This paper proposes a controller design method for the multi-input multi-output robust servo system based on the internal model principle using polynomial differential operator. To do this task, the followings are don...
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ISBN:
(纸本)9783319272474;9783319272450
This paper proposes a controller design method for the multi-input multi-output robust servo system based on the internal model principle using polynomial differential operator. To do this task, the followings are done. Firstly, the basic idea of internal model principle is described. Secondly, the extended system by operating the polynomial differential operator to a given system with disturbance under the given conditions of reference and disturbance expressed into polynomial differential equation form and an output error is introduced. Thirdly, the controllability checking of the extended systems is done. Fourthly, a state feedback law is obtained by solving the pole assignment problem with all the poles of the extended system. Fifthly, a full observer is designed to estimate unknown states. Sixthly, the proposed control method is applied to a four steering wheel vehicle. Simulation results show that the proposed method can successfully make the system with a step and ramp type of disturbance track three references such as step, ramp and parabola types.
Electric vehicles reduce the on-board emission of pollutants but fail in resource consumption since grid-charged batteries rely on fossil fuel consumption. Vehicles based on renewable sources further eliminate this is...
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This thesis aims to propose a covert authentication scheme that remains obfuscated to eavesdropping attacks by hiding the existence of the authentication tag. The attackers’ endeavor to impersonate a legitimate trans...
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This thesis aims to propose a covert authentication scheme that remains obfuscated to eavesdropping attacks by hiding the existence of the authentication tag. The attackers’ endeavor to impersonate a legitimate transmitter can be countered by generating the invisible tag. The essential concept we suggest is to superimpose the low-power tag onto the message such that we can effectively avoid the attention of malicious users. We derive the total detection error probability and demonstrate that it can converge to 1, implying that the tag is not detectable by the malicious users, as the number of transmit antennas increases. Also, the covert tag and authenticated message throughput are obtained and analyzed to see the influence of the number of antennas.
The Segmented Mirror Telescope (SMT) housed at the Naval Postgraduate School is a unique, state-of-the-art optical instrument built to explore new technologies needed for future space-based telescopes. A discrete Four...
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The Segmented Mirror Telescope (SMT) housed at the Naval Postgraduate School is a unique, state-of-the-art optical instrument built to explore new technologies needed for future space-based telescopes. A discrete Fourier transform wavefront reconstruction technique developed at Lawrence Livermore National Laboratory is discussed in this thesis as applied to a hexagonal aperture. A Fourier domain implementation of a spatial-frequency modal controller for a simple spring-mass model of a deformable mirror surface is provided by this thesis. This technique avoids more difficult time-domain solutions, is computationally efficient and scalable to much larger multi-input, multi-output systems than the SMT.
A compact multi-band multi-input multi-output (MIMO) antenna with high isolation is proposed for C and X bands applications. The antenna consists of two trapezoidal-shaped patches printed on FR-4 substrate with a thic...
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A compact multi-band multi-input multi-output (MIMO) antenna with high isolation is proposed for C and X bands applications. The antenna consists of two trapezoidal-shaped patches printed on FR-4 substrate with a thickness of 1.6 mm and compact size of 17 mm×42 mm. Defected ground structure (DGS) is wisely embedded in antenna body to reduce the mutual coupling between the antenna elements. This modification suitably enhances the isolation by 30dB in C-band extended from 6.6 GHz to 7.6 GHz and by 17 dB in X-band between 8.3 GHz to 10 GHz. Moreover, five meander line rectangular patches are properly included to further improve the mutual coupling and eliminate the antenna size increment, simultaneously. The aforementioned meander lines also improve impedance bandwidth of the antenna as well as impedance matching over the entire frequency band. Close agreement of simulated and measured results confirm the antenna outperformance. Design, simulation, and performance analysis of the proposed antenna is discussed in detail.
A multi-input multi-output (MIMO) antenna with high isolation using a decoupling network for long term evolution (LTE) services is proposed. To improve the isolation, a decoupling network consisting of two sections of...
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A multi-input multi-output (MIMO) antenna with high isolation using a decoupling network for long term evolution (LTE) services is proposed. To improve the isolation, a decoupling network consisting of two sections of a transmission line is placed at the center of two radiating elements. The isolation was enhanced by approximately 23 dB comparing to that without a decoupling network. The fabricated MIMO antenna satisfies a 6-dB return loss requirement and the envelope correlation coefficient is maintained below 0.4 over the LTE band 13 ranging from 746 to 787 MHz. The proposed antenna shows a low specific absorption rate value to meet regulations over the frequency band of interest. (C) 2014 Wiley Periodicals, Inc.
For multilevel-coded modulation, the cut-off rate of multiple antenna systems over frequency-flat, fast fading channels is derived. Following Wozencraft's approach, a closed-form expression for the cut-off rate is...
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For multilevel-coded modulation, the cut-off rate of multiple antenna systems over frequency-flat, fast fading channels is derived. Following Wozencraft's approach, a closed-form expression for the cut-off rate is obtained as a function of energy ratio per dimension It is shown that the maximum value of cut-off rate increases linearly with the number of transmit antennas.
The synchronous integration of numerous input and output loads is possible with multi-input (MI) and multi-output (MO) DC-DC converters. In this paper, the non-isolated DC-DC converter described, which has a high step...
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The synchronous integration of numerous input and output loads is possible with multi-input (MI) and multi-output (MO) DC-DC converters. In this paper, the non-isolated DC-DC converter described, which has a high step-up capability and multiple ports for outputs and inputs for energy storage system (ESS) applications. The voltage level of the converter is changeable. The capacity to provide the large voltage increases with a low duty cycle portion, the ease with which each duty cycle can be controlled, and minimal power losses are all advantages of the proposed design. The proposed system offers advantages for applications requiring energy storage. In the continuous conduction mode (CCM), the operation principles, steady-state evaluation, and extracting of the voltage and current coefficients are performed. The supply sources can be inserted or withdrawn without causing a cross-regulation issue in the proposed converter. Ultimately, the functionality of the proposed structure is examined using simulation and the laboratory prototype that has been implemented. The proposed converter achieved 94.3% efficiency at maximum power. In addition, the proposed converter attained minimum losses with a difference of 28.5 W when compared to a conventional converter.
We investigate the channel state information (CSI) in multi-input multi-output (MIMO) cooperative networks that employ the amplify-and-forward transmission scheme. Least squares and expectation conditional maximizatio...
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We investigate the channel state information (CSI) in multi-input multi-output (MIMO) cooperative networks that employ the amplify-and-forward transmission scheme. Least squares and expectation conditional maximization have been proposed in the system. However, neither of these two approaches takes advantage of channel sparsity, and they cause estimation performance loss. Unlike linear channel estimation methods, several compressed channel estimation methods are proposed in this study to exploit the sparsity of the MIMO cooperative channels based on the theory of compressed sensing. First, the channel estimation problem is formulated as a compressed sensing problem by using sparse decomposition theory. Second, the lower bound is derived for the estimation, and the MIMO relay channel is reconstructed via compressive sampling matching pursuit algorithms. Finally, based on this model, we propose a novel algorithm so called sparsity adaptive expectation maximization (SAEM) by using Kalman filter and expectation maximization algorithm so that it can exploit channel sparsity alternatively and also track the true support set of time-varying channel. Kalman filter is used to provide soft information of transmitted signals to the EM-based algorithm. Various numerical simulation results indicate that the proposed sparse channel estimation technique outperforms the previous estimation schemes.
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