Adaptive computing Technology (ACT) represents one of the key processing technologies being investigated for advanced sensorsystems. A processor architecture study was conducted for insertion feasibility of aided tar...
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Adaptive computing Technology (ACT) represents one of the key processing technologies being investigated for advanced sensorsystems. A processor architecture study was conducted for insertion feasibility of aided target acquisition technology in military ground vehicles. Preliminary results show that with the given set of constraints, an architecture augmented with ACT was able to meet many of the insertion requirements. Key aspects of ACT learned from the study are discussed in terms of emerging advanced sensorsystems.
We give an overview of ongoing development efforts and supporting research which is evolving the United States Air Force's Airborne Warning and Control System (AWACS). AWACS is an airplane-based sensor and command...
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We give an overview of ongoing development efforts and supporting research which is evolving the United States Air Force's Airborne Warning and Control System (AWACS). AWACS is an airplane-based sensor and command and control platform with an on-board mission computing system that presents operators with sensor and other information subject to real-time quality of service requirements. The legacy mission computing system is mainframe-based and relies on a centralized, cyclic scheduling approach which makes maintenance and improvement very difficult. We briefly discuss interesting aspects of our efforts to upgrade this system to use emerging real-time distributed object technology, object management, and modern scheduling and schedulability analysis. Advance demonstrations of this upgrade have been very successful, and test flights should be underway at the time of the conference. Within this context, we give examples of technology transfer.
In a previous paper by Payeur et al. (1997), probabilistic occupancy modeling has been successfully extended to 3D environments by means of a closed-form approximation of the probability distribution. In this paper, t...
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In a previous paper by Payeur et al. (1997), probabilistic occupancy modeling has been successfully extended to 3D environments by means of a closed-form approximation of the probability distribution. In this paper, the closed-form approximation is revisited in order to provide more reliable and meaningful models. A merging strategy of local probabilistic occupancy grids originating from each sensor viewpoint is introduced. The merging process takes advantage of the multiresolution characteristics of octrees to minimize the computational complexity and enhance performances. An experimental testbed is used to validate the approach and models computed from real range images are presented.
Probabilistic occupancy grids have proved to be very useful for workspace modeling in 2D environments. Due to the expansion of computational load, this approach was not tractable for mapping a 3D environment in real a...
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Probabilistic occupancy grids have proved to be very useful for workspace modeling in 2D environments. Due to the expansion of computational load, this approach was not tractable for mapping a 3D environment in real applications. In this paper, the original occupancy grid scheme is revisited and a generic closed-form function is introduced to avoid numerical computation of probabilities for a range sensor with Gaussian error distribution. Occupancy probabilities are computed and stored in a multiresolution octree for improved performance and compactness. Occupancy models are built in local reference frames and linked to a global reference frame through uncertain spatial relationships that can be updated dynamically. This scheme is used for building a 3D map in a telerobotic maintenance application of electric power lines where perturbations may cause motion of object assembly.
In this paper, a distributed interacting multiple model (DIMM) algorithm for multi-platform multi-sensor tracking is presented, where the overall target model space is decomposed into all platforms. Each platform cont...
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ISBN:
(纸本)078033700X
In this paper, a distributed interacting multiple model (DIMM) algorithm for multi-platform multi-sensor tracking is presented, where the overall target model space is decomposed into all platforms. Each platform contains only a model subset, and interacting multiple model filtering is performed on all platforms. By exchanging some moderate filtering results through a platform communication datalink, a distributed interacting multiple model algorithm can be obtained. Since the DIMM has the advantages of distributed models and distributed measurements as well, significant computation can be saved and good performance can be achieved.
The problem of optimal data fusion in multiple detector systems is studied in the case where training examples are available, but no a priori information is available about the probability distributions of errors comm...
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The problem of optimal data fusion in multiple detector systems is studied in the case where training examples are available, but no a priori information is available about the probability distributions of errors committed by the individual detectors. Earlier solutions to this problem require some knowledge of the error distributions of the detectors, for example, either in a parametric form or in a closed analytical form. Here we show that, given a sufficiently large training sample, an optimal fusion rule can be implemented with an arbitrary level of confidence. We first consider the classical cases of Bayesian rule and Neyman-Pearson test for a system of independent detectors. Then we show a general result that any test function with a suitable Lipschitz property can be implemented with arbitrary precision, based on a training sample whose size is a function of the Lipschitz constant, number of parameters, and empirical measures. The general case subsumes the cases of nonindependent and correlated detectors.
A novel optical proximity sensor system, HexEYE, capable of measuring the distance to, the orientation of, and the curvature at a local area of object surface has been designed and evaluated for robotic application. T...
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ISBN:
(纸本)0780319656
A novel optical proximity sensor system, HexEYE, capable of measuring the distance to, the orientation of, and the curvature at a local area of object surface has been designed and evaluated for robotic application. This paper presents: 1) the implementation of distance mapping from raw data based on a multilayer backpropagation neural network; 2) the hardware and software implementation of a single sensing unit; and 3) the experimental evaluation under various surface conditions. A prototype of a single sensing unit has been built with commercially available parts.
In this paper we present an experimental evaluation of a quasi-distributed fiber-optic strain and temperature sensor system based on time division multiplexing. The system relies on an advanced dual-core fiber to whic...
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ISBN:
(纸本)0819416991
In this paper we present an experimental evaluation of a quasi-distributed fiber-optic strain and temperature sensor system based on time division multiplexing. The system relies on an advanced dual-core fiber to which a set of Fabry-Perot interferometers is introduced with fiber Bragg gratings used as weak reflectors.
The design of spatially shaped distributedsensors for the control of infinite order structural systems has become a topic of interest in recent years. sensor shape optimization techniques were developed for the desig...
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ISBN:
(纸本)0819414859
The design of spatially shaped distributedsensors for the control of infinite order structural systems has become a topic of interest in recent years. sensor shape optimization techniques were developed for the design of optimal controllers on infinite order structural systems. In this paper, we investigate methods for the implementation of distributedsensors using polyvinylidene flouide (PVDF) film. The complexity of the sensor shapes depends on the mode shapes of the flexible structure and the performance measure of the controllers. The sensitivity of the sensor shape on the performance of the controller is being investigated. The problems associated with the practical implementation of distributedsensors with PVDF film are also identified. The shapes of the distributedsensors for the implementation of a linear quadratic regulator (LQR) and a pole- placement controller have been determined. These sensors are implemented on simple cantilever beam test articles using PVDF film. The details of hardware implementation of the controllers are presented. The closed loop performance of the controllers are compared with simulation studies. The sensitivity of the shapes of the distributedsensors for the LQR and pole-placement controllers is discussed.
Recent structural failure and damage associated with earthquakes and pipeline failures have underscored the need for structural integrity monitoring systems using distributed fiber optic sensors. Such sensors must be ...
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ISBN:
(纸本)0819417009
Recent structural failure and damage associated with earthquakes and pipeline failures have underscored the need for structural integrity monitoring systems using distributed fiber optic sensors. Such sensors must be low-cost, easily installed on new and existing structures, allow rapid assessment of structural integrity, and be capable of surviving and sensing large displacements associated with cracks and deflections in structural members. Experimental results for multimode fiber crack detection sensors based on the orientation angle approach are reported for both longitudinal and transverse crack displacements. In addition, we report results on a novel all-fiber sensor capable of sensing submillimeter cracks while surviving and sensing larger than 100% strains and cm level displacements.
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