In this paper, the robust control of constrained discrete-time linear time-varying or uncertain systems affected by bounded additive disturbance is considered. The main idea is to use an interpolation technique betwee...
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In this paper, the robust control of constrained discrete-time linear time-varying or uncertain systems affected by bounded additive disturbance is considered. The main idea is to use an interpolation technique between several local unconstrained robust optimal controls. From the implementation point of view, the scheme is shown to be computationally attractive, at each time instant a quadratic programming (QP) problem being solved on-line. The proofs of recursive feasibility of the optimization procedure and ISS stability of the closed loop system are given.
The feasible implementation of immersive 3D video systems entails the need for a substantial reduction in the amount of image information necessary for representation. Multiview image rendering algorithms based on dep...
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The feasible implementation of immersive 3D video systems entails the need for a substantial reduction in the amount of image information necessary for representation. Multiview image rendering algorithms based on depth data have radically reduced the number of images required to reconstruct a 3D scene. Nonetheless, the compression of depth maps still poses several challenges due to the particular nature and characteristics of the data. To this end, this paper outlines a depth representation technique, developed in our earlier work, that exploits the correlation intrinsically present between color intensity and depth images capturing a natural scene. In this technique, a segmentation-based algorithm that is backwards compatible with conventional video coding systems is implemented. The effectiveness of our previous technique is enhanced in this contribution by a region merging process on the segmented regions, which results in a decrease in the amount of information necessary for transmission or storage of multiview image data by a factor of 20.5 with respect to the reference H.264/AVC coding methodology. This is furthermore achieved whilst maintaining a 3D image reconstruction and viewing quality which is quasi identical to the referenced approach.
This paper is concerned with the finite-horizon recursive filtering problem for a class of nonlinear time-varying systems with missing measurements. The missing measurements are modeled by a series of mutually indepen...
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This paper presents a distributed event-based control approach to cope with communication delays and packet losses affecting a networked dynamical system consisting of N linear time-invariant coupled systems. Two comm...
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This paper presents a distributed event-based control approach to cope with communication delays and packet losses affecting a networked dynamical system consisting of N linear time-invariant coupled systems. Two communication protocols are proposed to deal with these communication effects. It is shown that both protocols preserve the system stability in the sense that the state of every subsystem converges to a small region around the origin if the delay and the number of packet losses are bounded. Analytical expressions for the delay bound and the maximum number of consecutive packet losses are derived. Simulations illustrate the results.
Load balancing is essential for efficient utilization of resources and enhancing the responsiveness of a computational grid, especially that hosts of services most frequently used, i.e. food, health and nutrition. Var...
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Load balancing is essential for efficient utilization of resources and enhancing the responsiveness of a computational grid, especially that hosts of services most frequently used, i.e. food, health and nutrition. Various techniques have been developed and applied;each has its own limitations due to the dynamic nature of the grid. Efficient load balancing can be achieved by an effective measure of the node's/cluster's utilization. In this paper, as a part of an NSTIP project # 10-INF1381-04 and in order to assess of FAQIH framework ability to support the load balance in a computational grid that hosts of food, health and nutrition inquire services. We detail the design and implementation of a proposed fuzzy-logic-based scheme for dynamic load balancing in grid computing services. The proposed scheme works by using a fuzzy logic inference system which uses some metrics to capture the variability of loads and specifies the state of each node per a cluster. Then, based on the overall nodes' states, the state of the corresponding cluster will be defined in order to assign the newly arrived inquires such that load balancing among different clusters and nodes is accomplished. Many experiments are conducted to investigate the effectiveness of the proposed fuzzy-logic-based scheme to support the load balance where the results show that the proposed scheme achieves really satisfactory and consistently load balance than of other randomize approaches in grid computing services.
This paper introduces some novel ideas for presenting PI tuning to chemical engineers who take just a single control and modelling module. It is shown how the tuning approach is simpler or more intuitive than the more...
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This paper introduces some novel ideas for presenting PI tuning to chemical engineers who take just a single control and modelling module. It is shown how the tuning approach is simpler or more intuitive than the more popular Zeigler-Nichols approach and thus easy to teach. Moreover, it is effective for plants with relatively tame dynamics. Some analysis is used to demonstrate that the method is expected to work well in many cases.
In this paper, we propose a mapping and navigation method for mobile robots with low computational resources and limited memory capacity. The proposed navigation method is based on topological mapping of visual featur...
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The problem of voltage/current ripples is a primary concern for DC systems, e.g. those with fuel cells and batteries. It could seriously deteriorate the system performance on both the source side and the load side. In...
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The problem of voltage/current ripples is a primary concern for DC systems, e.g. those with fuel cells and batteries. It could seriously deteriorate the system performance on both the source side and the load side. In this paper, a single-phase PWM-controlled rectifier is taken as an example to analyse the ripple energy that causes the voltage ripples on the DC bus. Moreover, a ripple-current compensator is proposed to absorb/inject ripple energy from/to the DC bus so that the voltage ripples are reduced actively. The compensator is a boost/buck converter with an auxiliary capacitor having a voltage higher than the DC-bus voltage. A repetitive controller is then proposed to compensate the ripple energy on the DC bus instantaneously, with a fixed switching frequency. Simulation results are presented to demonstrate that the proposed strategy is able to reduce the voltage ripples on the DC bus considerably. As a result, the DC-bus capacitor can be reduced significantly in order to achieve the same level of voltage ripples.
We present in this paper a design method for two-dimensional two-channel sparse nonseparable FIR filter banks using transformation of variables. In a first phase the transformation function is designed in a least-squa...
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We present in this paper a design method for two-dimensional two-channel sparse nonseparable FIR filter banks using transformation of variables. In a first phase the transformation function is designed in a least-squares fashion. The second stage of the algorithm introduces the sparseness in a greedy manner by removing at each step the minimum coefficient of the filter in absolute value. The obtained results show that the sparse filter banks offer the possibility of choosing the complexity of the filters and have also better stopband energy.
The stability analysis of a quad-rotor rotorcraft which uses a combination of imaging, inertial and altitude sensors to measure its states is addressed. A hierarchical controller is designed in two steps. The fast-tim...
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ISBN:
(纸本)9781467320658
The stability analysis of a quad-rotor rotorcraft which uses a combination of imaging, inertial and altitude sensors to measure its states is addressed. A hierarchical controller is designed in two steps. The fast-time scale dynamics are stabilized using classical PD controllers. The slow time-scale dynamics are analyzed with delay frequency and time domain techniques. The proposal is validated by simulation and experimental results, showing the effectiveness of the method.
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