Recent years has seen much progress in the theory and application of iterative learning control schemes for both linear and (classes of) nonlinear dynamics. In the case of the former, many algorithms based on minimizi...
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Recent years has seen much progress in the theory and application of iterative learning control schemes for both linear and (classes of) nonlinear dynamics. In the case of the former, many algorithms based on minimizing a suitable cost function have been reported. Here the interest is in the so-called norm optimal approach where the basic philosophy is to compute the control input on the current trial such that the tracking error is reduced in an optimal way without too much deviation from the control input used on the previous trial. This paper compares the performance of a range of controllers arising from use of the norm optimal approach - both stand alone and against alternatives.
The Object Oriented control Architecture for Autonomy (O 2 CA 2 ) is a control architecture being developed at the University of Girona for the GARBI underwater vehicle. Conceived as a hybrid, it is organised in three...
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The Object Oriented control Architecture for Autonomy (O 2 CA 2 ) is a control architecture being developed at the University of Girona for the GARBI underwater vehicle. Conceived as a hybrid, it is organised in three layers (Deliberative, control Execution and Reactive) merging the deliberation mechanisms of planning with reactive behaviours in charge of controlling the robot. The aim of this paper is to provide an overall description of the whole architecture and an in depth description of the Reactive-layer. The concepts of the architecture have been tested with the simulation of a simple mission consisting of navigating through a sequence of way-points while avoiding contact with obstacles.
Mosaics have been commonly used as visual maps for undersea exploration and navigation. The position and orientation of an underwater vehicle can be calculated by integrating the apparent motion of the images which fo...
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ISBN:
(纸本)0780365763
Mosaics have been commonly used as visual maps for undersea exploration and navigation. The position and orientation of an underwater vehicle can be calculated by integrating the apparent motion of the images which form the mosaic. A feature-based mosaicking method is proposed in this paper. The creation of the mosaic is accomplished in four stages: feature selection and matching, detection of points describing the dominant motion, homography computation and mosaic construction. In this work we demonstrate that the use of color and textures as discriminative properties of the image can improve, to a large extent, the accuracy of the constructed mosaic. The system is able to provide 3D metric information concerning the vehicle motion using the knowledge of the intrinsic parameters of the camera while integrating the measurements of an ultrasonic sensor. The experimental results of real images have been tested on the GARBI underwater vehicle.
New filter class for multichannel image processing is introduced and analyzed. The new technique of image enhancement is capable of reducing impulsive and Gaussian noise and it significantly outperforms the standard m...
New filter class for multichannel image processing is introduced and analyzed. The new technique of image enhancement is capable of reducing impulsive and Gaussian noise and it significantly outperforms the standard methods of noise reduction. In the paper a smoothing operator, based on a random walk model and a fuzzy similarity measure between pixels connected by a digital geodesic path is introduced. The efficiency of the proposed method was tested on the standard color images using the objective image quality measures. Obtained results show that the new method not only outperforms standard noise reduction algorithms, but has some interesting features useful for segmentation of noisy color images.
Analysis of complex systems such as hierarchically structured network systems that are employed in modelling and analysis various aspects and issues of control and management in telecommunications is investigated. The...
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The aim of the work is to determine the best landmark for its use in tasks such as precise positioning of AGVs or mobile robots in front of loading/unloading areas. The work developed aims at determining the precision...
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ISBN:
(纸本)0780365763
The aim of the work is to determine the best landmark for its use in tasks such as precise positioning of AGVs or mobile robots in front of loading/unloading areas. The work developed aims at determining the precision that can be achieved with different pattern landmarks, of use in positioning systems, based on computer vision. Different computer vision algorithms have been tested from the images acquired from different camera configurations and bending angles with respect to the vertical axis. As a result of the evaluation of these errors, we extract the recommendation of the most favourable bicolour pattern to be used, as well as the bounding errors obtained from the segmentation and recognition methods most frequently used.
Bluetooth is currently emerging as one of the most promising personal wireless network technologies. The automation industry is also showing interest in using Bluetooth for more industrial applications. However, probl...
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Bluetooth is currently emerging as one of the most promising personal wireless network technologies. The automation industry is also showing interest in using Bluetooth for more industrial applications. However, problems with unreliable links and time delays must be explicitly addressed in any wireless control application. This paper discusses two specific problems that may occur when using Bluetooth in a control loop: long random delays and bit errors. Simple solutions to these problems are presented. The ideas have been tried out, both in simulations and in experiments, on a rotating inverted pendulum controlled over a Bluetooth network.
Repetitive processes are a distinct class of 2D systems of both theoretical and applications interest. They are characterized by a series of sweeps through a set of dynamics with explicit interaction between the outpu...
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Repetitive processes are a distinct class of 2D systems of both theoretical and applications interest. They are characterized by a series of sweeps through a set of dynamics with explicit interaction between the outputs, or pass profiles, produced on successive passes. Their essential unique features are that (i) information propagation is over a finite duration in one of the two separate directions of information propagation; and (ii) the explicit interaction between successive pass profiles can lead to oscillations in the sequence of pass profiles that increase in amplitude in the pass to pass direction. In the case of processes with linear dynamics (either differential or discrete) a reasonably rich systems theory is available for models which are standard (or nonsingular). In this paper, we provide the first substantial results on discrete linear repetitive processes described by a singular state space model.
This paper presents a method of enhancing the execution time of a processor in implementing signal processing and control algorithms, through a process of minimisation of memory access time of the processor. The metho...
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This paper presents a method of enhancing the execution time of a processor in implementing signal processing and control algorithms, through a process of minimisation of memory access time of the processor. The method is based on the design and corresponding software coding of an algorithm, and thus can be adopted for a variety of real-timesignal processing and control applications. The finite difference simulation algorithm ofa flexible beam is considered to demonstrate the effectiveness of the proposed method. The algorithm is implemented on a general-purpose computing platform, and a comparative performance evaluation of the processor with the proposed method is presented and discussed.
This paper presents a software tool suitable for dynamic system modelling. The models generated by this tool are modular neural networks, see (Sharkey, 1999). Each module behaves like a functional block and is connect...
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This paper presents a software tool suitable for dynamic system modelling. The models generated by this tool are modular neural networks, see (Sharkey, 1999). Each module behaves like a functional block and is connected to the other modules like in classical block diagrams. This tool allows the inclusion of a priori knowledge and, furthermore, to extract physical information from the models, once the system has learned. The modelling tool is capable of automatic model generation, parameter estimation and model validation.
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