Experimental validation of a two-stage method for the identification of physical system parameters from experimental data is presented. The first stage compresses the data as an empirical model and the second stage th...
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Distributed processing of measurement results poses a number of challenges. Among important requirements are security, performance, robustness and ability to withstand network failures, need for flexibility and elegan...
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ISBN:
(纸本)9781634391887
Distributed processing of measurement results poses a number of challenges. Among important requirements are security, performance, robustness and ability to withstand network failures, need for flexibility and elegance of a proposed solution. We propose a novel approach to distributed processing, which capitalises on locality of data access. We propose a distributed software architecture that leverages a flexible consistency checking engine and takes advantage of software agency features in order to meet the mentioned distributed processing requirements.
For comments by R.J. Mantz and H. De Battisa see ibid. (vol. 51, p. 736-38, June 2004) . For original paper by A. S. Hodel and C. E. Hall see ibid.(vol. 48, p. 442-51, Apr. 2001).
For comments by R.J. Mantz and H. De Battisa see ibid. (vol. 51, p. 736-38, June 2004) . For original paper by A. S. Hodel and C. E. Hall see ibid.(vol. 48, p. 442-51, Apr. 2001).
IP network has been evolving significantly in last decade. Many computers and devices have been attached to the IP network and many applications were taken place over it. One of interesting applications is building em...
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IP network has been evolving significantly in last decade. Many computers and devices have been attached to the IP network and many applications were taken place over it. One of interesting applications is building embedded control system which has connectivity to Internet. This paper explains an implementation of embedded web server with security support which becomes an example of control application over IP network. A security algorithm, TEA (tiny encryption algorithm), has been implemented in a microprocessor system together with TCP/IP stack. The microprocessor system is based on 8051 family microcontroller which serves as web server. The encryption algorithm is processed both on server and client. Therefore in clients need a plug in, which run encryption mechanism, so that they can access the embedded Web server safely.
In this paper modeling of underwater vehicle dynamics using neural networks is investigated. Extensive knowledge is available on the behaviour of underwater vehicles. However, it may prove disadvantageous to use an of...
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In this paper modeling of underwater vehicle dynamics using neural networks is investigated. Extensive knowledge is available on the behaviour of underwater vehicles. However, it may prove disadvantageous to use an off line established model of the dynamics due to the varying nature of the underwater environment. Neural networks offer interesting possibilities as they can be used to update the model of the underwater craft during deployment. The literature mainly reports on neural networks used in parallel to the whole system model. The system is thus regarded as a black box and the neural network is required to obtain the desired behaviour without any a priori knowledge. This can result in training problems due to e.g. the inclusion of time delays, necessity of larger (training) data sets and the necessity of larger networks. Rather than using one neural network to approximate a functional representing the whole dynamics, it is proposed to use several neural networks to represent certain model parameters. In this way better use of the model structure, of which detailed information is available, can be made. Some of the parameters, notably the damping parameters, are inherently varying, as they are a function of the velocity. Furthermore, at best only empirical models are available to model the damping. It may thus prove advantageous to approximate the damping using neural networks. The advantages of the proposed 'divide and conquer' approach will be demonstrated
In this paper, a novel controller for parallel-connected online uninterruptible power supplies (UPS) without control interconnections based on the droop method is presented. The control approach consists in drop the f...
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In this paper, a novel controller for parallel-connected online uninterruptible power supplies (UPS) without control interconnections based on the droop method is presented. The control approach consists in drop the frequency of every module when its output power increases, resulting in an unavoidable nominal frequency deviation. Consequently, this method in its original form is only applicable to off-line or line-interactive UPS systems. As opposed to the conventional droop method, the proposed control scheme endows proper transient response, strictly frequency and phase synchronization with the AC mains, and excellent power sharing even for nonlinear loads. Hence, this controller is suitable for paralleled online UPS systems. Experimental results are obtained from two parallel-connected 1-kVA online UPS by using TMS320LF2407A DSP.
3-D topography of objects is often obtained only on a qualitative basis by a sequential reconstruction process using segmented images obtained under different illumination conditions. The approach we present in this p...
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3-D topography of objects is often obtained only on a qualitative basis by a sequential reconstruction process using segmented images obtained under different illumination conditions. The approach we present in this paper is based on the direct segmentation and topography analysis of a topographic scene using a sequence of images obtained by varying the illumination parameters in a pre-selected format. Thereby a correlation of the grey level variations of the individual pixels with the variations of the illumination parameters is employed to achieve superior segmentation and topographical information. An advantage is that the pipeline of separate operations viz. image fusion, segmentation topographical analysis is reduced to just one direct operation. The method has been successfully applied to determine the topography of grinding surfaces in machining in manufacturing processes.
Capturing 3-D information using several 2-D images of topological 3-D objects obtained by acquiring the images under varying illumination conditions is a technique, which can be employed in manufacturing systems. The ...
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Capturing 3-D information using several 2-D images of topological 3-D objects obtained by acquiring the images under varying illumination conditions is a technique, which can be employed in manufacturing systems. The paper deals with the tasks of acquiring the images from objects with hybrid reflecting behaviour and algorithms for extracting the 3-D information and gives results obtained for a grinding tool inspection system.
This paper studies the robustness of a platoon of identical vehicles subject to decentralized control, where each control agent is assumed to only have knowledge of the distance between itself and its immediate forwar...
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This paper studies the robustness of a platoon of identical vehicles subject to decentralized control, where each control agent is assumed to only have knowledge of the distance between itself and its immediate forward neighbour. Two different types of controllers: (i) a decentralized PID controller and (ii) a decentralized robust servomechanism controller, are considered in the control of such a platoon of identical vehicles, where it is assumed that the models of the vehicles are subject to perturbation. In this case two types of perturbations are considered: (i) the perturbations applied to the vehicles are identical from vehicle to vehicle, (ii) the perturbations applied to the vehicles are non-identical. A study of two types of robustness measures is then considered: (i) the “real stability radius” robustness with respect to the perturbed closed loop system and (ii): the “string stability margin robustness” with respect to the perturbed closed loop system. Various numerical examples are presented to illustrate the type of results which may be obtained. In this case it is shown that the “string stability margin robustness” measures obtained are much more fragile than the corresponding “real stability robustness measures obtained.
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