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Derivative Analysis and algorithm Modification of Transverse-Eccentricity-Based Lambert Problem

JOURNAL OF GUIDANCE CONTROL AND DYNAMICS 2014年第4期37卷 1195-1201页

作者： Wen, Changxuan Zhao, Yushan Shi, Peng Beihang Univ Sch Astronaut Beijing 100191 Peoples R China

The classical Lambert problem can be parameterized and solved through the transverse-eccentricity component. A further study is conducted to calculate the analytical derivative of the transverse-eccentricity-based Lambert problem and to modify its algorithm. Results show that the derivative of the direct Lambert problem is positive and continuous, verifying that the transfer time monotonically increases with the transverse eccentricity. However, the derivative of the multirevolution Lambert problem increases from negative to positive, indicating that the transfer time initially decreases to the minimum value and then increases to infinity. The original solution algorithm is improved by introducing the analytical derivative. Numerical simulations for different cases show that, compared with the two existing transverse-eccentricity-based methods, the average computational time cost decreases by 65.5 and 39.8%, respectively.

关键词： Lambert's Problem iterative algorithm Numerical Simulation Elliptical Orbit MATLAB Boundary Value Problems

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OUTPUT-FEEDBACK CONTROL FOR CONTINUOUS-TIME INTERVAL POSITIVE SYSTEMS UNDER L₁ PERFORMANCE

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ASIAN JOURNAL OF CONTROL 2014年第6期16卷 1592-1601页

作者： Chen, Xiaoming Lam, James Li, Ping Shu, Zhan Univ Hong Kong Dept Mech Engn Hong Kong Hong Kong Peoples R China Univ Southampton Fac Engn & Environm Electromech Engn Grp Southampton SO9 5NH Hants England

This paper is concerned with the design of an L-1-induced output-feedback controller for continuous-time positive systems with interval uncertainties. A necessary and sufficient condition for stability and an L-1-induced performance of interval positive linear systems is proposed in terms of linear inequalities. Based on this, conditions for the existence of robust static output-feedback controllers are established and an iterative convex optimization approach is developed to solve the conditions. For special single-input-multiple-output (SIMO) positive systems, the problem of controller synthesis is completely solved with the help of an analytical formula for the L-1-induced norm. An illustrative example is provided to show the effectiveness and applicability of the theoretical results.

关键词： Interval uncertainties iterative algorithm linear Lyapunov functions L-1-induced performance output-feedback positive systems

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Improvement to the Implementation of the QUEST algorithm

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JOURNAL OF GUIDANCE CONTROL AND DYNAMICS 2014年第1期37卷 301-305页

作者： Cheng, Yang Shuster, Malcolm D. Mississippi State Univ Dept Aerosp Engn Mississippi State MS 39762 USA Acme Spacecraft Co Germantown MD 20874 USA

The QUEST algorithm [1,2] has been the most widely and most frequently implemented algorithm for batch three-axis attitude estimation. It is also an important component of many attitude Kalman filters, where it serves as a preprocessor of star-tracker data [3]. The QUEST algorithm was first implemented for the Magsat Mission in 1979 [4]. The FORTRAN code for the QUEST algorithm, written by the second author of this Note, has gone through very few changes. The only change has been a rearrangement of terms by F. Landis Markley of the NASA Goddard Space Flight Center (unpublished and only affecting the computer code) to improve numerical significance. QUEST has supported hundreds of missions, both in Earth orbit and at the far reaches of the solar system, without an anomaly. Recently, however, a robustness issue of QUEST was raised [5]. Specifically, it was shown that the NewtonRaphson iteration, employed by the QUEST algorithm to solve the characteristic equation for the maximum eigenvalue of the Davenport matrix K, did not converge in an extreme case. This Note shows that, even in the extreme case of [5] and even without the data checks in the FORTRAN code, the implementation of the QUEST algorithm will be as robust as those of the other fast attitude estimation algorithms reviewed in [5], if the following substitution is made to the characteristic polynomial: lambda super(4)-(a+b) lambda super(2)-c lambda +(ab+cs-d) arrow right ( lambda super(2)-a)( lambda super(2)-b)-c lambda +(cs-d).

关键词： Singular Value Decomposition FORTRAN Newton Raphson Method NASA Goddard Space Flight Center Kalman Filter Star Tracker iterative algorithm Solar System Computing Magsat

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Design of delta-sigma modulators via generalized Kalman-Yakubovich-Popov lemma

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AUTOMATICA 2014年第10期50卷 2700-2708页

作者： Li, Xianwei Yu, Changbin (Brad) Gao, Huijun Harbin Inst Technol Res Inst Intelligent Control & Syst Harbin 150080 Peoples R China Hangzhou Dianzi Univ Hangzhou 310018 Peoples R China Australian Natl Univ Res Sch Engn Canberra ACT 0200 Australia King Abdulaziz Univ Jeddah 21413 Saudi Arabia

This paper is concerned with the design of delta-sigma modulators via the generalized Kalman-Yakubovich-Popov lemma. The shaped noise transfer function (NTF) is assumed to have infinite impulse response, and the optimization objective is minimizing the maximum magnitude of the NTF over the signal frequency band. By virtue of the GKYP lemma, the optimization of an NTF is converted into a minimization problem subject to quadratic matrix inequalities, and then an iterative algorithm is proposed to solve this alternative minimization problem. Each iteration of the algorithm contains linear matrix inequality constraints only and can be effectively solved by the existing numerical software packages. Moreover, specifications on the NTF zeros are also integrated in the design method. A design example demonstrates that the proposed design method has an advantage over the benchmark one in improving the signal-to-noise ratio. (C) 2014 Elsevier Ltd. All rights reserved.

关键词： Delta-sigma (Delta Sigma) modulator Noise transfer function (NTF) Infinite impulse response (IIR) iterative algorithm Generalized Kalman-Yakubovich-Popov (GKYP) lemma

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Interference alignment in cognitive radio networks

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IET COMMUNICATIONS 2014年第10期8卷 1769-1777页

作者： Rezaei, Fatemeh Tadaion, Aliakbar Yazd Univ Elect & Commun Engn Dept Signal Proc Lab Yazd Iran

A fast algorithm to perform interference alignment (IA) in a cognitive radio network is proposed. Here, the authors consider a network consisting of multiple primary users (PUs) and secondary users (SUs). Although the PUs are cooperating through IA and their rates are maximised by water-filling algorithm, in the secondary network, the authors try to choose the precoding matrices of the SUs such that the interferences at the primary receivers are aligned away from the desired subspaces of the primary receivers. Besides, the interference cancellation of the PUs on the secondary links is considered through designing the post-processing matrices for the secondary links. In this way, their mutual harmful effects are suppressed and SUs could transmit their information simultaneously on the same frequency or time without causing/receiving any interference to/from the primary links. Meanwhile, the feasibility condition for the secondary network regarding the mentioned constraints is investigated. In addition, the rates of the secondary links are maximised by water-filling algorithm. The proposed iterative algorithm is an improved version of minimum weighted leakage interference algorithm with a much faster convergence rate. The analytical results are confirmed through simulations.

关键词： cognitive radio interference suppression precoding iterative methods matrix algebra interference alignment cognitive radio networks IA primary users secondary users PU water-filling algorithm secondary network precoding matrices primary receivers interference cancellation secondary links post-processing matrices mutual harmful effect suppression primary links iterative algorithm minimum weighted leakage interference algorithm convergence rate

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iterative estimation methods for Hammerstein controlled autoregressive moving average systems based on the key-term separation principle

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NONLINEAR DYNAMICS 2014年第4期75卷 709-716页

作者： Shen, Qianyan Ding, Feng Jiangnan Univ Minist Educ Key Lab Adv Proc Control Light Ind Wuxi 214122 Peoples R China Jiangnan Univ Control Sci & Engn Res Ctr Wuxi 214122 Peoples R China

This paper considers iterative identification problems for a Hammerstein nonlinear system which consists of a memoryless nonlinear block followed by a linear dynamical block. The difficulty of identification is that the Hammerstein nonlinear system contains the products of the parameters of the nonlinear part and the linear part, which leads to the unidentifiability of the parameters. In order to obtain unique parameter estimates, we express the output of the system as a linear combination of all the system parameters by means of the key-term separation principle and derive a gradient based iterative identification algorithm by replacing the unknown variables in the information vectors with their estimates. The simulation results indicate that the proposed algorithm can work well.

关键词： iterative algorithm Parameter estimation Recursive identification Gradient search Hammerstein system Key-term separation principle

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Joint Subchannel Assignment and Power Allocation for OFDMA Femtocell Networks

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IEEE TRANSACTIONS ON WIRELESS COMMUNICATIONS 2014年第1期13卷 342-355页

作者： Duy Trong Ngo Khakurel, Suman Tho Le-Ngoc Univ Newcastle Sch Elect Engn & Comp Sci Callaghan NSW 2308 Australia McGill Univ Dept Elect & Comp Engn Montreal PQ H3A 0E9 Canada

In this paper, we propose a joint subchannel and power allocation algorithm for the downlink of an orthogonal frequency-division multiple access (OFDMA) mixed femtocell/macrocell network deployment. Specifically, the total throughput of all femtocell user equipments (FUEs) is maximized while the network capacity of an existing macrocell is always protected. Towards this end, we employ an iterative approach in which OFDM subchannels and transmit powers of base stations (BS) are alternatively assigned and optimized at every step. For a fixed power allocation, we prove that the optimal policy in each cell is to give each subchannel to the user with the highest signal-to-interference-plus-noise ratio (SINR) on that subchannel. For a given subchannel assignment, we adopt the successive convex approximation (SCA) approach and transform the highly nonconvex power allocation problem into a sequence of convex subproblems. In the arithmetic-geometric mean (AGM) approximation, we apply geometric programming to find optimal solutions after condensing a posynomial into a monomial. On the other hand, logarithmic and difference-of-two-concave-functions (D.C.) approximations lead us to solving a series of convex relaxation programs. With the three proposed SCA-based power optimization solutions, we show that the overall joint subchannel and power allocation algorithm converges to some local maximum of the original design problem. While a central processing unit is required to implement the AGM approximation-based solution, each BS locally computes the optimal subchannel and power allocation for its own servicing cell in the logarithmic and D.C. approximation-based solutions. Numerical examples confirm the merits of the proposed algorithm.

关键词： Convex optimization femtocell heterogeneous networks iterative algorithm power allocation macrocell QoS protection subchannel assignment successive convex approximation

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Hierarchical gradient based and hierarchical least squares based iterative parameter identification for CARARMA systems

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SIGNAL PROCESSING 2014年 97卷 31-39页

作者： Ding, Feng Liu, Ximei Chen, Huibo Yao, Guoyu Qingdao Univ Sci & Technol Coll Automat & Elect Engn Qingdao 266042 Peoples R China

According to the iterative identification technique and the hierarchical identification principle, this paper presents a two-stage gradient based and a least squares based iterative parameter estimation algorithms (i.e., the hierarchical gradient based iterative algorithm and the hierarchical least squares based iterative algorithm) for controlled autoregressive autoregressive moving average systems. The proposed two-stage least squares based iterative algorithm requires less computation compared with the least squares based iterative algorithm. The simulation results indicate that the two-stage least squares based iterative algorithm converges faster than the two-stage gradient based iterative algorithm. (C) 2013 Elsevier B.V. All rights reserved.

关键词： Parameter estimation Least squares iterative algorithm Two-stage identification Hierarchical identification principle

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Matrix algorithms for solving the generalized coupled Sylvester and periodic coupled matrix equations

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TRANSACTIONS OF THE INSTITUTE OF MEASUREMENT AND CONTROL 2014年第8期36卷 963-970页

作者： Hajarian, Masoud Shahid Beheshti Univ Dept Math Tehran 19839 Iran

This paper is concerned with numerical solutions to the generalized coupled Sylvester matrix equations {Sigma(m)(i) = 1 (A(1), iXB1, (i)+ C-1, iYD1, (i))= E-1 Sigma(m)(i)= 1 (A(2), iXB2, (i)+ C-2, iYD2, (i)) = E-2 and the periodic coupled matrix equations {A(1), tXtB1, (t) + C-1, X-t(t) (+) D-1(1, t) + E-1, tYtF (1, t) = G(1, t), A(2, t)X(t)B(2, t) + C2, tXt (+) D-1(2, t) + E2, tYtF (2, t) = G(2, t), for t = 1, 2,..., phi which have many applications in several areas, such as control theory, stability theory, signal processing and perturbation analysis. By extending the biconjugate gradients (Bi-CG) and bi-conjugate residual (Bi-CR) methods, we obtain effective iterative algorithms for finding the solutions of the generalized coupled Sylvester and periodic coupled matrix equations. In order to compare these new algorithms with some existing methods, we present some numerical examples.

关键词： Sylvester matrix equation Bi-CG method Bi-CR method Kronecker product iterative algorithm

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Optimal Trajectory Planning for Unmanned Aerial Vehicles in Three-Dimensional Space

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JOURNAL OF AIRCRAFT 2014年第2期51卷 681-687页

作者： Hota, Sikha Ghose, Debasish Indian Inst Sci Dept Aerosp Engn Bangalore 560012 Karnataka India

The article discusses the optimal trajectory optimization for a fixed-wing unmanned aerial vehicles (UAV) in three-dimensional (3-D) space. Details regarding the study including the time-optimal path in 3-D space both in the presence and absence of wind for a constant speed, fixed wing UAV are given. Several methods of the study including path generation using a kinematic model and tracking using a dynamic model, as well as the geometric methods are also explored.

关键词： UAV Flight Path Angle Heading Angle Ailerons Nonlinear Programming Path Planning Computing Autopilot Six Degree of Freedom iterative algorithm

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