcome time delays due to telemetry and signal propagation. New concepts, called time and position clutches, are introduced; these allow the time and position frames, respectively, between the local user control and the remote device being controlled to be desynchronized. The design and implementation of these mechanisms are described in detail. I t is demonstrated that these mechanisms lead to substantial telemanipulation performance improvements, including the novel result of improvements even in the absence of time delays. The novel controls also yield a simple protocol for handoffs of the control of manipulation tasks between local operators and remote systems.