A system for exhaustively inspecting a workpiece, not merely certain features, is presented. The system is based on comparing a volumetric representation of a reference object to a volumetric representation of an actu...
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A system for exhaustively inspecting a workpiece, not merely certain features, is presented. The system is based on comparing a volumetric representation of a reference object to a volumetric representation of an actual object iteratively created from sensor data. The use of volumetric representations gives this approach a number of distinct advantages over the more traditional boundary-based inspection methods. The method is capable of handling arbitrarily complex geometries and does not rely on the identification of features. It lends itself naturally to a multisensor environment, and facilitates true 3-D inspection as opposed to methods that require dimensional reductions of data by projection onto a 2-D plane. The authors focus on an important aspect of volumetric inspection which is the automatic generation of a sequence of sensor operations that will acquire the complete geometry of the object being inspected.< >
The kinematic path planning problem of a nonholonomic system can be posed as a point-to-point control problem of a nonlinear system. This system has the property that it is not locally stabilizable but is globally con...
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The kinematic path planning problem of a nonholonomic system can be posed as a point-to-point control problem of a nonlinear system. This system has the property that it is not locally stabilizable but is globally controllable. In this paper, we present a new algorithm for constructing a feasible path between specified initial and final configurations. Polyhedral constraints in both configuration and non-configuration spaces (possibly non-convex) can also be incorporated in this framework. The algorithm is based on the assumption that the system is usually controllable about a non-trivial trajectory, which is true for many cases. An initial trajectory is iteratively warped until the desired final configuration is reached. Examples of a front-wheel driven car, and tractors with one, two, and three trailers are included to illustrate the efficacy of the proposed algorithm.
The principle of a simple acoustic sensor system using three Polaroid transducers which can identify a plane, an edge, and a corner is discussed. Vector analysis of reflections involving one, two, and three mirror-lik...
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The principle of a simple acoustic sensor system using three Polaroid transducers which can identify a plane, an edge, and a corner is discussed. Vector analysis of reflections involving one, two, and three mirror-like orthogonal surfaces is presented. An algorithm to distinguish a corner from an edge using the triangular three-transceiver system is described, and computer simulated results are given.< >
The authors present a knowledge-based image description system that uses fractal features. A knowledge-based recognition process is incorporated in this natural scene description system to enhance the capability of na...
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The authors present a knowledge-based image description system that uses fractal features. A knowledge-based recognition process is incorporated in this natural scene description system to enhance the capability of natural scene understanding. The scene description system is based on a fractal model. The fractal model provides useful information. A set of fractal features was developed from the fractal model which can effectively be used in image segmentation. After an image is divided into many regions based on fractal features, the scene information is derived with a knowledge-based scene recognition process. The structure of this system and its interaction strategy for the extraction of scene description are presented. The experimental results are also discussed.< >
The reduction of the state space of generalized stochastic Petri net (GSPN) models is discussed. For a certain class of GSPNs it is possible to analyze subnets in isolation by keeping the number of tokens in the net c...
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The reduction of the state space of generalized stochastic Petri net (GSPN) models is discussed. For a certain class of GSPNs it is possible to analyze subnets in isolation by keeping the number of tokens in the net constant. The authors construct a flow equivalent net (FEN), which has the same temporal and input/output properties of the original net, but with a strongly reduced state space. The FEN is substituted back into the complement of the original net.< >
A parallel-jaw type multiple-d.o.f. robot hand is designed and implemented to manipulate workpieces within the hand by rotation and translation. An efficient manipulator control algorithm and part mating application i...
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A parallel-jaw type multiple-d.o.f. robot hand is designed and implemented to manipulate workpieces within the hand by rotation and translation. An efficient manipulator control algorithm and part mating application is developed. A simulation result is also presented to show the changes of force during part insertion to verify the models developed.< >
Dynamic segmentation is a method for improving the performance of cooperating tasks executed on loosely coupled multiprocessors. Four different data transfer techniques that can be used for intersegment data transfers...
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Dynamic segmentation is a method for improving the performance of cooperating tasks executed on loosely coupled multiprocessors. Four different data transfer techniques that can be used for intersegment data transfers in dynamically segmented buses are analyzed. Preemptive data transfers are considered for uniform message latencies and results are provided for message latency comparisons using various locality factors. These results indicate dynamic segmentation improves performance considerably, at a fraction of the cost of more complex interconnection networks such as multiple buses.< >
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