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Multiple-input multiple-output (MIMO) with N Input/ N Output processes are characterized by significant interactions between
their inputs and outputs. The control of MIMO processes is usually implemented using sets of single-input single-output (SISO)
loop controllers, which requires proper input–output pairing and development of decoupling compensator unit. In this paper,
a generalized decoupling technique is proposed. The proposed technique uses relative gain array (RGA) to select proper pairing
and particle swarm optimization (PSO) technique to estimate the optimal elements’ values of steady state decoupling compensation
matrix constituting the decoupling compensator unit. The proposed technique is applied on 4 Input/ 4 Output two coupled distillation
columns process, it proves remarkable success in minimizing the interaction between every input and all outputs except that
output has been proper paired with. 相似文献
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Ordered statistics is one of the proposed solutions to improve the detection in a multiple target environment. Some variants of this technique have been proposed for the SISO (Single Input Single Output) radars such as the OS-CFAR (Ordered Statistics CFAR), the GOSCA-CFAR (Generalized Ordered Statistics, Cell Averaging CFAR), the OSGO-CFAR (Ordered Statistics Greatest Of CFAR) and the OSSO-CFAR (Ordered Statistics Smallest Of CFAR) to deal with multiple target situations. In this paper, we generalize these CFAR detectors for the MIMO (Multi Input Multi Output) radars with three different schemes. We derive closed-form expressions of the probability of false alarm (Pfa) and the probability of detection (Pd) in a homogeneous environment for two schemes. The performance of these detectors for a non-homogeneous clutter environment (presence of interfering targets and clutter edge) has been assessed and compared. The results obtained showed that the best performance is obtained by the OSSO-CFAR. 相似文献
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Testbed are used to tune and assess automotive engines. As more High Dynamic (HD) scenarios need to be simulated, the testbeds require Multi Input Multi Output (MIMO) and robust control systems. A cooperation involving a major testbed manufacturer and two university laboratories was therefore set up. This paper presents the Control-System Design (CSD) methodology developed from system identification to the design and assessment of the MIMO robust controller for a HD testbed coupled with a spark-ignition engine. It is specially highlighted how the entire process has been automated and simplified and how the fractional order based MIMO CRONE CSD has been parameterized to obtain the best performance. Experimental results show that the proposed fractional order based MIMO control system is able to improve robustness and decoupling. 相似文献
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A. A. Pyrkin S. V. Aranovskiy A. A. Bobtsov S. A. Kolyubin N. A. Nikolaev 《Automation and Remote Control》2018,79(6):1074-1085
Consideration was given to the problem of adaptive output control of the class of MIMO (Multiple Input Multiple Output) systems that are functionally and parametrically uncertain. An approach to the design of the control law ensuring stabilization of the MIMO nonlinear Lurie system, that is, a system consisting of the linear part (strictly minimum-phase unit) and nonlinear static feedback unit, was proposed on the basis of the Fradkov theorem on feedback passification of linear systems. 相似文献
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Pinku Ranjan Mihir Patil Sneha Chand Arunesh Ranjan Satyam Singh Anand Sharma 《国际射频与微波计算机辅助工程杂志》2020,30(3)
In this communication, two port printed Multi Input Multi Output (MIMO) antenna with reduced radar cross section and low mutual coupling is designed and analyzed. Reduced mutual coupling (less than ?20 dB) is achieved by placing the electromagnetic band gap structure in between the two identical ports. Frequency selective surface has been used to reduce the radar cross section (more than 30 dB reduction) of the proposed antenna design, which makes it suitable for military applications. The proposed radiating design is fabricated and measured for the purpose of validation. It resonates at 6.8 GHz supporting an impedance bandwidth of 1.03 GHz from 6.12 to 7.15 GHz. It promises a gain of 4.75 dB in the working frequency range. This radiator is suitable for military radars works in C‐band. 相似文献
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A feature of many practical control systems is a Multi‐Input Multi‐Output (MIMO) interactive structure with one or more gross nonlinearities. A primary controller design task in such circumstances is to predict and ensure the avoidance of limit cycling conditions followed by achieving other design objectives. This paper outlines how such a system may be investigated using the Sinusoidal Input Describing Function (SIDF) philosophy quantifying magnitude, frequency and phase of any possible limit cycle operation. While Sinusoidal Input Describing function is a suitable linearization technique in the frequency domain for assessment of stability and limit cycle operation, it can not be employed in time domain. In order to be able to incorporate the time domain requirements in an overall controller design technique, the appropriate linearization technique suggested here is the Exponential Input Describing Function (EIDF). First, an evolutionary search based on a multi‐objective formulation is employed for the direct solution of the harmonic balance system matrix equation. The search is based on Multi‐Objective Genetic Algorithms (MOGA) and is capable of predicting specified modes of theoretically possible limit cycle operation. Second, the design requirements in time as well as frequency domain are formulated by a set of constraint inequalities. A numerical synthesis procedure also based on Multi‐Objective Genetic Algorithm is employed to adjust the initial compensator parameters to meet the imposed constraints. Robust stability and robust performance are investigated with respect to linearization uncertainty within the context of multiobjective formulation. In order to make the Genetic Algorithm (GA) search more amenable to design trade‐off between different and often contradictory specifications, a weighted sum of the functions is introduced. This criterion is subsequently optimized subject to the nonlinear system dynamics and a set of design requirements. Examples of use are given to illustrate the effectiveness of the proposed approach. 相似文献
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Moritz Diehl 《Automatic Control, IEEE Transactions on》2007,52(2):339-343
In this note, we show that min-max model predictive control (MPC) for linearly constrained polytopic systems with quadratic cost can be cast as a quadratically constrained quadratic program (QCQP). We use the rigorous closed loop formulation of min-max MPC, and show that any such min-max MPC problem with convex costs and constraints can be cast as a finite dimensional convex optimization problem, with the QCQP arising from quadratic costs as a special case. At the base of the proof is a lemma showing the convexity of the dynamic programming cost-to-go, which implies that the worst case on an infinite polytopic set is assumed on one of its finitely many vertices. As the approach is based on a scenario tree formulation, the number of variables in this problem grows exponentially with the horizon length. Fortunately, the QCQP is tree structured, and can thus be efficiently solved by specially tailored interior-point methods whose computational costs are linear in the number of variables. The new formulation as a tree sparse QCQP promises to facilitate online solution of the rigorous min-max MPC problem with quadratic costs 相似文献
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阿娜古丽·阿布拉 《网络安全技术与应用》2014,(2):7-7,9
在第4代移动通信技术(4G)飞速发展的今天,MIMO(MultipleInputMultipleOutput,多输入多输出)技术由于其在通信领域的先天技术优势,被广泛的应用于无线通信技术中。文章从MIMO从无线通信技术的发展引出MIMO的概念,详细介绍了MIMO的系统原理、关键技术应用研究、发展前景等。 相似文献
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In this paper, we investigated capacity maximization problem for Multiple Input Multiple Output Orthogonal Frequency Division Multiplexing systems with imperfect channel state information (CSI). To the best of our knowledge, the considered problem is still an open problem. However, the transceiver designs for MIMO OFDM systems have been extensively studied. It seems nobody gives closed-form solutions for resource allocation for MIMO OFDM systems with statistical channel estimation errors up to date. In our work, based on practical channel estimation algorithm, the channel estimation errors are first derived and then the robust resource allocation problem has been formulated. The structure of the optimal robust precoder is first derived, based on which the optimization problem will be simplified significantly. Furthermore, based on the Lagrangian dual method, a robust power allocation algorithm is proposed. The proposed power allocation can be considered as a variant of water-filling solution named cluster water-filling solution. Finally, simulation results show that our proposed robust design outperforms the non-robust design in terms of channel capacity. 相似文献
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In this work, we propose a dynamic output feedback robust model predictive control (RMPC) design method for linear uncertain systems with input constraints. In order to handle the input constraints, the control signals are permitted to saturate, which can fully utilize the capability of actuators and thus can reduce the conservatism. For the unavailable states, an ellipsoidal set is used to obtain an estimation, and it is updated at every time instant. A modified RMPC design requirement is used to ensure the recursive feasibility of the optimization problem. Then, the design method is formulated in terms of a convex optimization problem with linear matrix inequality constraints. The proposed output feedback RMPC design method is expected to further reduce the conservativeness. The improvements of the proposed algorithm over the other existing techniques is demonstrated by an example. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
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Massinissa Belazzoug Idris Messaoudene Salih Aidel Mourad Nedil Ahmed A. Kishk 《国际射频与微波计算机辅助工程杂志》2020,30(5)
Here, an ultra‐compact Multi‐Input‐Multi‐Output (MIMO) antenna system is presented for Wireless Local Area Network (WLAN) applications. The proposed antenna compactness approach is based on using Cylindrical‐Dielectric‐Resonator‐Antenna (CDRA) symmetry with the help of image theory to achieve the best size reduction of the resonators and maintain the resonance frequency of the original CDRA. The electric/magnetic walls approach is utilized to miniaturize the size by exploring the symmetry and antisymmetry of the resonant mode. First, a CDRA for MIMO system is designed and tested in terms of return loss and radiation efficiency. Then, two configurations of MIMO‐Antennas (two and four ports) are examined by using the same substrate size. The 2‐port‐MIMO antenna is built from two half‐CDRs (HCDRs) facing each other. Similarly, four‐quarter‐CDRs (QCDRs) are created to form a 4‐port MIMO antenna system. As a result, a 75% size reduction is achieved (size of 30 × 30 × 7.62 mm3). The measured impedance bandwidth for the 4‐port MIMO antenna is 5.4% (5.4‐5.7 GHz), with more than 15 dB isolation levels. Proper levels of Envelope Correlation Coefficients (ECCs) are also achieved (1 × 10?2‐4 × 10?2), with a channel capacity loss (CCL) of 0.04 bits/S/Hz. The proposed MIMO antennas are suitable for compact wireless communication systems. 相似文献
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The sensor network localization based on connectivity can be modeled as a non-convex optimization problem. It can be argued that the actual problem should be represented as an optimization problem with both convex and non-convex constraints. A two-objective evolutionary algorithm is proposed which utilizes the result of all convex constraints to provide a starting point on the location of the unknown nodes and then searches for a solution to satisfy all the convex and non-convex constraints of the problem. The final solution can reach the most suitable configuration of the unknown nodes because all the information on the constraints (convex and non-convex) related to connectivity have been used. Compared with current models that only consider the nodes that have connections, this method considers not only the connection constraints, but also the disconnection constraints. As a MOEA (Multi-Objective Evolution Algorithm), PAES (Pareto Archived Evolution Strategy) is used to solve the problem. Simulation results have shown that better solution can be obtained through the use of this method when compared with those produced by other methods. 相似文献
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M. A. Carravilla C. Ribeiro J. F. Oliveira 《International Transactions in Operational Research》2003,10(6):651-663
In this paper an application of constraint logic programming (CLP) to the resolution of nesting problems is presented. Nesting problems are a special case of the cutting and packing problems, in which the pieces generally have non‐convex shapes. Because of their combinatorial optimization nature, nesting problems have traditionally been tackled by heuristics and in the recent past by meta‐heuristics. When trying to formulate nesting problems as linear programming models, to achieve global optimal solutions, the difficulty of dealing with the disjunction of constraints arises. On the contrary, CLP deals easily with this type of relationships among constraints. A CLP implementation for the nesting problem is described for convex and non‐convex shapes. The concept of nofit polygon is used to deal with the geometric constraints inherent to all cutting and packing problems. Computational results are presented. 相似文献
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针对实际杂波环境中多输入多输出(MIMO)雷达与目标间检测与隐身的博弈问题,提出一种新的两步注水算法。首先建立时空编码模型;然后基于互信息量准则,用注水法分配目标干扰功率,用通用注水法分配雷达信号功率;最终得到强弱杂波环境Stackelberg博弈中目标占优和雷达占优的优化方案。仿真结果表明,雷达信号功率分配和通用注水水位变化规律均受杂波影响,两优化方案的互信息量在强杂波环境降低约50%,干扰影响系数分别降低0.2和0.25,互信息量受干扰影响程度降低,证明了所提算法的有效性。 相似文献