The planning problem is considered for a mobile manipulator system which must perform a sequence of tasks defined by position, orientation, force, and moment vectors at the end effector. Each task can be performed in ...
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The planning problem is considered for a mobile manipulator system which must perform a sequence of tasks defined by position, orientation, force, and moment vectors at the end effector. Each task can be performed in multiple configurations due to the redundancy introduced by mobility. The planning problem is formulated as an optimization problem in which the decision variables for mobility (base position) are separated from the manipulator joint angles in the cost function. The resulting numerical problem is nonlinear with nonconvex, unconnected feasible regions in the decision space. Simulated annealing is proposed as a general solution method for obtaining near-optimal results. The problem formulation and numerical solution by simulated annealing are illustrated for a positioning system with five degrees of freedom. These results are compared with results obtained by conventional nonlinear programming techniques customized for the particular example system.< >
An approach to online fault detection and diagnosis in automated manufacturing systems with discrete controls and sensing is described. The approach is based on the concept of behavioural models of the individual syst...
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An approach to online fault detection and diagnosis in automated manufacturing systems with discrete controls and sensing is described. The approach is based on the concept of behavioural models of the individual system components. These models, which can be developed while the system is being designed, characterize the responses of the devices in the system to arbitrary input signals over the range of acceptable operating conditions. The expected flow of signals through the system, from control inputs to sensor outputs, is captured in the behavioural model dynamics. This model provides the basis for online fault detection by generating expected system response signals which are compared online, in real-time, to the actual sensor signals from the system. Fault diagnosis is accomplished by maintaining a current set of operational assumptions which identify the system components which could cause deviations from the expected behavior.< >
The stability of the SMM (Steiglitz-McBride method) in the underparameterized case is studied. It is shown that the offline SMM can potentially produce intermediate unstable estimates. A projection technique is introd...
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The stability of the SMM (Steiglitz-McBride method) in the underparameterized case is studied. It is shown that the offline SMM can potentially produce intermediate unstable estimates. A projection technique is introduced and analytically shown to overcome such instability. The existence of multiple stable equilibria for the SMM in the underparametrized case is demonstrated.< >
Digital processing of black and white images has received most attention during the last 25 years, and has led to various algorithms for the enhancement, smoothing, and zooming of images. Due to the decreasing cost an...
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Many image compression techniques involve segmentation of a gray level image. With such techniques, information is extracted that describes the regions in the segmented image, and this information is then used to form...
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This paper concerns the supervisory coordination and control of concurrent activities in an automated manufacturing facility. In contrast to commonly used simulation models which integrate the control policy with the ...
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This paper concerns the supervisory coordination and control of concurrent activities in an automated manufacturing facility. In contrast to commonly used simulation models which integrate the control policy with the system model, the subsystem state transition logic is represented by a class of controlled Petri nets (CPNs) with external inputs to be determined by the control synthesis algorithm. We formulate the forbidden state control problem in the CPN context and present a computationally efficient algorithm for generating maximally permissive controls which guarantee the system will avoid the forbidden states while permitting a maximal amount of flexibility in the system operation. The problem formulation and control synthesis algorithm is illustrated for an example of AGV coordination, and several classes of manufacturing control problems which can be addressed within this framework are identified.
A technique is proposed for increasing the speech intelligibility of persons with profound sensorineural hearing loss. The processing is based on a modification of the chirp-z transform that allows for nonlinear sampl...
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A technique is proposed for increasing the speech intelligibility of persons with profound sensorineural hearing loss. The processing is based on a modification of the chirp-z transform that allows for nonlinear sampling along an arbitrary contour of the z-plane. Although the theory allows the nonlinear sampling to be arbitrary, an example showing that it is appropriate for nonlinear spectrum compression to aid the hearing-impaired is given. Samples are linearly spaced along the unit circle for a specified low-frequency segment; beyond the break-point the samples are nonlinearly spaced, perhaps spiraling inward to enhance spectral peaks, with the spacing width increasing with increasing frequency following an exponential function. A standard inverse DFT of these frequency samples returns the spectrum-compressed sequence. processing of continuous speech requires windowing and processing of data in a manner similar to the short-time Fourier transform (STFT). The authors present the theoretical basis for, and development of, the algorithm.< >
Several aspects of the multidimensional problem of providing monitoring support for the debugging and performance analysis of distributed and parallel systems and parallel applications are presented. The key elements ...
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Several aspects of the multidimensional problem of providing monitoring support for the debugging and performance analysis of distributed and parallel systems and parallel applications are presented. The key elements of the solution to the problem are a formal event-action model at the process level and a layered architectural model. The application of the event-action model to the development of the abstract layered architectural model is shown, as well as a proposed implementation sketch of a nonintrusive monitor for the PASM parallelprocessing system.< >
A technique to guide landmark matching known as hopping dynamic programming is described. The location of the model in the scene is estimated with a least-squares fit. A heuristic measure is then computed to decide if...
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A technique to guide landmark matching known as hopping dynamic programming is described. The location of the model in the scene is estimated with a least-squares fit. A heuristic measure is then computed to decide if the model is in the scene. The shape features of an object are the landmarks associated with the object. The landmarks of an object are defined as the points of interest of the object that have important shape attributes. Examples of landmarks are corners, holes, protrusions, and high-curvature points.< >
A novel structure for multirate adaptive filtering with lower computational complexity and improved performance of the adaptive algorithm is introduced. It uses auxiliary subbands and a modified filter bank with decim...
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A novel structure for multirate adaptive filtering with lower computational complexity and improved performance of the adaptive algorithm is introduced. It uses auxiliary subbands and a modified filter bank with decimated subbands. It avoids the aliasing distortions encountered in critically decimated overlapping filter banks as well as the spectral gaps in nonoverlapping filter banks. The authors show that this structure has a lower computational complexity than previously reported structures. computer simulations are included showing the improvement in performance that can be achieved with the new structure operating as an adaptive line enhancer (ALE) compared with the conventional ALE.< >
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