We present a texture analysis algorithm based on perceptual features. A specific architecture has been developed in order to implement texture features extraction which is low cast, easy-to-implement and reprogrammabl...
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We present a texture analysis algorithm based on perceptual features. A specific architecture has been developed in order to implement texture features extraction which is low cast, easy-to-implement and reprogrammable depending on the vision system conditions. We apply our algorithm in detection and tracking of submarine cable where underwater vehicles control requires high speed in visual information treatment.
We present the implementation of an architecture for the distributed control of an omnidirectional mobile robot driven by stepper motors. We have developed the kinematic modelling of such a robot from which control an...
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We present the implementation of an architecture for the distributed control of an omnidirectional mobile robot driven by stepper motors. We have developed the kinematic modelling of such a robot from which control and sensor equations are derived. These relations permit us to map in time, movements with respect to a fixed floor frame into wheels movements, and vice versa. A hierarchical control model has been selected for real time computation of control algorithm and parallel synchronisation of motors movement. It consists on a low cost specific hardware which includes one master processor (a PC) plus three slave microcontrollers (8051).
Static task scheduling in distributed computing systems is a very complex problem and known to be NP-hard. This problem is even harder when the module execution times become probabilistic. In this paper we study the e...
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Static task scheduling in distributed computing systems is a very complex problem and known to be NP-hard. This problem is even harder when the module execution times become probabilistic. In this paper we study the effect of probabilistic module execution times on the performance of task-scheduling algorithms. We show that in static task scheduling, for probabilistic module execution times, and in the existence of some factors there is no need to use an expensive task-scheduling algorithm. Given any two static task-scheduling algorithms that use deterministic module execution times in assigning task modules to the distributed system, the performance of these two algorithms will not remain the same when these module execution times become probabilistic rather than deterministic. We also study the effects of some factors an our results.
This paper studies the problem of global disturbance attenuation with stability for a class of multi-input multi-output nonlinear systems with penalty on input signal. The system under consideration is assumed to be i...
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ISBN:
(纸本)0780343948
This paper studies the problem of global disturbance attenuation with stability for a class of multi-input multi-output nonlinear systems with penalty on input signal. The system under consideration is assumed to be in a special form which is much more general than the lower triangular form, A recursive algorithm composed of backstepping and augmentation is applied to show that the global disturbance attenuation with stability can be achieved via a static state feedback.
Huge and expensive computation resources are usually required to perform graph labelling at high speed. This fact restricts an extensive use of this methodology in industrial applications such as visual inspection. A ...
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Huge and expensive computation resources are usually required to perform graph labelling at high speed. This fact restricts an extensive use of this methodology in industrial applications such as visual inspection. A new systolic architecture is presented which computes structural distances between cliques of different graphs based on a modified incremental Levenshtein distance algorithm. The distances obtained are used as a support function for graph labelling using probabilistic relaxation techniques. The proposed architecture computes the distances between k input cliques of an input graph and one reference clique of a reference graph. It does not limit the number of cliques nor cliques complexity of the input graph, so any input graph can be labelled. A low cost solution has been implemented based on FPGAs.
In this paper, an adaptive Kalman filtering algorithm is exploited for use to estimate the abrupt reduction of control effectiveness in dynamic systems. control effectiveness factors are used to quantify faults enteri...
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In this paper, an adaptive Kalman filtering algorithm is exploited for use to estimate the abrupt reduction of control effectiveness in dynamic systems. control effectiveness factors are used to quantify faults entering control systems through actuators. A set of covariance-dependent forgetting factors is introduced into the filtering algorithm. As a result, the change in the control effectiveness is accentuated to help achieve a more accurate estimate more rapidly. The algorithm is applied to an aircraft model for the identification of impairment in its control surfaces.
This paper refers to the fast implementation of the positional forward acceleration of the end effector of revolute robotic arms with spherical wrists, using the distributed arithmetic technique. The acceleration of t...
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This paper refers to the fast implementation of the positional forward acceleration of the end effector of revolute robotic arms with spherical wrists, using the distributed arithmetic technique. The acceleration of the end effector is calculated by a cascade configuration of two pipelined arrays that calculate the Jacobian matrix and its time derivative, as well as the centrifugal-Coriolis and linear accelerations. These partial accelerations are then added in the adder tree. The building blocks of the arrays are the distributed arithmetic-based circuits that implement the matrix-vector multiplications involved in the calculations. The digit-serial configuration of the proposed implementation of the positional forward acceleration of the end effector is described. The serial and the parallel configurations may result as special cases of the digit-serial configuration. The proposed distributed arithmetic (DA) implementation of the positional forward acceleration may be applied, after appropriate modifications, to the general case of robots having either revolute or prismatic joints, with any type of wrist.
Presents a methodology for autonomous navigation in weakly structured outdoor environments such as dirt roads or mountain ways. The main problem to solve is the detection of an ill-defined structure-the way-and the ob...
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Presents a methodology for autonomous navigation in weakly structured outdoor environments such as dirt roads or mountain ways. The main problem to solve is the detection of an ill-defined structure-the way-and the obstacles in the scene, when working in variable lighting conditions. First, we discuss the road description requirements to perform autonomous navigation in this kind of environment and propose a simple sensors configuration based on vision. A simplified road description is generated from the analysis of a sequence of color images, considering the constraints imposed by the model of ill-structured roads. This environment description is done in three steps: region segmentation, obstacle detection and coherence evaluation.
Object-oriented database systems aim at meeting the data modelling, performance, cooperative design and version management requirements of current advanced applications, such as CAD (computer-aided design), CAM (compu...
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Object-oriented database systems aim at meeting the data modelling, performance, cooperative design and version management requirements of current advanced applications, such as CAD (computer-aided design), CAM (computer-aided manufacturing), CASE (computer-aided software engineering), CIM (computer integrated manufacturing), hypermedia and expert systems. This paper presents the ALEX Object Manager, which is a part of the ALEX object-oriented database management system that is being developed based on the ODMG-93 standard. The system decomposition and process layout are presented, some implementation problems are discussed and the current status of the system is reported.
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