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.
A complete dynamic model of mobile vehicles moving on nonplanar surfaces under nonholonomic and dynamic constraints is presented. The kinematic control of such systems is examined, and the invariant manifold technique...
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A complete dynamic model of mobile vehicles moving on nonplanar surfaces under nonholonomic and dynamic constraints is presented. The kinematic control of such systems is examined, and the invariant manifold technique is introduced for steering a nonholonomic mobile vehicle to an invariant manifold which is relatively locally-locally controllable. A closed-loop control strategy based on the invariant manifold technique is formulated and applied to the control of nonholonomic vehicles. Tracking control of such vehicles is demonstrated with both holonomic and nonholonomic reference trajectories.< >
Expert systems and neural networks are new tools for the control of fermentation processes. With expert systems the fermentation plant and the process itself is modelled via a generalized, qualitative system descripti...
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Expert systems and neural networks are new tools for the control of fermentation processes. With expert systems the fermentation plant and the process itself is modelled via a generalized, qualitative system description based on the experience of human experts. On the other hand neural networks and interpolating associative memories can learn the process behaviour directly by process observation. The paper at hand reports, how both control techniques can be combined for purposes like process supervision, modelling and optimization of biological plants.
A technique for the calibration of an active camera system is presented. The calibration of manipulator, camera-to-manipulator, camera, and base-to-world is treated in a unified and elegant way. In this approach, the ...
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A technique for the calibration of an active camera system is presented. The calibration of manipulator, camera-to-manipulator, camera, and base-to-world is treated in a unified and elegant way. In this approach, the camera frames and manipulator link frames are all related to the world frame, therefore the camera-to-manipulator and base-to-world calibration is very straightforward. The approach is simple, since it uses the form of one equation solving one parameter. Two experiments that verify the accuracy of the technique are reported.< >
Computer Integrated Manufacturing (CIM) systems having determining role in the modern industry. These systems contain essentially two different equipments for transporting materials between workstations: - conveyors c...
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A novel approach to obstacle detection using optical flow without recovering range information has been developed. This method can be used for ground vehicles to navigate through man-made roadways or natural outdoor t...
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A novel approach to obstacle detection using optical flow without recovering range information has been developed. This method can be used for ground vehicles to navigate through man-made roadways or natural outdoor terrain or for air vehicles to land on known or unknown terrain. A linear relationship, plotted as a line and called a reference flow line, has been found. This reference flow line can be used to detect discrete obstacles above or below the reference terrain. Slopes of surface regions are also computed. The approach is simple, fast, and robust because: (1) the only required information is one component of the optical flow, (2) each image line can be processed in parallel, and (3) the error sources involved are reduced to a minimum. An initial experiment using noisy synthetic data is also included to demonstrate the applicability and robustness of the method.< >
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