Robust Structured Control Design via LMI Optimization
DEFF Research Database (Denmark)
Adegas, Fabiano Daher; Stoustrup, Jakob
2011-01-01
This paper presents a new procedure for discrete-time robust structured control design. Parameter-dependent nonconvex conditions for stabilizable and induced L2-norm performance controllers are solved by an iterative linear matrix inequalities (LMI) optimization. A wide class of controller...... structures including decentralized of any order, ﬁxed-order dynamic output feedback, static output feedback can be designed robust to polytopic uncertainties. Stability is proven by a parameter-dependent Lyapunov function. Numerical examples on robust stability margins shows that the proposed procedure can...
LMI-BASED AERO-ENGINE CONTROLLER DESIGN
Institute of Scientific and Technical Information of China (English)
无
2000-01-01
The problem of analysis and synthesis of robust control is addressed in this work. The approach transferring the robust control design into Linear Matrix Inequality(LMI) is provided. The LMI standard structure of robust controller is also given and the controller is obtained through solving three LMIs. As an example, a robust control law is designed to the twin-spool turbojet engine system using the given approach. The result shows that LMI approach is feasible.
LMI approach to reliable H∞ control of linear systems
Institute of Scientific and Technical Information of China (English)
Yao Bo; Wang Fuzhong
2006-01-01
The reliable design problem for linear systems is concerned with. A more practical model of actuator faults than outage is considered. An LMI approach of designing reliable controller is presented for the case of actuator faults that can be modeled by a scaling factor. The resulting control systems are reliable in that they provide guaranteed asymptotic stability and H∞ performance when some control component (actuator) faults occur. A numerical example is also given to illustrate the design procedure and their effectiveness. Furthermore, the optimal standard controller and the optimal reliable controller are compared to show the necessity of reliable control.
S-variable approach to LMI-based robust control
Ebihara, Yoshio; Arzelier, Denis
2015-01-01
This book shows how the use of S-variables (SVs) in enhancing the range of problems that can be addressed with the already-versatile linear matrix inequality (LMI) approach to control can, in many cases, be put on a more unified, methodical footing. Beginning with the fundamentals of the SV approach, the text shows how the basic idea can be used for each problem (and when it should not be employed at all). The specific adaptations of the method necessitated by each problem are also detailed. The problems dealt with in the book have the common traits that: analytic closed-form solutions are not available; and LMIs can be applied to produce numerical solutions with a certain amount of conservatism. Typical examples are robustness analysis of linear systems affected by parametric uncertainties and the synthesis of a linear controller satisfying multiple, often conflicting, design specifications. For problems in which LMI methods produce conservative results, the SV approach is shown to achieve greater accuracy...
Fault Tolerant Robust Control Applied for Induction Motor (LMI approach
Directory of Open Access Journals (Sweden)
Hamouda KHECHINI
2007-09-01
Full Text Available This paper foregrounds fault tolerant robust control of uncertain dynamic linear systems in the state space representation. In fact, the industrial systems are more and more complex and the diagnosis process becomes indispensable to guarantee their surety of functioning and availability, that’s why a fault tolerant control law is imperative to achieve the diagnosis. In this paper, we address the problem of state feedback H2 /H∞ mixed with regional pole placement for linear continuous uncertain system. Sufficient conditions for feasibility are derived for a general class of convex regions of the complex plan. The conditions are presented as a collection of linear matrix inequalities (LMI 's. The efficiency and performance of this approach are then tested taking into consideration the robust control of a three- phase induction motor drive with the fluctuation of its parameters during the functioning.
An LMI-based decoupling control for electromagnetic formation flight
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Huang Xianlin
2015-04-01
Full Text Available Electromagnetic formation flight (EMFF leverages electromagnetic force to control the relative position of satellites. EMFF offers a promising alternative to traditional propellant-based spacecraft flight formation. This novel strategy is very attractive since it does not consume fuel. Due to the highly coupled nonlinearity of electromagnetic force, it is difficult to individually design a controller for one satellite without considering others, which poses challenges to communications. This paper is devoted to decoupling control of EMFF, including regulations, constraints and controller design. A learning-based adaptive sliding mode decoupling controller is analyzed to illustrate the problem of existing results, and input rate saturation is introduced to guarantee the validity of frequency division technique. Through transformation, the imposed input rate saturation is converted to state and input constraints. A linear matrix inequalities (LMI-based robust optimal control method can then be used and improved to solve the transformed problem. Simulation results are presented to demonstrate the effectiveness of the proposed decoupling control.
Fault Tolerant Control for Civil Structures Based on LMI Approach
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Chunxu Qu
2013-01-01
Full Text Available The control system may lose the performance to suppress the structural vibration due to the faults in sensors or actuators. This paper designs the filter to perform the fault detection and isolation (FDI and then reforms the control strategy to achieve the fault tolerant control (FTC. The dynamic equation of the structure with active mass damper (AMD is first formulated. Then, an estimated system is built to transform the FDI filter design problem to the static gain optimization problem. The gain is designed to minimize the gap between the estimated system and the practical system, which can be calculated by linear matrix inequality (LMI approach. The FDI filter is finally used to isolate the sensor faults and reform the FTC strategy. The efficiency of FDI and FTC is validated by the numerical simulation of a three-story structure with AMD system with the consideration of sensor faults. The results show that the proposed FDI filter can detect the sensor faults and FTC controller can effectively tolerate the faults and suppress the structural vibration.
Mixed H2/H∞ State Feedback Attitude Control of Microsatellite Based on Extended LMI Method
Institute of Scientific and Technical Information of China (English)
Keke Shi; Chuang Liu; Feng Wang∗; Zhaowei Sun
2016-01-01
For the appearance of the additive perturbation of controller gain when the controller parameter has minute adjustment at the initial running stage of system, to avoid the adverse effects, this paper investigates the mixed H2/H∞ state feedback attitude control problem of microsatellite based on extended LMI method. Firstly, the microsatellite attitude control system is established and transformed into corresponding state space form. Then, without the equivalence restriction of the two Lyapunov variables of H2 and H∞ performance, this paper introduces additional variables to design the mixed H2/H∞ control method based on LMI which can also reduce the conservatives. Finally, numerical simulations are analyzed to show that the proposed method can make the satellite stable within 20 s whether there is additive perturbation of the controller gain or not. The comparative analysis of the simulation results between extended LMI method and traditional LMI method also demonstrates the effectiveness and feasibility of the proposed method in this paper.
Neng-Sheng Pai; Her-Terng Yau
2010-01-01
This paper focuses on the chaos control problem of the unified chaotic systems with structured uncertainties. Applying Schur-complement and some matrix manipulation techniques, the controlled uncertain unified chaotic system is then transformed into the linear matrix inequality (LMI) form. Based on Lyapunov stability theory and linear matrix inequality (LMI) formulation, a simple linear feedback control law is obtained to enforce the prespecified exponential decay dynamics of the uncertain un...
Decentralised stabilizing control based on H-infinity control theory making use of LMI
Energy Technology Data Exchange (ETDEWEB)
Niioka, S.; Yokoyama, R.; Ti, Z.X. [Tokyo Metropolitan University (Japan). Dept. of Electrical Engineering; Ishimaru, M.; Shirai, G. [Hosei University (Japan). Dept. of Electrical Engineering
2000-07-01
In this paper, two decentralized controller designs based on H{sub {infinity}} control theory are presented. In this controller design, LMI (Linear Matrix Inequality) is applied to obtain feedback gains for state feedback control. For an optimal linear regulator design, an index function of the quadratic form must be chosen. The question of how to decide weighting matrix in the quadratic index function used in Riccati equation arises. The problem is transformed into a pole allocation problem by making use of LMI. The effectiveness of the proposed method is shown by numerical simulations on a test system. (author)
Robust LMI-Based Control of Wind Turbines with Parametric Uncertainties
DEFF Research Database (Denmark)
Sloth, Christoffer; Esbensen, Thomas; Niss, Michael Odgaard Kuch
2009-01-01
This paper considers the design of robust LMI-based controllers for a wind turbine along its entire nominal operating trajectory. The proposed robust controller design takes into account parametric uncertainties in the model using a structured uncertainty description, which makes the controllers...... less conservative than controllers designed using unstructured uncertainty descriptions. The LMI-based approach enables additional constraints to be included in the design, which is exploited to include requirements for minimizing fatigue loads and actuator usage. Two different methods are adopted...
Directory of Open Access Journals (Sweden)
Neng-Sheng Pai
2010-01-01
Full Text Available This paper focuses on the chaos control problem of the unified chaotic systems with structured uncertainties. Applying Schur-complement and some matrix manipulation techniques, the controlled uncertain unified chaotic system is then transformed into the linear matrix inequality (LMI form. Based on Lyapunov stability theory and linear matrix inequality (LMI formulation, a simple linear feedback control law is obtained to enforce the prespecified exponential decay dynamics of the uncertain unified chaotic system. Numerical results validate the effectiveness of the proposed robust control scheme.
Directory of Open Access Journals (Sweden)
Kazuhiko Hiramoto
2012-01-01
Full Text Available An LMI-based method for the integrated system identification and controller design is proposed in the paper. We use the fact that a class of a system identification problem results in an LMI optimization problem. By combining LMIs for the system identification and those to obtain a discrete time controller we propose a framework to integrate two steps for the model-based control system design, that is, the system identification and the controller synthesis. The framework enables us to obtain a good model for control and a model-based feedback controller simultaneously in the sense of the closed-loop performance. An iterative design algorithm similar to so-called Windsurfer Approach is presented.
LMI-based output feedback fuzzy control of chaotic system with uncertainties
Institute of Scientific and Technical Information of China (English)
Tan Wen; Wang Yao-Nan; Duan Feng; Li Xiao-Hui
2006-01-01
This paper studies the robust fuzzy control for nonlinear chaotic system in the presence of parametric uncertainties. An uncertain Takagi-Sugeno (T-S) fuzzy model is employed for fuzzy modelling of an unknown chaotic system. A sufficient condition formulated in terms of linear matrix inequality (LMI) for the existence of fuzzy controller is obtained. Then the output feedback fuzzy-model-based regulator derived from the LMI solutions can guarantee the stability of the closed-loop overall fuzzy system. The T-S fuzzy model of the chaotic Chen system is developed as an example for illustration. The effectiveness of the proposed controller design methodology is finally demonstrated through computer simulations on the uncertain Chen chaotic system.
Energy Technology Data Exchange (ETDEWEB)
Yamamoto, I.; Hayashi, T. [Mitsubishi Heavy Industries, Ltd., Tokyo (Japan)
1997-10-01
Recently, with a progress of robust control such as H{infinity} control, the application of a control system design considering a robustness of controlled system fluctuation to real machinery became possible. In addition, LMI (Linear Matrix Inequality) control system design method is superior to conventional H{infinity} control, although including various difficult elements. The design algorithm permitting the robust control system design of non-linear problems by giving controlled systems was thus developed by introducing an inverse LMI control design method. This design algorithm determines the solution of models outputting the deviation between a target value and controlled variables by solving the simultaneous equations composed of a linear matrix inequality under an impulse response constraint condition and that under an H{infinity} norm constraint condition. This technique allows to give a pending step response as control condition. The technique was confirmed to be effective by its application to the position keeping control problem of marine floating structures. 6 refs., 11 figs., 2 tabs.
Positive Real Synthesis of Networked Control System An LMI Approach
Riyanto, Bambang
2008-01-01
This paper presents the positive real analysis and synthesis for Networked Control Systems (NCS) in discrete time. Based on the definition of passivity, the sufficient condition of NCS is given by stochastic Lyapunov functional. The controller via state feedback is designed to guarantee the stability of NCS and closed-loop positive realness. It is shown that a mode-dependent positive real controller exists if a set of coupled linear matrix inequalities has solutions. The controller can be then constructed in terms of the solutions.
State feedback control of switched linear systems: An LMI approach
Montagner, V. F.; Leite, V. J. S.; Oliveira, R. C. L. F.; Peres, P. L. D.
2006-10-01
This paper addresses the problem of state feedback control of continuous-time switched linear systems with arbitrary switching rules. A quadratic Lyapunov function with a common matrix is used to derive a stabilizing switching control strategy that guarantees: (i) the assignment of all the eigenvalues of each linear subsystem inside a chosen circle in the left-hand half of the complex plane; (ii) a minimum disturbance attenuation level for the closed-loop switched system. The proposed design conditions are given in terms of linear matrix inequalities that encompass previous results based on quadratic stability conditions with fixed control gains. Although the quadratic stability based on a fixed Lyapunov matrix has been widely used in robust control design, the use of this condition to provide a convex design method for switching feedback gains has not been fully investigated. Numerical examples show that the switching control strategy can cope with more stringent design specifications than the fixed gain strategy, being useful to improve the performance of this class of systems.
An LMI-based unified approach to reduced-order controller design
Institute of Scientific and Technical Information of China (English)
郭雷; 忻欣; 冯纯伯
1997-01-01
The design of reduced-order controllers is considered for stabilization control, covariance upper bound control, linear quadratic regulator, ∞ control, H∞ control, positive real control problems and robust H2 control, robust ∞ control and robust H∞ control problems for generalized linear plants without any additional assumptions. An upper bound of the order is obtained with which the (robust) controllers can guarantee stability constraints and satisfy the same design objectives as the so-called "full-order" controllers. A unified linear-matrix-inequality ( LMI) based approach to reduced-order (robust) controller design for all the above-mentioned problems is provided. It us shown that each of these problems is solvable if and only if two uncoupled LMIs with an LMI-type constraint have a pair of positive definite solutions, one of which has a lower dimension than that given by Skelton and iwasaki (1995). All desired reduced-order (robust) controllers are parameterized via the solutions of LMIs Moreov
基于观测器的 LMI 振动控制算法%Observer-based LMI vibration control algorithm
Institute of Scientific and Technical Information of China (English)
王露健; 周星德; 秦飞马; 张翔; 李勇直
2014-01-01
针对基于观测器的 LMI 控制器设计中一个线性矩阵不等式中出现双变量的问题，提出一种赋初值迭代求解方法。考虑到双变量中一个为正定矩阵变量、一个为标量的特点，为了保证迭代收敛性和满足矩阵正定的要求，把正定矩阵变量作为初值赋予对象。仿真分析发现所设计的控制器仅能保证控制趋势，达不到预期控制效果，为此提出了调节因子的概念。最后，以3层基准建筑物为例进行仿真分析，结果表明该方法是可行的。%In the design of an observer-based LMI (linear matrix inequality) controller, bivariate values appear in one linear matrix inequality. To solve this problem, we propose an initial value-iteration method in this paper. Of the bivariate values, one is a positive definite matrix variable and the other is a scalar. Considering these two characteristics, we take the positive definite matrix variable as the initial value, in order to ensure the astringency of the iteration and to meet the requirements of positive definite matrices. Simulation analysis shows that the designed controller can guarantee the control trend, which was far from the expected control result. We subsequently put forward the concept of a regulatory factor. As a case study, the simulation analysis of a three-storey benchmark building shows that the proposed method is feasible.
LMI Approach to Robust H∞/H2 Controller Design with Regional Poles Constraint of a Pump-Motor System
Institute of Scientific and Technical Information of China (English)
无
2006-01-01
The time domain guideposts requirements of a pump-motor system is transferred into a series of constraints which express the robust performance upper bound and regional poles limits of the closed loop system. Then the servo system control problem is transferred into the problem of robust performance optimizing under regional poles constrains described by linear matrix inequality (LMI). These LMIs are easy to solve through the Matlab LMI-toolbox. Simulations indicate that the controller has excellent dynamic, static and disturbance rejection performance, and the control system is robust and has perfect H2 performance to the bounded external torque disturbance.
Institute of Scientific and Technical Information of China (English)
WANG Limin; CHEN Xi; GAO Furong
2013-01-01
Based on an equivalent two-dimensional Fornasini-Marchsini model for a batch process in industry,a closed-loop robust iterative learning fault-tolerant guaranteed cost control scheme is proposed for batch processes with actuator failures.This paper introduces relevant concepts of the fault-tolerant guaranteed cost control and formulates the robust iterative learning reliable guaranteed cost controller (ILRGCC).A significant advantage is that the proposed ILRGCC design method can be used for on-line optimization against batch-to-batch process uncertainties to realize robust tracking of set-point trajectory in time and batch-to-batch sequences.For the convenience of implementation,only measured output errors of current and previous cycles are used to design a synthetic controller for iterative learning control,consisting of dynamic output feedback plus feed-forward control.The proposed controller can not only guarantee the closed-loop convergency along time and cycle sequences but also satisfy the H∞ performance level and a cost function with upper bounds for all admissible uncertainties and any actuator failures.Sufficient conditions for the controller solution are derived in terms of linear matrix inequalities (LMIs),and design procedures,which formulate a convex optimization problem with LMI constraints,are presented.An example of injection molding is given to illustrate the effectiveness and advantages of the ILRGCC design approach.
LMI-Based 2-Degrees-of-Freedom Controller Design for Robust Vibration Suppression Positioning
Kato, Takanori; Maeda, Yoshihiro; Iwasaki, Makoto; Hirai, Hiromu
This paper presents a novel 2-degrees-of-freedom (2-DOF) controller design for the robust vibration suppression positioning of mechatronic systems against the frequency perturbation in mechanical vibration modes. The authors have already proposed an linear matrix inequality (LMI)-based feedforward (FF) compensator design method to provide the robust properties in positioning against the perturbation, while the feedback (FB) controller has been independently designed to ensure the robust stability on the basis of the 2-DOF controller design concept. However, a problem still remains in the conventional design that the FB characteristic causes the deterioration of the FF control performance because the undesired response in the FB system due to the perturbation affects the ideal response by the FF compensation. The proposed controller design in this paper, therefore, includes the FB control system with the perturbation in the FF design model to solve the problem in the conventional design. In addition, the FB controller is optimally designed to improve the positioning performance as a cooperated design between FB and FF controllers. The effectiveness of the proposed approach has been verified by numerical simulations and experiments using a prototype.
Synthesis of robust feedback missile control strategies by using LMI techniques
Trottemant, E.J.; Weiss, M.; Vermeulen, A.
2009-01-01
Robust programming, and more specific LMI techniques, have proven to be an extremely effective tool for the synthesis of missile guidance laws. The advantage of this model-based approach is that a large class of uncertainties can be taken into account and a robust guidance law is obtained. In this p
Multi-loop decentralized PID control based on covariance control criteria: an LMI approach.
Huang, Xin; Huang, Biao
2004-01-01
PID control is well known and widely applied in industry and many design algorithms are readily available in the literature. However, systematic design of multi-loop or decentralized PID control for multivariable processes to meet certain objectives simultaneously is still a challenging task. Designing multi-loop PID controllers such that the process variables satisfy the generalized covariance constraints is studied in this paper. A convergent computational algorithm is proposed to calculate the multi-loop PID controller for a process with stable disturbances. This algorithm is then extended to a process with random-walk disturbances. The feasibility of the proposed algorithm is verified by applying it to several simulation examples.
Robust control of uncertain time delay system: a novel sliding mode control design via LMI
Institute of Scientific and Technical Information of China (English)
Qu Shaocheng; Wang Yongji
2006-01-01
The sliding mode control problem (SMC) is studied for a class of uncertain delay system in the presence of both parameter uncertainties and external disturbances. A novel virtual feedback control method is presented. Based on Lyapunov theory, sufficient conditions for design of the robust sliding mode plane are derived. Sliding mode controller based on reaching law concept is developed, which is to ensure system trajectories from any initial conditions asymptotically convergent to sliding mode plane. The global asymptotically stability of the closed-loop system is guaranteed. A numerical example with simulation results is given to illustrate the effectiveness of the methodology.
Chiang, Tung-Sheng; Chiu, Chian-Song
This paper proposes the sliding mode control using LMI techniques and adaptive recurrent fuzzy neural network (RFNN) for a class of uncertain nonlinear time-delay systems. First, a novel TS recurrent fuzzy neural network (TS-RFNN) is developed to provide more flexible and powerful compensation of system uncertainty. Then, the TS-RFNN based sliding model control is proposed for uncertain time-delay systems. In detail, sliding surface design is derived to cope with the non-Isidori-Bynes canonical form of dynamics, unknown delay time, and mismatched uncertainties. Based on the Lyapunov-Krasoviskii method, the asymptotic stability condition of the sliding motion is formulated into solving a Linear Matrix Inequality (LMI) problem which is independent on the time-varying delay. Furthermore, the input coupling uncertainty is also taken into our consideration. The overall controlled system achieves asymptotic stability even if considering poor modeling. The contributions include: i) asymptotic sliding surface is designed from solving a simple and legible delay-independent LMI; and ii) the TS-RFNN is more realizable (due to fewer fuzzy rules being used). Finally, simulation results demonstrate the validity of the proposed control scheme.
Directory of Open Access Journals (Sweden)
C. Oktay Azeloglu
2015-01-01
Full Text Available This paper studies the design of a linear matrix inequality (LMI based mixed H2/H∞ state-feedback controller for vibration attenuation problem of seismic-excited container cranes. In order to show effectiveness of the designed controller, a six-degree-of-freedom container crane structural system is modeled using a spring-mass-damper subsystem. The system is then simulated against the real ground motion of El Centro and Northridge earthquakes. Finally, the time history of the crane parts displacements, accelerations, control forces, and frequency responses of both uncontrolled and controlled cases are presented. Additionally, the performance of the designed controller is also compared with a nominal state-feedback H∞ controller performance. Simulations of the designed controller show better seismic performance than a nominal state-feedback H∞ controller. Simulation results show that the designed controller is all effective in reducing vibration amplitudes of crane parts.
An LMI approach to stabilization of linear port-controlled Hamiltonian systems
Prajna, Stephen; Schaft, van der Arjan; Meinsma, Gjerrit
2002-01-01
In this paper, it is shown that controllers for stabilizing linear port-controlled Hamiltonian (PCH) systems via interconnection and damping assignment can be obtained by solving a set of linear matrix inequalities (LMIs). Two sets of (almost) equivalent LMIs are proposed. In the first set, the inte
LMI-Based Generation of Feedback Laws for a Robust Model Predictive Control Algorithm
Acikmese, Behcet; Carson, John M., III
2007-01-01
This technical note provides a mathematical proof of Corollary 1 from the paper 'A Nonlinear Model Predictive Control Algorithm with Proven Robustness and Resolvability' that appeared in the 2006 Proceedings of the American Control Conference. The proof was omitted for brevity in the publication. The paper was based on algorithms developed for the FY2005 R&TD (Research and Technology Development) project for Small-body Guidance, Navigation, and Control [2].The framework established by the Corollary is for a robustly stabilizing MPC (model predictive control) algorithm for uncertain nonlinear systems that guarantees the resolvability of the associated nite-horizon optimal control problem in a receding-horizon implementation. Additional details of the framework are available in the publication.
LMI-Based Fuzzy Optimal Variance Control of Airfoil Model Subject to Input Constraints
Swei, Sean S.M.; Ayoubi, Mohammad A.
2017-01-01
This paper presents a study of fuzzy optimal variance control problem for dynamical systems subject to actuator amplitude and rate constraints. Using Takagi-Sugeno fuzzy modeling and dynamic Parallel Distributed Compensation technique, the stability and the constraints can be cast as a multi-objective optimization problem in the form of Linear Matrix Inequalities. By utilizing the formulations and solutions for the input and output variance constraint problems, we develop a fuzzy full-state feedback controller. The stability and performance of the proposed controller is demonstrated through its application to the airfoil flutter suppression.
Improved State Feedback H∞ Control for Flexible Air-Breathing Hypersonic Vehicles on LMI Approach
Directory of Open Access Journals (Sweden)
Zhang Xue
2017-01-01
Full Text Available Focusing on a nonlinear longitudinal dynamical model for Air-breathing Hypersonic Flight Vehicles (AHFV, a linearized model on a nominal trim condition is proposed. To stabilize the flight of an AHFV in the presence of external disturbances and actuator uncertainties, a state feedback H∞ control is designed. With bounds on the uncertainties, a feedback stabilization problem is converted to an optimal control problem and the cost function is minimized by solving a set of linear matrix inequalities. Since uncertainties in the design of AHFV are inevitable, to make a comparison, a general H∞ robust controller is constructed by only considering the disturbances firstly. Then the results are extended by incorporating the actual existing uncertainties as well as the external disturbances in the AHFV system. Numerical simulation shows that the controller, which takes both disturbances and uncertainties into account, can effectively stabilize the AHFV system.
LMI-based robust iterative learning controller design for discrete linear uncertain systems
Institute of Scientific and Technical Information of China (English)
Jianming XU; Mingxuan SUN; Li YU
2005-01-01
This paper addresses the design problem of robust iterative learning controllers for a class of linear discrete-time systems with norm-bounded parameter uncertainties.An iterative learning algorithm with current cycle feedback is proposed to achieve both robust convergence and robust stability.The synthesis problem of the proposed iterative learning control (ILC) system is reformulated as a γ-suboptimal H-infinity control problem via the linear fractional transformation (LFT).A sufficient condition for the convergence of the ILC algorithm is presented in terms of linear matrix inequalities (LMIs).Furthermore,the linear transfer operators of the ILC algorithm with high convergence speed are obtained by using existing convex optimization techniques.The simulation results demonstrate the effectiveness of the proposed method.
An LMI approach to robust H-infinity control for uncertain singular time-delay systems
Institute of Scientific and Technical Information of China (English)
Xiaofu JI; Hongye SU; Jian CHU
2006-01-01
The problem of robust H-infinity control for a class of uncertain singular time-delay systems is studied in this paper. A new approach is proposed to describe the relationship between slow and fast subsystems of singular time-delay systems, based on which, a sufficient condition is presented for a singular time-delay system to be regular, impulse free and stable with an H-infinity performance. The robust H-infinity control problem is solved and an explicit expression of the desired state-feedback control law is also given. The obtained results are formulated in terms of strict linear matrix inequalities (LMIs) involving no decomposition of system matrices. A numerical example is given to show the effectiveness of the proposed method,
An LMI-based variable structure control for a class of uncertain singular Markov switched systems
Institute of Scientific and Technical Information of China (English)
无
2007-01-01
An H-infinifty variable structure control is presented for singular Markov switched systems with mismatched norm-bounded uncertainties and mismatched norm-bounded external disturbances.It iS shown that the sliding mode dynamics on the given switching surface is regular,impulse-free,and stochastically stable and satisfies H-infinity performance.A variable structure controller is designed to guarantee that the system trajectory converges to the linear switching surface in some finite time.Finally,a numencal example is solved to show the effectiveness and validness of the theoretical results.
LMI-based gain scheduled controller synthesis for a class of linear parameter varying systems
DEFF Research Database (Denmark)
Bendtsen, Jan Dimon; Anderson, Brian; Lanzon, Alexander
2006-01-01
This paper presents a novel method for constructing controllers for a class of single-input multiple-output (SIMO) linear parameter varying (LPV) systems. This class of systems encompasses many physical systems, in particular systems where individual components vary with time, and is therefore...... the parameters are varying, with the degree of stability related directly to a bound on the average rate of allowable parameter variations. Thus, if knowledge of the parameter variations is available, the conservativeness of the design can be kept at a minimum. The construction of the controller is formulated...
Directory of Open Access Journals (Sweden)
Chao-Jun Chen
2017-01-01
Full Text Available Active mass damper (AMD control system is proposed for high-rise buildings to resist a strong wind. However, negative influence of noise in sensors impedes the application of AMD systems in practice. To reduce the adverse influence of noise on AMD systems, a Kalman filter and a linear matrix inequality- (LMI- based filter are designed. Firstly, a ten-year return period fluctuating wind load is simulated by mixed autoregressive-moving average (MARMA method, and its reliability is tested by wind speed power spectrum and correlation analysis. Secondly, a designed state observer with different filters uses wind-induced acceleration responses of a high-rise building as the feedback signal that includes noise to calculate control force in this paper. Finally, these methods are applied to a numerical example of a high-rise building and an experiment of a single span four-storey steel frame. Both numerical and experimental results are presented to verify that both Kalman filter and LMI-based filter can effectively suppress noise, but only the latter can guarantee the stability of AMD parameters.
建筑结构基于LMI的鲁棒非脆弱H∞控制%ROBUST AND NON-FRAGILE H∞ CONTROL FOR BUILDINGS VIA LMI APPROACH
Institute of Scientific and Technical Information of China (English)
李志军; 王社良
2013-01-01
考虑一维地震动作用和结构参数不确定性影响,提出一种基于线性矩阵不等式(Linear Matrix Inequalities,LMI)的鲁棒非脆弱H∞控制方法.引入工程中常用的二次型最优指标,并应用线性矩阵不等式减小求解的复杂度,使得控制器的性能指标容易衡量,设计相对简单,便于工程应用.以一个三层剪切型结构模型为例进行数值分析,并与传统H∞控制方法进行对比,仿真结果初步表明:1)所提方法具有很好的控制效果和鲁棒性；2)合理地计算结构参数值,可使控制系统在具有最优反应品质的前提下,获得相对更好的鲁棒性和非脆弱性.%The behavior of building structures is naturally uncertain because of the numerous uncertainties of seismic disturbances and structural parameters. In this paper, we present a new robust and non-fragile H∞ control approach that can provide a convenient design procedure for active controllers to facilitate practical implementations of control systems through the use of a quadratic performance index and the use of an efficient solution procedure based on linear matrix inequalities (LMI). Such a new robust and non-fragile H∞, controller for buildings can be designed to guarantee the robust stability and performance of the closed-loop system in the presence of parameter uncertainties. In view of the uncertainty of seismic disturbance and the model errors of the building structure, a three-storey shear building model containing active brace systems is analyzed. The simulation results obtained from the proposed control method are compared with those obtained from traditional H∞ control method, which shows preliminarily that the performance of robust and non-fragile H∞ controllers is remarkable and robust. Considering reasonable parameter values, the controller can acquire considerably better performance of robust and non-fragile than traditional H∞ controller under the optimal response quantities
Narimani, Mohammand; Lam, H K; Dilmaghani, R; Wolfe, Charles
2011-06-01
Relaxed linear-matrix-inequality-based stability conditions for fuzzy-model-based control systems with imperfect premise matching are proposed. First, the derivative of the Lyapunov function, containing the product terms of the fuzzy model and fuzzy controller membership functions, is derived. Then, in the partitioned operating domain of the membership functions, the relations between the state variables and the mentioned product terms are represented by approximated polynomials in each subregion. Next, the stability conditions containing the information of all subsystems and the approximated polynomials are derived. In addition, the concept of the S-procedure is utilized to release the conservativeness caused by considering the whole operating region for approximated polynomials. It is shown that the well-known stability conditions can be special cases of the proposed stability conditions. Simulation examples are given to illustrate the validity of the proposed approach.
Institute of Scientific and Technical Information of China (English)
侯倩; 程月华; 姜斌; 陆宁云
2011-01-01
During satellite orbit maneuver, the orbit control force causes disturbing torque and affects attitude of a satellite if the control force does not pass through the mass center of the satellite. In this paper, a set of reduced order nonlinear unknown input observers (RO-NUIO) are designed to detect and isolate faults. During the design process, the system is divided into three sub-systems to ensure that some states are not affected by the disturbance. Observers are designed by using the observable information. Meanwhile, some parameters of the observers can be obtained by using the LMI approach to reduce effects of nonlinear part on observers. The existence conditions of the observer proposed in this paper only depend on the inherent feature of the system. Combination of the reduced order idea and the LMI method make the structure of observers easy to be applied to nonlinear satellite attitude control systems. Numerical simulation is carried out to demonstrate the efficiency of the proposed fault diagnosis scheme for satellite attitude control systems.%卫星轨控期间,由于推力偏心,会产生较大的干扰力矩,直接影响卫星姿态.针对轨道控制期间的挠性卫星姿态控制系统,设计了干扰解耦的降阶非线性未知输入观测器(RO-NUIO),用于故障检测与故障隔离.在设计过程中,首先通过坐标变换,使得不可观的状态及部分可观状态不受干扰影响,然后针对不可观的子系统利用可观状态的信息设计观测器,观测器中的部分参数利用LMI方法获得,可以弱化非线性部分对观测器的影响.所设计观测器的存在条件仅依赖于系统本身特性,无需在线验证.观测器采用降阶设计,同时借助LMI思想,结构简单,适合于非线性卫星姿态控制系统.仿真结果验证了降阶非线性未知输入观测器实现卫星姿态控制故障诊断的可行性与有效性.
LMI Approach to Observer-based FD Systems Designing
Institute of Scientific and Technical Information of China (English)
钟麦英; 汤兵勇; 丁·史蒂芬·先春
2001-01-01
Increasing the robustness to the unknown uncertainty and simultaneously enhancing the sensibility to the faults is one of the important issues considered in the fault detection development. Considering the L2-gain of residual system, this paper deals the observer-based fault detection problem. By using of H∞ control theory,an LMI approach to design fault detection observer is given. A numerical example is used to illustrate the effectiveness of the proposed approach.
Robust stabilization using LMI techniques of neutral time-delay systems subject to input saturation
El Fezazi, Nabil; El Haoussi, Fatima; Houssaine Tissir, El; Alvarez, Teresa; Tadeo, Fernando
2017-01-01
The robust stabilization of uncertain saturated neutral systems with state delay is solved in this paper: based on a free weighting matrix approach, sufficient conditions are obtained via an LMI formulation. From these conditions, state feedback gains that ensure stability for the largest set of admissible initial conditions can be calculated solving optimization problems with LMI constraints. Some applications of this methodology to feedback control are then presented and compared with previous results in the literature.
Directory of Open Access Journals (Sweden)
Zrida Jalel
2010-01-01
Full Text Available This paper introduces new dilated LMI conditions for continuous-time linear systems which not only characterize stability and performance specifications, but also, performance specifications. These new conditions offer, in addition to new analysis tools, synthesis procedures that have the advantages of keeping the controller parameters independent of the Lyapunov matrix and offering supplementary degrees of freedom. The impact of such advantages is great on the multiobjective full-order dynamic output feedback control problem as the obtained dilated LMI conditions always encompass the standard ones. It follows that much less conservatism is possible in comparison to the currently used standard LMI based synthesis procedures. A numerical simulation, based on an empirically abridged search procedure, is presented and shows the advantage of the proposed synthesis methods.
Directory of Open Access Journals (Sweden)
MohammadReza Davoodi
2009-12-01
Full Text Available This paper offers a design procedure for robust stability, robust H-infinity control and robust H2 control via dynamic output feedback for a class of uncertain linear systems. The uncertainties are of norm bounded type. Then in order to support a high-speed energy storage flywheel, these procedures are applied to an active radial magnetic bearing system. The state space matrices of this controller are the solution of some linear matrix inequalities (LMIs.
基于LMI方法的机器人LPV鲁棒H∞控制器设计%Robot Manipulator LPV Robust H∞ Controller Design Based on LMI Approach
Institute of Scientific and Technical Information of China (English)
虞忠伟; 陈辉堂; 王月娟
2001-01-01
对平面两关节直接驱动机器人，提出一种同时将闭环极点配置到满足动态响应区域内的变增益LPV鲁棒H∞控制器设计新方法。利用LPV的凸分解方法，将机器人模型化为具有凸多面体结构的LPV模型，然后利用LMI技术对凸多面体各顶点分别设计满足H∞性能和闭环极点配置的反馈增益，再利用各顶点设计的反馈控制器综合得到具有凸多面体结构的LPV控制器。仿真结果验证了该控制器可使机器人随关节位置变化始终具有良好的控制性能。%A new approach to design robust H∞ contr ollers for a two-jointdirect drive planar manipulator is presented. The time- varying nonlinear model of robot is translated into a linear parameter varyin g(LPV) system with convex polytopic version via the LPV convex decomposition tec h nique. State feedback controllers satisfying H∞ performance and pole plac ement at every vertex of convex polyhedron parameter space are designed via line ar matrix inequalities(LMIs) approach. Using these designed controllers at every vertex, a LPV controller with smaller on-line calculating capacity is synthesi zed via convex decomposition techniques. Simulation results prove that the robot with the LPV controller has good performance as the joint angles vary.
Evaluasi Sistem Informasi Penjualan dan Piutang Dagang pada PT. LMY
Directory of Open Access Journals (Sweden)
Henny Hendarti
2011-06-01
Full Text Available The purpose of this research is to evaluate and test the reliability of sales and accounts receivable information system of PT. LMY in order to help overcome the problems faced by the company. The methods used are literature review and field researches such as interviews, checked-question lists, observations and analysis. Audit around the Computer is used as the audit method. The evaluation results in some discoveries of the advantages and disadvantages of the sales and account receivable information systems used, where the disadvantages allow for the potential risks. The conclusion based on the obtained evaluation results on the control of information systems sales and accounts receivable company is that any improvement is still needed, especially on the control of security management as well as boundary. Thus, it is necessary for the company to do audits regularly on sales and account receivable information system so that the information system can be more reliable.
Institute of Scientific and Technical Information of China (English)
黄东胜; 邹富顺; 冯波
2011-01-01
For practical application,this paper presented a fuzzy static output feedback controller design approach for vehicle electro-hydraulic active suspensions.Takagi-Sugeno（T-S） fuzzy modeling was applied for approximating the dynamic nonlinear active suspension model.Three main performance requirements should be considered in designing suspension,ride comfort,handing stability and suspension deflection,this paper took the vertical acceleration of the car body as H2 performance,and suspension deflection and tyre deflection as the H∞ performance.NSGA_2 was atilized for searching the feedback gain matrix,the H2 and H∞ norm were acquired via solving LMI.The comparison of the simulation results between active suspension and passive suspension in MATLAB/simulink shows that the three main performances of active suspension are better.%考虑实际应用,提出一种考虑电液作动器动态特性的主动悬架模糊静态输出反馈控制器的设计方法。利用T-S模糊模型逼近具有非线性动态特性的主动悬架模型,将悬架设计考虑的三个指标中的行驶平顺性（车身垂直加速度）作为H2性能指标,操纵稳定性（轮胎动载荷）和悬架动行程作为H∞性能指标,利用多目标遗传算法——NSGA_2对控制增益进行搜索,通过解线性矩阵不等式得到H2和H∞范数。用MATLAB/Simulink仿真进行比较,结果表明,所得主动悬架的三个性能指标都优于被动悬架。
Energy Technology Data Exchange (ETDEWEB)
Yu, Ming; Bozek, Jody; Lamoy, Melanie; Kagan, Mikhail; Benites, Pedro; Onthank, David; Robinson, Simon P. [Lantheus Medical Imaging, Discovery Research, N. Billerica, MA (United States)
2012-12-15
Regional cardiac sympathetic denervation (RCSD) associated with reduced noradrenaline transporter (NAT) function has been linked to cardiac arrhythmia. This study examined the association of LMI1195, an {sup 18}F-labeled NAT substrate developed for positron emission tomography (PET) imaging, with NAT in vitro, and its imaging to detect RCSD and guide antiarrhythmic drug treatment in vivo. LMI1195 association with NAT was assessed in comparison with other substrates, noradrenaline (NA) and {sup 123}I-metaiodobenzylguanidine (MIBG), in NAT-expressing cells. LMI1195 cardiac imaging was performed for evaluation of RCSD in a rabbit model surgically developed by regional phenol application on the left ventricular (LV) wall. The normal LV areas in images were quantified as regions with radioactivity {>=}50 % maximum. Potential impact of RCSD on dofetilide, an antiarrhythmic drug, induced ECG changes was assessed. NAT blockade with desipramine reduced LMI1195 cell uptake by 90 {+-} 3 %, similar to NA and MIBG. NA, MIBG, or self inhibited LMI1195 cell uptake concentration-dependently with comparable IC{sub 50} values (1.09, 0.21, and 0.90 {mu}M). LMI1195 cardiac imaging differentiated innervated and denervated areas in RCSD rabbits. The surgery resulted in a large denervated LV area at 2 weeks which was partially recovered at 12 weeks. Myocardial perfusion imaging with flurpiridaz F 18 showed normal perfusion in RCSD areas. Dofetilide induced more prominent QTc prolongation in RCSD than control animals. However, changes in heart rate were comparable. LMI1195 exhibits high association with NAT and can be used for imaging RCSD. The detected RCSD increases cardiac risks to the antiarrhythmic drug, dofetilide, by inducing more QTc prolongation. (orig.)
H{sub {infinity}} with reference model for active suspension system : an LMI approach
Energy Technology Data Exchange (ETDEWEB)
Abdellahi, E.; Mehdi, D. [LAII ESIP, Poitiers (France); Ramirez Mendoza, R. [LAII ESIP, Poitiers (France)]|[Dept. of Mechatronic and Automation, ITESM Garza Sada, Monterrey (Mexico); M' saad, M. [LAII ESIP, Poitiers (France)]|[LAP-ISMRA, Caen (France)
2001-07-01
This paper deals with active suspension systems. A two-degree-of-freedom quarter-car model is used to implement an LMI-based H{sub {infinity}} approach with reference model. The results are compared with those obtained with H{sub {infinity}} control without reference model. The main purpose of the controller is to ensure vibration isolation between different parts of the system. Careful tuning of weighting functions are necessary for H{sub {infinity}} design method. (orig.)
Robust Admissibilization of Descriptor Systems by Static Output-Feedback: An LMI Approach
Directory of Open Access Journals (Sweden)
M. Chaabane
2011-01-01
static output-feedback is studied in this paper and an approach to solve it is proposed. For this, sufficient conditions are derived for the closed-loop system to be admissible (i.e., stable, regular, and impulse-free. These conditions are expressed in terms of a strict Linear Matrix Inequality (LMI; so they are tractable using numerical computations. The proposed controller design methodology is based on two steps: the first is dedicated to synthesizing a classical state-feedback controller, which is used as the initial value for the second step, which uses an LMI problem to obtain static output-feedback controllers that give admissibility. Finally, a numerical example is given to illustrate the results.
ABSOLUTE STABILIZATION RELATED TO CIRCLE CRITERION: AN LMI-BASED APPROACH
Institute of Scientific and Technical Information of China (English)
杨莹; 黄琳
2003-01-01
A method is proposed for synthesizing output feedback controllers for nonlinear Lur' e systems. The problem of designing an output dynamic controller for uncertain-free systems and systems subject to multiplicative norm-bounded perturbations in the linear part were proposed respectively. The procedure is based on the use of the absolute stability,through the circle criterion, and a linear matrix inequalities (LMI) formulation. The controller existence conditions are given in terms of existence of suitable solutions to a set of parameter- dependent LMIs.
Directory of Open Access Journals (Sweden)
Jinxing Lin
2013-01-01
Full Text Available This paper is concerned with the problems of delay-dependent robust stability and stabilization for a class of continuous singular systems with time-varying delay in range and parametric uncertainties. The parametric uncertainties are assumed to be of a linear fractional form, which includes the norm bounded uncertainty as a special case and can describe a class of rational nonlinearities. In terms of strict linear matrix inequalities (LMIs, delay-range-dependent robust stability criteria for the unforced system are presented. Moreover, a strict LMI design approach is developed such that, when the LMI is feasible, a desired state feedback stabilizing controller can be constructed, which guarantees that, for all admissible uncertainties, the closed-loop dynamics will be regular, impulse free, and robustly asymptotically stable. Numerical examples are provided to demonstrate the effectiveness of the proposed methods.
LMI1-like genes involved in leaf margin development of Brassica napus.
Ni, Xiyuan; Liu, Han; Huang, Jixiang; Zhao, Jianyi
2017-06-01
In rapeseed (Brassica napus L.), leaf margins are variable and can be entire, serrate, or lobed. In our previous study, the lobed-leaf gene (LOBED-LEAF 1, BnLL1) was mapped to a 32.1 kb section of B. napus A10. Two LMI1-like genes, BnaA10g26320D and BnaA10g26330D, were considered the potential genes that controlled the lobed-leaf trait in rapeseed. In the present study, these two genes and another homologous gene (BnaC04g00850D) were transformed into Arabidopsis thaliana (L.) Heynh. plants to identify their functions. All three LMI1-like genes of B. napus produced serrate leaf margins. The expression analysis indicated that the expression level of BnaA10g26320D determined the difference between lobed- and entire-leaved lines in rapeseed. Therefore, it is likely that BnaA10g26320D corresponds to BnLL1.
LMI Conditions for Global Stability of Fractional-Order Neural Networks.
Zhang, Shuo; Yu, Yongguang; Yu, Junzhi
2016-08-02
Fractional-order neural networks play a vital role in modeling the information processing of neuronal interactions. It is still an open and necessary topic for fractional-order neural networks to investigate their global stability. This paper proposes some simplified linear matrix inequality (LMI) stability conditions for fractional-order linear and nonlinear systems. Then, the global stability analysis of fractional-order neural networks employs the results from the obtained LMI conditions. In the LMI form, the obtained results include the existence and uniqueness of equilibrium point and its global stability, which simplify and extend some previous work on the stability analysis of the fractional-order neural networks. Moreover, a generalized projective synchronization method between such neural systems is given, along with its corresponding LMI condition. Finally, two numerical examples are provided to illustrate the effectiveness of the established LMI conditions.
Stability analysis of stochastic delayed cellular neural networks by LMI approach
Energy Technology Data Exchange (ETDEWEB)
Zhu Wenli [Department of Economic Mathematics, South Western University of Finance and Economics, Chengdu 610074 (China)]. E-mail: zhuwenli67@hotmail.com; Hu Jin [School of Applied Mathematics, University of Electronic Science and Technology of China, Chengdu 610054 (China)
2006-07-15
Some sufficient mean square exponential stability conditions for a class of stochastic DCNN model are obtained via the LMI approach. These conditions improve and generalize some existing global asymptotic stability conditions for DCNN model.
Lam, H K; Leung, Frank H F
2007-10-01
This correspondence presents the stability analysis and performance design of the continuous-time fuzzy-model-based control systems. The idea of the nonparallel-distributed-compensation (non-PDC) control laws is extended to the continuous-time fuzzy-model-based control systems. A nonlinear controller with non-PDC control laws is proposed to stabilize the continuous-time nonlinear systems in Takagi-Sugeno's form. To produce the stability-analysis result, a parameter-dependent Lyapunov function (PDLF) is employed. However, two difficulties are usually encountered: 1) the time-derivative terms produced by the PDLF will complicate the stability analysis and 2) the stability conditions are not in the form of linear-matrix inequalities (LMIs) that aid the design of feedback gains. To tackle the first difficulty, the time-derivative terms are represented by some weighted-sum terms in some existing approaches, which will increase the number of stability conditions significantly. In view of the second difficulty, some positive-definitive terms are added in order to cast the stability conditions into LMIs. In this correspondence, the favorable properties of the membership functions and nonlinear control laws, which allow the introduction of some free matrices, are employed to alleviate the two difficulties while retaining the favorable properties of PDLF-based approach. LMI-based stability conditions are derived to ensure the system stability. Furthermore, based on a common scalar performance index, LMI-based performance conditions are derived to guarantee the system performance. Simulation examples are given to illustrate the effectiveness of the proposed approach.
PHOTOMETRIC ANALYSIS OF HS Aqr, EG Cep, VW LMi, AND DU Boo
Energy Technology Data Exchange (ETDEWEB)
Djurasevic, G.; Latkovic, O. [Astronomical Observatory, Volgina 7, 11000 Belgrade (Serbia); Bastuerk, Oe.; Y Latin-Small-Letter-Dotless-I lmaz, M. [Astronomy and Space Sciences Research and Application Center, Ankara University, TR-06837 Ahlatl Latin-Small-Letter-Dotless-I bel, Ankara (Turkey); Cal Latin-Small-Letter-Dotless-I skan, S.; Senavc Latin-Small-Letter-Dotless-I , H. V.; K Latin-Small-Letter-Dotless-I l Latin-Small-Letter-Dotless-I coglu, T.; Ekmekci, F. [Department of Astronomy and Space Sciences, Faculty of Science, Ankara University, TR-06100 Tandogan, Ankara (Turkey); Tanr Latin-Small-Letter-Dotless-I verdi, T., E-mail: olivia@aob.rs [Department of Physics, Faculty of Arts and Sciences, Nigde University, 51240 Nigde (Turkey)
2013-03-15
We analyze new multicolor light curves for four close late-type binaries: HS Aqr, EG Cep, VW LMi, and DU Boo, in order to determine the orbital and physical parameters of the systems and estimate the distances. The analysis is done using the modeling code of G. Djurasevic, and is based on up-to-date measurements of spectroscopic elements. All four systems have complex, asymmetric light curves that we model by including bright or dark spots on one or both components. Our findings indicate that HS Aqr and EG Cep are in semi-detached, while VW LMi and DU Boo are in overcontact configurations.
LMI-based Gain Scheduled Robust Flux Observer for Induction Motors
DEFF Research Database (Denmark)
Trangbæk, Klaus
2000-01-01
In this paper a robust flux observer for an induction motor is developed through an LMI approach. The observer is robust to changes in rotational speed and in rotor and stator resistances. The problem is formulated as complex-valued rank constrained LMIs and solved through alternating projections...
New Sufficient LMI Conditions for Static Output Stabilization
DEFF Research Database (Denmark)
Adegas, Fabiano Daher
2014-01-01
This paper presents new linear matrix inequality conditions to the static output feedback stabilization problem. Although the conditions are only sufficient, numerical experiments show excellent success rates in finding a stabilizing controller.......This paper presents new linear matrix inequality conditions to the static output feedback stabilization problem. Although the conditions are only sufficient, numerical experiments show excellent success rates in finding a stabilizing controller....
Development of Analysis Tools for Certification of Flight Control Laws
2009-03-31
In Proc. Conf. on Decision and Control, pages 881-886, Bahamas, 2004. [7] G. Chesi, A. Garulli, A. Tesi , and A. Vicino. LMI-based computation of...Minneapolis, MN, 2006, pp. 117-122. [10] G. Chesi, A. Garulli, A. Tesi . and A. Vicino, "LMI-based computation of optimal quadratic Lyapunov functions...Convex Optimization. Cambridge Univ. Press. Chesi, G., A. Garulli, A. Tesi and A. Vicino (2005). LMI-based computation of optimal quadratic Lyapunov
LMI Fuzzy Observer Design for Cryptography in Wireless Mobile Communications
Directory of Open Access Journals (Sweden)
P.Sivakumar
2013-07-01
Full Text Available Recently the engineering community began to seek the possibly application of chaos. The fact that the cryptographic community had used discrete pseudo-chaotic systems for a long time to generate cipher keys that leads to the initiation of applying chaos to secure communications. This paper presents a schematic design methodology for a fuzzy observer based secure communication of hyper chaotic systems in cryptographic applications. The transmitter and receiver, which are based on a 3D hyper chaotic oscillator, are synchronized by exploiting the concept on the observer from the control theory. The scalar transmitted signal is designed so that the hyper chaotic carrier masks the encrypted signal, which in turn hides the message signal. To encrypt the message signal, an n-shirt cipher with multiple key algorithms is proposed. In receiver side, the fuzzy observer of chaotic system is designed based on the general Takagi-Sugeno fuzzy model. This approach leads to the design of communication systems with higher security.
FREQUENCY DOMAIN CRITERIA FOR ROBUST D-STABILITY OF MIMO SYSTEMS BASED ON LMI METHOD
Institute of Scientific and Technical Information of China (English)
LI Hai-bin; WANG Zhi-zhen; WANG Long; LI Zhao-ping; LI Er-xiao
2006-01-01
The problem of checking robust D-stability of multi-in and multi-out (MIMO) systems was studied. Three system models were introduced, i.e. multilinear polynomial matrix, polytopic polynomial matrix and feedback system model. Furthermore, the convex property of each model with respect to the parametric uncertainties was estabilished respectively. Based on this, sufficient conditions for D-stability were expressed in terms of linear matrix inequalities (LMIs) involving only the convex vertices. Therefore, the robust D-stability was tested by solving an LMI optimal problem.
An Equivalent LMI Representation of Bounded Real Lemma for Continuous-Time Systems
Directory of Open Access Journals (Sweden)
Xie Wei
2008-01-01
Full Text Available Abstract An equivalent linear matrix inequality (LMI representation of bounded real lemma (BRL for linear continuous-time systems is introduced. As to LTI system including polytopic-type uncertainties, by using a parameter-dependent Lyapunov function, there are several LMIs-based formulations for the analysis and synthesis of performance. All of these representations only provide us with different sufficient conditions. Compared with previous methods, this new representation proposed here provides us the possibility to obtain better results. Finally, some numerical examples are illustrated to show the effectiveness of proposed method.
Unknown Input Observer Design for Fuzzy Bilinear System: An LMI Approach
Directory of Open Access Journals (Sweden)
D. Saoudi
2012-01-01
Full Text Available A new method to design a fuzzy bilinear observer (FBO with unknown inputs is developed for a class of nonlinear systems. The nonlinear system is modeled as a fuzzy bilinear model (FBM. This kind of T-S fuzzy model is especially suitable for a nonlinear system with a bilinear term. The proposed fuzzy bilinear observer subject to unknown inputs is developed to ensure the asymptotic convergence of the error dynamic using the Lyapunov method. The proposed design conditions are given in linear matrix inequality (LMI formulation. The paper studies also the problem of fault detection and isolation. An unknown input fuzzy bilinear fault diagnosis observer design is proposed. This work is given for both continuous and discrete cases of fuzzy bilinear models. Illustrative examples are chosen to provide the effectiveness of the given methodology.
TCSC controller design based on output feedback control with linear matrix inequality
Energy Technology Data Exchange (ETDEWEB)
Ishimaru, Masachika; Shirai, Goro [Hosei University, Tokyo (Japan). Dept. of Electrical Engineering; Niioka, Satoru; Yokoyama, Ryuichi [Tokyo Metropolitan University (Japan). Dept. of Electrical Engineering
2000-07-01
The authors aim at designing the fast responsible and robust stabilizing controller. Recently, many researches propose robust stabilizing compensators based on H{sub {infinity}} control theory. Especiady, the LMI (Linear Matrix Inequality) solving efficient convex problems is very effective. LMI is based on a linear function composed by matrices, and it is expansion of conventional H{sub {infinity}} control. In addition to the LMI approach, authors pay attention to the output-feedback control for stabilizing a system using observable output values. This paper presents a stabilizing control using measurable values by using the output-feedback method. In order to discuss the advantage of the proposed method, 3-machine 9-bus system is used. Moreover, this system is applied TCSC (Thyristor Controlled Series Capacitor) controllers, and H{sub {infinity}} control based on the LMI is proposed for the design method of TCSC controllers to attain the robust stability. (author)
Staða tímarita á íslenskum fjölmiðlamarkaði
Róbert Hlynur Baldursson
2007-01-01
Í essu lokaverkefni er leita svara vi ví hver sta a „sölutímarita“ sé á íslenskum fjölmi lamarka i. ar er átt vi au tímarit sem gefin eru út á almennum marka i af fyrirtækjum me ar semiskröfu a lei arljósi, .e. me ví a selja í eim augl singar og/e a selja au lesendum. Í ritger inni er liti yfir sögu útgáfustarfseminnar frá upphafi til vorra daga. Einnig er fari yfir fjölmi lakannanir sem s na róun útgáfu tímarita gagnvart ö rum mi lum á marka inum sí ustu tvo ...
Directory of Open Access Journals (Sweden)
Wrastawa Ridwan
2011-08-01
Full Text Available This paper investigates the problem of H∞ performance analysis for continous–time systems with two additive time-varying delays in the state. Our objective is focused on stability analysis of a continuous system with two time-varying delays with an H∞ disturbance attenuation level γ. By exploiting Lyapunov-Krasovski functional and introducing free weighting matrix variables, LMI stability condition have been derived.
VW LMi: tightest quadruple system known. Light-time effect and possible secular changes of orbits
Pribulla, T; Dubovsky, P; Kudzej, I; Parimucha, S; Siwak, M; Vanko, M
2008-01-01
Tightest known quadruple systems VW LMi consists of contact eclipsing binary with P_12 = 0.477551 days and detached binary with P_34 = 7.93063 days revolving in rather tight, 355.0-days orbit. This paper presents new photometric and spectroscopic observations yielding 69 times of minima and 36 disentangled radial velocities for the component stars. All available radial velocities and minima times are combined to better characterize the orbits and to derive absolute parameters of components. The total mass of the quadruple system was estimated at 4.56 M_sun. The detached, non-eclipsing binary with orbital period P = 7.93 days is found to show apsidal motion with U approximately 80 years. Precession period in this binary, caused by the gravitational perturbation of the contact binary, is estimated to be about 120 years. The wide mutual orbit and orbit of the non-eclipsing pair are found to be close to coplanarity, preventing any changes of the inclination angle of the non-eclipsing orbit and excluding occurrenc...
Curious Variables Experiment (CURVE). RZ LMi - the most active SU UMa star
Olech, A; Zloczewski, K; Cook, L M; Mularczyk, K; Kedzierski, P
2008-01-01
We report extensive photometry of the frequently outbursting dwarf nova RZ Leo Minoris. During two seasons of observations we detected 12 superoutbursts and 7 normal outbursts. The V magnitude of the star varied in range from 16.5 to 13.9 mag. The superoutbursts occur quite regularly flashing every 19.07(4) days and lasting slightly over 10 days. The average interval between two successive normal outbursts is 4.027(3) days. The mean superhump period observed during the superoutbursts is 0.059396(4) days (85.530(6) min). The period of the superhumps was constant except for one superoutburst when it increased with a rate of $\\dot P/P_{\\rm sh} = 7.6(1.9)\\cdot 10^{-5}$. Our observations indicate that RZ LMi goes into long intervals of showing permanent superhumps which are observed both in superoutbursts and quiescence. This may indicate that decoupling of thermal and tidal instabilities play important role in ER UMa systems. No periodic light variations which can be connected with orbital period of the binary we...
Multiobjective H2/H? Control Design with Regional Pole Constraints
Directory of Open Access Journals (Sweden)
Junaidi Junaidi
2012-03-01
Full Text Available This paper presents multiobjective H2/H? control design with regional pole constraints. The state feedback gain can be obtained by solving a linear matrix inequality (LMI feasibility problem that robustly assigns the closed-loop poles in a prescribed LMI region. The proposed technique is illustrated with applications to the design of stabilizer for a typical single-machine infinite-bus (SMIB power system. The LMI-based control ensures adequate damping for widely varying system operating conditions. The simulation results illustrate the effectiveness and robustness of the proposed stabilizer.
Institute of Scientific and Technical Information of China (English)
无
2009-01-01
The guaranteed cost control problem for a continuous-time uncertain singular system with state and control delays, and a given quadratic cost function is studied in this paper. Sufficient conditions for the existence of the guaranteed cost controller are derived based on the linear inequality (LMI) approach. A parameterized characterization of the guaranteed cost laws is given in terms of the feasible solutions to a certain LMI, and the cost function of guaranteed cost controller exists an upper bound.
Directory of Open Access Journals (Sweden)
Ruofeng Rao
2013-01-01
Full Text Available The robust exponential stability of delayed fuzzy Markovian-jumping Cohen-Grossberg neural networks (CGNNs with nonlinear p-Laplace diffusion is studied. Fuzzy mathematical model brings a great difficulty in setting up LMI criteria for the stability, and stochastic functional differential equations model with nonlinear diffusion makes it harder. To study the stability of fuzzy CGNNs with diffusion, we have to construct a Lyapunov-Krasovskii functional in non-matrix form. But stochastic mathematical formulae are always described in matrix forms. By way of some variational methods in W1,p(Ω, Itô formula, Dynkin formula, the semi-martingale convergence theorem, Schur Complement Theorem, and LMI technique, the LMI-based criteria on the robust exponential stability and almost sure exponential robust stability are finally obtained, the feasibility of which can efficiently be computed and confirmed by computer MatLab LMI toolbox. It is worth mentioning that even corollaries of the main results of this paper improve some recent related existing results. Moreover, some numerical examples are presented to illustrate the effectiveness and less conservatism of the proposed method due to the significant improvement in the allowable upper bounds of time delays.
Robust ‚H-2 static output feedback to control an automotive throttle valve
Vargas A.N.; Acho L.; Pujol G.; Oliveira R.C.L.F.; Do Val J.B.R.; Peres P.L.D.
2014-01-01
The paper presents a control strategy for an automotive electronic throttle body, a device largely used into vehicles to increase the efficiency of the combustion engines. The synthesis of the proposed controller is based on a linear matrix inequality (LMI) formulation, which allows us to deal with uncertainties on the measurements of the position of the throttle valve. The LMI approach generates a suboptimal solution for the robust ‚Ñã2 static output feedback control problem, and the corresp...
Stability Analysis of Uncertain Discrete Time-Delay Control Systems
Institute of Scientific and Technical Information of China (English)
Long Xuming; Duan Ping
2006-01-01
Based on Lyapunov stability theory, a less conservative sufficient conditions for the stabilities of uncertain discrete delay-independent and delay-dependent control systems are obtained by using the linear matrix inequality (LMI) approach. Judgement of the stability of time-delay systems is transformed to judgement of the feasible solution of an LMI, and hence is solved by use of MATLAB. Numerical simulations verify the validity of the proposed method.
An integrated approach to the design of an aircraft gain scheduled controller
Berglund, Erik
1995-01-01
This thesis addresses the problem of integrated design of the aircraft plant parameters and of the corresponding feedback controller. The plant parameters are typically the sizes of the control surfaces or other aerodynamical surfaces of the aircraft. The approach is to rewrite the aircraft dynamic requirements as linear matrix inequalities (LMI's) and to optimize a linear cost function associated with aircraft plant parameters, while meeting the LMI constraints. An algorithm using Matlab and...
Sugiyama, Ryusuke; Kanazawa, Kengo; Seki, Mika; Azuma, Takashi; Sasaki, Akira; Takeuchi, Hideki; Fujiwara, Keisuke; Itani, Kazunori; Tamano, Satoshi; Yoshinaka, Kiyoshi; Takagi, Shu; Matsumoto, Yoichiro
2015-07-01
High-intensity focused ultrasound (HIFU) is one of the noninvasive treatment for tumors. Visualizing the treated area inside the human body is necessary to control the HIFU exposure. Localized motion imaging (LMI) using ultrasound to induce and detect tissue deformation is one technique to detect a change in tissue stiffness caused by thermal coagulation. In experiments with porcine liver, LMI has shown to detect deformation with less than 20% accuracy. We have developed a prototype feedback control system using real-time LMI. In this system, coagulation size was measured every 1 s and controlled to correspond to a targeted size. The typical size error was reduced to 14% from 35%. LMI displacements in normal and coagulated tissues were sufficiently different to discriminate between coagulated areas and noncoagulated ones after HIFU sonication and to visualize treated areas after HIFU treatment.
Energy Technology Data Exchange (ETDEWEB)
Ishimaru, Masachika; Yokoyama, Ryuichi [Tokyo Metropolitan Univ., Hachioji, Tokyo (Japan); Shirai, Goro [Hosei Univ., Koganei, Tokyo (Japan); Niimura, Takahide [British Columbia Univ., Vancouver, BC (Canada)
2002-10-01
Power system stabilizing control has an important role in maintaining synchronism in power systems during major disturbances resulting from sudden changes of load and configuration. The thyristor- controlled series capacitor (TCSC) is one of the representative devices in flexible AC transmission systems. In this paper, robust TCSC controllers are applied to suppress disturbances in realistic power systems. H{sub {infinity}} control is adopted as the methodology of the robust controller design along with a linear matrix inequality (LMI), which solves the Lyapunov inequality without the weighting coefficients used in other control theories. In the proposed design, load changes are treated as a system uncertainty in the LMI approach. The proposed LMI -based approach is shown to be effective in the design of TCSC controllers to enhance robustness and response by simulations on a test system. (Author)
Robust chaos synchronization using input-to-state stable control
Indian Academy of Sciences (India)
Choon Ki Ahn
2010-05-01
In this paper, we propose a new input-to-state stable (ISS) synchronization method for a general class of chaotic systems with disturbances. Based on Lyapunov theory and linear matrix inequality (LMI) approach, for the first time, the ISS synchronization controller is presented not only to guarantee the asymptotic synchronization but also to achieve the bounded synchronization error for any bounded disturbance. The proposed controller can be obtained by solving a convex optimization problem represented by the LMI. Simulation studies are presented to demonstrate the effectiveness of the proposed ISS synchronization scheme.
LMI Condition of Quadratic D-stability for a Class of Uncertain Linear Systems%一类不确定线性系统二次D-稳定的LMI条件
Institute of Scientific and Technical Information of China (English)
周武能; 苏宏业; 褚健
2005-01-01
A necessary and sufficient condition of the quadratic D-stability for a class of uncertain linear systems is presented in terms of linear matrix inequslity (LMI) technology. Finally, the validity and less conservatism of the obtained results in this paper are illustrated by a benchmark example.
基于圆判据的一种LMI绝对镇定方法%Absolute Stabilization Related to Circle Criterion: an LMI-Based Approach
Institute of Scientific and Technical Information of China (English)
杨莹; 黄琳
2003-01-01
针对非线性Lur'e系统,提出了一种输出反馈控制器综合方法.对于系统在无摄动及线性部分存在乘性范数摄动的情况,分别设计了保证闭环系统绝对稳定的动态输出反馈控制器.由圆判据出发,通过把绝对稳定性问题等价地转化成H∞控制问题,得到了一组由线性矩阵不等式(LMI)表达的控制器存在的充分性条件.
Directory of Open Access Journals (Sweden)
Francisco Palacios-Quiñonero
2014-07-01
Full Text Available In this paper, we present a novel two-step strategy for static output-feedback controller design. In the first step, an optimal state-feedback controller is obtained by means of a linear matrix inequality (LMI formulation. In the second step, a transformation of the LMI variables is used to derive a suitable LMI formulation for the static output-feedback controller. This design strategy can be applied to a wide range of practical problems, including vibration control of large structures, control of offshore wind turbines, control of automotive suspensions, vehicle driving assistance and disturbance rejection. Moreover, it allows designing decentralized and semi-decentralized static output-feedback controllers by setting a suitable zero-nonzero structure on the LMI variables. To illustrate the application of the proposed methodology, two centralized static velocity-feedback H-Infinity controllers and two fully decentralized static velocity-feedback H-Infinity controllers are designed for the seismic protection of a five-story building.
Robust stabilization for a class of nonlinear networked control systems
Institute of Scientific and Technical Information of China (English)
Jinfeng GAO; Hongye SU; Xiaofu JI; Jian CHU
2008-01-01
The problem of robust stabilization for a class of uncertain networked control systems(NCSs)with nonlinearities satisfying a given sector condition is investigated in this paper.By introducing a new model of NCSs with parameter uncertainty,network.induced delay,nonlinearity and data packet dropout in the transmission,a strict linear matrix inequality(LMI)criterion is proposed for robust stabilization of the uncenmn nonlinear NCSs based on the Lyapunov stability theory.The maximum allowable transfer interval(MATI)can be derived by solving the feasibility problem of the corresponding LMI.Some numerical examples are provided to demonstrate the applicability of the proposed algorithm.
An ellipsoid algorithm for probabilistic robust controller design
Kanev, S.K.; de Schutter, B.; Verhaegen, M.H.G.
2003-01-01
In this paper, a new iterative approach to probabilistic robust controller design is presented, which is applicable to any robust controller/filter design problem that can be represented as an LMI feasibility problem. Recently, a probabilistic Subgradient Iteration algorithm was proposed for solving
H∞ State Feedback Delay-dependent Control for Discrete Systems with Multi-time-delay
Institute of Scientific and Technical Information of China (English)
Bai-Da Qu
2005-01-01
In this paper,H∞ state feedback control with delay information for discrete systems with multi-time-delay is discussed. Making use of linear matrix inequality (LMI) approach, a time-delay-dependent criterion for a discrete system with multi-time-delay to satisfy H∞ performance indices is induced, and then a strategy for H∞ state feedback control with delay values for plant with multi-time-delay is obtained. By solving corresponding LMI, a delay-dependent state feedback controller satisfying H∞ performance indices is designed. Finally, a simulation example demonstrates the validity of the proposed approach.
Institute of Scientific and Technical Information of China (English)
ZHANG Yan-hu; YAN Wen-jun; LU Jian-ning; ZHAO Guang-zhou
2005-01-01
Multi-objective robust state-feedback controller synthesis problems for linear discrete-time uncertain systems are addressed. Based on parameter-dependent Lyapunov functions, the Gl2 and GH2 norm expressed in terms of LMI (Linear Matrix Inequality) characterizations are further generalized to cope with the robust analysis for convex polytopic uncertain system.Robust state-feedback controller synthesis conditions are also derived for this class of uncertain systems. Using the above results,multi-objective state-feedback controller synthesis procedures which involve the LMI optimization technique are developed and less conservative than the existing one. An illustrative example verified the validity of the approach.
On stabilizing PI controller ranges for multivariable systems
Energy Technology Data Exchange (ETDEWEB)
Lin Chong [Institute of Complexity Science, Qingdao University, Qingdao, Shandong 266071 (China); Wang Qingguo; He Yong [Department of Electrical and Computer Engineering, National University of Singapore, 10 Kent Ridge Crescent, Singapore 119260 (Singapore); Wen Guilin [State Key Laboratory of Advanced Design and Manufactory for Vehicle Body, Hunan University, College of Mechanical and Automotive Engineering, Hunan University, Changsha, Hunan 410082 (China)], E-mail: wenguilin@yahoo.com.cn; Han Xu; Li Guangyao; Zhong Zhihua [State Key Laboratory of Advanced Design and Manufactory for Vehicle Body, Hunan University, College of Mechanical and Automotive Engineering, Hunan University, Changsha, Hunan 410082 (China)
2008-02-15
The paper is concerned with the computation of the maximum ranges of stabilizing proportional-integral (PI) controllers for multiple-input and multiple-output (MIMO) systems. A time-domain scheme is proposed by converting the considered problem to a robust stability problem for a polytopic system. An algorithm based on linear matrix inequality (LMI) is established to find the maximum ranges.
GALEX and Optical Light Curves of WX LMi, SDSSJ103100.5+202832.2 and SDSSJ121209.31+013627.7
Linnell, Albert P; Plotkin, Richard M; Holtzman, Jon; Seibert, Mark; Harrison, Thomas E; Howell, Steve B
2010-01-01
{\\it GALEX} near ultraviolet (NUV) and far-ultraviolet (FUV) light curves of three extremely low accretion rate polars show distinct modulations in their UV light curves. While these three systems have a range of magnetic fields from 13 to 70 MG, and of late type secondaries (including a likely brown dwarf in SDSSJ121209.31+013627.7), the accretion rates are similar, and the UV observations imply some mechanism is operating to create enhanced emission zones on the white dwarf. The UV variations match in phase to the two magnetic poles viewed in the optical in WX LMi and to the single poles evident in the optical in SDSSJ1212109.31+013627.7 and SDSSJ103100.55+202832.2. Simple spot models of the UV light curves show that if hot spots are responsible for the UV variations, the temperatures are on the order of 10,000-14,000K. For the single pole systems, the size of the FUV spot must be smaller than the NUV and in all cases, the geometry is likely more complicated than a simple circular spot.
DESIGNING REDUCED-ORDER CONTROLLERS OF MIXED SENSITIVITY PROBLEM FOR FLIGHT CONTROL SYSTEMS
Institute of Scientific and Technical Information of China (English)
无
2000-01-01
Based on linear matrix inequalities (LMI), the design method of reduced-order controllers of mixed sensitivity problem is studied for flight control systems. It is shown that there exists a controller with order not greater than the difference between the generalized plant order and the number of independent control variables, if the mixed sensitivity problem is solvable for strict regular flight control plants. The proof is constructive, and an approach to design such a controller can be obtained in terms of a pair of feasible solution to the well-known 3 LMI. Finally, an example of mixed sensitivity problem for a flight control system is given to demonstrate practice of the approach.
Institute of Scientific and Technical Information of China (English)
Zhang Yougang; Xu Bugong
2006-01-01
Decentralized robust stabilization problem of discrete-time fuzzy large-scale systems with parametric uncertainties is considered. This uncertain fuzzy large-scale system consists of N interconnected T-S fuzzy subsystems, and the parametric uncertainties are unknown but norm-bounded. Based on Lyapunov stability theory and decentralized control theory of large-scale system, the design schema of decentralized parallel distributed compensation (DPDC) fuzzy controllers to ensure the asymptotic stability of the whole fuzzy large-scale system is proposed. The existence conditions for these controllers take the forms of LMIs. Finally a numerical simulation example is given to show the utility of the method proposed.
Azizi, Sajad
2017-05-01
The robust stability of a class of feedback linearizable minimum-phase nonlinear system, having parametric uncertainties, is investigated in this study. The system in new coordinates is represented to an equivalent formulation after the attempt of feedback linearization. Due to the parametric uncertainties the approximately linearized system entails a norm bounded input nonlinearity such that the equilibrium point condition in error dynamics can not be satisfied. Accordingly, to guarantee the regional asymptotic stability a control synthesis problem is proposed by means of sufficient Linear Matrix Inequalities (LMIs) together with an amended nonlinear control term, derived from the Lyapunov redesign method, which tackles zero steady-state error condition. The numerical examples of a general aviation aircraft's longitudinal dynamics and inverted pendulum are simulated to show the proficiency of the proposed control technique. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.
广义时滞系统时滞依赖H∞控制的改进结果%Improved Results on Delay-dependent H∞ Control for Singular Time-delay Systems
Institute of Scientific and Technical Information of China (English)
吴争光; 苏宏业; 褚健
2009-01-01
The problem of delay-dependent H∞ control for singular systems with state delay is discussed. In terms of linear matrix inequality (LMI) approach, a delay-dependent bounded real lemma (BRL) is presented to ensure the system to be regular,impulse free, and stable with H∞ performance condition via an augmented Lyapunov functional. Based on the BRL obtained, the delay-dependent condition for the existence of H∞ state feedback controller is presented via strict LMI. An explicit expression for the desired state feedback controller is also given. Numerical examples are presented to illustrate the significant improvement on the conservativeness of some reported results in the literature.
H(infinity) output tracking control for nonlinear systems via T-S fuzzy model approach.
Lin, Chong; Wang, Qing-Guo; Lee, Tong Heng
2006-04-01
This paper studies the problem of H(infinity) output tracking control for nonlinear time-delay systems using Takagi-Sugeno (T-S) fuzzy model approach. An LMI-based design method is proposed for achieving the output tracking purpose. Illustrative examples are given to show the effectiveness of the present results.
LPV control of a tensegrity-membrane system
Yang, Shu; Sultan, Cornel
2017-10-01
This article presents the details of designing a linear parameter-varying (LPV) controller for a tensegrity-membrane system. The major control objective is to deploy the system from its initial packaged configuration to its final deployed configuration. Since LPV synthesis naturally leads to an infinite-dimensional linear matrix inequality (LMI) problem, a gridding method is used to reduce it to a finite-dimensional LMI problem and the control design is performed using a control-oriented model based on the linearized system dynamics at a set of system equilibriums. To test the performance of the resulting controller, a nonlinear finite element model and the control-oriented model are used in numerical simulations. To test the robustness of the controller, sensor noise is considered in another nonlinear finite element simulation and the results are compared with the simulation results given by the nominal system.
Kun, David William
Unmanned aircraft systems (UASs) are gaining popularity in civil and commercial applications as their lightweight on-board computers become more powerful and affordable, their power storage devices improve, and the Federal Aviation Administration addresses the legal and safety concerns of integrating UASs in the national airspace. Consequently, many researchers are pursuing novel methods to control UASs in order to improve their capabilities, dependability, and safety assurance. The nonlinear control approach is a common choice as it offers several benefits for these highly nonlinear aerospace systems (e.g., the quadrotor). First, the controller design is physically intuitive and is derived from well known dynamic equations. Second, the final control law is valid in a larger region of operation, including far from the equilibrium states. And third, the procedure is largely methodical, requiring less expertise with gain tuning, which can be arduous for a novice engineer. Considering these facts, this thesis proposes a nonlinear controller design method that combines the advantages of adaptive robust control (ARC) with the powerful design tools of linear matrix inequalities (LMI). The ARC-LMI controller is designed with a discontinuous projection-based adaptation law, and guarantees a prescribed transient and steady state tracking performance for uncertain systems in the presence of matched disturbances. The norm of the tracking error is bounded by a known function that depends on the controller design parameters in a known form. Furthermore, the LMI-based part of the controller ensures the stability of the system while overcoming polytopic uncertainties, and minimizes the control effort. This can reduce the number of parameters that require adaptation, and helps to avoid control input saturation. These desirable characteristics make the ARC-LMI control algorithm well suited for the quadrotor UAS, which may have unknown parameters and may encounter external
Institute of Scientific and Technical Information of China (English)
何勇; 吴敏
2005-01-01
Some delay-dependent absolute stability criteria for Lurie control systems with timevarying delay are derived, in which some free-weighting matrices are used to express the relationships between the terms in the Leibniz-Newton formula. These criteria are based on linear matrix inequality(LMI) such that the upper bound of time-delay guaranteeing the absolute stability and the free-weighting matrices can be obtained through the solutions of the LMI. Moreover, the Lyapunov functional constructed by the solutions of these LMIs is adopted to guarantee the absolute stability of the systems. Finally, some examples axe provided to demonstrate the effectiveness of the proposed methods.
Structured Control of LPV Systems with Application to Wind Turbines
DEFF Research Database (Denmark)
Adegas, Fabiano Daher; Stoustrup, Jakob
2012-01-01
can synthesize structured controllers like decentralized, static output and reduced order output feedback for discrete-time LPV systems. Based on a coordinate decent, it relies on a sufficient matrix inequality condition extended with slack variables to an upper bound on the induced L2-norm...... of the closed-loop system. Algorithms for the computation of feasible as well as optimal controllers are presented. The general case where no restrictions are imposed on the parameter dependence is treated here due to its suitability for modeling wind turbines. A comprehensive numerical example of a gain......This paper deals with structured control of linear parameter varying systems (LPV) with application to wind turbines. Instead of attempting to reduce the problem to linear matrix inequalities (LMI), we propose to design the controllers via an LMI-based iterative algorithm. The proposed algorithm...
Modeling and Model Predictive Power and Rate Control of Wireless Communication Networks
Directory of Open Access Journals (Sweden)
Cunwu Han
2014-01-01
Full Text Available A novel power and rate control system model for wireless communication networks is presented, which includes uncertainties, input constraints, and time-varying delays in both state and control input. A robust delay-dependent model predictive power and rate control method is proposed, and the state feedback control law is obtained by solving an optimization problem that is derived by using linear matrix inequality (LMI techniques. Simulation results are given to illustrate the effectiveness of the proposed method.
Pan, Indranil; Ghosh, Soumyajit; Gupta, Amitava; 10.1109/PACC.2011.5978958
2012-01-01
Networked Control Systems (NCSs) are often associated with problems like random data losses which might lead to system instability. This paper proposes a method based on the use of variable controller gains to achieve maximum parametric robustness of the plant controlled over a network. Stability using variable controller gains under data loss conditions is analyzed using a suitable Linear Matrix Inequality (LMI) formulation. Also, a Particle Swarm Optimization (PSO) based technique is used to maximize parametric robustness of the plant.
H{sup {infinity}} State Feedback Control for Generalized Continuous/Discrete Time Delay System
Energy Technology Data Exchange (ETDEWEB)
Kim, J.H.; Lee, S.K.; Park, H.B. [Kyungpook National University, Taegu (Korea, Republic of); Jeung, E.T. [Changwon National University, Changwon (Korea, Republic of)
1998-04-01
In this paper, we consider the problem of designing H{sup {infinity}} state feedback controller for the generalized time delay systems with delayed states and control inputs in continuous and discrete time cases, respectively. The generalized time delay system problems are solved on the basis of LMI(linear matrix inequality) technique considering time delays. The sufficient condition for the existence of controller and H{sup {infinity}} state feedback controller design methods are presented. Also, using some changes of variables and Schur complements, the obtained sufficient condition can be rewritten as a LMI form in terms of transformed variables. The proposed controller design method can be extended into the problem of robust H{sup {infinity}} state feedback controller design method easily. (author). 15 refs.
H∞ tracking control of coupled spatiotemporal chaos based on fuzzy models
Institute of Scientific and Technical Information of China (English)
Dou Chun-Xia
2005-01-01
Due to the interactions among coupled spatiotemporal subsystems, it is difficult to achieve the tracking control of the coupled spatiotemporal chaos. However, every subsystem of the coupled spatiotemporal chaos can be approximated by a set of fuzzy models, of which each represents a linearized model of the subsystem corresponding to the operating point of the controlled system. Based on these fuzzy models, an H∞ fuzzy tracking control scheme is suggested,where a linear matrix inequalities (LMI) is employed to represent the feedback controller. The parameters of controller are obtained by using convex optimization techniques of LMI. The model reference tracking control of the coupled spatiotemporal chaos is achieved, and the stability of the system is also guaranteed. The tracking performance is tested by simulation as an example.
TP-model transformation-based-control design frameworks
Baranyi, Péter
2016-01-01
This book covers new aspects and frameworks of control, design, and optimization based on the TP model transformation and its various extensions. The author outlines the three main steps of polytopic and LMI based control design: 1) development of the qLPV state-space model, 2) generation of the polytopic model; and 3) application of LMI to derive controller and observer. He goes on to describe why literature has extensively studied LMI design, but has not focused much on the second step, in part because the generation and manipulation of the polytopic form was not tractable in many cases. The author then shows how the TP model transformation facilitates this second step and hence reveals new directions, leading to powerful design procedures and the formulation of new questions. The chapters of this book, and the complex dynamical control tasks which they cover, are organized so as to present and analyze the beneficial aspect of the family of approaches (control, design, and optimization). Additionally, the b...
Energy Technology Data Exchange (ETDEWEB)
Wen Guilin [Key Laboratory of Advanced Technology for Vehicle Body Design and Manufactory, M.O.E, College of Mechanical and Automotive Engineering, Hunan University, Changsha, Hunan 410082 (China); Wang Qingguo [Department of Electrical and Computer Engineering, National University of Singapore, 10 Kent Ridge Crescent, Singapore 119260 (Singapore)]. E-mail: elewqg@nus.edu.sg; Lin Chong [Department of Electrical and Computer Engineering, National University of Singapore, 10 Kent Ridge Crescent, Singapore 119260 (Singapore); Han Xu [Key Laboratory of Advanced Technology for Vehicle Body Design and Manufactory, M.O.E, College of Mechanical and Automotive Engineering, Hunan University, Changsha, Hunan 410082 (China); Li Guangyao [Key Laboratory of Advanced Technology for Vehicle Body Design and Manufactory, M.O.E, College of Mechanical and Automotive Engineering, Hunan University, Changsha, Hunan 410082 (China)
2006-09-15
Synchronization under output feedback control with multiple random time delays is studied, using the paradigm in nonlinear physics-Chua's circuit. Compared with other synchronization control methods, output feedback control with multiple random delay is superior for a realistic synchronization application to secure communications. Sufficient condition for global stability of delay-dependent synchronization is established based on the LMI technique. Numerical simulations fully support the analytical approach, in spite of the random delays.
Cao, YY; Lam, J.
2001-01-01
This paper is concerned with simultaneous linear-quadratic (LQ) optimal control design for a set of LTI systems via piecewise constant output feedback. First, the discrete-time simultaneous LQ optimal control design problem is reduced to solving a set of coupled matrix inequalities and an iterative LMI algorithm is presented to compute the feedback gain. Then, simultaneous stabilization and simultaneous LQ optimal control design of a set of LTI continuous-time systems are considered via perio...
Directory of Open Access Journals (Sweden)
O. P. Bharti
2016-08-01
Full Text Available This paper describes the controller design for a DFIG based wind energy generation system using the static output feedback technique through the LMI Toolbox. The features of the DFIG, its converters and their controllers are discussed. The lower order nominal representation of DFIG is obtained using numerical differentiation of the SIMULINK model which is subsequently used for PID controller design. The obtained results are compared with existing methods for performance enhancement of the DFIG and wind energy conversion systems.
Dichotomy of nonlinear systems: Application to chaos control of nonlinear electronic circuit
Energy Technology Data Exchange (ETDEWEB)
Wang Jinzhi [State Key Laboratory for Turbulence and Complex Systems and Department of Mechanics and Engineering Science, Peking University, Beijing 100871 (China)]. E-mail: jinzhiw@pku.edu.cn; Duan Zhisheng [State Key Laboratory for Turbulence and Complex Systems and Department of Mechanics and Engineering Science, Peking University, Beijing 100871 (China); Huang Lin [State Key Laboratory for Turbulence and Complex Systems and Department of Mechanics and Engineering Science, Peking University, Beijing 100871 (China)
2006-02-27
In this Letter a new method of chaos control for Chua's circuit and the modified canonical Chua's electrical circuit is proposed by using the results of dichotomy in nonlinear systems. A linear feedback control based on linear matrix inequality (LMI) is given such that chaos oscillation or hyperchaos phenomenon of circuit systems injected control signal disappear. Numerical simulations are presented to illustrate the efficiency of the proposed method.
Directory of Open Access Journals (Sweden)
İsmail AVCI
2014-03-01
Full Text Available Crete Island is one of the most significant place by virtue of Turkish cultural history and often remembered by the authors and poets who lived in this island during the Ottoman period. The subject of this paper Hasan İlmi is amongst such authors commemorated as of the Crete. Hasan İlmi of the Crete worked as a government officer in various places in the Ottoman Empire and wrote several works of which only three works are available today. The first of these works is an unpublished Ottoman dictionary titled Osmanlı Dili. The second work of the author is titled Yemen Salnamesi with co-writer Hüseyin Hüsnü written during the period when the author served in Yemen. The last work of Hasan İlmi is a divanche (collection of his poems titled Me'alimü'l-garam. This work is composed of 2 praises dedicated to the Prophet Muhammad, 24 odes, 1 poem, and 3 ballads. In this paper, information about Hasan İlmi of the Crete and works will be provided and then his work Me'alimü'l-garam will be presented in more detail. Girit Adası, Osmanlı Dönemi'nde yetiştirdiği yazar ve şairlerle adından çokça söz edilen, Türk kültür tarihi bakımından dikkate değer yerlerden biridir. Bu yazıya konu olan Hasan İlmî de "Giridî" olarak anılan müelliflerdendir. Hayatını imparatorluğun farklı yerlerinde çeşitli devlet görevlerinde bulunarak geçiren Giritli Hasan İlmî'nin elde üç eseri bulunmaktadır. Bunlardan ilki Osmanlı Dili adlı basılamamış bir sözlük çalışmasıdır. İkinci eser müellifin Yemen'de bulunduğu dönemde Hüseyin Hüsnü ile birlikte hazırladığı Yemen Salnâmesi'dir. Hasan İlmî'nin üçüncü eseri ise şiirlerini bir araya getirdiği Me'âlimü'l-garâm adlı divançesidir. Eserde 2 naat, 24 gazel, 1 manzume ve 3 şarkı bulunmaktadır. Bu yazıda önce Giritli Hasan İlmî ve eserleri hakkında bilgi verilecek, ardından Me'âlimü'l-garâm üzerinde durulacak ve eserin metni verilecektir.
Stability of singular networked control systems with control constraint
Institute of Scientific and Technical Information of China (English)
Qiu Zhanzhi; Zhang Qingling; Zhao Zhiwu
2007-01-01
Based on bounded network-induced time-delay, the networked control system is modeled as a linear time-variant singular system.Using the Lyapunov theory and the linear matrix inequality approach, the criteria for delay-independent stability and delay-dependent stability of singular networked control systems are derived and transformed to a feasibility problem of linear matrix inequality formulation, which can be solved by the Matlab LMI toolbox, and the feasible solutions provide the maximum allowable delay bound that makes the system stable.A numerical example is provided, which shows that the analysis method is valid and the stability criteria are feasible.
Guaranteed cost control with constructing switching law of uncertain discrete-time switched systems
Institute of Scientific and Technical Information of China (English)
Zhang Ying; Duan Guangren
2007-01-01
A guaranteed cost control problem for a class of linear discrete-time switched systems with normbounded uncertainties is considered in this article. The purpose is to construct a switching rule and design a state feedback control law, such that, the closed-loop system is asymptotically stable and the closed-loop cost function value is not more than a specified upper bound for all admissible uncertainties under the constructed switching rule.A sufficient condition for the existence of guaranteed cost controllers and switching rules is derived based on the Lyapunov theory together with the linear matrix inequality (LMI) approach. Furthermore, a convex optimization problem with LMI constraints is formulated to select the suboptimal guaranteed cost controller. A numerical example demonstrates the validity of the proposed design approach.
Reliable gain-scheduled control of discrete-time systems and its application to CSTR model
Sakthivel, R.; Selvi, S.; Mathiyalagan, K.; Shi, Y.
2016-10-01
This paper is focused on reliable gain-scheduled controller design for a class of discrete-time systems with randomly occurring nonlinearities and actuator fault. Further, the nonlinearity in the system model is assumed to occur randomly according to a Bernoulli distribution with measurable time-varying probability in real time. The main purpose of this paper is to design a gain-scheduled controller by implementing a probability-dependent Lyapunov function and linear matrix inequality (LMI) approach such that the closed-loop discrete-time system is stochastically stable for all admissible randomly occurring nonlinearities. The existence conditions for the reliable controller is formulated in terms of LMI constraints. Finally, the proposed reliable gain-scheduled control scheme is applied on continuously stirred tank reactor model to demonstrate the effectiveness and applicability of the proposed design technique.
Robust control of an aircraft model
Energy Technology Data Exchange (ETDEWEB)
Werner, H. [Bochum Univ. (Germany). Fakultaet fuer Elektrotechnik
1999-12-01
A new multimodel approach to robust controller design is illustrated by a practical application: for a laboratory aircraft model, a robust controller is designed simultaneously for normal operating conditions and for propeller failure. Based on a linear model for each operating mode, an LMI formulation of the problem and convex programming are used to search for a state feedback controller which achieves the objective. This state feedback design is then realized simultaneously in both operating modes by a controller which is based on fast output sampling. Robust performance is demonstrated by experimental results. (orig.)
Robust control of an aircraft model
Energy Technology Data Exchange (ETDEWEB)
Werner, H. (Bochum Univ. (Germany). Fakultaet fuer Elektrotechnik)
1999-01-01
A new multimodel approach to robust controller design is illustrated by a practical application: for a laboratory aircraft model, a robust controller is designed simultaneously for normal operating conditions and for propeller failure. Based on a linear model for each operating mode, an LMI formulation of the problem and convex programming are used to search for a state feedback controller which achieves the objective. This state feedback design is then realized simultaneously in both operating modes by a controller which is based on fast output sampling. Robust performance is demonstrated by experimental results. (orig.)
PASSIVE CONTROL FOR A CLASS OF UNCERTAIN TIME-DELAY SYSTEMS
Institute of Scientific and Technical Information of China (English)
李志虎; 邵惠鹤
2001-01-01
This paper focuses on the passive control for a class of linear time-delay system with norm-bounded time-varying parameter uncertainties by using a linear matrix inequality (LMI) approach. A sufficient condition under which the uncertain time-delay system is quadratically stable and strictly passive for all admissible uncertainties was derived. It is shown that the solvability of problem of the robust passive controller design is implied by the feasibility of a linear matrix inequality.
Control design for discrete-time state-multiplicative noise stochastic systems
Krokavec, Dušan; Filasová, Anna
2015-11-01
Design conditions for existence of the H∞ linear state feedback control for discretetime stochastic systems with state-multiplicative noise and polytopic uncertainties are presented in the paper. Using an enhanced form of the bounded real lemma for discrete-time stochastic systems with state-multiplicative noise, the LMI-based procedure is provided for computation of the gains of linear, as well as nonlinear, state control law. The approach is illustrated on an example demonstrating the validity of the proposed method.
Robust H-infinity reliable control for a class of nonlinear uncertain neutral delay systems
Institute of Scientific and Technical Information of China (English)
Ximing SUN; Jun ZHAO; Bing CHEN
2004-01-01
This paper focuses on the robust H-infinity reliable control for a class of nonlinear neutral delay systems with uncertainties and actuator failures.We design a state feedback controller in terms of linear matrix inequality(LMI)such that the plant satisfies robust H-infinity performance for all admissible uncertainties,and actuator failures among a prespecified subset of actuators.An example is also given to illustrate the effectiveness of the proposed approach.
Improved Stability Analysis of Nonlinear Networked Control Systems over Multiple Communication Links
Delavar, Rahim; Tavassoli, Babak; Beheshti, Mohammad Taghi Hamidi
2015-01-01
In this paper, we consider a nonlinear networked control system (NCS) in which controllers, sensors and actuators are connected via several communication links. In each link, networking effects such as the transmission delay, packet loss, sampling jitter and data packet miss-ordering are captured by time-varying delays. Stability analysis is carried out based on the Lyapunov Krasovskii method to obtain a condition for stability of the nonlinear NCS in the form of linear matrix inequality (LMI...
2013-06-01
STABILITY BY COMPUTING A SINGLE QUADRATIC LYAPUNOV FUNCTION Mehrdad Pakmehr∗ PhD Candidate Decision and Control Laboratory (DCL) School of Aerospace...linearization and linear matrix inequality (LMI) techniques. Using convex optimization tools, a single quadratic Lyapunov function is computed for multiple...Scheduling Control of Gas Turbine Engines: Stability by Computing a Single Quadratic Lyapunov Function 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c
Guaranteed Cost Control for Uncertain Nonlinear Time-Delay Neutral Systems Based on T-S Fuzzy Model
Institute of Scientific and Technical Information of China (English)
无
2005-01-01
The problem of guaranteed cost fuzzy controller is studied for a class of nonlinear time-delay neutral systems with norm-bounded uncertainty based on T-S model. The sufficient conditions are first derived for the existence of guaranteed cost fuzzy controllers. These sufficient conditions are equivalent to a kind of linear matrix inequalities. Furthermore, a convex optimization problem with LMI constraints is formulated to design the optimal guaranteed cost controller.
Hamdy, M; Hamdan, I
2015-07-01
In this paper, a robust H∞ fuzzy output feedback controller is designed for a class of affine nonlinear systems with disturbance via Takagi-Sugeno (T-S) fuzzy bilinear model. The parallel distributed compensation (PDC) technique is utilized to design a fuzzy controller. The stability conditions of the overall closed loop T-S fuzzy bilinear model are formulated in terms of Lyapunov function via linear matrix inequality (LMI). The control law is robustified by H∞ sense to attenuate external disturbance. Moreover, the desired controller gains can be obtained by solving a set of LMI. A continuous stirred tank reactor (CSTR), which is a benchmark problem in nonlinear process control, is discussed in detail to verify the effectiveness of the proposed approach with a comparative study.
Synchronisation of chaotic systems using a novel sampled-data fuzzy controller
Institute of Scientific and Technical Information of China (English)
Feng Yi-Fu; Zhang Qing-Ling
2011-01-01
This paper presents the synchronisation of chaotic systems using a sampled-data fuzzy controller and is meaningful for many physical real-life applications. Firstly, a Takagi-Sugeno (T-S) fuzzy model is employed to represent the chaotic systems that contain some nonlinear terms, then a type of fuzzy sampled-data controller is proposed and an error system formed by the response and drive chaotic system. Secondly, relaxed LMI-based synchronisation conditions are derived by using a new paraneter-dependent Lyapunov-Krasovskii functional and relaxed stabilisation techniques for the underlying error system. The derived LMI-based conditions are used to aid the design of a sampled-data fuzzy controller to achieve the synchronisation of chaotic systems. Finally, a numerical example is provided to illustrate the effectiveness of the proposed results.
Synthesis Methods for Robust Passification and Control
Kelkar, Atul G.; Joshi, Suresh M. (Technical Monitor)
2000-01-01
The research effort under this cooperative agreement has been essentially the continuation of the work from previous grants. The ongoing work has primarily focused on developing passivity-based control techniques for Linear Time-Invariant (LTI) systems. During this period, there has been a significant progress made in the area of passivity-based control of LTI systems and some preliminary results have also been obtained for nonlinear systems, as well. The prior work has addressed optimal control design for inherently passive as well as non- passive linear systems. For exploiting the robustness characteristics of passivity-based controllers the passification methodology was developed for LTI systems that are not inherently passive. Various methods of passification were first proposed in and further developed. The robustness of passification was addressed for multi-input multi-output (MIMO) systems for certain classes of uncertainties using frequency-domain methods. For MIMO systems, a state-space approach using Linear Matrix Inequality (LMI)-based formulation was presented, for passification of non-passive LTI systems. An LMI-based robust passification technique was presented for systems with redundant actuators and sensors. The redundancy in actuators and sensors was used effectively for robust passification using the LMI formulation. The passification was designed to be robust to an interval-type uncertainties in system parameters. The passification techniques were used to design a robust controller for Benchmark Active Control Technology wing under parametric uncertainties. The results on passive nonlinear systems, however, are very limited to date. Our recent work in this area was presented, wherein some stability results were obtained for passive nonlinear systems that are affine in control.
Fault-tolerant control of linear uncertain systems using H∞ robust predictive control
Institute of Scientific and Technical Information of China (English)
Chen Xueqin; Geng Yunhai; Zhang Yingchun; Wang Feng
2008-01-01
The robust fault-tolerant control problem of linear uncertain systems is studied. It is shown that a solution for this problem can be obtained from a H∞ robust predictive controller (RMPC) by the method of linear matrix inequality (LMI). This approach has the advantages of both H∞ control and MPC: the robustness and ability to handle constraints explicitly. The robust closed-loop stability of the linear uncertain system with input and output constraints is proven under an actuator and sensor faults condition. Finally, satisfactory results of simulation experiments verify the validity of this algorithm.
Flight Control System Design by Quadratic Stabilization with Partial Pole Placement
Satoh, Atsushi; Sugimoto, Kenji
The most fundamental requirements for flight control system are ensuring robust stability and improving flying quality. Quadratic stabilization is a powerful technique ensuring robust stability against parameter change of aircraft due to flight condition. Furthermore, flying quality requirements are regarded as eigenstructure assignment specifications. This paper proposes a new design method of feedback gain which simultaneously achieves quadratic stabilization and partial pole placement. This design method is reduced to a numerical optimization problem including linear matrix inequality (LMI) constraints.
Observer-based H∞ control over packet dropping networks
Institute of Scientific and Technical Information of China (English)
无
2008-01-01
A new controller design problem of networked control systems with packet dropping is proposed. Depending on the place that the observer is put in the system, the network control systems with packet dropping are modeled as stochastic systems with the random variables satisfying the Bernoulli random binary distribution. The observer-based controller is designed to stabilize the networked system in the sense of mean square, and the prescribed H∞ disturbance attenuation level is achieved. The controller design problem is formulated as the feasibility of the convex optimization problem, which can be solved by a linear matrix inequality (LMI) approach. Numerical examples illustrate the effectiveness of the proposed methods.
A Modified Model Predictive Control Scheme
Institute of Scientific and Technical Information of China (English)
Xiao-Bing Hu; Wen-Hua Chen
2005-01-01
In implementations of MPC (Model Predictive Control) schemes, two issues need to be addressed. One is how to enlarge the stability region as much as possible. The other is how to guarantee stability when a computational time limitation exists. In this paper, a modified MPC scheme for constrained linear systems is described. An offline LMI-based iteration process is introduced to expand the stability region. At the same time, a database of feasible control sequences is generated offline so that stability can still be guaranteed in the case of computational time limitations. Simulation results illustrate the effectiveness of this new approach.
Institute of Scientific and Technical Information of China (English)
Wo Songlin; Shi Guodong; Zou Yun
2007-01-01
The decentralized robust guaranteed cost control problem is studied for a class ofinterconnected singular large-scale systems with time-delay and norm-bounded time-invariant parameter uncertainty under a given quadratic cost performance function. The problem that is addressed in this study is to design a decentralized robust guaranteed cost state feedback controller such that the closed-loop system is not only regular, impulse-free and stable, but also guarantees an adequate level of performance for all admissible uncertainties. A sufficient condition for the existence of the decentralized robust guaranteed cost state feedback controllers is proposed in terms of a linear matrix inequality (LMI) via LMI approach. When this condition is feasible, the desired state feedback decentralized robust guaranteed cost controller gain matrices can be obtained. Finally, an illustrative example is provided to demonstrate the effectiveness of the proposed approach.
Satisfactory control of discrete-time linear periodic systems
Institute of Scientific and Technical Information of China (English)
Shiqian LIU; Jihong ZHU; JinChun HU
2007-01-01
In this paper satisfactory control for discrete-time linear periodic systems is studied.Based on a suitable time-invariant state sampled reformulation,periodic state feedback controller has been designed such that desired requirements of steady state covariance,H-infinity rejection bound and regional pole assignment for the periodic system are met simultaneously.By using satisfactory control theory,the problem of satisfactory periodic controller can be transformed into a linear programming problem subject to a set of linear matrix inequalities(LMIs).and a feasible designing approach is presented via LMI technique.Numeric example validates the obtained conclusion.
Generalized H2 Control Synthesis for Periodic Systems
DEFF Research Database (Denmark)
Wisniewski, Rafal; Stoustrup, Jakob
2001-01-01
A control synthesis of periodic processes is addressed in this paper. A class of linear discrete time periodic systems with performance specified by the generalized $H_2$ operator norm, is considered. The paper proposes an LMI solution to this problem, the sufficient and necessary conditions...... for solvability of $H_2$ suboptimal control are stated. An algorithm for state feedback control synthesis is provided. The findings are applied for the attitude control of a satellite equipped with electro-magnetic coils, which comprises a very attractive means of attitude corrections for small low...
Design of Dynamic Controller for Neutral Differential Systems with Multiple Delays in Control Input
Institute of Scientific and Technical Information of China (English)
Zi-Xin Liu; Shu Lü; Shou-Ming Zhong
2009-01-01
The design problem of dynamic output feedback controller for a class of multi-delayed neutral systems has been considered. A criterion for the existence and asymptotic stability of such controller is derived via defining a new integral operator. The criterion is expressed in terms of the linear matrix inequalities (LMIs), which can be checked numerically using the effective LMI toolbox in MATLAB. One numerical example is given to illustrate the proposed design method. Numerical simulation shows that the new design method is valid.
Wei Guan; Qiao Zhu; Xu-Dong Wang; Xu-Hui Liu
2014-01-01
This paper is concerned with the variable initial states problem in iterative learning control (ILC) for linear continuous systems. Firstly, the properties of the trajectory of 2-D continuous-discrete Roesser model are analyzed by using Lyapunov's method. Then, for any variable initial states which absolutely converge to the desired initial state, some ILC design criteria in the form of linear matrix inequalities (LMI) are given to ensure the convergence of the PD-type ILC rules. The converge...
Yi-You Hou; Zhang-Lin Wan
2014-01-01
This paper considers the problem of the robust stability for the nonlinear system with time-varying delay and parameters uncertainties. Based on the H∞ theorem, Lyapunov-Krasovskii theory, and linear matrix inequality (LMI) optimization technique, the H∞ quasi-sliding mode controller and switching function are developed such that the nonlinear system is asymptotically stable in the quasi-sliding mode and satisfies the disturbance attenuation (H∞-norm performance). The effectiveness and accura...
Indian Academy of Sciences (India)
Qian Lin; Xiaofeng Wu; Yun Chen
2015-12-01
This paper studies the global synchronization of non-autonomous, time-delay, chaotic power systems via linear state-error feedback control. The frequency domain criterion and the LMI criterion are proposed and applied to design the coupling matrix. Some algebraic criteria via a single-variable linear coupling are derived and formulated in simple algebraic inequalities. The effectiveness of the new criteria is illustrated with numerical examples.
H∞ Control for Uncertain Discrete-Dime Systems with Delays
Institute of Scientific and Technical Information of China (English)
潘俊涛
2007-01-01
In this paper,a new approach to H∞ controller design for a class of uncertain discrete-time T-S fuzzy systems are proposed.According to the Lyapunov stability theory as well as parallel distributed compensation (PDC),several sufficient conditions for stabilization of considered systems are derived.The design procedures based on LMI for the fuzzy robust controller are given, which guarantee the closed-loop system is asymptotically stable and the effect of disturbance input on the controlled output is reduced to a prescribed level.The simulation results show the proposed method is effective.
Event-triggered output feedback control for distributed networked systems.
Mahmoud, Magdi S; Sabih, Muhammad; Elshafei, Moustafa
2016-01-01
This paper addresses the problem of output-feedback communication and control with event-triggered framework in the context of distributed networked control systems. The design problem of the event-triggered output-feedback control is proposed as a linear matrix inequality (LMI) feasibility problem. The scheme is developed for the distributed system where only partial states are available. In this scheme, a subsystem uses local observers and share its information to its neighbors only when the subsystem's local error exceeds a specified threshold. The developed method is illustrated by using a coupled cart example from the literature.
Mixed H2／H∞ Optimal Guaranteed Cost Control of Uncertain Linear Systems
Institute of Scientific and Technical Information of China (English)
GuodingChen; MayingYang; LiYu
2004-01-01
The mixed H2/H∞ guaranteed cost control problem via state feedback control laws is considered in this paper for linear systems with norm-bounded parameter uncertainty. Based on the linear matrix inequality (LMI) approach, sufficient conditions are derived for the existence of guaranteed cost controllers whihc guarantee not only a prespecified H∞ disturbance attenuation level on one controlled output for all admissible parameter uncertainties, but also the worst-case H2 performance index on the other controlled output to be no more than a specified bound. Furthermore, a convex optimization problem is formulated to design an optimal H2/H∞ guaranteed cost controller.
Robust H∞ control for uncertain descriptor systems with state and control delay
Institute of Scientific and Technical Information of China (English)
Piao Fengxian; Zhang Qingling; Ma Xiuzhen
2006-01-01
The problem of robust stabilization for uncertain continuous descriptor system with state and control delay is considered. The time-varying parametric uncertainty is assumed to be norm-bounded. The purpose of the robust stabilization is to design a memoryless state feedback law such that the resulting closed-loop system is robustly stable. A sufficient condition that uncertain continuous descriptor system is robustly stabilizabled by state feedback law is derived in terms of linear matrix inequality (LMI). Finally, a numerical example is provided to demonstrate the application of the proposed method.
Adaptive control of uncertain time-delay chaotic systems
Institute of Scientific and Technical Information of China (English)
Zhuhong ZHANG
2005-01-01
This work investigates adaptive control of a large class of uncertain me-delay chaotic systems (UTCSs) with unknown general perturbation terms bounded by a polynomial ( unknown gains). Associated with the different cases of known and unknown system matrices, two corresponding adaptive controllers are proposed to stabilize unstable fixed points of the systems by means of Lyapunov stability theory and linear matrix inequalities (LMI) which can be solved easily by convex optimization algorithms. Two examples are used for examining the effectiveness of the proposed methods.
Two-Link Flexible Manipulator Control Using Sliding Mode Control Based Linear Matrix Inequality
Zulfatman; Marzuki, Mohammad; Alif Mardiyah, Nur
2017-04-01
Two-link flexible manipulator is a manipulator robot which at least one of its arms is made of lightweight material and not rigid. Flexible robot manipulator has some advantages over the rigid robot manipulator, such as lighter, requires less power and costs, and to result greater payload. However, suitable control algorithm to maintain the two-link flexible robot manipulator in accurate positioning is very challenging. In this study, sliding mode control (SMC) was employed as robust control algorithm due to its insensitivity on the system parameter variations and the presence of disturbances when the system states are sliding on a sliding surface. SMC algorithm was combined with linear matrix inequality (LMI), which aims to reduce the effects of chattering coming from the oscillation of the state during sliding on the sliding surface. Stability of the control algorithm is guaranteed by Lyapunov function candidate. Based on simulation works, SMC based LMI resulted in better performance improvements despite the disturbances with significant chattering reduction. This was evident from the decline of the sum of squared tracking error (SSTE) and the sum of squared of control input (SSCI) indexes respectively 25.4% and 19.4%.
Directory of Open Access Journals (Sweden)
Birgir Guðmundsson
2010-12-01
Full Text Available Hefðbundnir fjölmiðlar voru ekki í aðalhlutverki við kynningu og umfjöllun um einstaka frambjóðendur í kosningunum til stjórnlagaþings í nóvember 2010. Persónukjör með landið sem eitt kjördæmi þar sem yfir 500 frambjóðendur voru í kjöri er fyrirkomulag sem ekki hentar verklagi og vinnubrögðum hefðbundinna miðla og því er lýðræðislegt hlutverk þeirra takmarkað að þessu leyti. Í greininni er greint frá niðurstöðum könnunar meðal frambjóðenda til þingsins á því hvernig þeir höguðu kynningarmálum sínum og kemur í ljós að netmiðlar voru í aðalhlutverki, sérstaklega samfélagsvefurinn Facebook og miðlar sem ekki teljast til stóru hefðbundnu miðlanna. Í gegnum þessa miðla reyndu frambjóðendur að koma sér og stefnumálum sínum á framfæri inn í almannarými þjóðfélagsumræðunnar. Lítil sem engin tilraun var gerð meðal frambjóðenda til að kaupa sér leið inn í almannarýmið með auglýsingum.
Stability analysis and design of fuzzy control system with bounded uncertain delays
Institute of Scientific and Technical Information of China (English)
Jianguo GUO; Juntao LI; Fengqi ZHOU; Jun ZHOU
2005-01-01
Fuzzy control problems for systems with bounded uncertain delays were studied.Based on Lyapunov stability theory and matrix theory,a nonlinear state feedback fuzzy controller was designed by linear matrix inequalities (LMI) approach,and the global exponential stability of the closed-loop system was strictly proved.For a fuzzy control system with bounded uncertain delays,under the global exponential stability condition which is reduced to p linear matrix inequalities,the controller guarantees stability performances of state variables.Finally,the simulation shows the validity of the method in this paper.
DEFF Research Database (Denmark)
Wisniewski, Rafal; Stoustrup, Jakob
2001-01-01
A control synthesis for a spacecraft equipped with a set of mutually perpendicular coils and a vector magnetometer is addressed in this paper. The interaction between the Earth's magnetic field and an artificial magnetic field generated by the coils produces a control torque. Comparison between...... the expected magnetic field vector and the true magnetometer data is used for the attitude determination. The magnetic attitude control and determination is intrinsically periodic due to periodic nature of the geomagnetic field variation in orbit. The control performance is specified by the generalized H2...... operator norm. The paper proposes an LMI solution to this problem...
The Robust H∞ Control of a Stochastic Inventory-Production System
Institute of Scientific and Technical Information of China (English)
ZHONG Mai-ying; TANG Bing-yong
2002-01-01
Considering both the stochastic demand rate and norm-bounded unknown demand uncertainty,this paper deals with the inventory-production control problem where the stocked products may deteriorate with a rate that depends on the stochastic demand rate. By using robust H∞ control technique, the existing conditions of state feedback control strategies is given and proved, and the robust optimal policy that solves this problem is obtained in terms of a set of linear matrix inequality (LMI). Finally, an example illustrates the usefulness of the proposed methods and shows that robust H∞ control inventory-production strategy could attenuate the influence of demand uncertainty more efficiently than linear quadratic optimal policy.
Robust H {sub {infinity}} output dynamic observer-based control of uncertain time-delay systems
Energy Technology Data Exchange (ETDEWEB)
Chen, J.-D. [Department of Electronic Engineering, National Kinmen Institute of Technology, Jinning, Kinmen 892, Taiwan (China)]. E-mail: tdchen@mail.kmit.edu.tw
2007-01-15
In this paper, the robustness and H {sub {infinity}} control problems of output dynamic observer-based control for a class of uncertain linear systems with time delay are considered. Under no disturbance input, the asymptotic stabilization for uncertain time-delay systems will be guaranteed. Linear matrix inequality (LMI) optimization approach is used to design three classes of the H {sub {infinity}} output dynamic controls. Based on the results of this paper, the constraint of matrix equality is not necessary for designing the observer-based controls.
Robust output feedback H-infinity control and filtering for uncertain linear systems
Chang, Xiao-Heng
2014-01-01
"Robust Output Feedback H-infinity Control and Filtering for Uncertain Linear Systems" discusses new and meaningful findings on robust output feedback H-infinity control and filtering for uncertain linear systems, presenting a number of useful and less conservative design results based on the linear matrix inequality (LMI) technique. Though primarily intended for graduate students in control and filtering, the book can also serve as a valuable reference work for researchers wishing to explore the area of robust H-infinity control and filtering of uncertain systems. Dr. Xiao-Heng Chang is a Professor at the College of Engineering, Bohai University, China.
Institute of Scientific and Technical Information of China (English)
Ruiquan LIN; Fuwen YANG; Renchong PENG
2009-01-01
Considering that the controller feedback gain and the observer gain are of additive norm-bounded variations, a design method of observer-based H-infinity output feedback controller for uncertain Delta operator systems is proposed in this paper. A sufficient condition of such controllers is presented in linear matrix inequality (LMI) forms. A numerical example is then given to illustrate the effectiveness of this method, that is, the obtained controller guarantees the closed-loop system asymptotically stable and the expected H-infinity performance even if the controller feedback gain and the observer gain are varied.
Robust control of linear descriptor systems
Feng, Yu
2017-01-01
This book develops original results regarding singular dynamic systems following two different paths. The first consists of generalizing results from classical state-space cases to linear descriptor systems, such as dilated linear matrix inequality (LMI) characterizations for descriptor systems and performance control under regulation constraints. The second is a new path, which considers descriptor systems as a powerful tool for conceiving new control laws, understanding and deciphering some controller’s architecture and even homogenizing different—existing—ways of obtaining some new and/or known results for state-space systems. The book also highlights the comprehensive control problem for descriptor systems as an example of using the descriptor framework in order to transform a non-standard control problem into a classic stabilization control problem. In another section, an accurate solution is derived for the sensitivity constrained linear optimal control also using the descriptor framework. The boo...
Guaranteed Cost Fault-Tolerant Control for Networked Control Systems with Sensor Faults
Directory of Open Access Journals (Sweden)
Qixin Zhu
2015-01-01
Full Text Available For the large scale and complicated structure of networked control systems, time-varying sensor faults could inevitably occur when the system works in a poor environment. Guaranteed cost fault-tolerant controller for the new networked control systems with time-varying sensor faults is designed in this paper. Based on time delay of the network transmission environment, the networked control systems with sensor faults are modeled as a discrete-time system with uncertain parameters. And the model of networked control systems is related to the boundary values of the sensor faults. Moreover, using Lyapunov stability theory and linear matrix inequalities (LMI approach, the guaranteed cost fault-tolerant controller is verified to render such networked control systems asymptotically stable. Finally, simulations are included to demonstrate the theoretical results.
Adaptive control for a class of discrete-time time-delay systems with regard to delay parameter
Institute of Scientific and Technical Information of China (English)
Chai Lin; Cheng Ming; Fei Shumin; Zhai Junyong
2009-01-01
The memory state feedback control problem for a class of discrete-time systems with input delay and unknown state delay is addressed based on LMIs and Lyapunov-Krasovskii functional method. Under the action of our designed adaptive control law, the unknown time-delay parameter is included in memory state feedback controller. Using LMI technique, delay-dependent sufficient conditions for the existence of the feedback controller are obtained. Finally, the effectiveness of the proposed design method is demonstrated by a numerical example.
Optimal guaranteed cost control for an uncertain discrete T-S fuzzy system with time-delay
Institute of Scientific and Technical Information of China (English)
Renming WANG; Thierry Marie GUERRA; Juntao PAN
2009-01-01
This paper considers the guaranteed cost control problem for a class of uncertain discrete T-S fuzzy systems with time delay and a given quadratic cost function. Sufficient conditions for the existence of such controllers are derived based on the linear matrix inequalities (LMI) approach by constructing a specific nonquadratic Lyapunov-Krasovskii functional and a nonlinear PDC-like control law. A convex optimization problem is also formulated to select the optimal guaranteed cost controller that minimizes the upper bound of the closed-loop cost function. Finally, numerical examples are presented to demonstrate the effectiveness of the proposed approaches.
Cheng, Xiang-Qin; Qu, Jing-Yuan; Yan, Zhe-Ping; Bian, Xin-Qian
2010-03-01
In order to improve the security and reliability for autonomous underwater vehicle (AUV) navigation, an H∞ robust fault-tolerant controller was designed after analyzing variations in state-feedback gain. Operating conditions and the design method were then analyzed so that the control problem could be expressed as a mathematical optimization problem. This permitted the use of linear matrix inequalities (LMI) to solve for the H∞ controller for the system. When considering different actuator failures, these conditions were then also mathematically expressed, allowing the H∞ robust controller to solve for these events and thus be fault-tolerant. Finally, simulation results showed that the H∞ robust fault-tolerant controller could provide precise AUV navigation control with strong robustness.
The Design of Robust Controller for Networked Control System with Time Delay
Directory of Open Access Journals (Sweden)
Zhongda Lu
2015-01-01
Full Text Available This paper considers the stability and H∞ control problem of networked control systems with time delay. Taking into account the influence of network with delay, unknown input disturbance, and uncertainties of the system modeling, meanwhile we establish a precise, closed-loop model for networked control systems with time delay. By selecting a proper Lyapunov-Krasovskii function and using Lyapunov theorem, a sufficient condition for stability of the system in the form of LMI is demonstrated, corresponding controller parameters are acquired, and the convergence of the control algorithm is proved. The simulation example shows that the construction of the network robust control system with time delay indeed improves the stability performance of the system, which indicates the effectiveness of the design.
Passivity-Sliding Mode Control of Uncertain Chaotic Systems with Stochastic Disturbances
Directory of Open Access Journals (Sweden)
Zhumu Fu
2014-01-01
Full Text Available This paper is concerned with the stabilization problem of uncertain chaotic systems with stochastic disturbances. A novel sliding function is designed, and then a sliding mode controller is established such that the trajectory of the system converges to the sliding surface in a finite time. Using a virtual state feedback control technique, sufficient condition for the mean square asymptotic stability and passivity of sliding mode dynamics is derived via linear matrix inequality (LMI. Finally, a simulation example is presented to show the validity and advantage of the proposed method.
Wang, Tianbo; Zhou, Wuneng; Zhao, Shouwei; Yu, Weiqin
2014-03-01
In this paper, the robust exponential synchronization problem for a class of uncertain delayed master-slave dynamical system is investigated by using the adaptive control method. Different from some existing master-slave models, the considered master-slave system includes bounded unmodeled dynamics. In order to compensate the effect of unmodeled dynamics and effectively achieve synchronization, a novel adaptive controller with simple updated laws is proposed. Moreover, the results are given in terms of LMIs, which can be easily solved by LMI Toolbox in Matlab. A numerical example is given to illustrate the effectiveness of the method.
H∞ Enhanced Control Design of Discrete-Time Takagi-Sugeno State-Multiplicative Noisy Systems
Directory of Open Access Journals (Sweden)
Dušan Krokavec
2014-01-01
Full Text Available Design conditions for existence of the H∞ state feedback control for Takagi-Sugeno fuzzy discrete-time stochastic systems with state-multiplicative noise, stabilizing the closed-loop in such way that the quadratic performance in the mean is satisfied, are presented in the paper. Using newly introduced enhanced form of the bounded real lemma for such stochastic systems, the LMI-based procedure is provided for computation of gain matrices of the state control law, realized in the parallel distributed compensation structure. The approach is illustrated on an example, demonstrating the validity of the proposed method.
Passive Fault-tolerant Control of Discrete-time Piecewise Affine Systems against Actuator Faults
DEFF Research Database (Denmark)
Tabatabaeipour, Seyed Mojtaba; Izadi-Zamanabadi, Roozbeh; Bak, Thomas
2012-01-01
In this paper, we propose a new method for passive fault-tolerant control of discrete time piecewise affine systems. Actuator faults are considered. A reliable piecewise linear quadratic regulator (LQR) state feedback is designed such that it can tolerate actuator faults. A sufficient condition...... for the exis- tence of a passive fault-tolerant controller is derived and formulated as the feasibility of a set of linear matrix inequalities (LMIs). The upper bound on the performance cost can be minimized using a convex optimization problem with LMI constraints which can be solved efficiently. The approach...
A new positive real characterization and robust positive real control of descriptor systems
Institute of Scientific and Technical Information of China (English)
Hanyong SHAO; Chunbo FENG
2005-01-01
This paper investigates the positive real control problem for uncertain descriptor systems.The parametric uncertainty is assumed to be norm bounded.Firstly,for the nominal system,a new positive real characterization is given,which is expressed by a strict linear matrix inequality(LMI) without equality constraints.Secondly,for the uncertain system,necessary and sufficient conditions for the solvability of the positive real control problem are derived.Based on these conditioos a state feedback law is obtained,which renders the resultant closed-loop system robustly positive real.
Directory of Open Access Journals (Sweden)
Lun Zhai
2014-01-01
Full Text Available A parametric learning based robust iterative learning control (ILC scheme is applied to the time varying delay multiple-input and multiple-output (MIMO linear systems. The convergence conditions are derived by using the H∞ and linear matrix inequality (LMI approaches, and the convergence speed is analyzed as well. A practical identification strategy is applied to optimize the learning laws and to improve the robustness and performance of the control system. Numerical simulations are illustrated to validate the above concepts.
Robust H∞ Control for Uncertain Markovian Jump Linear Time-Delay Systems
Institute of Scientific and Technical Information of China (English)
无
2002-01-01
This paper studies the robust stochastic stabilization and robust H∞ control for linear time-delay systems with both Markovian jump parameters and unknown norm-bounded parameter uncertainties. This problem can be solved on the basis of stochastic Lyapunov approach and linear matrix inequality (LMI) technique. Sufficient conditions for the existence of stochastic stabilization and robust H∞ state feedback controller are presented in terms of a set of solutions of coupled LMIs. Finally, a numerical example is included to demonstrate the practicability of the proposed methods.
Exponential stability of a PI plus reset integrator controller by a sampled-data system approach
Davó, M. A.; Gouaisbaut, F.; Baños, A; Tarbouriech, S.; Seuret, A.
2016-01-01
The paper deals with the stability analysis of time-delay reset control systems, for which the resetting law is assumed to satisfy a time-dependent condition. A stability analysis of the closed-loop system is performed based on an appropriate sampled-data system. New linear matrix inequality (LMI) conditions are proposed to ensure the exponential stability of the closed-loop resulting of the connection of a plant with a proportional and integral controller together with a reset integrator (PI...
Linear matrix inequalities for analysis and control of linear vector second-order systems
Energy Technology Data Exchange (ETDEWEB)
Adegas, Fabiano D. [Aalborg Univ. (Denmark); Stoustrup, Jakob [Aalborg Univ. (Denmark)
2014-10-06
Many dynamical systems are modeled as vector second-order differential equations. This paper presents analysis and synthesis conditions in terms of LMI with explicit dependence in the coefficient matrices of vector second-order systems. These conditions benefit from the separation between the Lyapunov matrix and the system matrices by introducing matrix multipliers, which potentially reduce conservativeness in hard control problems. Multipliers facilitate the usage of parameter-dependent Lyapunov functions as certificates of stability of uncertain and time-varying vector second-order systems. The conditions introduced in this work have the potential to increase the practice of analyzing and controlling systems directly in vector second-order form.
Mixed Gl2/GH2 multi-channel multi-objective control synthesis for discrete time systems
Institute of Scientific and Technical Information of China (English)
颜文俊; 张森林
2004-01-01
This paper proposes a new approach for multi-objective robust control.The approach extends the standard generalized l2(Gl2)and generalized H2(GH2)conditions to a set of new linear matrix inequality(LMI)constraints based on a new stability condition.A technique for variable parameterization is introduced to the multi-objective control problem to preserve the linearity of the synthesis variables.Consequently,the multi-channel multi-objective mixed Gl2/GH2 control problem can be solved less conservatively using computationally tractable algorithms developed in the paper.
A unified approach to fixed-order controller design via linear matrix inequalities
Directory of Open Access Journals (Sweden)
Iwasaki T.
1995-01-01
Full Text Available We consider the design of fixed-order (or low-order linear controllers which meet certain performance and/or robustness specifications. The following three problems are considered; covariance control as a nominal performance problem, 𝒬 -stabilization as a robust stabilization problem, and robust L ∞ control problem as a robust performance problem. All three control problems are converted to a single linear algebra problem of solving a linear matrix inequality (LMI of the type B G C + ( B G C T + Q < 0 for the unknown matrix G . Thus this paper addresses the fixed-order controller design problem in a unified way. Necessary and sufficient conditions for the existence of a fixed-order controller which satisfies the design specifications for each problem are derived, and an explicit controller formula is given. In any case, the resulting problem is shown to be a search for a (structured positive definite matrix X such that X ∈ 𝒞 1 and X − 1 ∈ 𝒞 2 where 𝒞 1 and 𝒞 2 are convex sets defined by LMIs. Computational aspects of the nonconvex LMI problem are discussed.
Model Predictive Control of Nonlinear Systems: Stability Region and Feasible Initial Control
Institute of Scientific and Technical Information of China (English)
Xiao-Bing Hu; Wen-Hua Chen
2007-01-01
This paper proposes a new method for model predictive control (MPC) of nonlinear systems to calculate stability region and feasible initial control profile/sequence, which are important to the implementations of MPC. Different from many existing methods,this paper distinguishes stability region from conservative terminal region. With global linearization, linear differential inclusion (LDI)and linear matrix inequality (LMI) techniques, a nonlinear system is transformed into a convex set of linear systems, and then the vertices of the set are used off-line to design the controller, to estimate stability region, and also to determine a feasible initial control profile/sequence. The advantages of the proposed method are demonstrated by simulation study.
Attitude Control for an Aero-Vehicle Using Vector Thrusting and Variable Speed Control Moment Gyros
Shin, Jong-Yeob; Lim, K. B.; Moerder, D. D.
2005-01-01
Stabilization of passively unstable thrust-levitated vehicles can require significant control inputs. Although thrust vectoring is a straightforward choice for realizing these inputs, this may lead to difficulties discussed in the paper. This paper examines supplementing thrust vectoring with Variable-Speed Control Moment Gyroscopes (VSCMGs). The paper describes how to allocate VSCMGs and the vectored thrust mechanism for attitude stabilization in frequency domain and also shows trade-off between vectored thrust and VSCMGs. Using an H2 control synthesis methodology in LMI optimization, a feedback control law is designed for a thrust-levitated research vehicle and is simulated with the full nonlinear model. It is demonstrated that VSCMGs can reduce the use of vectored thrust variation for stabilizing the hovering platform in the presence of strong wind gusts.
Guo, Xiang-Gui; Yang, Guang-Hong
2013-04-01
The problem of designing insensitive H ∞ output tracking controller for discrete-time systems is studied in a unified framework by using the delta operator approach. A type of coefficient sensitivity performance measure is first developed tomeasure the sensitivity of the transfer function with respect to controller coefficient variations, and the corresponding controller design problem is naturally reformulated as a mixed-objective H ∞ control problem. It is worth mentioning that a novel bounded real lemma (BRL), i.e. Theorem 1 in this article, for delta operator systems is obtained, which is adapted to deal with the multi-objective optimisation problem or polytopic uncertain systems in a potentially less conservative framework. Then, based on the novel lemma, an linear matrix inequality (LMI)-based design method is proposed for achieving the output tracking purpose. Finally, a numerical example based on the linearised model of F-18 aircraft is given to illustrate the effectiveness of the proposed method.
Robust reliable control design for networked control system with sampling communication
Sakthivel, R.; Santra, Srimanta; Mathiyalagan, K.; Su, Hongye
2015-12-01
In this article, the problem of robust exponential stability and reliable stabilisation for a class of continuous-time networked control systems (NCSs) with a sample-data controller and unknown time-varying sampling rate is considered. The analysis is based on average dwell-time, Lyapunov-Krasovskii functional and linear matrix inequality (LMI) technique. The delay-dependent criteria are developed for ensuring the robust exponential stability of the considered NCSs. The obtained conditions are formulated in terms of LMIs that can easily be solved by using standard software packages. Furthermore, the result is extended to study the robust stabilisation for NCS with parameter uncertainties. A state feedback controller is constructed in terms of the solution to a set of LMIs, which guarantee the robust exponential stabilisation of NCS and the controller. Finally, numerical examples are presented to illustrate the effectiveness of the obtained results.
T-S Fuzzy Model Based Control Strategy for the Networked Suspension Control System of Maglev Train
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Guang He
2015-01-01
Full Text Available The control problem for the networked suspension control system of maglev train with random induced time delay and packet dropouts is investigated. First, Takagi-Sugeno (T-S fuzzy models are utilized to represent the discrete-time nonlinear networked suspension control system, and the parameters uncertainties of the nonlinear model have also been taken into account. The controllers take the form of parallel distributed compensation. Then, a sufficient condition for the stability of the networked suspension control system is derived. Based on the criteria, the state feedback fuzzy controllers are obtained, and the controller gains can be computed by using MATLAB LMI Toolbox directly. Finally, both the numerical simulations and physical experiments on the full-scale single bogie of CMS-04 maglev train have been accomplished to demonstrate the effectiveness of this proposed method.
Institute of Scientific and Technical Information of China (English)
无
2007-01-01
The H∞ output feedback control problem for uncertain discrete-time switched systems is reasearched. A new characterization of stability and H∞ performance for the switched system under arbitrary switching is obtained by using switched Lyapunov function.Then,based on the characterization,a linear matrix inequality (LMI)approach is developed to design a switched output feedback controller which guarantees the stability and H∞ performance of the closed-loop system.A numerical example is presented to demonstrate the application of the proposed method.
Directory of Open Access Journals (Sweden)
Xia Zhou
2013-01-01
Full Text Available The problem of bounded-input bounded-output (BIBO stabilization in mean square for a class of discrete-time stochastic control systems with mixed time-varying delays and nonlinear perturbations is investigated. Some novel delay-dependent stability conditions for the previously mentioned system are established by constructing a novel Lyapunov-Krasovskii function. These conditions are expressed in the forms of linear matrix inequalities (LMIs, whose feasibility can be easily checked by using MATLAB LMI Toolbox. Finally, a numerical example is given to illustrate the validity of the obtained results.
Flexible-link Robot Control Using a Linear Parameter Varying Systems Methodology
Directory of Open Access Journals (Sweden)
Houssem Halalchi
2014-03-01
Full Text Available This paper addresses the issues of the Linear Parameter Varying (LPV modelling and control of flexible-link robot manipulators. The LPV formalism allows the synthesis of nonlinear control laws and the assessment of their closed-loop stability and performances in a simple and effective manner, based on the use of Linear Matrix Inequalities (LMI. Following the quasi-LPV modelling approach, an LPV model of a flexible manipulator is obtained, starting from the nonlinear dynamic model stemming from Euler-Lagrange equations. Based on this LPV model, which has a rational dependence in terms of the varying parameters, two different methods for the synthesis of LPV controllers are explored. They guarantee the asymptotic stability and some level of closed-loop L2-gain performance on a bounded parametric set. The first method exploits a descriptor representation that simplifies the rational dependence of the LPV model, whereas the second one manages the troublesome rational dependence by using dilated LMI conditions and taking the particular structure of the model into account. The resulting controllers involve the measured state variables only, namely the joint positions and velocities. Simulation results are presented that illustrate the validity of the proposed control methodology. Comparisons with an inversion-based nonlinear control method are performed in the presence of velocity measurement noise, model uncertainties and high-frequency inputs.
DEFF Research Database (Denmark)
Langkilde, Anne; Petersen, Janne; Henriksen, Jens Henrik
2015-01-01
was significantly positively associated with fat mass index (FMI) and abdominal VAT, but not with lean mass index (LMI). IL-6 was significantly associated with both FMI and VAT, and low LMI. High suPAR was associated with low LMI, and weakly with high FMI and VAT. CONCLUSIONS: Leptin reflected adiposity...
Institute of Scientific and Technical Information of China (English)
Yu-Ping Zhang; Hong Zhu; Shou-Ming Zhong
2007-01-01
This paper concerns the robust non-fragile guaranteed cost control for nonlinear time delay discrete-time systems based on Takagi-Sugeno (T-S) model. The problem is to design a guaranteed cost state feedback controller which can tolerate uncertainties from both models and gain variation. Sufficient conditions for the existence of such controller are given based on the linear matrix inequality (LMI) approach combined with Lyapunov method and inequality technique. A numerical example is given to illustrate the feasibility and effectiveness of our result.
Robust H2 estimation and control
Institute of Scientific and Technical Information of China (English)
Lihua XIE; Yeng Chai SOH; Chunling DU; Yun ZOU
2004-01-01
This paper is concerned with the H2 estimation and control problems for uncertain discretetime systems with norm-bounded parameter uncertainty. We first present an analysis result on H2 norm bound for a stable uncertain system in terms of linearmatrix inequalities (LMIs). A solution to the robust H2 estimation problem is then derived in terms of two LMIs. As compared tothe existing results, our result on robust H2 estimation is more general. In addition, explicit search of appropriate scaling parametersis not needed as the optimization is convex in the scaling parameters. The LMI approach is also extended to solve the robust H2control problem which has been difficult for the traditional Riccati equation approach since no separation principle has been knownfor uncertain systems. The design approach is demonstrated through a simple example.
Multi-objective optimization framework for networked predictive controller design.
Das, Sourav; Das, Saptarshi; Pan, Indranil
2013-01-01
Networked Control Systems (NCSs) often suffer from random packet dropouts which deteriorate overall system's stability and performance. To handle the ill effects of random packet losses in feedback control systems, closed over communication network, a state feedback controller with predictive gains has been designed. To achieve improved performance, an optimization based controller design framework has been proposed in this paper with Linear Matrix Inequality (LMI) constraints, to ensure guaranteed stability. Different conflicting objective functions have been optimized with Non-dominated Sorting Genetic Algorithm-II (NSGA-II). The methodology proposed in this paper not only gives guaranteed closed loop stability in the sense of Lyapunov, even in the presence of random packet losses, but also gives an optimization trade-off between two conflicting time domain control objectives.
Directory of Open Access Journals (Sweden)
Cheng-Dong Yang
2014-01-01
Full Text Available This paper addresses the problem of robust H∞ control design via the proportional-spatial derivative (P-sD control approach for a class of nonlinear distributed parameter systems modeled by semilinear parabolic partial differential equations (PDEs. By using the Lyapunov direct method and the technique of integration by parts, a simple linear matrix inequality (LMI based design method of the robust H∞ P-sD controller is developed such that the closed-loop PDE system is exponentially stable with a given decay rate and a prescribed H∞ performance of disturbance attenuation. Moreover, a suboptimal H∞ controller is proposed to minimize the attenuation level for a given decay rate. The proposed method is successfully employed to address the control problem of the FitzHugh-Nagumo (FHN equation, and the achieved simulation results show its effectiveness.
Li, Zhifu; Hu, Yueming; Li, Di
2016-08-01
For a class of linear discrete-time uncertain systems, a feedback feed-forward iterative learning control (ILC) scheme is proposed, which is comprised of an iterative learning controller and two current iteration feedback controllers. The iterative learning controller is used to improve the performance along the iteration direction and the feedback controllers are used to improve the performance along the time direction. First of all, the uncertain feedback feed-forward ILC system is presented by an uncertain two-dimensional Roesser model system. Then, two robust control schemes are proposed. One can ensure that the feedback feed-forward ILC system is bounded-input bounded-output stable along time direction, and the other can ensure that the feedback feed-forward ILC system is asymptotically stable along time direction. Both schemes can guarantee the system is robust monotonically convergent along the iteration direction. Third, the robust convergent sufficient conditions are given, which contains a linear matrix inequality (LMI). Moreover, the LMI can be used to determine the gain matrix of the feedback feed-forward iterative learning controller. Finally, the simulation results are presented to demonstrate the effectiveness of the proposed schemes.
Directory of Open Access Journals (Sweden)
Yuanchun Li
2015-01-01
Full Text Available The goal of this paper is to describe an active decentralized fault-tolerant control (ADFTC strategy based on dynamic output feedback for reconfigurable manipulators with concurrent actuator and sensor failures. Consider each joint module of the reconfigurable manipulator as a subsystem, and treat the fault as the unknown input of the subsystem. Firstly, by virtue of linear matrix inequality (LMI technique, the decentralized proportional-integral observer (DPIO is designed to estimate and compensate the sensor fault online; hereafter, the compensated system model could be derived. Then, the actuator fault is estimated similarly by another DPIO using LMI as well, and the sufficient condition of the existence of H∞ fault-tolerant controller in the dynamic output feedback is presented for the compensated system model. Furthermore, the dynamic output feedback controller is presented based on the estimation of actuator fault to realize active fault-tolerant control. Finally, two 3-DOF reconfigurable manipulators with different configurations are employed to verify the effectiveness of the proposed scheme in simulation. The main advantages of the proposed scheme lie in that it can handle the concurrent faults act on the actuator and sensor on the same joint module, as well as there is no requirement of fault detection and isolation process; moreover, it is more feasible to the modularity of the reconfigurable manipulator.
Directory of Open Access Journals (Sweden)
Yi-You Hou
2014-01-01
Full Text Available This paper considers the problem of the robust stability for the nonlinear system with time-varying delay and parameters uncertainties. Based on the H∞ theorem, Lyapunov-Krasovskii theory, and linear matrix inequality (LMI optimization technique, the H∞ quasi-sliding mode controller and switching function are developed such that the nonlinear system is asymptotically stable in the quasi-sliding mode and satisfies the disturbance attenuation (H∞-norm performance. The effectiveness and accuracy of the proposed methods are shown in numerical simulations.
Fuzzy robust attitude controller design for hydrofoil catamaran
Institute of Scientific and Technical Information of China (English)
Ren Junsheng; Yang Yansheng
2005-01-01
A robust attitude controller for hydrofoil catamaran throughout its operating envelope is proposed, based on Tagaki-Sugeno (T-S) fuzzy model. Firstly, T-S fuzzy model and robust attitude control strategy for hydrofoil catamaran is presented by use of linear matrix inequality (LMI) techniques. Secondly, a nonlinear mathematical model of hydrofoil catamaran is established, acting as the platform for further researches. The specialty in interpolation of T-S fuzzy model guarantees that feedback gain can be obtained smoothly, while boat's speed is shifting over the operating envelope. The external disturbances are also attenuated to achieve H∞ control performance, meanwhile. Finally, based on such a boat,HC200B-A1, simulation researches demonstrate the design procedures and the effectiveness of fuzzy robust attitude controller.
Synchronization and Control of Linearly Coupled Singular Systems
Directory of Open Access Journals (Sweden)
Fang Qingxiang
2013-01-01
Full Text Available The synchronization and control problem of linearly coupled singular systems is investigated. The uncoupled dynamical behavior at each node is general and can be chaotic or, otherwise the coupling matrix is not assumed to be symmetrical. Some sufficient conditions for globally exponential synchronization are derived based on Lyapunov stability theory. These criteria, which are in terms of linear matrix inequality (LMI, indicate that the left and right eigenvectors corresponding to eigenvalue zero of the coupling matrix play key roles in the stability analysis of the synchronization manifold. The controllers are designed for state feedback control and pinning control, respectively. Finally, a numerical example is provided to illustrate the effectiveness of the proposed conditions.
The Stabilization of Continuous-Time Networked Control Systems with Data Drift
Directory of Open Access Journals (Sweden)
Qixin Zhu
2015-01-01
Full Text Available By data drift, we mean the data received by the controller may be different from that sent by the sensor, or the data received by actuator may be different from that sent by the controller. The issues of guaranteed cost control for a class of continuous-time networked control systems with data drift are investigated. Firstly, with the consideration of data drift between sensor and controller, a closed-loop model of networked control systems including network factors such as time-delay and data-dropouts is established. And then, selecting an appropriate Lyapunov function, a guaranteed cost controller in terms of linear matrix inequality (LMI is designed to asymptotically stabilize the networked control system with data drift. Finally, simulations are included to demonstrate the theoretical results.
Robust linear parameter varying induction motor control with polytopic models
Directory of Open Access Journals (Sweden)
Dalila Khamari
2013-01-01
Full Text Available This paper deals with a robust controller for an induction motor which is represented as a linear parameter varying systems. To do so linear matrix inequality (LMI based approach and robust Lyapunov feedback controller are associated. This new approach is related to the fact that the synthesis of a linear parameter varying (LPV feedback controller for the inner loop take into account rotor resistance and mechanical speed as varying parameter. An LPV flux observer is also synthesized to estimate rotor flux providing reference to cited above regulator. The induction motor is described as a polytopic model because of speed and rotor resistance affine dependence their values can be estimated on line during systems operations. The simulation results are presented to confirm the effectiveness of the proposed approach where robustness stability and high performances have been achieved over the entire operating range of the induction motor.
TCP Congestion Control for the Networks with Markovian Jump Parameters
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MOMENI, H. R.
2011-05-01
Full Text Available This paper is concerned with the problem of TCP congestion control for the class of communication networks with random parameters. The linear dynamic model of TCP New Reno in congestion avoidance mode is considered which contains round trip delays in both state and input. The randomness of link capacity, round trip time delay and the number of TCP sessions is modeled with a continuous-time finite state Markov process. An Active Queue Management (AQM technique is then used to adjust the queue level of the congested link to a predefined value. For this purpose, a dynamic output feedback controller with mode dependent parameters is synthesized to stochastically stabilize the TCP/AQM dynamics. The procedure of the control synthesis is implemented by solving a linear matrix inequality (LMI. The results are tested within a simulation example and the effectiveness of the proposed design method is verified.
Design of robust non-fragile H-infinity controller based on Delta operator theory
Institute of Scientific and Technical Information of China (English)
无
2007-01-01
Considering that the controller parameters are of additive norm-bounded uncertainties when realized,a design method of robust non-fragile H-infinity controller for uncertain systems based on Delta operator theory is illustrated in this paper.A sufficient and necessary condition of the existence for the controller is given,which is presented in LMI forms.Finally,the designed method is used in the speed control system of a permanent magnet linear synchronous motor (PMLSM).With the designed controller,the resulting speed closed-loop system is still stable and has the expected Hinfinity performance even if the sample period is reduced and the parameters of the controller and the controlled object are varied.The results show that the designed method is effective.
Feedforward Compensation by Specified Step Settling Considering Constraint on Control Input
Hirose, Noriaki; Iwasaki, Makoto; Hirai, Hiromu
This paper presents a novel design approach for feedforward compensation by employing specified step settling to provide fast and precise positioning control of mechatronic systems. In the conventional approach, the saturation of control input essentially deteriorates the control performance in terms of response time and residual vibration suppression. However, in the proposed method of feedforward compensation, command shaping is performed within the deadbeat control framework, wherein a constraint on the control input can be imposed by using the LMI technique to ensure the desired control performance. Therefore, by using the proposed approach, a 2-degrees-of-freedom positioning controller can achieve the required settling performance without causing residual vibration under the constraint. The effectiveness of the proposed approach has been verified by carrying out numerical simulations and experiments on a prototype.
Formation control for a network of small-scale robots.
Kim, Yoonsoo
2014-10-01
In this paper, a network of small-scale robots (typically centimeter-scale robots) equipped with artificial actuators such as electric motors is considered. The purpose of this network is to have the robots keep a certain formation shape (or change to another formation shape) during maneuvers. The network has a fixed communication topology in the sense that robots have a fixed group of neighbors to communicate during maneuvers. Assuming that each robot and its actuator can be modeled as a linear system, a decentralized control law (such that each robot activates its actuator based on the information from its neighbors only) is introduced to achieve the purpose of formation keeping or change. A linear matrix inequality (LMI) for deriving the upper bound on the actuator's time constant is also presented. Simulation results are shown to demonstrate the merit of the introduced control law.
Modified active disturbance rejection control for time-delay systems.
Zhao, Shen; Gao, Zhiqiang
2014-07-01
Industrial processes are typically nonlinear, time-varying and uncertain, to which active disturbance rejection control (ADRC) has been shown to be an effective solution. The control design becomes even more challenging in the presence of time delay. In this paper, a novel modification of ADRC is proposed so that good disturbance rejection is achieved while maintaining system stability. The proposed design is shown to be more effective than the standard ADRC design for time-delay systems and is also a unified solution for stable, critical stable and unstable systems with time delay. Simulation and test results show the effectiveness and practicality of the proposed design. Linear matrix inequality (LMI) based stability analysis is provided as well.
Pinning control of a generalized complex dynamical network model
Institute of Scientific and Technical Information of China (English)
Huizhong YANG; Li SHENG
2009-01-01
This paper investigates the local and global synchronization of a generalized complex dynamical network model with constant and delayed coupling.Without assuming symmetry of the couplings,we proved that a single controller can pin the generalized complex network to a homogenous solution.Some previous synchronization results are generalized.In this paper,we first discuss how to pin an array of delayed neural networks to the synchronous solution by adding only one controller.Next,by using the Lyapunov functional method,some sufficient conditions are derived for the local and global synchronization of the coupled systems.The obtained results are expressed in terms of LMIs,which can be efficiently checked by the Matlab LMI toolbox.Finally,an example is given to illustrate the theoretical results.
Modern linear control design a time-domain approach
Caravani, Paolo
2013-01-01
This book offers a compact introduction to modern linear control design. The simplified overview presented of linear time-domain methodology paves the road for the study of more advanced non-linear techniques. Only rudimentary knowledge of linear systems theory is assumed - no use of Laplace transforms or frequency design tools is required. Emphasis is placed on assumptions and logical implications, rather than abstract completeness; on interpretation and physical meaning, rather than theoretical formalism; on results and solutions, rather than derivation or solvability. The topics covered include transient performance and stabilization via state or output feedback; disturbance attenuation and robust control; regional eigenvalue assignment and constraints on input or output variables; asymptotic regulation and disturbance rejection. Lyapunov theory and Linear Matrix Inequalities (LMI) are discussed as key design methods. All methods are demonstrated with MATLAB to promote practical use and comprehension. ...
Satisfactory fault-tolerant controller design for uncertain systems subject to actuator faults
Institute of Scientific and Technical Information of China (English)
Zhang Dengfeng; Su Hongye; Wang Zhiquan
2008-01-01
Based on satisfactory control strategy, a new method for robust passive fault tolerant controller is proposed for a class of uncertain discrete-time systems subject to actuator faults. The state-feedback gain matrix is calculated by linear matrix inequality (LMI) technique. The designed controller guarantees that the closed-loop system meets the pre-specified consistent constraints on circular pole index and steady-state variance index simultaneously for normal case and possible actuator fault case. The consistency of the performance indices is discussed. Furthermore, with the mentioned indices constraints, a solution is obtained by convex optimal technique for the robust satisfactory fault-tolerant controller with optimal control-cost.
Institute of Scientific and Technical Information of China (English)
Zhihu WU; Run PEI
2009-01-01
This paper proposes a delay-dependent guaranteed cost control scheme for engine idle speed control (ISC) with induction-to-torque delay and external load disturbance.An augmented linearization model of engine at idle speed operating mode was developed based on physical principle and experiment data.To provide a compromise between disturbance rejection and other performance requirements of ISC,a multi-objective cost function upper bound was given,which can help us to take into account the fuel economy and disturbance rejection performance together in ISC.Poles constraint was added to the closed-loop system to guarantee convergence rates of state.The whole optimization solution to ISC can be solved under the framework of LMI.A commercial engine model was utilized to assess the performance of the controller.Simulation results on this model show us that designed controller can achieve desired performance.
Robust and Non-fragile H{sup {infinity}} Control of Time Delay Systems with Parameter Uncertainties
Energy Technology Data Exchange (ETDEWEB)
Kim, J.H.; Park, H.B. [Kyungpook National University, Taegu (Korea); Jeung, E.T. [Changwon National University, Changwon (Korea)
1999-12-01
This paper describes the synthesis of robust and non-fragile H{sup {infinity}} state feedback controllers for linear systems with time delay and parameter uncertainties, and static state feedback controller with multiplicative uncertainty. The sufficient condition of controller existence, the design method of robust and non-fragile H{sup {infinity}} state feedback controller, and the measure of non-fragility in controller are presented. Also, through some changes of variables and Schur complements, the obtained sufficient condition can be rewritten as an LMI(linear matrix inequality) form in terms of transformed variables. Therefore, the obtained robust and non-fragile H{sup {infinity}} controller guarantees the asymptotic stability and disturbance attenuation of the closed loop system in spite of controller gain variations within a certain degree. (author). 9 refs., 2 figs.
Robust Moving Horizon H∞ Control of Discrete Time-Delayed Systems with Interval Time-Varying Delays
Directory of Open Access Journals (Sweden)
F. Yıldız Tascikaraoglu
2014-01-01
Full Text Available In this study, design of a delay-dependent type moving horizon state-feedback control (MHHC is considered for a class of linear discrete-time system subject to time-varying state delays, norm-bounded uncertainties, and disturbances with bounded energies. The closed-loop robust stability and robust performance problems are considered to overcome the instability and poor disturbance rejection performance due to the existence of parametric uncertainties and time-delay appeared in the system dynamics. Utilizing a discrete-time Lyapunov-Krasovskii functional, some delay-dependent linear matrix inequality (LMI based conditions are provided. It is shown that if one can find a feasible solution set for these LMI conditions iteratively at each step of run-time, then we can construct a control law which guarantees the closed-loop asymptotic stability, maximum disturbance rejection performance, and closed-loop dissipativity in view of the actuator limitations. Two numerical examples with simulations on a nominal and uncertain discrete-time, time-delayed systems, are presented at the end, in order to demonstrate the efficiency of the proposed method.
具有随机丢包的网络控制系统的镇定%Stabilization of networked control systems with random packet dropouts
Institute of Scientific and Technical Information of China (English)
高守婉; 唐功友
2011-01-01
The stabilization problem for networked control systems(NCS) with random packet dropouts is studied in this paper. Both sensor-to-controller(S/C) and controller-to-actuator(C/A) packet dropouts are considered, which are modeled respectively. Based on Lyapunov stability theory, sufficient condition is derived, which ensures the globally mean-square asymptotically stability for the closed-loop systems. Moreover, the gain matrix of the state feedback control law is obtained by using the linear matrix inequality(LMI) approach. Numerical examples illustrate the effectiveness of the results.%研究具有随机丢包的网络控制系统(NCS)的镇定问题.同时考虑传感器节点到控制器节点(S/C)和控制器节点到执行器节点(C/A)的随机丢包,并分别对这两种丢包现象建模.幕于Lyapunov稳定性理论.得到闭环系统令局均方渐近稳定的充分条件.进一步利用线性矩阵不等式(LMI)方法,得到状态反馈控制律的增益矩阵.数值仿真算例验证了所得结果的有效性.
Li, Zhijun; Su, Chun-Yi
2013-09-01
In this paper, adaptive neural network control is investigated for single-master-multiple-slaves teleoperation in consideration of time delays and input dead-zone uncertainties for multiple mobile manipulators carrying a common object in a cooperative manner. Firstly, concise dynamics of teleoperation systems consisting of a single master robot, multiple coordinated slave robots, and the object are developed in the task space. To handle asymmetric time-varying delays in communication channels and unknown asymmetric input dead zones, the nonlinear dynamics of the teleoperation system are transformed into two subsystems through feedback linearization: local master or slave dynamics including the unknown input dead zones and delayed dynamics for the purpose of synchronization. Then, a model reference neural network control strategy based on linear matrix inequalities (LMI) and adaptive techniques is proposed. The developed control approach ensures that the defined tracking errors converge to zero whereas the coordination internal force errors remain bounded and can be made arbitrarily small. Throughout this paper, stability analysis is performed via explicit Lyapunov techniques under specific LMI conditions. The proposed adaptive neural network control scheme is robust against motion disturbances, parametric uncertainties, time-varying delays, and input dead zones, which is validated by simulation studies.
Institute of Scientific and Technical Information of China (English)
王永强; 叶昊; Ding X.Steven; 王桂增
2008-01-01
Fault detection of networked control systems (NCSs) with random and unknown network-induced delay that might be larger than one sampling period is studied in this paper. First, influence caused by network-induced delay is transformed into structured modeling error, then an existent continuous time domain robust fault detection method based on reference model is extended to discrete time domain and applied to fault detec-tion of networked control systems. The proposed method can be easily implemented by Matlab LMI toolbox, and its performance is finally evaluated by a simulation example.
Institute of Scientific and Technical Information of China (English)
年晓红; 杨莹; 黄琳
2005-01-01
This paper deals with a general class of optimization problems in robust control with given expectation value of performance index, which can be transformed into the problem of matrix approximation with matrix inequalities constraints. Theorem for existence and the uniqueness of the solutions of matrix approximation with linear matrix inequalities (LMIs) constraints is presented and algorithms for solving the problems of matrix approximation with matrix inequalities constraints are given based on the fact that such problems can be converted into the generalized eigenvalue problem (GEVP) of LMI. Examples are given to illustrate the main results of the paper.
Robust H∞ Control of Neutral System with Time-Delay for Dynamic Positioning Ships
Directory of Open Access Journals (Sweden)
Dawei Zhao
2015-01-01
Full Text Available Due to the input time-delay existing in most thrust systems of the ships, the robust H∞ controller is designed for the ship dynamic positioning (DP system with time-delay. The input delay system is turned to a neutral time-delay system by a state-derivative control law. The less conservative result is derived for the neutral system with state-derivative feedback by the delay-decomposition approach and linear matrix inequality (LMI. Finally, the numerical simulations demonstrate the asymptotic stability and robustness of the controller and verify that the designed DP controller is effective in the varying environment disturbances of wind, waves, and ocean currents.
Jia, Qingxian; Chen, Wen; Zhang, Yingchun; Li, Huayi
2016-12-01
This paper addresses the problem of integrated fault reconstruction and fault-tolerant control in linear systems subject to actuator faults via learning observers (LOs). A reconfigurable fault-tolerant controller is designed based on the constructed LO to compensate for the influence of actuator faults by stabilising the closed-loop system. An integrated design of the proposed LO and the fault-tolerant controller is explored such that their performance can be simultaneously considered and their coupling problem can be effectively solved. In addition, such an integrated design is formulated in terms of linear matrix inequalities (LMIs) that can be conveniently solved in a unified framework using LMI optimisation technique. At last, simulation studies on a micro-satellite attitude control system are provided to verify the effectiveness of the proposed approach.
Robust H∞ output-feedback control for path following of autonomous ground vehicles
Hu, Chuan; Jing, Hui; Wang, Rongrong; Yan, Fengjun; Chadli, Mohammed
2016-03-01
This paper presents a robust H∞ output-feedback control strategy for the path following of autonomous ground vehicles (AGVs). Considering the vehicle lateral velocity is usually hard to measure with low cost sensor, a robust H∞ static output-feedback controller based on the mixed genetic algorithms (GA)/linear matrix inequality (LMI) approach is proposed to realize the path following without the information of the lateral velocity. The proposed controller is robust to the parametric uncertainties and external disturbances, with the parameters including the tire cornering stiffness, vehicle longitudinal velocity, yaw rate and road curvature. Simulation results based on CarSim-Simulink joint platform using a high-fidelity and full-car model have verified the effectiveness of the proposed control approach.
Novel controller design demonstration for vibration alleviation of helicopter rotor blades
Ulker, Fatma Demet; Nitzsche, Fred
2012-04-01
This paper presents an advanced controller design methodology for vibration alleviation of helicopter rotor sys- tems. Particularly, vibration alleviation in a forward ight regime where the rotor blades experience periodically varying aerodynamic loading was investigated. Controller synthesis was carried out under the time-periodic H2 and H∞ framework and the synthesis problem was solved based on both periodic Riccati and Linear Matrix Inequality (LMI) formulations. The closed-loop stability was analyzed using Floquet-Lyapunov theory, and the controller's performance was validated by closed-loop high-delity aeroelastic simulations. To validate the con- troller's performance an actively controlled trailing edge ap strategy was implemented. Computational cost was compared for both formulations.
H∞ output tracking control of discrete-time nonlinear systems via standard neural network models.
Liu, Meiqin; Zhang, Senlin; Chen, Haiyang; Sheng, Weihua
2014-10-01
This brief proposes an output tracking control for a class of discrete-time nonlinear systems with disturbances. A standard neural network model is used to represent discrete-time nonlinear systems whose nonlinearity satisfies the sector conditions. H∞ control performance for the closed-loop system including the standard neural network model, the reference model, and state feedback controller is analyzed using Lyapunov-Krasovskii stability theorem and linear matrix inequality (LMI) approach. The H∞ controller, of which the parameters are obtained by solving LMIs, guarantees that the output of the closed-loop system closely tracks the output of a given reference model well, and reduces the influence of disturbances on the tracking error. Three numerical examples are provided to show the effectiveness of the proposed H∞ output tracking design approach.
H2 control of discrete-time periodic systems with Markovian jumps and multiplicative noise
Ma, Hongji; Jia, Yingmin
2013-10-01
This paper addresses the problem of optimal and robust H2 control for discrete-time periodic systems with Markov jump parameters and multiplicative noise. To analyse the system performance in the presence of exogenous random disturbance, an H2 norm is firstly established on the basis of Gramian matrices. Further, under the condition of exact observability, a necessary and sufficient condition is presented for the solvability of H2 optimal control problem by means of a generalised Riccati equation. When the transition probabilities of jump parameter are incompletely measurable, an H2-guaranteed cost norm is exploited and the robust H2 controller is designed through a linear matrix inequality (LMI) optimisation approach. An example of a networked control system is supplied to illustrate the proposed results.
Resilient predictive control for a class of uncertain time-delay systems
Institute of Scientific and Technical Information of China (English)
Zhang Qunliang; Xi Yugeng
2007-01-01
In practice, gain perturbations of controllers which are caused by actuator degradation and other reasons often lead to performance degradation.They are capable of violating the closed-loop stability.For a system with constrained inputs, the actual controllers might exceed their limits because of gain perturbations.By the reason, this article considers the problem of resilient predictive control for a class of uncertain time-delay systems.By describing the gain perturbation as a time-varying uncertainty, the sufficient conditions to ensure the closedloop stability and the input constraints are derived.Additionally, an approach to design the resilient predictive controllers is presented in terms of LMI.Finally, the simulation shows that the proposed approach is very effective.
Robust H∞ control for aseismic structures With uncertainties in model parameters
Institute of Scientific and Technical Information of China (English)
Song Gang; Lin Jiahao; Zhao Yan; W.Paul Howson; Fred W Williams
2007-01-01
This paper presents a robust H∞ output feedback control approach for structural systems with uncertainties in model parameters by using available acceleration measurements and proposes conditions for the existence of such a robust ontput feedback controller.The uncertainties of structural stiffness,damping and mass parameters are assumed to be norm-bounded.The proposed control approach is formulated within the framework of linear matrix inequalities,for which existing convex optimization techniques,such as the LMI toolbox in MATLAB,can be used effectively and conveniently.To illustrate the effectiveness of the proposed robust H∞ strategy,a six-story building was subjected both to the 1940 El Centro earthquake record and to a suddenly applied Kanai-Tajimi filtered white noise random excitation.The results show that the proposed robust H∞ controller provides satisfactory results with or without variation of the structural stiffness,damping and mass parameters.
Directory of Open Access Journals (Sweden)
Baoyan Zhu
2015-01-01
Full Text Available Delay-dependent finite-time H∞ controller design problems are investigated for a kind of nonlinear descriptor system via a T-S fuzzy model in this paper. The solvable conditions of finite-time H∞ controller are given to guarantee that the loop-closed system is impulse-free and finite-time bounded and holds the H∞ performance to a prescribed disturbance attenuation level γ. The method given is the ability to eliminate the impulsive behavior caused by descriptor systems in a finite-time interval, which confirms the existence and uniqueness of solutions in the interval. By constructing a nonsingular matrix, we overcome the difficulty that results in an infeasible linear matrix inequality (LMI. Using the FEASP solver and GEVP solver of the LMI toolbox, we perform simulations to validate the proposed methods for a nonlinear descriptor system via the T-S fuzzy model, which shows the application of the T-S fuzzy method in studying the finite-time control problem of a nonlinear system. Meanwhile the method was also applied to the biological economy system to eliminate impulsive behavior at the bifurcation value, stabilize the loop-closed system in a finite-time interval, and achieve a H∞ performance level.
Jung, Hoeguk; Wang, Haifeng; Hu, Tingshu
2014-12-01
This paper considers some control design problems in a power system driven by battery/supercapacitor hybrid energy storage devices. The currents in the battery and the supercapacitor are actively controlled by two bidirectional buck-boost converters. Two control objectives are addressed in this paper: one is to achieve robust tracking of two reference variables, the battery current and the load voltage, the other is to achieve smooth transition of these variables during load switch. Based on the state-space averaged model we newly developed, the control design problems are converted into numerically efficient optimization problems with linear matrix inequality (LMI) constraints. An experimental system is constructed to validate the control design methods.
Robust chaos synchronization based on adaptive fuzzy delayed feedback $\\mathcal{H}_{∞}$ control
Indian Academy of Sciences (India)
Choon Ki Ahn
2012-03-01
In this paper, we propose a new adaptive $\\mathcal_{∞}$ synchronization strategy, called an adaptive fuzzy delayed feedback $\\mathcal_{∞}$ synchronization (AFDFHS) strategy, for chaotic systems with uncertain parameters and external disturbances. Based on Lyapunov–Krasovskii theory, Takagi–Sugeno (T–S) fuzzy model and adaptive delayed feedback $\\mathcal_{∞}$ control scheme, the AFDFHS controller is presented such that the synchronization error system is asymptotically stable with a guaranteed $\\mathcal_{∞}$ performance. It is shown that the design of the AFDFHS controller with adaptive law can be achieved by solving a linear matrix inequality (LMI), which can be easily facilitated by using some standard numerical packages. An illustrative example is given to demonstrate the effectiveness of the proposed AFDFHS approach.
FLIGHT／THRUST INTEGRATED CONTROL USINGH∞SYNTHESIS IN AUTOMATIC CARRIER LANDING
Institute of Scientific and Technical Information of China (English)
YuYong; YangYidong; DaiShijun
2002-01-01
The landing task of an aircraft under low aerodynamic pressure on carrier requires precise airplane control,A flight/thrust integrated control system(FTICS)with constant ad,actual angle of attack,is developed using LMI-based H∞synthesis.The typical single input/outputspecifications are translated into the weighting functions of an H∞output-feedback synthesis problem.The motiva-tion of the work is to improve the key performance of dy-namic tracking and air disturbance attenuation.The FTICS can keep the attitude andgle and the path angle un-changeable as the airplane is passing through the ramp at which the tracking radar doesnot work and the guidance signal is terminated.For engineering application,an or-der-reduction method of the H∞controller is also pro-posed,Simulational results indicate that the system satis-fies the design requirements quite well.
Observer-based Adaptive Iterative Learning Control for Nonlinear Systems with Time-varying Delays
Institute of Scientific and Technical Information of China (English)
Wei-Sheng Chen; Rui-Hong Li; Jing Li
2010-01-01
An observer-based adaptive iterative learning control (AILC) scheme is developed for a class of nonlinear systems with unknown time-varying parameters and unknown time-varying delays. The linear matrix inequality (LMI) method is employed to design the nonlinear observer. The designed controller contains a proportional-integral-derivative (PID) feedback term in time domain. The learning law of unknown constant parameter is differential-difference-type, and the learning law of unknown time-varying parameter is difference-type. It is assumed that the unknown delay-dependent uncertainty is nonlinearly parameterized. By constructing a Lyapunov-Krasovskii-like composite energy function (CEF), we prove the boundedness of all closed-loop signals and the convergence of tracking error. A simulation example is provided to illustrate the effectiveness of the control algorithm proposed in this paper.
Robust reliable guaranteed cost control for nonlinear singular stochastic systems with time delay
Institute of Scientific and Technical Information of China (English)
Zhang Aiqing; Fang Huajing
2008-01-01
To study the design problem of robust reliable guaranteed cost controller for nonlinear singular stochastic systems,the Takagi-Sugeno(T-S)fuzzy model is used to represent a nonlinear singular stochastic system with norm-bounded parameter uncertainties and time delay.Based on the linear matrix inequality(LMI)techniques and stability theory of stochastic differential equations,a stochastic Lyapunov function method is adopted to design a state feedback fuzzy controller.The resulting closed-loop fuzzy system is robustly reliable stochastically stable,and the corresponding quadratic cost function is guarauteed to be no more than a certain upper bound for all admissible uncertainties,as well as different actuator fault cases.A sufficient condition of existence and design method of robust reliable guaranteed cost controller is presented.Finally,a numerical simulation is given to illustrate the effectiveness of the proposed method.
Guaranteed cost control with pole constraints for uncertain discrete-time switched systems
Institute of Scientific and Technical Information of China (English)
Ying ZHANG; Guangren DUAN; Liyan CHEN
2009-01-01
For a class of discrete-time switched systems with norm-bounded uncertainties and a quadratic cost index, the problem of designing a guaranteed cost state feedback controller with pole constraints is considered. A sufficient condition on the existence of robust guaranteed controllers is derived by a quadratic Lyapunov function approach together with linear matrix inequality (LMI)technique. Based on a constructed switching law, the closed-loop system is quadratic D-stable and the closedloop cost function value is not more than a specified upper bound. Furthermore, the design of suboptimal guaranteed cost controllers is turned into a convex optimization problem with linear matrix inequalities constraints. A numerical example demonstrates the effect of the proposed design approach.
Institute of Scientific and Technical Information of China (English)
Sheng-Guo WANG; Libin BAI; Mingzhi CHEN
2014-01-01
This paper presents a new robust sliding mode control (SMC) method with well-developed theoretical proof for general uncertain time-varying delay stochastic systems with structural uncertainties and the Brownian noise (Wiener process). The key features of the proposed method are to apply singular value decomposition (SVD) to all structural uncertainties and to introduce adjustable parameters for control design along with the SMC method. It leads to a less-conservative condition for robust stability and a new robust controller for the general uncertain stochastic systems via linear matrix inequality (LMI) forms. The system states are able to reach the SMC switching surface as guaranteed in probability 1. Furthermore, it is theoretically proved that the proposed method with the SVD and adjustable parameters is less conservatism than the method without the SVD. The paper is mainly to provide all strict theoretical proofs for the method and results.
Adaptive fault-tolerant control of linear systems with actuator saturation and L2-disturbances
Institute of Scientific and Technical Information of China (English)
Wei GUAN; Guanghong YANG
2009-01-01
This paper studies the problem of designing adaptive fault-tolerant H-infinity controllers for linear timeinvariant systems with actuator saturation. The disturbance tolerance ability of the closed-loop system is measured by an optimal index. The notion of an adaptive H-infinity performance index is proposed to describe the disturbance attenuation performances of closed-loop systems. New methods for designing indirect adaptive fault-tolerant controllers via state feedback are presented for actuator fault compensations. Based on the on-line estimation of eventual faults, the adaptive fault-tolerant controller parameters are updated automatically to compensate for the fault effects on systems. The designs are developed in the framework of the linear matrix inequality (LMI) approach, which can guarantee the disturbance tolerance ability and adaptive H-infinity performances of closed-loop systems in the cases of actuator saturation and actuator failures. An example is given to illustrate the efficiency of the design method.
Institute of Scientific and Technical Information of China (English)
P. Balasubramaniam; M. Kalpana; R. Rakkiyappan
2012-01-01
Fuzzy cellular neural networks (FCNNs) are special kinds of cellular neural networks (CNNs).Each cell in an FCNN contains fuzzy operating abilities.The entire network is governed by cellular computing laws.The design of FCNNs is based on fuzzy local rules.In this paper,a linear matrix inequality (LMI) approach for synchronization control of FCNNs with mixed delays is investigated.Mixed delays include discrete time-varying delays and unbounded distributed delays.A dynamic control scheme is proposed to achieve the synchronization between a drive network and a response network.By constructing the Lyapunov-Krasovskii functional which contains a triple-integral term and the free-weighting matrices method an improved delay-dependent stability criterion is derived in terms of LMIs.The controller can be easily obtained by solving the derived LMIs.A numerical example and its simulations are presented to illustrate the effectiveness of the proposed method.
Predictive Function Control for Communication-Based Train Control (CBTC Systems
Directory of Open Access Journals (Sweden)
Bing Bu
2013-01-01
Full Text Available In Communication‐Based Train Control (CBTC systems, random transmission delays and packet drops are inevitable in the wireless networks, which could result in unnecessary traction, brakes or even emergency brakes of trains, losses of line capacity and passenger dissatisfaction. This paper applies predictive function control technology with a mixed H 2 / H ∞ control approach to improve the control performances. The controller is in the state feedback form and satisfies the requirement of quadratic input and state constraints. A linear matrix inequality (LMI approach is developed to solve the control problem. The proposed method attenuates disturbances by incorporating H 2 / H ∞ into the control scheme. The control command from the automatic train operation (ATO is included in the reward function to optimize the train’s running profile. The influence of transmission delays and packet drops is alleviated through improving the performances of the controller. Simulation results show that the method is effective to improve the performances and robustness of CBTC systems.
Non-fragile control of discrete-time fuzzy bilinear system with time delay%离散模糊时滞双线性系统的非脆弱控制
Institute of Scientific and Technical Information of China (English)
张果; 蒋建虎; 段春霞
2011-01-01
The non-fragile control problem for a class of fuzzy bilinear systems with delay in both state and input was discussed. The objective was to design non-fragile state feedback controllers via the parallel distributed compensation (PDC) approach such that the closed-loop system was asymptotically stable. Some sufficient conditions for the existence of such non-fragile controllers were derived via the linear matrix inequality (LMI) approach and the design problem of the fuzzy controller was formulated as an LMI problem. The simulation example shows that the proposed approach was effective.%研究了一类输入和状态都带有时滞的离散模糊双线性系统的非脆弱控制问题.在控制器存在加性摄动的情况下,通过并行分布补偿算法导出了非脆弱控制律的存在条件,使得闭环系统是渐近稳定的.利用线性矩阵不等式,提出了非脆弱模糊控制器的设计方法.数值仿真验证了所提方法的有效性.
Institute of Scientific and Technical Information of China (English)
张学龙; 王云峰
2014-01-01
平稳运行是精敏供应链管理的重要基础，针对具有区间灰色非线性特征的精敏供应链系统波动性的难题，以非线性时滞精敏供应链系统为研究基础，建立了灰色非线性精敏供应链系统，采用线性矩阵不等式算法分析其稳定性问题，并获取了一种灰色非线性精敏供应链系统的稳定性判定方法。为验证该方法的有效性和可行性，以医药行业YL集团核心产品的供应链系统为案例分析对象，通过观测两个时点的运行数据，使用Matlab7.0计算工具，得出[0，20]和[20，40]2个时间段供应链系统的稳定性状态变化图。并假设当客户订货分离点（ CODP）下移时，运用同样的观测数据，模拟系统稳定性状态的变化。对比案例分析的结果得出结论：随着CODP从精敏供应链的上游端在下移至下游端时，不仅仅体现的是供应链系统类型的改变，而且更重要的是揭示了精益供应链和敏捷供应链稳定性的影响因素不同，前者受订单量大小程度的影响，而后者由市场需求预测的准确性程度决定。%In leagile supply chain management , it is important to operate a supply chain smoothly .Howev-er, with grey and non-linearity, it is very challenging to model and control such a supply chain .On the basis of non-linear and time delay leagile supply chain systems , a grey and non-linear model is developed for a leagile supply chain .Then, a linear matrix inequality method is used to analyze its stability and an effective stability criterion is obtained .In order to verify the feasibility and effectiveness of the proposed method, a core product supply chain systems of YL Group in the medicine industry is used as a case stud -y.By using Matlab 7.0, the stability of the system state diagram is drawn before and after customer order decoupling point ( CODP) .Results show that when CODP moves down , not only the supply chain type is changed but
The Feedback Control Strategy of the Takagi-Sugeno Fuzzy Car-Following Model with Two Delays
Directory of Open Access Journals (Sweden)
Cong Zhai
2016-01-01
Full Text Available Considering the driver’s sensing the headway and velocity the different time-varying delays exist, respectively, and the sensitivity of drivers changes with headway and speed. Introducing the fuzzy control theory, a new fuzzy car-following model with two delays is presented, and the feedback control strategy of the new fuzzy car-following model is studied. Based on the Lyapunov function theory and linear matrix inequality (LMI approach, the sufficient condition that the existence of the fuzzy controller is given making the closed-loop system is asymptotic, stable; namely, traffic congestion phenomenon can effectively be suppressed, and the controller gain matrix can be obtained via solving linear matrix inequality. Finally, the simulation examples verify that the method which suppresses traffic congestion and reduces fuel consumption and exhaust emissions is effective.
Robust Dissipative Control for Linear Multi-variable Systems%线性多变量系统的鲁棒耗散控制
Institute of Scientific and Technical Information of China (English)
邵汉永; 冯纯伯
2005-01-01
Robust quadratic dissipative control for a class of linear multi-variable systems with parameter uncertainties is considered, where the uncertainties are expressed in a linear fractional form.For the nominal system without uncertainties, the equivalence between quadratic dissipativeness and positive realness is established, and conditions are derived for linear systems to be quadratic dissipative. As for uncertain systems, it is shown that the robust quadratic dissipative control problem for the uncertain system can be reduced to the corresponding problem for a related system without uncertainties. The control problem concerned can be solved using LMI approach. The results of the paper unify existing results on H∞ control and positive real control and provide a more flexible and less conservative control design method.
Finite-time stability and control
Amato, Francesco; Ariola, Marco; Cosentino, Carlo; De Tommasi, Gianmaria
2014-01-01
Finite-time stability (FTS) is a more practical concept than classical Lyapunov stability, useful for checking whether the state trajectories of a system remain within pre-specified bounds over a finite time interval. In a linear systems framework, FTS problems can be cast as convex optimization problems and solved by the use of effective off-the-shelf computational tools such as LMI solvers. Finite-time Stability and Control exploits this benefit to present the practical applications of FTS and finite-time control-theoretical results to various engineering fields. The text is divided into two parts: · linear systems; and · hybrid systems. The building of practical motivating examples helps the reader to understand the methods presented. Finite-time Stability and Control is addressed to academic researchers and to engineers working in the field of robust process control. Instructors teaching graduate courses in advanced control will also find parts of this book useful for the...
Directory of Open Access Journals (Sweden)
Hwanyub Joo
2015-01-01
Full Text Available This paper addresses the output regulation problem of synchronous buck converters with piecewise-constant load fluctuations via linear parameter varying (LPV control scheme. To this end, an output-error state-space model is first derived in the form of LPV systems so that it can involve a mismatch error that temporally arises from the process of generating a feedforward control. Then, to attenuate the mismatch error in parallel with improving the transient behavior of the converter, this paper proposes an LMI-based stabilization condition capable of achieving both H∞ and pole-placement objectives. Finally, the simulation and experimental results are provided to show the validity of our approach.
Linear parameter-varying and time-delay systems analysis, observation, filtering & control
Briat, Corentin
2015-01-01
This book provides an introduction to the analysis and control of Linear Parameter-Varying Systems and Time-Delay Systems and their interactions. The purpose is to give the readers some fundamental theoretical background on these topics and to give more insights on the possible applications of these theories. This self-contained monograph is written in an accessible way for readers ranging from undergraduate/PhD students to engineers and researchers willing to know more about the fields of time-delay systems, parameter-varying systems, robust analysis, robust control, gain-scheduling techniques in the LPV fashion and LMI based approaches. The only prerequisites are basic knowledge in linear algebra, ordinary differential equations and (linear) dynamical systems. Most of the results are proved unless the proof is too complex or not necessary for a good understanding of the results. In the latter cases, suitable references are systematically provided. The first part pertains on the representation, analysis and ...
Robust H∞ control for discrete-time polytopic uncertain systems with linear fractional vertices
Institute of Scientific and Technical Information of China (English)
Shaosheng ZHOU; James LAM; Shengyuan XU
2004-01-01
The robust H∞ control problem for discrete-time uncertain systems is investigated in this paper. The uncertain systems are modelled as a polytopic type with linear fractional uncertainty in the vertices. A new linear matrix inequality (LMI) characterization of the H∞ performance for discrete systems is given by introducing a matrix slack variable which decouples the matrix of a Lyapunov function candidate and the parametric matrices of the system. This feature enables one to derive sufficient conditions for discrete uncertain systems by using parameter-dependent Lyapunov functions with less conservativeness. Based on the result, H∞ performance analysis and controller design are carried out. A numerical example is included to demonstrate the effectiveness of the proposed results.
Robust H∞ control of uncertain systems with two additive time-varying delays
Syed, Ali M.; Saravanakumar, R.
2015-09-01
This paper is concerned with the problem of delay-dependent robust H∞ control for a class of uncertain systems with two additive time-varying delays. A new suitable Lyapunov-Krasovskii functional (LKF) with triple integral terms is constructed and a tighter upper bound of the derivative of the LKF is derived. By applying a convex optimization technique, new delay-dependent robust H∞ stability criteria are derived in terms of linear matrix inequalities (LMI). Based on the stability criteria, a state feedback controller is designed such that the closed-loop system is asymptotically stable. Finally, numerical examples are given to illustrate the effectiveness of the proposed method. Comparison results show that our results are less conservative than the existing methods. Project supported by the Fund from the Department of Science and Technology of India (Grant No. SR/FTP/MS-039/2011).
Institute of Scientific and Technical Information of China (English)
童长飞; 章辉; 孙优贤
2007-01-01
By means of polynomial decomposition, a control scheme for polynomial nonlinear systems with affine timevarying uncertain parameters is presented. The idea of polynomial decomposition is to convert the coefficients of polynomial into a matrix with free variables, so that the nonnegativity of polynomials with even orders can be checked by linear matrix inequality (LMI) solvers or bilinear matrix inequality (BMI)solvers. Control synthesis for polynomial nonlinear system is based on Lyapunov stability theorem in this paper. Constructing Lyapunov function and finding feedback controller are automatically finished by computer programming with algorithms given in this paper. For multidimension systems with relatively high-order controller, the controller constructed with full monomial base will be in numerous terms. To overcome this problem,the reduced-form controller with minimum monomial terms is derived by the proposed algorithm. Then a suboptimal control aiming at minimum cost performance with gain constraints is advanced. The control scheme achieves effective performance as illustrated by numerical examples.
Institute of Scientific and Technical Information of China (English)
Wei GUAN; Guanghong YANG
2009-01-01
This paper studies the problem of designing adaptive fault-tolerant controllers for linear time-invariant systems with actuator saturation.New methods for designing indirect adaptive fault-tolerant controllers via state feedback are presented for actuator fault compensations.Based on the on-line estimation of eventual faults,the adaptive fault-tolerant controller parameters are updating automatically to compensate the fault effects on systems.The designs are developed in the framework of linear matrix inequality (LMI) approach,which can enlarge the domain of attraction of closed-loop systems in the cases of actuator saturation and actuator failures.Two examples are given to illustrate the effectiveness of the design method.
Directory of Open Access Journals (Sweden)
Jinxing Lin
2010-01-01
Full Text Available This paper is concerned with the problems of exponential admissibility and dynamic output feedback (DOF control for a class of continuous-time switched singular systems with interval time-varying delay. A full-order, dynamic, synchronously switched DOF controller is considered. First, by using the average dwell time approach, a delay-range-dependent exponential admissibility criterion for the unforced switched singular time-delay system is established in terms of linear matrix inequalities (LMIs. Then, based on this criterion, a sufficient condition on the existence of a desired DOF controller, which guarantees that the closed-loop system is regular, impulse free and exponentially stable, is proposed by employing the LMI technique. Finally, some illustrative examples are given to show the effectiveness of the proposed approach.
Directory of Open Access Journals (Sweden)
Li Qiu
2013-01-01
Full Text Available This paper is concerned with the problem of modeling and output feedback controller design for a class of discrete-time networked control systems (NCSs with time delays and packet dropouts. A Markovian jumping method is proposed to deal with random time delays and packet dropouts. Different from the previous studies on the issue, the characteristics of networked communication delays and packet dropouts can be truly reflected by the unified model; namely, both sensor-to-controller (S-C and controller-to-actuator (C-A time delays, and packet dropouts are modeled and their history behavior is described by multiple Markov chains. The resulting closed-loop system is described by a new Markovian jump linear system (MJLS with Markov delays model. Based on Lyapunov stability theory and linear matrix inequality (LMI method, sufficient conditions of the stochastic stability and output feedback controller design method for NCSs with random time delays and packet dropouts are presented. A numerical example is given to illustrate the effectiveness of the proposed method.
Directory of Open Access Journals (Sweden)
Fetah Kolonic
2006-10-01
Full Text Available The Tensor Product (TP model transformation is a recently proposed techniquefor transforming given Linear Parameter Varying (LPV state-space models into polytopicmodel form, namely, to parameter varying convex combination of Linear Time Invariant(LTI systems. The main advantage of the TP model transformation is that it is executablein a few minutes and the Linear Matrix Inequality (LMI-based control design frameworkscan immediately be applied to the resulting polytopc models to yield controllers withtractable and guaranteed performance. Various applications of the TP modeltransformation-based design were studied via academic complex and benchmark problems,but no real experimental environment-based study was published. Thus, the main objectiveof this paper is to study how the TP model transformation performs in a real world problemand control setup. The laboratory concept for TP model-based controller design,simulation and real time running on an electromechanical system is presented.Development system for TP model-based controller with one hardware/software platformand target system with real-time hardware/ software support are connected in the uniquesystem. Proposed system is based on microprocessor of personal computer (PC forsimulation and software development as well as for real-time control. Control algorithm,designed and simulated in MATLAB/SIMULINK environment, use graphically orientedsoftware interface for real-time code generation. Some specific conflicting industrial tasksin real industrial crane application, such as fast load positioning control and load swingangle minimization, are considered and compared with other controller types.
Reliable Finite Frequency Filter Design for Networked Control Systems with Sensor Faults
Directory of Open Access Journals (Sweden)
He-Hua Ju
2012-06-01
Full Text Available This paper is concerned with the reliable finite frequency filter design for networked control systems (NCSs subject to quantization and data missing. Taking into account quantization, possible data missing and sensor stuck faults, NCSs are modeled in the framework of discrete time-delay switched systems, and the finite frequency l_{2} gain is adopted for the filter design of discrete time-delay switched systems, which is converted into a set of linear matrix inequality (LMI conditions. By the virtues of the derived conditions, a procedure of reliable filter synthesis is presented. Further, the filter gains are characterized in terms of solutions to a convex optimization problem which can be solved by using the semi-definite programme method. Finally, an example is given to illustrate the effectiveness of the proposed method.
Energy Technology Data Exchange (ETDEWEB)
Freitas Junior, Fernando Sousa e; Fleury, Agenor de Toledo [Sao Paulo Univ. SP (Brazil). Escola Politecnica. Dept. de Engenharia Mecanica]. E-mails: ffreitas@usp.br; agfleury@ipt.br
2006-07-01
The objective of this work is the study of advanced control techniques for the reduction of pollutant gases generated by internal combustion engines powered by natural gas. In this paper three techniques are applied to control the fuel injection and the ignition timing: the Generalized Predictive Control (GPC), the Linear Quadratic Regulator (LQR) and H{infinity} Control by Linear Matrix Inequalities (LMI). To each one of those techniques were developed a multiple model structure seeking to include the vast operation region of the engine. The controller's performance is measured by the efficiency in maintaining the fuel/air ratio around 1% of maximum deviation in relation to the stoichiometric value. The results show the possibility of controlling pollutant emission generated by this kind of engine to conform to international emission standards, improving life quality. (author)
Institute of Scientific and Technical Information of China (English)
陆妹; 金成波; 邵惠鹤
2009-01-01
A finite horizon predictive control algorithm, which applies a saturated feedback control law as its local control law, is presented for nonlinear systems with time-delay subject to input constraints. In the algorithm, N free control moves, a saturated local control law and the terminal weighting matrices are solved by a minimization problem based on linear matrix inequality (LMI) constraints online. Compared with the algorithm with a nonsatu-rated local law, the presented algorithm improves the performances of the closed-loop systems such as feasibility and optimality. This model predictive control (MPC) algorithm is applied to an industrial continuous stirred tank reac-tor (CSTR) with explicit input constraint. The simulation results demonstrate that the presented algorithm is effective.
Li, Xiaofan; Fang, Jian-An; Li, Huiyuan
2017-09-01
This paper investigates master-slave exponential synchronization for a class of complex-valued memristor-based neural networks with time-varying delays via discontinuous impulsive control. Firstly, the master and slave complex-valued memristor-based neural networks with time-varying delays are translated to two real-valued memristor-based neural networks. Secondly, an impulsive control law is constructed and utilized to guarantee master-slave exponential synchronization of the neural networks. Thirdly, the master-slave synchronization problems are transformed into the stability problems of the master-slave error system. By employing linear matrix inequality (LMI) technique and constructing an appropriate Lyapunov-Krasovskii functional, some sufficient synchronization criteria are derived. Finally, a numerical simulation is provided to illustrate the effectiveness of the obtained theoretical results. Copyright © 2017 Elsevier Ltd. All rights reserved.
On fuzzy sampled-data control of chaotic systems via a time-dependent Lyapunov functional approach.
Wang, Zi-Peng; Wu, Huai-Ning
2015-04-01
In this paper, a novel approach to fuzzy sampled-data control of chaotic systems is presented by using a time-dependent Lyapunov functional. The advantage of the new method is that the Lyapunov functional is continuous at sampling times but not necessarily positive definite inside the sampling intervals. Compared with the existing works, the constructed Lyapunov functional makes full use of the information on the piecewise constant input and the actual sampling pattern. In terms of a new parameterized linear matrix inequality (LMI) technique, a less conservative stabilization condition is derived to guarantee the exponential stability for the closed-loop fuzzy sampled-data system. By solving a set of LMIs, the fuzzy sampled-data controller can be easily obtained. Finally, the chaotic Lorenz system and Rössler's system are employed to illustrate the feasibility and effectiveness of the proposed method.
Directory of Open Access Journals (Sweden)
Wei Guan
2014-01-01
Full Text Available This paper is concerned with the variable initial states problem in iterative learning control (ILC for linear continuous systems. Firstly, the properties of the trajectory of 2-D continuous-discrete Roesser model are analyzed by using Lyapunov's method. Then, for any variable initial states which absolutely converge to the desired initial state, some ILC design criteria in the form of linear matrix inequalities (LMI are given to ensure the convergence of the PD-type ILC rules. The convergence for variable initial states implies that the ILC rules can be used to achieve the perfect tacking for variable initial states, even if the system dynamic is unknown. Finally, the micropropulsion system is considered to illustrate efficiency of the proposed ILC design criteria.
Indian Academy of Sciences (India)
Vahid Azimi; Mohammad Bagher Menhaj; Ahmad Fakharian
2015-04-01
In this paper, a robust H2/H∞ control with regional Pole-Placement is considered for tool position control of a nonlinear uncertain flexible robot manipulator. The uncertain nonlinear system is first approximated by Takagi and Sugeno's (T-S) fuzzy model. To achieve a better tracking, an extra state (error of tracking) is then augmented to the T-S model. Based on each local linear subsystem with augmented state, a regional pole-placement state feedback H2/H∞ controller is properly designed via linear matrix inequality (LMI) approach. Parallel Distributed Compensation (PDC) is also used to establish the whole controller for the overall system and the total linear system is obtained by using the weighted sum of the local linear systems. A fuzzy weighted online computation (FWOC) component is employed to update fuzzy weights in real time for different operating points of the system. Simula-tion results are presented to validate the effectiveness of the proposed controller like robustness and good load disturbance attenuation and accurate tracking, even in the presence of parameter variations and also load disturbances on the motor and the tool. The superiority of the proposed control scheme is finally highlighted in comparison with the Quantitative feedback theory (QFT) controller, the QFT controller of order 13, a polynomial controller and the so-called linear sliding-mode controller methods.
Passivity Control for Uncertain T-S Fuzzy Descriptor Systems%不确定T-S模糊广义系统的无源控制
Institute of Scientific and Technical Information of China (English)
朱宝彦; 张庆灵; 佟绍成
2006-01-01
By means of matrix decomposition method a criterion is presented for the admissibility of T-S fuzzy descriptor system. Then, the problem of passivity control is studied for a kind of T-S fuzzy descriptor system with uncertain parameters, and sufficient conditions which make the closedloop system admissible and strictly passive are obtained based on linear matrix inequality (LMI).The nonstrict LMIs restricted conditions which characterize the descriptor system are transformed nnto strict ones, so testing admissibility and passivity of the system can be finished simultaneously.The design scheme of state feedback controller is also obtained. Finally, a numerical example is given to show the validity and feasibility of the proposed approach.
Institute of Scientific and Technical Information of China (English)
M.Kalpana; P.Balasubramaniam
2013-01-01
We investigate the stochastic asymptotical synchronization of chaotic Markovian jumping fuzzy cellular neural networks (MJFCNNs) with discrete,unbounded distributed delays,and the Wiener process based on sampled-data control using the linear matrix inequality (LMI) approach.The Lyapunov-Krasovskii functional combined with the input delay approach as well as the free-weighting matrix approach is employed to derive several sufficient criteria in terms of LMIs to ensure that the delayed MJFCNNs with the Wiener process is stochastic asymptotical synchronous.Restrictions (e.g.,time derivative is smaller than one) are removed to obtain a proposed sampled-data controller.Finally,a numerical example is provided to demonstrate the reliability of the derived results.
Controller Based Observer in Switched System with Norm Bounded Uncertainty
Directory of Open Access Journals (Sweden)
Mongi Besbes
2012-01-01
Full Text Available Problem statement: This study discusses the robust stabilization of norm bounded discrete switched systems. Approach: The proposed method is using the second Lyapunov approach and the poly-quadratic function concept. The stabilization conditions are written through linear matrix inequality relations. The control law is based on a static output feedback with the use of a switched observer. The synthesis conditions of the controller are written in the form of linear matrix inequalities difficult to resolve by current numerical solvers. Thatâs why relaxations are proposed to mitigate the pessimism of LMI conditions obtained. Results: The poly-quadratic Lyapunov approach provides a constructive way to tackle uncertainty in the switched framework. The feasibility is illustrated by the example of discrete uncertain switched systems. Conclusion: With these results, the study of stability can be achieved for arbitrary switching laws, state-dependent, time dependent or generated by a controller. However, the implementation of the control law is possible only if the switching status is well known in real time.
Switching control of an R/C hovercraft: stabilization and smooth switching.
Tanaka, K; Iwasaki, M; Wang, H O
2001-01-01
This paper presents stable switching control of an radio-controlled (R/C) hovercraft that is a nonholonomic (nonlinear) system. To exactly represent its nonlinear dynamics, more importantly, to maintain controllability of the system, we newly propose a switching fuzzy model that has locally Takagi-Sugeno (T-S) fuzzy models and switches them according to states, external variables, and/or time. A switching fuzzy controller is constructed by mirroring the rule structure of the switching fuzzy model of an R/C hovercraft. We derive linear matrix inequality (LMI) conditions for ensuring the stability of the closed-loop system consisting of a switching fuzzy model and controller. Furthermore, to guarantee smooth switching of control input at switching boundaries, we also derive a smooth switching condition represented in terms of LMIs. A stable switching fuzzy controller satisfying the smooth switching condition is designed by simultaneously solving both of the LMIs. The simulation and experimental results for the trajectory control of an R/C hovercraft show the validity of the switching fuzzy model and controller design, particularly, the smooth switching condition.
Institute of Scientific and Technical Information of China (English)
苏晓明; 刘芳玲
2011-01-01
针对一类参数不确定离散时滞广义系统,研究其鲁棒非脆弱H∞状态反馈控制器的设计问题.系统中的不确定项参数与控制器的增益变化同时具有线性分式形式的范数有界.首先,利用Lyapunov函数理论,研究该标称系统的鲁棒H∞控制问题；其次,以线性矩阵不等式(LMI)形式给出该系统的鲁棒非脆弱H∞控制器存在的充分条件及设计方法.该控制器既能使闭环系统是允许的,又能保证系统具有一定的H∞性能.最后,通过数值算例说明该方法的有效性.%The design problem of robust and non-fragile H-infinity state-feedback controller for a class of uncertain dis crete time-delay singular systems is investigated. System of uncertainties parameters and controller gain change has simultaneously linear fractional form of norm bounded. First of all, using Lyapunov function theory, robust h-infinity control problem of the nominal system is studied) Secondly the sufficient condition for the existence of robust and non-fragile H-infinity controller and design methods are presented via linear matrix inequality (LMI). This controller can make closed-loop sys tem allows, and can guarantee system has certain h-infinity performance; Finally, a numerical simulation shows the effec tiveness of this approach.
A set of decentralized PID controllers for an – link robot manipulator
Indian Academy of Sciences (India)
G Leena; G Ray
2012-06-01
A class of stabilizing decentralized proportional integral derivative (PID) controllers for an -link robot manipulator system is proposed. The range of decentralized PID controller parameters for an -link robot manipulator is obtained using Kharitonov theorem and stability boundary equations. Basically, the proposed design technique is based on the gain-phase margin tester and Kharitonov’s theorem that synthesizes a set of PID controllers for the linear model while nonlinear interaction terms involve in system dynamics are treated as zero. The stability analysis of the composite system with the designed set of decentralized PID controllers is investigated by incorporating bounding parameters of interconnection terms in LMI formulation. From the range of controller gains obtained by the proposed method, a genetic algorithm is adopted to get an optimal controller gains so that the tracking error is minimum. Simulation results are shown to demonstrate the applicability of the proposed control scheme for solution of ﬁxed as well as time-varying trajectory tracking control problems.
一类离散时间广义系统的迭代学习控制∗%Iterative learning control of a class of discrete-time singular system
Institute of Scientific and Technical Information of China (English)
曹伟; 郭媛; 孙明
2016-01-01
Singular systems are also called descriptor systems. Compared with normal systems, singular systems have become one of effective tools which can describe and characterize varieties of real systems, because they can better describe physical properties of the systems. Up to now, the analyses and syntheses of singular systems have been widespread applied to linear matrix inequality (LMI) method. The method requires known systems to have accurate mathematical model information, however, real systems have diﬃculties in obtaining their accurate mathematical models, owing to the fact that real systems are frequently subjected to all kinds of interferences, uncertainties, and nonlinear factors. Specially, in the case of singular systems, obtained LMI conditions often have a constraint equation or LMI is semi-definite, which makes it more diﬃcult to solve LMI. Therefore, in order to avoid the above two problems occurring in settling state tracking issue for singular systems, in the meantime, for convenience of computating control algorithm and information storage, in this paper we propose a discrete-time iterative learning control algorithm for a class of discrete-time singular system with repetitive running characteristics in finite time interval. The specific process is divided into two steps. First, the class of discrete-time singular system is decomposed into normal discrete-time state equation and algebraic equation form by nonsingular transformation. Accordingly, the singular system state is also decomposed into two parts. Among them, the dimension of the first part state is equal to singular matrix rank and another is equal to system dimension minus singular matrix rank. In addition, the control law of last iterative learning is modified by using two tracking errors at two different times: one error is real-time tracking error generated from the comparison between the first part state and its desired state and another is tracking error at a previous time
Directory of Open Access Journals (Sweden)
Ming-Kun Chang
2014-01-01
Full Text Available It is difficult to achieve excellent tracking performance for a two-joint leg rehabilitation machine driven by pneumatic artificial muscles (PAMs because the system has a coupling effect, highly nonlinear and time-varying behavior associated with gas compression, and the nonlinear elasticity of bladder containers. This paper therefore proposes a T-S fuzzy theory with supervisory control in order to overcome the above problems. The T-S fuzzy theory decomposes the model of a nonlinear system into a set of linear subsystems. In this manner, the controller in the T-S fuzzy model is able to use simple linear control techniques to provide a systematic framework for the design of a state feedback controller. Then the LMI Toolbox of MATLAB can be employed to solve linear matrix inequalities (LMIs in order to determine controller gains based on the Lyapunov direct method. Moreover, the supervisory control can overcome the coupling effect for a leg rehabilitation machine. Experimental results show that the proposed controller can achieve excellent tracking performance, and guarantee robustness to system parameter uncertainties.
L∞-gain adaptive fuzzy fault accommodation control design for nonlinear time-delay systems.
Wu, Huai-Ning; Qiang, Xiao-Hong; Guo, Lei
2011-06-01
In this paper, an adaptive fuzzy fault accommodation (FA) control design with a guaranteed L(∞)-gain performance is developed for a class of nonlinear time-delay systems with persistent bounded disturbances. Using the Lyapunov technique and the Razumikhin-type lemma, the existence condition of the L(∞) -gain adaptive fuzzy FA controllers is provided in terms of linear matrix inequalities (LMIs). In the proposed FA scheme, a fuzzy logic system is employed to approximate the unknown term in the derivative of the Lyapunov function due to the unknown fault function; a continuous-state feedback control strategy is adopted for the control design to avoid the undesirable chattering phenomenon. The resulting FA controllers can ensure that every response of the closed-loop system is uniformly ultimately bounded with a guaranteed L(∞)-gain performance in the presence of a fault. Moreover, by the existing LMI optimization technique, a suboptimal controller is obtained in the sense of minimizing an upper bound of the L(∞)-gain. Finally, the achieved simulation results on the FA control of a continuous stirred tank reactor (CSTR) show the effectiveness of the proposed design procedure.
Wang, Gang; Chen, Changzheng; Yu, Shenbo
2016-09-01
In this paper, the static output-feedback control problem of active suspension systems with information structure constraints is investigated. In order to simultaneously improve the ride comfort and stability, a half car model is used. Other constraints such as suspension deflection, actuator saturation, and controller constrained information are also considered. A novel static output-feedback design method based on the variable substitution is employed in the controller design. A single-step linear matrix inequality (LMI) optimization problem is solved to derive the initial feasible solution with a sparsity constraint. The initial infeasibility issue of the static output-feedback is resolved by using state-feedback information. Specifically, an optimization algorithm is proposed to search for less conservative results based on the feasible controller gain matrix. Finally, the validity of the designed controller for different road profiles is illustrated through numerical examples. The simulation results indicate that the optimized static output-feedback controller can achieve better suspension performances when compared with the feasible static output-feedback controller.
H2 control of a one-quarter semi-active ground vehicle suspension
Directory of Open Access Journals (Sweden)
L.C. Félix-Herrán
2016-06-01
Full Text Available Magneto-rheological (MR dampers are effective solutions in improving vehicle stability and passenger comfort. However, handling these dampers implies a strong effort in modeling and control. This research proposes an H2 controller, based on a Takagi–Sugeno (T–S fuzzy model, for a two-degrees-of-freedom (2-DOF one-quarter vehicle semi-active suspension with an MR damper; a system with important applications in automotive industry. Regarding performance criteria (in frequency domain handled herein, the developed controller considerably improves the passive suspension's efficiency. Moreover, nonlinear actuator dynamics usually avoided in reported work, is included in controller's synthesis; improving the relevance of research outcomes because the controller is synthesized from a closer-to-reality suspension model. Going further, outcomes of this research are compared (based on frequency domain performance criteria and a common time domain test with reported work to highlight the outstanding results. H2 controller is given in terms of quadratic Lyapunov stability theory and carried out by means of Linear Matrix Inequalities (LMI, and the command signal is applied via the Parallel Distributed Compensation (PDC approach. A case of study, with real data, is developed and simulation work supports the results. The methodology applied herein can be extended to include other vehicle suspension's dynamics towards a general chassis control.
Institute of Scientific and Technical Information of China (English)
张勇; 张凯
2011-01-01
研究了一类具有状态时滞的不确定非线性系统的非脆弱保成本控制问题.通过利用Lyapunov稳定性理论和线性矩阵不等式方法,设计非脆弱保成本控制律,使得闭环系统渐近稳定,并且系统的性能指标不超过某个确定的上界.通过求解一个具有线性矩阵不等式约束的凸优化问题来设计最优非脆弱保成本控制器,以使得闭环不确定系统的性能指标最小化.仿真结果验证了该控制算法的有效性.%This paper considers the non-fragile guaranteed cost control problem for a class of uncertain nonlinear systems with states time-delay.The Lyapunov stability theory and the LMI approach are applied to design a non-fragile guaranteed cost control law,which results that the closed-loop system is asymptotically stable and the system's performance index is less than a determinate super bound.A convex optimization problem with LMI constraints is formulated to design the optimal non-fragile guaranteed cost controller for minimizing the performance index of the closed-loop uncertain system. Simulation results show the validity of the proposed control algorithm.
Fuzzy adaptive tracking control within the full envelope for an unmanned aerial vehicle
Institute of Scientific and Technical Information of China (English)
Liu Zhi; Wang Yong
2014-01-01
Motivated by the autopilot of an unmanned aerial vehicle (UAV) with a wide flight enve-lope span experiencing large parametric variations in the presence of uncertainties, a fuzzy adaptive tracking controller (FATC) is proposed. The controller consists of a fuzzy baseline controller and an adaptive increment, and the main highlight is that the fuzzy baseline controller and adaptation laws are both based on the fuzzy multiple Lyapunov function approach, which helps to reduce the conservatism for the large envelope and guarantees satisfactory tracking performances with strong robustness simultaneously within the whole envelope. The constraint condition of the fuzzy baseline controller is provided in the form of linear matrix inequality (LMI), and it specifies the satisfactory tracking performances in the absence of uncertainties. The adaptive increment ensures the uniformly ultimately bounded (UUB) predication errors to recover satisfactory responses in the presence of uncertainties. Simulation results show that the proposed controller helps to achieve high-accuracy tracking of airspeed and altitude desirable commands with strong robustness to uncertainties throughout the entire flight envelope.
Fuzzy virtual reference model sensorless tracking control for linear induction motors.
Hung, Cheng-Yao; Liu, Peter; Lian, Kuang-Yow
2013-06-01
This paper introduces a fuzzy virtual reference model (FVRM) synthesis method for linear induction motor (LIM) speed sensorless tracking control. First, we represent the LIM as a Takagi-Sugeno fuzzy model. Second, we estimate the immeasurable mover speed and secondary flux by a fuzzy observer. Third, to convert the speed tracking control into a stabilization problem, we define the internal desired states for state tracking via an FVRM. Finally, by solving a set of linear matrix inequalities (LMIs), we obtain the observer gains and the control gains where exponential convergence is guaranteed. The contributions of the approach in this paper are threefold: 1) simplified approach--speed tracking problem converted into stabilization problem; 2) omit need of actual reference model--FVRM generates internal desired states; and 3) unification of controller and observer design--control objectives are formulated into an LMI problem where powerful numerical toolboxes solve controller and observer gains. Finally, experiments are carried out to verify the theoretical results and show satisfactory performance both in transient response and robustness.
Controller Design for Electric Power Steering System Using T-S Fuzzy Model Approach
Institute of Scientific and Technical Information of China (English)
Xin Li; Xue-Ping Zhao; Jie Chen
2009-01-01
Pressure ripples in electric power steering (EPS) systems can be caused by the phase lag between the driver's steering torque and steer angle, the nonlinear frictions, and the disturbances from road and sensor noise especially during high-frequency maneuvers. This paper investigates the use of the robust fuzzy control method for actively reducing pressure ripples for EPS systems. Remarkable progress on steering maneuverability is achieved. The EPS dynamics is described with an eight-order nonlinear state-space model and approximated by a Takagi-Sugeno (T-S) fuzzy model with time-varying delays and external disturbances. A stabilization approach is then presented for nonlinear time-delay systems through fuzzy state feedback controller in parallel distributed compensation (PDC) structure. The closed-loop stability conditions of EPS system with the fuzzy controller are parameterized in terms of the linear matrix inequality (LMI) problem. Simulations and experiments using the proposed robust fuzzy controller and traditional PID controller have been carried out for EPS systems. Both the simulation and experiment results show that the proposed fuzzy controller can reduce the torque ripples and allow us to have a good steering feeling and stable driving.
H∞ reference tracking control design for a class of nonlinear systems with time-varying delays
Institute of Scientific and Technical Information of China (English)
Mei-qin LIU; Hai-yang CHEN; Sen-lin ZHANG
2015-01-01
This paper investigates the H∞ trajectory tracking control for a class of nonlinear systems with time-varying delays by virtue of Lyapunov-Krasovskii stability theory and the linear matrix inequality (LMI) technique. A unifi ed model consisting of a linear delayed dynamic system and a bounded static nonlinear operator is introduced, which covers most of the nonlinear systems with bounded nonlinear terms, such as the one-link robotic manipulator, chaotic systems, complex networks, the continuous stirred tank reactor (CSTR), and the standard genetic regulatory network (SGRN). First, the defi nition of the tracking control is given. Second, the H∞ performance analysis of the closed-loop system including this unifi ed model, reference model, and state feedback controller is presented. Then criteria on the tracking controller design are derived in terms of LMIs such that the output of the closed-loop system tracks the given reference signal in the H∞ sense. The reference model adopted here is modifi ed to be more fl exible. A scaling factor is introduced to deal with the disturbance such that the control precision is improved. Finally, a CSTR system is provided to demonstrate the effectiveness of the established control laws.
Fuzzy adaptive tracking control within the full envelope for an unmanned aerial vehicle
Directory of Open Access Journals (Sweden)
Liu Zhi
2014-10-01
Full Text Available Motivated by the autopilot of an unmanned aerial vehicle (UAV with a wide flight envelope span experiencing large parametric variations in the presence of uncertainties, a fuzzy adaptive tracking controller (FATC is proposed. The controller consists of a fuzzy baseline controller and an adaptive increment, and the main highlight is that the fuzzy baseline controller and adaptation laws are both based on the fuzzy multiple Lyapunov function approach, which helps to reduce the conservatism for the large envelope and guarantees satisfactory tracking performances with strong robustness simultaneously within the whole envelope. The constraint condition of the fuzzy baseline controller is provided in the form of linear matrix inequality (LMI, and it specifies the satisfactory tracking performances in the absence of uncertainties. The adaptive increment ensures the uniformly ultimately bounded (UUB predication errors to recover satisfactory responses in the presence of uncertainties. Simulation results show that the proposed controller helps to achieve high-accuracy tracking of airspeed and altitude desirable commands with strong robustness to uncertainties throughout the entire flight envelope.
Institute of Scientific and Technical Information of China (English)
丁衍; 魏晨; 鲍树语
2014-01-01
为实现存在时变通信时延与自时延情况下多无人机的编队控制，利用分散化控制策略与分层控制结构并结合一种带时变参考值的leader-following一致性算法设计状态估计器估计加速度信息和编队控制器使编队保持给定的队形。通过构造Lyapunov函数，获得了无人机编队系统实际位置与期望位置误差收敛到0的充分条件。利用线性矩阵不等式( LMI)给出了时延的上界。最后通过仿真实例实现了无人机编队飞行与保持，表明了方法的正确性与有效性。%In order to achieve the formation control of Unmanned Aerial vehicle ( UAVs) with time-varying communication and self delay, by using the decentralization strategy and a level control structure, a leader-following consensus protocol with time-varying communication and self delay was proposed. By employing Lyapunov method, it can be proven that the deviation of UAV's actual position and desired position can converge to 0 asymptotically and the Linear Matrix Inequality ( LMI ) is obtained to determine the maximal allowable upper bounds of delays. The consensus protocol with time-varying reference values was applied as an estimator to estimate the acceleration and a controller to keep the desired formation. Simulation results are given to demonstrate the effectiveness of the proposed method.
Directory of Open Access Journals (Sweden)
Cristian J. B. de Lima
2010-01-01
Full Text Available Two response surface methodologies involving central composite designs have been successfully applied to evaluate the effect of cheese whey, corn steep liquor, ammonium sulphate, temperature and pH control on lactic acid fermentation by Lactobacillus sp. LMI8 isolated from cassava flour wastewater. In the first central composite design, corn steep liquor and ammonium sulphate were investigated as low-cost nitrogen sources in combination with other components to substitute yeast extract for economical production. The best results were obtained with 55 g/L of lactose, 15 g/L of corn steep liquor and 5.625 g/L of ammonium sulphate. At the maximum point, the lactic acid concentration reached 18.68 g/L. After defining the optimal nutritional conditions for lactic acid production, a second central composite design was performed to determine the extent to which temperature and pH influence the lactic acid production with the aim of improving the fermentation process. The second-order polynomial regression model determined that the maximum lactic acid production of 52.37 g/L would be obtained when the optimum temperature and pH were 39.6 °C and 5.9, respectively. Comparing the lactic acid production in shake flask fermentation, there was an increase of 180 % after 30 h of processing, with a conversion efficiency of about 86.12 % of the initial lactose. In addition, lactic acid produced from whey lactose by Lactobacillus sp. LMI8 was optically almost pure D-lactic acid (over 98 % of total lactic acid produced.
Sliding mode H∞ control for a class of uncertain nonlinear state-delayed systems
Institute of Scientific and Technical Information of China (English)
Wu Ligang; Wang Changhong; Gao Huijun; Zhang Lixian
2006-01-01
A new proportional-integral (PI) sliding surface is designed for a class of uncertain nonlinear state-delayed systems. Based on this, an adaptive sliding mode controller (ASMC) is synthesized, which guarantees the occurrence of sliding mode even when the system is undergoing parameter uncertainties and external disturbance. The resulting sliding mode has the same order as the original system, so that it becomes easy to solve the H∞ control problem by designing a memoryless H∞ state feedback controller. A delay-dependent sufficient condition is proposed in terms of linear matrix inequalities (LMIs), which guarantees the sliding mode robust asymptotically stable and has a noise attenuation level γ in an H∞ sense. The admissible state feedback controller can be found by solving a sequential minimization problem subject to LMI constraints by applying the cone complementary linearization method. This design scheme combines the strong robustness of the sliding mode control with the H∞ norm performance. A numerical example is given to illustrate the effectiveness of the proposed scheme.
Constrained model predictive control, state estimation and coordination
Yan, Jun
guarantee local stability or convergence to a target state. If these conditions are met for all subsystems, then this stability is inherited by the overall system. For the case when each subsystem suffers from disturbances in the dynamics, own self-measurement noises, and quantization errors on neighbors' information due to the finite-bit-rate channels, the constrained MPC strategy developed in Part (i) is appropriate to apply. In Part (iii), we discuss the local predictor design and bandwidth assignment problem in a coordinated vehicle formation context. The MPC controller used in Part (ii) relates the formation control performance and the information quality in the way that large standoff implies conservative performance. We first develop an LMI (Linear Matrix Inequality) formulation for cross-estimator design in a simple two-vehicle scenario with non-standard information: one vehicle does not have access to the other's exact control value applied at each sampling time, but to its known, pre-computed, coupling linear feedback control law. Then a similar LMI problem is formulated for the bandwidth assignment problem that minimizes the total number of bits by adjusting the prediction gain matrices and the number of bits assigned to each variable. (Abstract shortened by UMI.)
Institute of Scientific and Technical Information of China (English)
王云良; 王敏其; 程凌
2014-01-01
针对智能家居网络系统，对家庭内部网络进行设计。对以数据为中心的定向扩散路由算法进行改进，将节点按房间的顺序规划在不同的矩形区域，每个矩形区域设立一个源节点，用来接收网关节点发布的消息。同时，研究了短时延情况下不确定时延网络控制系统的稳定性，并利用Lyapunov函数和线性矩阵不等式( LMI)方法，给出网络控制系统渐进稳定的充分条件。仿真结果显示，改进算法可延长网络生命周期，节省能耗，提高网络能效。%For smart home network system, the interior network of home has been designed. The directed diffusion routing algorithm with data as the core is improved, the nodes are arranged in different rectangular areas according to the sequencing of the rooms;a source node is set up in each rectangular area to receive the messages released from gateway. In addition, the stability of uncertain delay network control system under short time delay is researched. The sufficient condition for network control system asymptotic stability is given by adopting Lyapunov function and linear matrix inequalities ( LMI) . The results of simulation show that the improved algorithm extends the life cycle of the network, increases energy efficiency of network, and reduces energy consumption.
Dairy Logistics Supply Chain Dynamic Model and Robust HI Control%乳制品物流供应链动态模型及其鲁棒H∞控制
Institute of Scientific and Technical Information of China (English)
杜轩; 尹春华
2016-01-01
文中针对乳制品物流供应链系统实际运作过程中存在的时滞、参数和外部环境输入等不确定性问题，建立了相应的乳制品物流供应链动态模型，采用鲁棒H∞控制的方法和线性矩阵不等式（LMI ）算法处理了乳制品物流供应链系统实际运作问题。借助乳制品物流供应链库存状态的静态反馈控制，使供应链动态系统达到克制不确定性因素干扰的作用，并使供应链系统实际运作总成本达到最优。最后，通过Matlab仿真计算验证了所得结果。%Aiming uncertainty Delay dairy supply chain logistics systems that exist in the actual operation of the process, the input parameters and the external environment,the establishment of the corresponding dairy logistics supply chain dynamic model using the method of robust H∞ control and linear matrix inequality (LMI)algorithm processing the dairy supply chain logistics system is actually functioning.With the dairy supply chain logistics static feedback control inventory status,dynamic supply chain system to achieve the role of restraint uncertainties interference,and the actual operation of the supply chain system to achieve optimal total cost.Finally,Matlab simulation to verify the results obtained.
Shao, Xinxin; Naghdy, Fazel; Du, Haiping
2017-03-01
A fault-tolerant fuzzy H∞ control design approach for active suspension of in-wheel motor driven electric vehicles in the presence of sprung mass variation, actuator faults and control input constraints is proposed. The controller is designed based on the quarter-car active suspension model with a dynamic-damping-in-wheel-motor-driven-system, in which the suspended motor is operated as a dynamic absorber. The Takagi-Sugeno (T-S) fuzzy model is used to model this suspension with possible sprung mass variation. The parallel-distributed compensation (PDC) scheme is deployed to derive a fault-tolerant fuzzy controller for the T-S fuzzy suspension model. In order to reduce the motor wear caused by the dynamic force transmitted to the in-wheel motor, the dynamic force is taken as an additional controlled output besides the traditional optimization objectives such as sprung mass acceleration, suspension deflection and actuator saturation. The H∞ performance of the proposed controller is derived as linear matrix inequalities (LMIs) comprising three equality constraints which are solved efficiently by means of MATLAB LMI Toolbox. The proposed controller is applied to an electric vehicle suspension and its effectiveness is demonstrated through computer simulation.
Wang, Jun-Wei; Wu, Huai-Ning; Li, Han-Xiong
2012-06-01
In this paper, a distributed fuzzy control design based on Proportional-spatial Derivative (P-sD) is proposed for the exponential stabilization of a class of nonlinear spatially distributed systems described by parabolic partial differential equations (PDEs). Initially, a Takagi-Sugeno (T-S) fuzzy parabolic PDE model is proposed to accurately represent the nonlinear parabolic PDE system. Then, based on the T-S fuzzy PDE model, a novel distributed fuzzy P-sD state feedback controller is developed by combining the PDE theory and the Lyapunov technique, such that the closed-loop PDE system is exponentially stable with a given decay rate. The sufficient condition on the existence of an exponentially stabilizing fuzzy controller is given in terms of a set of spatial differential linear matrix inequalities (SDLMIs). A recursive algorithm based on the finite-difference approximation and the linear matrix inequality (LMI) techniques is also provided to solve these SDLMIs. Finally, the developed design methodology is successfully applied to the feedback control of the Fitz-Hugh-Nagumo equation.
Active control of smart structures with optimal actuator and sensor locations
Liu, Pengxiang; Rao, Vittal S.; Derriso, Mark M.
2002-07-01
Sensors and actuators used in active control of smart structures have to be located appropriately in order to ensure maximum control and measurement effectiveness. Many placement techniques are based on the structure itself and overlook the effects of the applied control law. The optimal locations determined from open-loop system can not guarantee the best performance of the closed-loop system because the performance is closely related with the design requirements and applied controller. In this paper, we presented a method of obtaining the optimal locations of actuators/sensors by combining the open-loop and closed-loop optimal criterions. First, for open-loop system, location indices of the controlled modes are calculated on the basis of modal controllability and observability. The controlled modes are weighted based on the controller design requirements. To reduce the spill-over effect of uncontrolled modes, the location index values of uncontrolled modes are added as penalty terms. Locations with high index values are chosen as candidate locations of actuator/sensor for the next determining step on the closed-loop system. Three control techniques, optimal H2, H(infinity ) norms and optimal pole-placement, are utilized for two different control objectives, disturbance rejection and damping property enhancement. Linear matrix inequality (LMI) techniques are utilized to formulate the control problems and synthesize the controllers. For each candidate location of actuator/sensor, a controller is designed and the obtained performance is taken as location index. By solving the location problem in two steps, we reduced the computational burden and ensured good control performance of the closed-loop system. The proposed method is tested on a clamped plate with piezoelectric actuators and sensors.
Institute of Scientific and Technical Information of China (English)
Huang Yiqing; Sun Changyin; Qian Chengshan; Wang Li
2013-01-01
This article proposes a linear parameter varying (LPV) switching tracking control scheme for a flexible air-breathing hypersonic vehicle (FAHV).First,a polytopic LPV model is constructed to represent the complex nonlinear longitudinal model of the FAHV by using Jacobian linearization and tensor-product (T-P) model transformation approach.Second,for less conservative controller design purpose,the flight envelope is divided into four sub-regions and a non-fragile LPV controller is designed for each parameter sub-region.These non-fragile LPV controllers are then switched in order to guarantee the closed-loop FAHV system to be asymptotically stable and satisfy a specified performance criterion.The desired non-fragile LPV switching controller is found by solving a convex constraint problem which can be efficiently solved using available linear matrix inequality (LMI) techniques,and robust stability analysis of the closed-loop FAHV system is verified based on multiple Lypapunov functions (MLFs).Finally,numerical simulations have demonstrated the effectiveness of the proposed approach.
Mehdi, Niaz; Rehan, Muhammad; Malik, Fahad Mumtaz; Bhatti, Aamer Iqbal; Tufail, Muhammad
2014-05-01
This paper describes the anti-windup compensator (AWC) design methodologies for stable and unstable cascade plants with cascade controllers facing actuator saturation. Two novel full-order decoupling AWC architectures, based on equivalence of the overall closed-loop system, are developed to deal with windup effects. The decoupled architectures have been developed, to formulate the AWC synthesis problem, by assuring equivalence of the coupled and the decoupled architectures, instead of using an analogy, for cascade control systems. A comparison of both AWC architectures from application point of view is provided to consolidate their utilities. Mainly, one of the architecture is better in terms of computational complexity for implementation, while the other is suitable for unstable cascade systems. On the basis of the architectures for cascade systems facing stability and performance degradation problems in the event of actuator saturation, the global AWC design methodologies utilizing linear matrix inequalities (LMIs) are developed. These LMIs are synthesized by application of the Lyapunov theory, the global sector condition and the ℒ2 gain reduction of the uncertain decoupled nonlinear component of the decoupled architecture. Further, an LMI-based local AWC design methodology is derived by utilizing a local sector condition by means of a quadratic Lyapunov function to resolve the windup problem for unstable cascade plants under saturation. To demonstrate effectiveness of the proposed AWC schemes, an underactuated mechanical system, the ball-and-beam system, is considered, and details of the simulation and practical implementation results are described.
Iqbal, Kamran; Roy, Anindo
2004-12-01
In this paper we address the problem of PID stabilization of a single-link inverted pendulum-based biomechanical model with force feedback, two levels of position and velocity feedback, and with delays in all the feedback loops. The novelty of the proposed model lies in its physiological relevance, whereby both small and medium latency sensory feedbacks from muscle spindle (MS), and force feedback from Golgi tendon organ (GTO) are included in the formulation. The biomechanical model also includes active and passive viscoelastic feedback from Hill-type muscle model and a second-order low-pass function for muscle activation. The central nervous system (CNS) regulation of postural movement is represented by a proportional-integral-derivative (PID) controller. Padé approximation of delay terms is employed to arrive at an overall rational transfer function of the biomechanical model. The Hermite-Biehler theorem is then used to derive stability results, leading to the existence of stabilizing PID controllers. An algorithm for selection of stabilizing feedback gains is developed using the linear matrix inequality (LMI) approach.
ROBUST MIXED H2/H8 ACTIVE VIBRATION CONTROLLER IN ATTENUATION OF SMART BEAM
Directory of Open Access Journals (Sweden)
Atta Oveisi
2014-12-01
Full Text Available The lack of robustness of the mechanical systems due to the unmodeled dynamics and the external disturbances withholds the performance and optimality of the structures. In this paper, this deficiency is obviated in order to reach the desired robust stability and performance on smart structures. For this purpose a multi-objective robust control strategy is proposed for vibration suppression of a clamped-free smart beam with piezoelectric actuator and vibrometer sensor in an LMI framework which is capable of handling weighted exogenous input signals and provides desired pole placement and robust performance at the same time. An accurate model of a homogeneous beam is derived by means of the finite element modal analysis. Then a low order modal system is considered as the nominal model and remaining modes are left as the multiplicative unstructured uncertainty. Next, a robust controller with a regional pole placement constraint is designed based on the augmented plant composed of the nominal model and its accompanied uncertainty by solving a convex optimization problem. Finally, the robustness of the uncertain closed-loop model and the effect of performance index weights on the system output are investigated both in simulation and practice.
Robust H∞ Control for a Class of Uncertain Switched Fuzzy Time-Delay Systems Based on T-S Models
Directory of Open Access Journals (Sweden)
Yang Cui
2013-01-01
Full Text Available The problem of robust H∞ control for a class of uncertain switched fuzzy time-delay systems is discussed for system described by T-S fuzzy model with Lyapunov stable theory and linear matrix inequality approach. A sufficient condition in terms of the LMI is derived such that the stability of the closed-loop systems is guaranteed. The continuous state feedback controller is built to ensure the asymptotically stable closed-loop system for all allowable uncertainties, with the switching law designed to implement the global asymptotic stability of uncertain switched fuzzy time-delay systems. In this model, each and every subsystem of the switched systems is an uncertain fuzzy one to which the parallel distributed compensation (PDC controller of each sub fuzzy system system is proposed with its main condition given in a more solvable form of convex combinations. Such a switched control system is highly robust to varying parameters. A simulation shows the feasibility and effectiveness of the design method.
Carson, John M., III; Ackmese, A. Behcet
2005-01-01
The guidance and control (G&C) algorithms for enabling small-body proximity operations are developed by using a model predictive control approach along with a convexification of the governing dynamics, control constraints, and trajectory/state constraints. The open-loop guidance is solved ahead of time or in a resolvable, real-time manner through the use of PWG (Pseudo Way-point Generation), a technique developed in this research. The PWG scheme ensures required thruster silent times during trajectory maneuvers. The feedback control is implemented to track the PWG trajectories in a manner that guarantees the resolvability for the open-loop problem, enabling the ability to update the G&C in a model-predictive manner. The schemes incorporate gravity models and thruster ring times into discrete dynamics that are solved as a optimal control problem to minimize fuel consumption or thruster energy expenditure. The optimal control problem is cast as an LMI (Linear Matrix Inequality) and then solved through Semi-Definite Programming techniques in a computationally efficient manner that provides convergence and constraint guarantees.
Control of nonlinear systems with applications
Pan, Haizhou
In practical applications of feedback control, most actuators exhibit physical constraints that limit the control amplitude and/or rate. The principal challenge of control design problem for linear systems with input constraints is to ensure closed-loop stability and yield a good transient performance in the presence of amplitude and/or rate-limited control. Since actuator saturation manifests itself as a nonlinear behavior in an otherwise linear system, the development of a nonconservative saturation control design methodology poses a significant challenge. In particular, it is well known that unstable linear systems can be stabilized using smooth controllers only in a local sense in the presence of actuator saturation. Thus, it is of paramount importance to develop a saturation control design methodology that yields a nonconservative estimate of the stability domain for closed-loop system. The first part of this research focuses on a numerically tractable formulation of the control synthesis problem for linear systems with actuator amplitude and rate saturation nonlinearity using a linear-matrix-inequality (LMI) framework. Following the recent trend in the actuator saturation control research, we (i) utilize absolute stability theory to ensure closed-loop stability and (ii) minimize a quadratic cost to account for the closed-loop system performance degradation. In order to reduce the inherent conservatism of the absolute stability based saturation control framework, we exploit stability multipliers (of, e.g., weighted circle criterion, Popov criterion, etc.). For the control of linear systems with simultaneous actuator amplitude and rate saturation nonlinearities, by virtue of a rate limiter that is predicated on designing the control amplitude and then computing the control rates, we directly account for rate constraints. Both continuous- and discrete-time systems with actuator saturation are considered. A number of design examples are presented to demonstrate
Li, Huiping; Shi, Yang
2012-10-01
This article focuses on the state-feedback ℋ∞ control problem for the stochastic nonlinear systems with state and disturbance-dependent noise and time-varying state delays. Based on the maxmin optimisation approach, both the delay-independent and the delay-dependent Hamilton-Jacobi-inequalities (HJIs) are developed for synthesising the state-feedback ℋ∞ controller for a general type of stochastic nonlinear systems. It is shown that the resulting control system achieves stochastic stability in probability and the prescribed disturbance attenuation level. For a class of stochastic affine nonlinear systems, the delay-independent as well as delay-dependent matrix-valued inequalities are proposed; the resulting control system satisfies global asymptotic stability in the mean-square sense and the required disturbance attenuation level. By modelling the nonlinearities as uncertainties in corresponding stochastic time-delay systems, the sufficient conditions in terms of a linear matrix inequality (LMI) and a bilinear matrix inequality (BMI) are derived to facilitate the design of the state-feedback ℋ∞ controller. Finally, two numerical examples are provided to illustrate the effectiveness of the proposed methods.
压电柔性结构振动的鲁棒控制%Robust vibration control of flexible piezoelectric structure
Institute of Scientific and Technical Information of China (English)
杨海峰; 王晓军; 邱志平
2009-01-01
针对具有多面体型参数不确定性和外界扰动的柔性悬臂梁系统,研究其振动的鲁棒控制问题.基于压电柔性悬臂梁系统的状态方程,利用一种扩展LMI(Linear Matrix Inequality),对柔性悬臂梁的振动提出了改进的H_2/H_∞综合状态反馈鲁棒控制方法.此方法针对多面体型参数不确定性系统引入不同的Lyapunov函数,降低了原来H_2/H_∞综合鲁棒控制方法中由于使用一个公共Lyapunov函数而产生的保守性.通过Matlab分别采用改进和未改进的H_2/H_∞鲁棒控制方法对柔性悬臂梁系统的振动控制进行了数值仿真.仿真结果表明,2种方法都使柔性悬臂梁的振动得到了良好控制,而改进方法的控制效果更好.%The robust vibration control for the flexible cantilever beam system with polytopic-type uncertainties and environmental disturbances is studied. Based on the state equation, the improved multi-objective H_2/H_∞ state-feedback robust control method is proposed for the flexible cantilever beam system by using a kind of extended linear matrix inequality (LMI). The presented method, which introduces multi Lyapunov functions for the polytopic-type uncertainties system, reduces the conservatism stemmed from the single Lyapunov function used in the unimproved method. The robust vibration control for the flexible cantilever beam system is simulated in Matlab by these two methods respectively. The results show that the flexible cantilever beam is well controlled via the two methods, and the improved method gets a better result.
Delay-Dependent Exponential Stability Criterion for BAM Neural Networks with Time-Varying Delays
Institute of Scientific and Technical Information of China (English)
Wei-Wei Su; Yi-Ming Chen
2008-01-01
By employing the Lyapunov stability theory and linear matrix inequality (LMI) technique, delay dependent stability criterion is derived to ensure the exponential stability of bi-directional associative memory (BAM) neural networks with time-varying delays. The proposed condition can be checked easily by LMI control toolbox in Matlab. A numerical example is given to demonstrate the effectiveness of our results.
Directory of Open Access Journals (Sweden)
Chen Bor-Sen
2012-10-01
Full Text Available Abstract Background Collective rhythms of gene regulatory networks have been a subject of considerable interest for biologists and theoreticians, in particular the synchronization of dynamic cells mediated by intercellular communication. Synchronization of a population of synthetic genetic oscillators is an important design in practical applications, because such a population distributed over different host cells needs to exploit molecular phenomena simultaneously in order to emerge a biological phenomenon. However, this synchronization may be corrupted by intrinsic kinetic parameter fluctuations and extrinsic environmental molecular noise. Therefore, robust synchronization is an important design topic in nonlinear stochastic coupled synthetic genetic oscillators with intrinsic kinetic parameter fluctuations and extrinsic molecular noise. Results Initially, the condition for robust synchronization of synthetic genetic oscillators was derived based on Hamilton Jacobi inequality (HJI. We found that if the synchronization robustness can confer enough intrinsic robustness to tolerate intrinsic parameter fluctuation and extrinsic robustness to filter the environmental noise, then robust synchronization of coupled synthetic genetic oscillators is guaranteed. If the synchronization robustness of a population of nonlinear stochastic coupled synthetic genetic oscillators distributed over different host cells could not be maintained, then robust synchronization could be enhanced by external control input through quorum sensing molecules. In order to simplify the analysis and design of robust synchronization of nonlinear stochastic synthetic genetic oscillators, the fuzzy interpolation method was employed to interpolate several local linear stochastic coupled systems to approximate the nonlinear stochastic coupled system so that the HJI-based synchronization design problem could be replaced by a simple linear matrix inequality (LMI-based design problem
Fan, Xiaozheng; Wang, Yan; Hu, Manfeng
2016-01-01
In this paper, the fuzzy [Formula: see text] output-feedback control problem is investigated for a class of discrete-time T-S fuzzy systems with channel fadings, sector nonlinearities, randomly occurring interval delays (ROIDs) and randomly occurring nonlinearities (RONs). A series of variables of the randomly occurring phenomena obeying the Bernoulli distribution is used to govern ROIDs and RONs. Meanwhile, the measurement outputs are subject to the sector nonlinearities (i.e. the sensor saturations) and we assume the system output is [Formula: see text], [Formula: see text]. The Lth-order Rice model is utilized to describe the phenomenon of channel fadings by setting different values of the channel coefficients. The aim of this work is to deal with the problem of designing a full-order dynamic fuzzy [Formula: see text] output-feedback controller such that the fuzzy closed-loop system is exponentially mean-square stable and the [Formula: see text] performance constraint is satisfied, by means of a combination of Lyapunov stability theory and stochastic analysis along with LMI methods. The proposed fuzzy controller parameters are derived by solving a convex optimization problem via the semidefinite programming technique. Finally, a numerical simulation is given to illustrate the feasibility and effectiveness of the proposed design technique.
Directory of Open Access Journals (Sweden)
Jian-ming Wei
2015-01-01
Full Text Available This paper presents an adaptive iterative learning control scheme for the output tracking of a class of nonlinear systems with unknown time-varying delays and input saturation nonlinearity. An observer is presented to estimate the states and linear matrix inequality (LMI method is employed for observer design. The assumption of identical initial condition for ILC is relaxed by introducing boundary layer function. The possible singularity problem is avoided by introducing hyperbolic tangent function. The uncertainties with time-varying delays are compensated for by the combination of appropriate Lyapunov-Krasovskii functional and Young’s inequality. Both time-varying and time-invariant radial basis function neural networks are employed to deal with system uncertainties. On the basis of a property of hyperbolic tangent function, the system output is proved to converge to a small neighborhood of the desired trajectory by constructing Lyapunov-like composite energy function in two cases, while keeping all the closed-loop signals bounded. Finally, a simulation example is presented to verify the effectiveness of the proposed approach.
DEFF Research Database (Denmark)
Kallesøe, Carsten; Vadstrup, Pierre; Rasmussen, Henrik;
2006-01-01
This paper addresses the subject of inter-turn short circuit estimation in the stator of an induction motor. In the paper an adaptive observer scheme is proposed. The proposed observer is capable of simultaneously estimating the speed of the motor, the amount turns involved in the short circuit a...... derived. The efficiency of the proposed observer is demonstrated by tests performed on a test setup with a customized designed induction motor. With this motor it is possible to simulate inter-turn short circuit faults....
Parity Relation Based Fault Estimation for Nonlinear Systems: An LMI Approach
Institute of Scientific and Technical Information of China (English)
Sing Kiong Nguang; Ping Zhang; Steven X. Ding
2007-01-01
This paper proposes a parity relation based fault estimation for a class of nonlinear systems which can be modelled by Takagi-Sugeno (TS) fuzzy models. The design of a parity relation based residual generator is formulated in terms of a family of linear matrix inequalities (LMIs). A numerical example is provided to illustrate the effectiveness of the proposed design techniques.
Enhanced LMI Representations for H2 Performance of Polytopic Uncertain Systems: Continuous-time Case
Institute of Scientific and Technical Information of China (English)
Ai-Guo Wu; Guang-Ren Duan
2006-01-01
Based on two recent results, several new criteria of H2 performance for continuous-time linear systems are established by introducing two slack matrices. When used in robust analysis of systems with polytopic uncertainties, they can reduce conservatism inherent in the earlier quadratic method and the established parameter-dependent Lyapunov function approach. Two numerical examples are included to illustrate the feasibility and advantage of the proposed representations.
LMI-based approach for global asymptotic stability analysis of continuous BAM neural networks
Institute of Scientific and Technical Information of China (English)
ZHANG Sen-lin; LIU Mei-qin
2005-01-01
Studies on the stability of the equilibrium points of continuous bidirectional associative memory (BAM) neural network have yielded many useful results. A novel neural network model called standard neural network model (SNNM) is advanced. By using state affine transformation, the BAM neural networks were converted to SNNMs. Some sufficient conditions for the global asymptotic stability of continuous BAM neural networks were derived from studies on the SNNMs' stability. These conditions were formulated as easily verifiable linear matrix inequalities (LMIs), whose conservativeness is relatively low. The approach proposed extends the known stability results, and can also be applied to other forms of recurrent neural networks (RNNs).
Stability analysis of extended discrete-time BAM neural networks based on LMI approach
Institute of Scientific and Technical Information of China (English)
无
2005-01-01
We propose a new approach for analyzing the global asymptotic stability of the extended discrete-time bidirectional associative memory (BAM) neural networks. By using the Euler rule, we discretize the continuous-time BAM neural networks as the extended discrete-time BAM neural networks with non-threshold activation functions. Here we present some conditions under which the neural networks have unique equilibrium points. To judge the global asymptotic stability of the equilibrium points, we introduce a new neural network model - standard neural network model (SNNM).For the SNNMs, we derive the sufficient conditions for the global asymptotic stability of the equilibrium points, which are formulated as some linear matrix inequalities (LMIs). We transform the discrete-time BAM into the SNNM and apply the general result about the SNNM to the determination of global asymptotic stability of the discrete-time BAM. The approach proposed extends the known stability results, has lower conservativeness, can be verified easily, and can also be applied to other forms of recurrent neural networks.
Institute of Scientific and Technical Information of China (English)
马静; 高翔; 李益楠; 邱扬
2016-01-01
An adaptive control strategy based on continuous Markov model for time-varying power system is proposed to deal with the large variation in operating condition of power system caused by the wind generator output fluctuation.First, Lyapunov functional containing a continuous Markov model of time-varying power system is developed and Dynkin lemma is used to deduce the robust stochastic stabilization theorem with H ∞ norm boundγ.On this basis,Schur complement lemma is used to deduce robust stochastic stabilization linear matrix inequalities (LMI) meeting decay rate γ and minimum variance constraints considering steady-state variance constraints of various operating conditions.Then it is turned into a minimization problem of linear objective function to obtain the sub-controllers.The operating condition is identified online with the stochastic gradient method and the weighted coefficient of each condition is determined to construct the adaptive control strategy.Time-domain simulation results show that the strategy has efficiently solved the problem that fixed fault sets cannot be matched with current operating condition reasonably.%针对风电机组出力波动等时变因素导致电力系统运行工况变化较大的问题，提出了一种基于连续马尔可夫(Markov)模型的时变电力系统自适应控制策略。首先，构建含连续 Markov 时变电力系统模型的 Lyapunov 泛函，利用 Dynkin 引理，推导出具有 H ∞范数界γ的鲁棒随机稳定性定理。在此基础上，利用 Schur 补引理，考虑系统各子工况下稳态方差约束，推导出满足干扰衰减度γ和最小方差约束的鲁棒随机稳定线性矩阵不等式(LMI)，并将该 LMI 转化为线性目标函数的最小化问题求解各子控制器。然后，利用随机梯度法辨识系统工况，确定各子控制器加权系数，构造自适应控制策略。时域仿真表明，该控制策略有效避免了固定故障集无法与当前工况合理匹配的问题。
Institute of Scientific and Technical Information of China (English)
米焕荣; 马跃超; 张庆灵; 刘美静
2011-01-01
This paper studied a class of decentralize control problems of time-delay largescale interconnected systems with saturation actuators. First, the saturation actuators are dealt with skillfully, and then by modifying Lyapunov functions and using linear matrix inequality approach, the design method of the decentralized control condition feedback controller is given. Controller can be obtained by solving linear matrix inequalities, and calculated simply .At last, the numerical example and simulation illustrate the validity of this approach.%研究了一类具有饱和因子的滞后关联大系统的分散控制问题.首先对饱和因子进行了巧妙地处理,再通过构造Lyapunov泛函,利用(LMI)方法给出了分散控制状态反馈控制器的设计方法.控制器通过解线性矩阵不等式即可得到,计算简便.最后,数值例子和仿真说明了该设计方法的有效性.
Institute of Scientific and Technical Information of China (English)
李可柏; 曹杰; 陈理飞
2012-01-01
工业化程度不同的城市,其工业用水供需参数也不相同。建立了多城市工业供需水离散控制系统模型。以工业增加值为控制变量,根据Lyapunov稳定性理论和线性矩阵不等式求解方法,实现了工业化程度不同的多城市工业供需水离散系统同时镇定的鲁棒控制目标,减少了控制的复杂性。%The industrial water supply and demand parameters of cities with different degrees of industrialization are diverse.A model of multi-city industrial water supply-demand discrete control system is set up.By using the industrial added value as the control variables,according to the Lyapunov stability theory and linear matrix inequality(LMI) solution method,this method realizes the simultaneous stabilization robust control goal of multi-city industrial water supply-demand discrete system with different degrees of industrialization,thus reducing the complexity of the control.
Institute of Scientific and Technical Information of China (English)
刘碧玉; 桂卫华; 吴敏
2005-01-01
Passivity is not only an important property of a system,but also an important approach to control a system. Based on decentralized control method, the passivity of interconnected systems with time-delays is studied. Employing Lyapunov-Krasovskii functional method and Hamiltonian function method, the decentralized and passive controllers are presented explicitly by solving some linear matrix inequalities (LMIs). The new passivity criteria and the parameters of the passive controllers presented here are delay-dependent. By using the LMI toolbox in software Matlab, the conditions in the new results are easy to be verified and the parameters of the passive controllers are easy to be well set too, when the interconnected delays are known. A numerical example illustrates the availability of the theorems of passivity and the design procedure of the passive controllers.%无源性不仅是系统的一个重要性质,而且是控制一个系统的重要途径.本文基于分散控制方法研究了关联大系统的无源性.利用Lyapunov-Krasovskii泛函方法和Hamilton函数方法,通过求解线性矩阵不等式(LMIs)得到了分散无源控制器的显式表达.所得到的新的无源性判据和无源控制器的参数是与时滞相关的.当关联时滞已知时,这些新结果的条件易于用Matlab中的LMI工具箱进行验证,因而控制器的设计也容易实现.最后用数值例子说明了所得到定理的有效性和无源控制器的设计过程.
Controlling Light to Make the Most Energy From the Sun
Energy Technology Data Exchange (ETDEWEB)
Callahan, Dennis; Corcoran, Chris; Eisler, Carissa; Flowers, Cris; Goodman, Matt; Hofmann, Carrie; Sadtler, Bryce
2013-07-18
Representing the Light-Material Interactions in Energy Conversion (LMI), this document is one of the entries in the Ten Hundred and One Word Challenge. As part of the challenge, the 46 Energy Frontier Research Centers were invited to represent their science in images, cartoons, photos, words and original paintings, but any descriptions or words could only use the 1000 most commonly used words in the English language, with the addition of one word important to each of the EFRCs and the mission of DOE energy. The mission of LMI to tailor the morphology, complex dielectric structure, and electronic properties of matter so as to sculpt the flow of sunlight and heat, enabling light conversion to electrical and chemical energy with unprecedented efficiency.
Identification and robust control of linear parameter-varying systems
Lee, Lawton Hubert
This dissertation deals with linear parameter-varying (LPV) systems: linear dynamic systems that depend on time-varying parameters. These systems appear in gain scheduling problems, and much recent research has been devoted to their prospective usefulness for systematic gain scheduling. We primarily focus on robust control of uncertain LPV systems and identification of LPV systems that are modelable as linear-fractional transformations (LFTs). Using parameter-dependent quadratic Lyapunov functions, linear matrix inequalities (LMIs), and scaled small-gain arguments, we define notions of stability and induced-{cal L}sb2 performance for uncertain LPV systems whose parameters and rates of parameter variation satisfy given bounds. The performance criterion involves integral quadratic constraints and implies naturally parameter-dependent induced-{cal L}sb2 norm bounds. We formulate and solve an {cal H}sb{infty}-like control problem for an LPV plant with measurable parameters and an "Output/State Feedback" structure: the feedback outputs include some noiselessly measured states. Necessary and sufficient solvability conditions reduce to LMIs that can be solved approximately using finite-dimensional convex programming. Reduced-order LPV controllers are constructed from the LMI solutions. A D-K iteration-like procedure provides robustness to structured, time-varying, parametric uncertainty. The design method is applied to a motivating example: flight control for the F-16 VISTA throughout its subsonic flight envelope. Parameter-dependent weights and {cal H}sb{infty} design principles describe the performance objectives. Closed-loop responses exhibited by nonlinear simulations indicate satisfactory flying qualities. Identification of linear-fractional LPV systems is treated using maximum-likelihood parameter estimation. Computing the gradient and Hessian of a maximum-likelihood cost function reduces to simulating one LPV filter per identified parameter. We use nonlinear
Institute of Scientific and Technical Information of China (English)
夏丹; 肖民卿
2011-01-01
文章基于线性矩阵不等式（LMI）方法和Lyapunov稳定性理论，研究参数不确6定算子时滞系统的非脆弱保性能控制问题，提出非脆弱状态反馈保性能控制器的存在条件和设计方法，在此基础上，通过建立和求解一个凸优化问题，给出最优保性能控制律的设计。最后用数值算例说明方法的有效性。%Based on LMI approach and Lyapunov theory, non-fragile guaranteed cost control for a class of delta-operator uncertain time-delay systems is studied. A sufficient condition for the existence of non--fragile state feedback guaranteed cost controller is presented, and the design method of such controller is proposed. Based on that mentioned, the design problem of the optimal guaranteed cost controller is given by solving a corresponding convex optimization problem. Finally, a numerical example is given to illustrate the feasibility and advantage of the design method.
Institute of Scientific and Technical Information of China (English)
王世刚; 武俊峰
2011-01-01
为一类不确定时滞采样系统提出了基于观测器的非脆弱H∞控制问题.针对不确定性均存在于被控对象、控制器和观测器的情形,运用Lyapunov稳定性理论和线性矩阵不等式方法,得到了非脆弱H∞控制器和观测器存在的充分条件与设计方法.最后,数值仿真结果表明了所提算法的有效性.%The problem of non-fragile H∞ control for a class of uncertain sampled-data systems with time-delay is considered via observer-based state feedback control. According to the case that there exist uncertainties not only in the plant but also in controller gains and observer gains, and the Lyapunov function theory and linear matrix inequality (LMI) approach are applied. A sufficient condition on the existence and designing method of non-fragile observer and H∞ controller are derived. Finally, a numerical example is illustrated to show the effectiveness of the proposed results.
Institute of Scientific and Technical Information of China (English)
刘红霞; 胥布工; 朱学峰; 唐韶华
2001-01-01
研究了具有N×N个任意未知常时滞的线性连续大系统的分散H∞状态反馈控制器和H∞输出反馈控制器的设计问题,分别给出了使系统渐近稳定且具有H∞-扰动抑制度γ的分散H∞状态反馈控制器和分散 H∞输出反馈控制器存在的充分条件,该条件以线性矩阵不等式的形式给出,因而具有数值易解性。最后用一个事例来说明分散H∞状态反馈控制器和输出反馈控制器的设计。%In this paper,H∞-state feedback controller and H∞-output feedback controller design for a class of large-scale interconnected continuous systems with N×N unknown but constant delays in the interconnections are addressed. Sufficient conditions for the existence of memoryless H∞-state feedback control law and H∞-output feedback control law for large-scale interconnected time-delay systems are presented with LMI approach,which is numerically tractable. Finally,an example is given to show the design procedure of the decentralized H∞-state feedback controller and H∞-output feedback controller.
具有分布时滞不确定系统的滑模控制%Sliding Mode Control of Uncertain Systems with Distributed Delays
Institute of Scientific and Technical Information of China (English)
李延波
2011-01-01
针对一类含有分布时滞的不确定系统,通过利用Lyapunov稳定性理论和线性矩阵不等式方法进行滑模控制研究.首先,构造滑模控制器,使得系统满足滑模到达条件;其次,通过构造适当的Lyapunov泛函,给出闭环系统渐近稳定的充分条件.该充分条件通过采用虚拟反馈控制思想,结合状态反馈的极点配置方法,转换为线性矩阵不等式的形式,利用Matlab中的LMI工具箱进行求解.最后,仿真算例说明此方法的有效性.%Based on the Lyapunov stability theory and the linear matrix inequality approach, the sliding mode control for a class of uncertain systems with distributed delays is researched. Firstly,the sliding mode controller is constructed to satisfy the sliding mode reaching conditions. Secondly, the suffient conditions of closed-loop systems' asymptotical stability is given by constructing the appropriate Lyapunov functionals. In terms of virtual feedback control method and combinating pole assignment of state feedback, the suffient conditions can be shown in LMIs and sovled easily by LMI toolbox in Matlab. Finally, the simulation example is given to illustrate the validity of the method.
Formation Fight Control of Multi-UAVs with Communication Delay%具有通信延迟的多无人机编队飞行控制
Institute of Scientific and Technical Information of China (English)
李少斌; 陈炎财; 杨忠; 黄宵宁; 杨成顺
2012-01-01
针对固定通信拓扑下的具有时变通信延迟的多无人机(multi- UAVs)系统,在一致性协议的基础上提出了分布式的编队控制算法.利用Lyapunov-Krasovskii函数分析了时延多无人机系统的稳定性,并以线性不等式(LMI)的形式给出了系统稳定的条件.当满足稳定性条件时,编队控制算法将使系统中无人机的速度和编队队形分别渐近地收敛至期望速度和期望队形.仿真实例验证了控制算法的有效性.%A distributed formation control algorithm is proposed based on consensus protocol for multi-UAVs (multi-unmanned aerial vehicles) system with time-varying communication delays and fixed communication network topology. System stability of multi-UAVs system with time delays is analyzed by using Lyapunov-Krasovskii function and the stability condition in terms of LM1 is given. When the stability condition is satisfied, the formation control algorithm will guide the UAVs velocity vectors and the formation to asymptotically converge to the desired velocity vector and the desired formation respectively. Simulation example verifies the effectiveness of the control algorithm.
DEFF Research Database (Denmark)
2010-01-01
A switch-mode power circuit comprises a controllable element and a control unit. The controllable element is configured to control a current in response to a control signal supplied to the controllable element. The control unit is connected to the controllable element and provides the control...
Robust Congestion Control for Input and State Delay Network Systems%具有输入和状态延时网络系统的鲁棒拥塞控制
Institute of Scientific and Technical Information of China (English)
侯萍; 王执铨
2009-01-01
Active Queue Management(AQM) algorithm based on state space is studied in this paper. The model of TCP/AQM including the state and the input delay is presented in state variables. State feedback control based observer is introduced to estimate online output of congestion control for AQM router. According to the Linear Matrix Inequality(LMI) technique and the Lyapunov-Krasovskii theorem, control laws and delay-independent stability criteria for the AQM controllers are derived. The NS2 simulation results show that this algorithm is capableof achieving the desired queue length fast under the two conditions of delay change and sudden traffic flow. The performance of the proposed algorithm increases greatly compared with the existing PI control algorithm.%研究基于状态空间的主动队列管理算法,以状态变量的形式描述具有状态延时和输入延时的TCWAQM模型,设计基于观测器的状态反馈控制器,观测器在线测量控制器的输出.应用线性矩阵不等式和Lyapunov-Krasovskii定理,给出AQM控制器的控制率和不依赖于延时的稳定条件.NS2仿真表明该控制算法在延时变化和突发业务流情况下,能够快速收敛于期望队列长度,动静态性能优干已有的PI控制算法.
Non-fragile H∞ Control for a Class of Singular Time-delay Systems%一类时滞广义系统的非脆弱H∞控制
Institute of Scientific and Technical Information of China (English)
马跃超; 张娜; 梁建云
2013-01-01
针对一类时滞广义系统,讨论其时滞相关非脆弱H∞控制问题.通过构造Lyapunov-Krasovskii泛函,利用线性矩阵不等式方法和最新建立的积分不等式,给出了时滞广义系统的鲁棒H∞控制的时滞相关判据,设计非脆弱记忆反馈控制器,使得时滞广义系统正则、无脉冲、渐近稳定且满足H∞范数小于给定界γ.数值例子与已有文献进行比较,说明了所给方法的有效性及优越性.%In this paper,the problem of delay-dependent robust and non-fragile H∞ control for singular systems with state-delay is investigated.Based on linear matrix inequality(LMI)approach and a new integral inequality,a delay-dependent sufficient condition for the problem of H∞ control for a class of singular systems is proposed by constructing generalized Lyapunov-Krasovskii function.We design a memory state feedback controller under controller gain perturbations,which guarantees that,the resultant closed-loop system is regular,impulse free,and stable with anH∞ norm bound constraint.Numerical examples show that the proposed methods are less conservative than existing ones.
Department of Homeland Security — This feature class represents electric power Control Areas. Control Areas, also known as Balancing Authority Areas, are controlled by Balancing Authorities, who are...
Fault-tolerant Control of Spacecraft Dynamic System Based on Control Network%基于网络控制的航空器动力系统的容错控制
Institute of Scientific and Technical Information of China (English)
罗小元; 尚美杰; 陈彩莲; 关新平
2011-01-01
研究了基于网络控制的航空器时变时滞横向动力学系统的容错控制问题.利用Lyapunov稳定性方法和LMI技术,综合网络的特点采用鲁棒完整性方法设计了针时执行器失效的容错控制器.首先给出了航空器横向动力学系统的时滞线性化一般模型,考虑到网络控制系统的运行特点以及网络中的诱导时延和数据包丢失现象,采用一种分段常值的控制器,设计了使系统对执行器失效故障具有容错性能的控制器.进行了仿真研究,仿真结果说明容错控制器作用下当出现执行器故障时系统仍可保持较好的性能,验证了提出的设计方法的有效性.%The fault-tolerant contrpl problem of the spacecraft lateral dynamics with time-varying delay states based on networked control os studied.Combining with the characteristics of the networked control system(NCS),a controller to stabilize the system with actuator failure is proposed based on robust intefrity method by using Lyapunov stabilization theory together with the LMI technique.The soacecraft dynamic system is modeled as a linearized plant with time-varying state delay.Then considering the characteristics of the NCS induced delay and the data dropout,a piecewise constant controller is adopted to design the controller against the actuator failure.The simulation resullts show that the system performance can be guaranteed well under the proposed fault tolerant controller when the acruator failure appears.
Controllable dose; Dosis controlable
Energy Technology Data Exchange (ETDEWEB)
Alvarez R, J.T.; Anaya M, R.A. [ININ, A.P. 18-1027, 11801 Mexico D.F. (Mexico)]. E-mail: jtar@nuclear.inin.mx
2004-07-01
With the purpose of eliminating the controversy about the lineal hypothesis without threshold which found the systems of dose limitation of the recommendations of ICRP 26 and 60, at the end of last decade R. Clarke president of the ICRP proposed the concept of Controllable Dose: as the dose or dose sum that an individual receives from a particular source which can be reasonably controllable by means of any means; said concept proposes a change in the philosophy of the radiological protection of its concern by social approaches to an individual focus. In this work a panorama of the foundations is presented, convenient and inconveniences that this proposal has loosened in the international community of the radiological protection, with the purpose of to familiarize to our Mexican community in radiological protection with these new concepts. (Author)
Energy Technology Data Exchange (ETDEWEB)
Cheng, George Shu-Xing; Mulkey, Steven L; Wang, Qiang; Chow, Andrew J
2013-11-26
A method and apparatus for intelligently controlling continuous process variables. A Dream Controller comprises an Intelligent Engine mechanism and a number of Model-Free Adaptive (MFA) controllers, each of which is suitable to control a process with specific behaviors. The Intelligent Engine can automatically select the appropriate MFA controller and its parameters so that the Dream Controller can be easily used by people with limited control experience and those who do not have the time to commission, tune, and maintain automatic controllers.
Cheng, George Shu-Xing; Mulkey, Steven L; Wang, Qiang; Chow, Andrew J
2013-11-26
A method and apparatus for intelligently controlling continuous process variables. A Dream Controller comprises an Intelligent Engine mechanism and a number of Model-Free Adaptive (MFA) controllers, each of which is suitable to control a process with specific behaviors. The Intelligent Engine can automatically select the appropriate MFA controller and its parameters so that the Dream Controller can be easily used by people with limited control experience and those who do not have the time to commission, tune, and maintain automatic controllers.
Soliño, Lucía; Widgy, Saha; Pautonnier, Anthony; Turquet, Jean; Loeffler, Christopher R; Flores Quintana, Harold A; Diogène, Jorge
2015-08-01
Lionfish (Pterois spp.) are invasive species that have recently spread throughout the Caribbean. Lionfish are available for purchase in local markets for human consumption in several islands of the region. We examined the prevalence of ciguatoxins (CTXs) in lionfish from the French Antilles, a ciguatera-endemic region. The neuroblastoma-2a (N2a) cell assay was used to assess composite cytotoxicity in 120 fish samples collected from the surrounding waters of Guadeloupe (n = 60), Saint Barthélemy Islands (n = 55) and Saint Martin (n = 5). Twenty-seven of these samples exhibited CTX-like activity by the N2a assay. Ciguatoxin (CTX) was confirmed by liquid chromatography-tandem mass spectrometry (LC-MS/MS) in multiple samples that presented highest composite toxicity levels by N2a. Those fish found to contain CTXs were all from Saint Barthélemy. Lionfish from Guadeloupe and Saint Martin did not exhibit toxin activity, although the sample size from Saint Martin was insufficient to draw any conclusions as to the incidence of CTXs. In this study, we provide information about the potential hazard of ciguatera associated with the consumption of lionfish from known endemic areas. We also demonstrate the utility of the cell-based assay combined with LC-MS/MS to assess activity and to provide structural confirmation of CTXs respectively.
An improved LMI-based approach for stability of piecewise affine time-delay systems with uncertainty
Duan, Shiming; Ni, Jun; Galip Ulsoy, A.
2012-09-01
The stability problem for uncertain piecewise affine (PWA) time-delay systems is investigated in this article. It is assumed that there exists a known constant time delay in the system and the uncertainly is norm-bounded. Sufficient conditions for the stability of nominal systems and the stability of systems subject to uncertainty are derived using the Lyapunov-Krasovskii functional with a triple integration term. This approach handles switching based on the delayed states (in addition to the states) for a PWA time-delay system, considers structured as well as unstructured uncertainty and reduces the conservativeness of previous approaches. The effectiveness of the proposed approach is demonstrated by comparing with the existing methods through numerical examples.
Birth control, also known as contraception, is designed to prevent pregnancy. Birth control methods may work in a number of different ... eggs that could be fertilized. Types include birth control pills, patches, shots, vaginal rings, and emergency contraceptive ...
... Share Facebook Twitter Google+ Pinterest Contact Us Mosquito Control About Mosquitoes General Information Life Cycle Information from ... Repellent that is Right for You DEET Mosquito Control Methods Success in mosquito control: an integrated approach ...
Directory of Open Access Journals (Sweden)
2006-01-01
Full Text Available This paper presents sufficient conditions of asymptotic stability for discrete-time linear systems subject to actuator saturations with an output feedback law. The derived stability results are given in terms of LMIs. A new proof is presented to obtain previous conditions of asymptotic stability. A numerical example is used to illustrate this technique by using a linear optimization problem subject to LMI constraints.
Energy Technology Data Exchange (ETDEWEB)
Di Caprio, U.
1982-01-01
The main trends in the development of techniques presently used for emergency control of electric power systems are illustrated, from load-shedding to islanding, generator control, automatic reclosure of circuits, reactive power control and auxiliary aids in the control centers. Methods for improving the design criteria are reviewed. 61 refs.
Oxidative stress and leukocyte migration inhibition response in cutaneous adverse drug reactions
Directory of Open Access Journals (Sweden)
Prashant Verma
2012-01-01
Full Text Available Background: Cutaneous adverse drug reactions (CADRs may either be immunological or non-immunological. The precise mechanisms, however, are largely obscure. Other concomitant mechanisms may amplify and/or contribute to the severity and duration of a reaction. One such mechanism could be oxidative stress, a state of imbalance between reactive oxygen species, and their subsequent detoxification by antioxidants. Aims: (a to assess the oxidative stress status in the blood of cutaneous drug reaction patients by assaying for reduced glutathione (GSH and malondialdehyde (MDA levels, (b to determine the leukocyte migration inhibition (LMI response in these patients in response to the suspected drug (s, and (c to look for the association between oxidative stress parameters and LMI. Methods: Ethical committee approval was obtained for this study. Fresh venous blood samples were obtained from the patients of CADRs (group A during the acute phase of reaction and healthy control subjects (group B. MDA levels, a measure of oxidative lipid damage, and reduced GSH levels, a measure of anti-oxidant capacity, were assayed in the blood samples of both groups using spectrophotometry. LMI response was measured by challenging the patients′ peripheral blood mononuclear cells with the suspected drug to confirm immunological perturbation. Results: Totally 66 participants, 33 cases in group A and equal number of controls in group B, were studied. The mean MDA levels were found to be raised (P < 0.001, but GSH levels were significantly reduced in group A when compared with group B (P = <0.001. LMI response against drug(s was performed in 33 cases (group A, out of which 25 cases showed a positive LMI response as follows: fixed drug eruption (10/25, SJS (5/25, urticaria (3/25, exfoliative dermatitis (2/25, morbilliform rash (2/25, erythroderma (1/25, vasculitis (1/25, and dapsone syndrome (1/25. The mean MDA levels were found to be significantly higher in the LMI positive
DEFF Research Database (Denmark)
Jantzen, Jan
1997-01-01
These notes are for a course in fuzzy control and neural networks. By neural networks we more precisely mean neurofuzzy systems rather than pure neural network theory. The notes are an extension to the existing notes on fuzzy control (Jantzen, Fuzzy Control, 1994).......These notes are for a course in fuzzy control and neural networks. By neural networks we more precisely mean neurofuzzy systems rather than pure neural network theory. The notes are an extension to the existing notes on fuzzy control (Jantzen, Fuzzy Control, 1994)....
... obese. Achieving a healthy weight can help you control your cholesterol, blood pressure and blood sugar. It ... use more calories than you eat. A weight-control strategy might include Choosing low-fat, low-calorie ...
Enden, van der E.; Laan, van der R.
2008-01-01
The article reports on the efforts of companies to find a solution for tax risk management, tax accounting and being in control. In trying to find a solution, companies work towards an integrated tax control framework (TCF), a tax risk management and control environment embedded in the internal cont
Enden, van der E.; Laan, van der R.
2008-01-01
The article reports on the efforts of companies to find a solution for tax risk management, tax accounting and being in control. In trying to find a solution, companies work towards an integrated tax control framework (TCF), a tax risk management and control environment embedded in the internal cont
Carico, Dean
1989-01-01
Approved for public release; distribution is unlimited The concept of helicopter controllability is explained. A background study reviews helicopter development in the U.S. General helicopter configurations, linearized equations of motion, stability, and piloting requirements are discussed. Helicopter flight controls, handling qualities, and associated specification are reviewed. Analytical, simulation and flight test methods for evaluating helicopter automatic flight control systems ar...
Enden, van der E.; Laan, van der R.
2008-01-01
The article reports on the efforts of companies to find a solution for tax risk management, tax accounting and being in control. In trying to find a solution, companies work towards an integrated tax control framework (TCF), a tax risk management and control environment embedded in the internal
Filtering and fault tolerant control of parameter-varying time-delay systems and applications
Mohammadpour Velni, Javad
This dissertation addresses some open problems in control systems theory. The problems considered include the dynamic controller and filter design for Linear Parameter Varying (LPV) time-delay systems, the reconfigurable control design in Fault Tolerant Control Systems (FTCS) and fault diagnostics in Diesel engines. In the first part of this thesis, we investigate the problem of designing parameter-dependent filters for output estimation of LPV time-delay systems. The filters are designed such that the filtering error system guarantees an optimum level of H2 or Hinfinity performance. A state-delay term is included in the filter dynamics to reduce the design conservatism and improve the performance. The Linear Matrix Inequality (LMI)-based synthesis conditions developed for the filter design purposes are categorized into the rate-dependent and delay-dependent conditions which could handle the time-varying state-delay and bounded small delay cases, respectively. Among these two, the latter one is shown to provide a significant reduction in the conservativeness in the filter design. The second part of the thesis examines the analysis and synthesis of Fault Tolerant Control (FTC) systems in an LPV framework. For reconfigurable control design purposes, the information from Fault Detection and Isolation (FDI) module, that provides an estimate of the fault parameters, is utilized to schedule the controller matrices. We will also present a formulation that incorporates the factor of detection delay in the FTC supervisory system. It is shown that including this delay in the synthesis conditions leads to improved performance and reduced control effort. For analysis of the FTC systems including time-delay, where the fault parameters might be identified inaccurately, we first introduce the notion of brief instability for LPV time-delay systems. In these systems it is possible that the output trajectory converges to zero even though there are parameter trajectories for which
Aschepkov, Leonid T; Kim, Taekyun; Agarwal, Ravi P
2016-01-01
This book is based on lectures from a one-year course at the Far Eastern Federal University (Vladivostok, Russia) as well as on workshops on optimal control offered to students at various mathematical departments at the university level. The main themes of the theory of linear and nonlinear systems are considered, including the basic problem of establishing the necessary and sufficient conditions of optimal processes. In the first part of the course, the theory of linear control systems is constructed on the basis of the separation theorem and the concept of a reachability set. The authors prove the closure of a reachability set in the class of piecewise continuous controls, and the problems of controllability, observability, identification, performance and terminal control are also considered. The second part of the course is devoted to nonlinear control systems. Using the method of variations and the Lagrange multipliers rule of nonlinear problems, the authors prove the Pontryagin maximum principle for prob...
2012-03-06
DISTRIBUTION A: Approved for public release; distribution is unlimited. Quantum Linear Systems Theory : Matt James, Ian Peterson • Why Quantum Control? Is...Classical linear systems theory has a history going back some 50 years, to the birth of modern control theory with Kalman’s foundational work on filtering...and LQG optimal control. Gaussian Distributions play a fundamental role in classical linear systems theory . • The PIs have shown that classical
Energy Technology Data Exchange (ETDEWEB)
Yoon, Wan Kee [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)
1995-02-01
International cooperation in nuclear industries requires nuclear control as prerequisites. The concept of nuclear control is based on the Treaty on the Non-proliferation of Nuclear Weapon (NPT). The International Atomic Energy Agency (IAEA) plays central role in implementing nuclear control. Nuclear control consists of nuclear safeguards, physical protection, and export/import control. Each member state of NPT is subject to the IAEA`s safeguards by concluding safeguards agreements with the IAEA. IAEA recommends member states to implement physical protection on nuclear materials by `The Physical Protection of Nuclear Material` and `The Convention on the Physical Protection of Nuclear Material` of IAEA. Export/Import Control is to deter development of nuclear weapons by controlling international trade on nuclear materials, nuclear equipments and technology. Current status of domestic and foreign nuclear control implementation including recent induction of national inspection system in Korea is described and functions of recently set-up Technology Center for Nuclear Control (TCNC) under the Korea Atomic Energy Research Institute (KAERI) are also explained. 6 tabs., 11 refs. (Author).
DEFF Research Database (Denmark)
Hvid, Helge Søndergaard; Lund, Henrik Lambrecht; Grosen, Sidsel Lond
2010-01-01
Over the last 30 years, the concept of control has had a central position in research into the psychological working environment. Control has been understood as individual autonomy and individual opportunities for development. This article examines whether the concept of control has the same key...... significance in the modern workplace which is simultaneously characterized by self-management and standardization. It is concluded that the concept of control remains important, but needs to evolve from its focus on the work of individuals to a focus on the associational aspects of work if it is to retain its...... critical potential. This conclusion is supported by case studies of four Danish banks....
Centers for Disease Control (CDC) Podcasts
2007-11-01
This podcast gives action steps and reasons to control diabetes. Created: 11/1/2007 by National Diabetes Education Program (NDEP), a joint program of the Centers for Disease Control and Prevention and the National Institutes of Health. Date Released: 11/2/2007.
Directory of Open Access Journals (Sweden)
L. I. Rozonoer
1999-01-01
Full Text Available Necessary and sufficient conditions for existence of optimal control for all initial data are proved for LQ-optimization problem. If these conditions are fulfilled, necessary and sufficient conditions of optimality are formulated. Basing on the results, some general hypotheses on optimal control in terms of Pontryagin's maximum condition and Bellman's equation are proposed.
Mace, Jonathan L.; Seitz, Gerald J.; Bronisz, Lawrence E.
2016-10-25
Detonation control modules and detonation control circuits are provided herein. A trigger input signal can cause a detonation control module to trigger a detonator. A detonation control module can include a timing circuit, a light-producing diode such as a laser diode, an optically triggered diode, and a high-voltage capacitor. The trigger input signal can activate the timing circuit. The timing circuit can control activation of the light-producing diode. Activation of the light-producing diode illuminates and activates the optically triggered diode. The optically triggered diode can be coupled between the high-voltage capacitor and the detonator. Activation of the optically triggered diode causes a power pulse to be released from the high-voltage capacitor that triggers the detonator.
Mandik, Pete
2010-10-01
Control consciousness is the awareness or experience of seeming to be in control of one's actions. One view, which I will be arguing against in the present paper, is that control consciousness is a form of sensory consciousness. In such a view, control consciousness is exhausted by sensory elements such as tactile and proprioceptive information. An opposing view, which I will be arguing for, is that sensory elements cannot be the whole story and must be supplemented by direct contributions of nonsensory, motor elements. More specifically, I will be arguing for the view that the neural basis of control consciousness is constituted by states of recurrent activation in relatively intermediate levels of the motor hierarchy. Copyright © 2010 Cognitive Science Society, Inc.
1987-10-01
positive definite solution of A1Qy+QyAo+I--QyBBTQY=O (5.2) The logarithmic residence time of system (3.1) with the stabilizing control (5.1) in a I...a bounded is E bou,,,,dby, ii I)-2=(6 2 This completes the prooof the necesity. Suffidency: The proof is by conatnction. Select a stabilizing control u...a - . Q.LD. Proof of Theorem 3.3: It follows from the results of [151, [21] that for each y > 0, K? defined by (3.4) is a stabilizing control and
... lives are lost because of the spread of infections in hospitals. Health care workers can take steps ... of infectious diseases. These steps are part of infection control. Proper hand washing is the most effective ...
U.S. Environmental Protection Agency — This dataset consists of institutional control data from multiple Superfund sites in U.S. EPA Region 8. These data were acquired from multiple sources at different...
Zinn, W.H.; Ross, H.V.
1958-11-18
A control rod is described for a nuclear reactor. In certaln reactor designs it becomes desirable to use a control rod having great width but relatively llttle thickness. This patent is addressed to such a need. The neutron absorbing material is inserted in a triangular tube, leaving volds between the circular insert and the corners of the triangular tube. The material is positioned within the tube by the use of dummy spacers to achleve the desired absorption pattern, then the ends of the tubes are sealed with suitable plugs. The tubes may be welded or soldered together to form two flat surfaces of any desired width, and covered with sheetmetal to protect the tubes from damage. This design provides a control member that will not distort under the action of outside forces or be ruptured by gases generated within the jacketed control member.
National Research Council Canada - National Science Library
P. Susana Aguilera, DRA; M.D. Peter Soothill, MR
2014-01-01
Los principales objetivos del control prenatal son identificar aquellos pacientes de mayor riesgo, con el fin de realizar intervenciones en forma oportuna que permitan prevenir dichos riesgos y así...
2011-02-02
TITLE AND SUBTITLE Airspace Control 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT NUMBER 5e. TASK...include, but are not limited to, sensors, communications, data processing, and common operating databases. Information assurance programs such as...working group charters and coordinated quarterly meetings between the deputy CFACC (DCFACC)/deputy ACA ( DACA ), ACCE, regional air movement control
2013-04-08
an aerodynamic design. A few examples of this type of flow control are winglets , fins, or dimples on a golf ball. The other type of flow control is...represented the density states of the flow field. The first parameter was the composition of the regression vector, Θ j. This regression vector was...Development Using Proper Orthogonal De- composition and Volterra Theory. In AIAA 2003-1922, 2003. A. Mani, M. Wang, and P. Moin. Resolution requirements
Robust L2-L∞ Control for Continuous Stirred Tank Reactor Based on T-S Model%基于T-S模型的连续搅拌反应釜鲁棒L2-L∞控制
Institute of Scientific and Technical Information of China (English)
李艳辉; 冯岩
2014-01-01
To realize precise control for CSTR( Continuous Stirring Tank Reactor) systems in actual reactions, a robust L2-L∞ state feedback control problem is studied by using a T-S fuzzy model to approximate the nonlinear object according to reaction characteristics of the CSTR. All reactor temperatures which are easier to be measured can be treated as premise variables in the model, where fewer number of fuzzy rules are employed. The design method of partial controllers is given by applying the PDC ( Parallel Distributed Compensation ) algorithm. A global controller is designed by adopting the LMI ( Linear Matrix Inequality ) technique, and the design of controllers is cast into a convex optimization problem. Simulations are provided to demonstrate the effectiveness of the proposed design scheme, which can be applied to other chemical industrial reactions.%为实现对连续搅拌反应釜( CSTR：Continuous Stirring Tank Reactor)系统在实际反应中的精确控制，根据CSTR反应特点，采用T-S模糊模型逼近非线性对象，研究鲁棒L2-L∞状态反馈控制问题。模型中将更易测量的反应器温度作为前件变量，模糊规则少。应用平行分配补偿算法( PDC：Parallel Distributed Compensation)，给出局部控制器的设计方法，并利用线性矩阵不等式( LMI：Linear Matrix Inequality)技术设计全局控制器，在此基础上把控制器的设计转化为一个凸优化的求解问题。最后仿真验证了该方法的有效性，从而可扩展到其他化学工业反应中。
Robust H∞ absolute stability control for a supercavitating vehicle%超空泡航行体鲁棒H∞ 绝对稳定控制
Institute of Scientific and Technical Information of China (English)
韩云涛; 强宝琛; 孙尧; 白涛
2015-01-01
In cruise phase, high-speed supercavitating vehicles ( HSSV) face a strong nonlinear planing force and noise disturbance. To solve these problems, a synthesis method for robust H∞ absolute stability controller was pro-posed based on absolute stability in the time domain. The original system was transformed into a cascade connection of two subsystems. Then, based on the connection, the sector bounded conditions of the planing force were ana-lyzed. Next, in order to handle the noise disturbance, the method was included in the form of a linear matrix ine-quality, by applying Lyapunov theory together with the sector bounded conditions. Simulation results show that the closed-loop system can obtain absolute stability with the resulting controller, and simultaneously achieve the pre-scribed H∞performance under zero initial conditions.%针对超空泡航行体( HSSV)在巡航阶段会受到强非线性滑行力,且伴随噪声干扰等问题,提出一种基于时域绝对稳定性的鲁棒H∞绝对稳定控制器的综合方法. 利用backstepping方法,将原系统转化成子系统级联形式的跟踪模型,并在其基础上分析了滑行力的扇形区域条件. 考虑系统中存在噪声干扰的情况,利用Lyapunov理论结合滑行力的扇形区域条件,给出了线性矩阵不等式( LMI)约束形式的鲁棒H∞ 绝对稳定控制器综合方法. 仿真结果表明,所设计的鲁棒H∞绝对稳定控制器可以实现闭环系统的绝对稳定,同时在零初始条件下具有给定的H∞ 性能.
Institute of Scientific and Technical Information of China (English)
2008-01-01
In this article,we review the recent development of controlled teleportation which can be used for sharing quantum information and has important applications in remote quantum computation.We introduce the principles of a couple of controlled teleportation schemes with maximally entangled quantum channels and those with pure entangled quantum channels (non-maximally entangled states).The schemes based on maximally entangled states have the advantage of having maximal efficiency although there are differences in their implementations in experiment.In the controlled teleportation schemes using non-maximally entangled states as the quantum channels,the receiver can reconstruct the originally unknown state by adding an auxiliary particle and performing a unitary evolution.No matter what the unknown state is (a single qubit state or an m-qudit state),the auxiliary particle required is only a two-level quantum system.
H∞ Controller Design for Asynchronous Hybrid Systems with Multiple Delays
Directory of Open Access Journals (Sweden)
Xiaoqiang Sun
2016-01-01
Full Text Available Solutions for the H∞ synthesis problems of asynchronous hybrid systems with input-output delays are proposed. The continuous-time lifting approach of sampled-data systems is extended to a hybrid system with multiple delays, and some feasible formulas to calculate the operators of the equivalent discrete-time (DT system are given. Different from the existing methods derived from symplectic pair theory or by state augmentation, a Lyapunov-Krasovskii functional to solve the synthesis problem is explicitly constructed. The delay-dependent stability conditions we obtained can be described in terms of nonstrict linear matrix inequalities (LMIs, which are much more convenient to be solved by LMI tools.
Kühnen, Jakob; Hof, Björn
2015-11-01
We show that a simple modification of the velocity profile in a pipe can lead to a complete collapse of turbulence and the flow fully relaminarises. The annihilation of turbulence is achieved by a steady manipulation of the streamwise velocity component alone, greatly reducing control efforts. Several different control techniques are presented: one with a local modification of the flow profile by means of a stationary obstacle, one employing a nozzle injecting fluid through a small gap at the pipe wall and one with a moving wall, where a part of the pipe is shifted in the streamwise direction. All control techniques act on the flow such that the streamwise velocity profile becomes more flat and turbulence gradually grows faint and disappears. In a smooth straight pipe the flow remains laminar downstream of the control. Hence a reduction in skin friction by a factor of 8 and more can be accomplished. Stereoscopic PIV-measurements and movies of the development of the flow during relaminarisation are presented.
Institute of Scientific and Technical Information of China (English)
无
2003-01-01
Managing risk is essential for positioning a company for growth in the current business environment.Yet as companies around the world clamber to inplement integrated risk controls in light of corlporate meltdowns and terrorist concems,many firms fail to pull the weeds out of their own backyard in China before trying to harvest the profitable crops!
DEFF Research Database (Denmark)
Leppink, Eric; Odlaug, Brian Lawrence; Lust, Katherine
2014-01-01
with respondents without lifetime assaultive behavior, those with a history of assaultive or destructive behavior reported more depressive symptoms, more stress, and higher rates of a range of impulse control disorders (intermittent explosive disorder, compulsive sexual behavior, compulsive buying, and skin...
Institute of Scientific and Technical Information of China (English)
滕青芳; 孙金龙; 范多旺
2012-01-01
The problem of robust H∞ fault-tolerant control for structural nonlinear vibration systems with multi-constraints is investigated. According to structural dynamics theory, a state-space model containing multi-constraints such as input time-varying delay, actuator failure, parameter nonlinear, disturbance, etc is established. Based on state feedback and Lyapunov stability theory, a sufficient condition of the existence of robust H∞, fault-tolerant controller is derived and then transformed to the corresponding Linear Matrix Inequality (LMI). During inferential reasoning, the matrix inequality is only amplified twice and relied on system's delay-time, so that it is possible to sufficently reduce conservative of controller design. The resultant controller enables structural nonlinear vibration systems to retain robust stability and disturbance attenuation as well as to tolerate actuator failure. A building model with four degrees of freedom subjected to the El Centro earthquake wave is simulated and studied to examine the effectiveness of the algorithm provided above, and the results show that the proposed method is feasible.%研究了多约束条件下非线性结构振动系统的鲁棒H∞容错控制问题.根据建筑结构力学原理,建立了包含输入时变时滞、执行器故障、非线性参数摄动以及干扰等多约束条件的结构振动系统状态模型,基于状态反馈和Lyapunov稳定性理论,提出了一个可满足多约束条件的时滞相关鲁棒H∞容错控制算法,该结果以线性矩阵不等式形式给出.在推导过程中只对矩阵不等式进行了两次放大,结果与输入时滞有关,以尽可能降低控制器设计的保守性.该方法设计的控制器能够使得时滞非线性结构振动系统具有指定H∞范数的干扰抑制能力,对执行器故障具有容错性.通过对一个四自由度建筑结构模型在E1 Centro地震波作用下振动的控制仿真,验证了所提方法的可行性和有效性.
Qu, Xiaolei; Azuma, Takashi; Sugiyama, Ryusuke; Kanazawa, Kengo; Seki, Mika; Sasaki, Akira; Takeuchi, Hideki; Fujiwara, Keisuke; Itani, Kazunori; Tamano, Satoshi; Takagi, Shu; Sakuma, Ichiro; Matsumoto, Yoichiro
2016-07-01
Visualizing an area subjected to high-intensity focused ultrasound (HIFU) therapy is necessary for controlling the amount of HIFU exposure. One of the promising monitoring methods is localized motion imaging (LMI), which estimates coagulation length by detecting the change in stiffness. In this study, we improved the accuracy of our previous LMI by dynamic cross-correlation window (DCCW) and maximum vibration amount (MVA) methods. The DCCW method was used to increase the accuracy of estimating vibration amplitude, and the MVA method was employed to increase signal-noise ratio of the decrease ratio at the coagulated area. The qualitative comparison of results indicated that the two proposed methods could suppress the effect of noise. Regarding the results of the quantitative comparison, coagulation length was estimated with higher accuracy by the improved LMI method, and the root-mean-square error (RMSE) was reduced from 2.51 to 1.69 mm.
Institute of Scientific and Technical Information of China (English)
韩东颖; 时培明; 赵东伟
2016-01-01
While considering parametric excitation nonlinearity,uncertainty and load torque,the nonlinear torsional vibration dynamic model of a mechanical and electrical transmission system in a strip-rolling mill is built.The problem of the strip-rolling mill's motor-speed robust tracking and non-fragile control of the DC motor is studied.As the nonlinearity of the strip-rolling mill's mechanical and electrical drive system is translated into parameter uncertainty,the sufficient condition that lets the system attain quadratic stability and outside-disturbance attenuation is obtained using H∞theory,Lyapunov stability theory and the LMI method.In order to achieve the given speed-signal tracking and non-fragile control,a feedforward and compensatory controller is designed.The results of the real strip-rolling mill's simulation example verify the effectiveness of the proposed method,and the non-fragility of the controller is reflected as the controller's parameter robustness.This means that the effect of the torsional vibration non-fragile control of the strip-rolling mill's mechanical and electrical drive system can be fulfilled by choosing the parameters of the controller directly.%建立了含参激非线性、不确定性、负载转矩的轧机机电传动系统扭振动力学模型，研究了板带轧机电机速度鲁棒跟踪非脆弱控制问题。将板带轧机机电传动系统的非线性按参数不确定性处理，通过 H∞理论、Lyapunov 稳定性理论和线性矩阵不等式（LMI）方法得到了通过状态反馈使得系统满足二次稳定、抑制外界干扰的充分条件；为了实现给定速度信号跟踪非脆弱控制，设计了前馈补偿器。轧机实例仿真结果验证了方法的有效性，并发现控制器的非脆弱性表现为控制器参数的鲁棒性，即可以通过控制器参数的直接选取达到板带轧机机电传动系统扭振非脆弱控制效果。
Luenberger-Type Observer Design for Stochastic Time-Delay Systems
Wu, Gang; Li, Long-Suo; Miao, Xiu-Feng; Cong, Xin-Rong
2013-06-01
This paper deals with the problem of an observer design for stochastic time-delay systems. The system states are unmeasured. We derive delay-dependent LMI criteria by means of the Leibniz-Newton formula, the Itô's differential operator and stochastic Lyapunov stability theory in order to obtain sufficient conditions for the asymptotic stability in the mean square for the closed-loop stochastic time-delay system. The proposed conditions are easily and numerically tractable via a Matlab LMI toolbox. The effectiveness of the control strategy is verified by numerical experiments.
Kaehler, James A.
1984-01-01
An improvement in a system and method of controlling heliostat in which the heliostat is operable in azimuth and elevation by respective stepper motors and including the respective steps or means for calculating the position for the heliostat to be at a commanded position, determining the number of steps in azimuth and elevation for each respective motor to get to the commanded position and energizing both the azimuth and elevation stepper motors to run in parallel until predetermined number of steps away from the closest commanded position in azimuth and elevation so that the closest position has been achieved, and thereafter energizing only the remaining motor to bring it to its commanded position. In this way, the heliostat can be started from a stowed position in the morning and operated by a computer means to its commanded position and kept correctly oriented throughout the day using only the time of the day without requiring the usual sensors and feedback apparatus. A computer, or microprocessor, can then control a plurality of many heliostats easily and efficiently throughout the day.
Directory of Open Access Journals (Sweden)
P. Susana Aguilera, DRA.
2014-11-01
Full Text Available Los principales objetivos del control prenatal son identificar aquellos pacientes de mayor riesgo, con el fin de realizar intervenciones en forma oportuna que permitan prevenir dichos riesgos y así lograr un buen resultado perinatal. Esto se realiza a través de la historia médica y reproductiva de la mujer, el examen físico, la realización de algunos exámenes de laboratorio y exámenes de ultrasonido. Además es importante promover estilos de vida saludables, la suplementación de ácido fólico, una consejería nutricional y educación al respecto.
Chronic obstructive pulmonary disease - control drugs; Bronchodilators - COPD - control drugs; Beta agonist inhaler - COPD - control drugs; Anticholinergic inhaler - COPD - control drugs; Long-acting inhaler - COPD - ...
Institute of Scientific and Technical Information of China (English)
韩文伟; 栾秀春; 杨爱民; 周杰
2013-01-01
为提高核反应堆运行的负荷跟随能力，设计了基于T-S模糊模型的包含模糊状态观测器的积分控制系统。该方法将非线性的点堆动力学方程在一些选定工况点进行线性化，采用并行分布补偿（PDC ）方法，设计模糊积分控制器和模糊状态观测器，以相对于额定功率平衡状态的相对中子密度为前件变量，构造T-S模糊控制系统。引入模糊状态观测器，成功解决了部分状态变量不能测量的困难。使用线性矩阵不等式（LM I）方法进行稳定性分析，保证了此控制系统的大范围稳定性。仿真结果验证了这种控制系统能在大范围运行工况下工作良好。%An integral control system with fuzzy state observer based on Takagi-Sugeno (T-S) fuzzy model was designed in order to improve the load-following capability of nuclear reactor .Linear models were derived from the original nonlinear point reactor kinetics equations on several operating points . The fuzzy integral controller and the fuzzy state observer were designed by using the parallel distributed compensation (PDC) technique ,and the T-S fuzzy control system was constructed with the relative neutron density referenced to the equilibrium condition of rated power as the premise variable . The problem that part of state variables can not be measured was successfully solved by introducing fuzzy state observer .The stability analysis was given by means of linear matrix inequality (LMI) approach ,and the control system was guaranteed to be stable within the large range . The simulation results demonstrate that the control system works well over a wide region of operation .
Relationship between fuzzy controllers and PID controllers
Institute of Scientific and Technical Information of China (English)
李洪兴
1999-01-01
The internal relations between fuzzy controllers and PID controllers are revealed. First, it is pointed out that a fuzzy controller with one input and one output is just a piecewise P controller. Then it is proved that a fuzzy controller with two inputs and one output is just a piecewise PD (or I) controller with interaction between P and D (or PI). At last, the conclusion that a fuzzy controller with three inputs and one output is just a piecewise PID controller with interaction among P, I and D is given. Moreover, a kind of difference scheme of fuzzy controllers is designed.
Design of Controllers for Liquid Level Control
Directory of Open Access Journals (Sweden)
Augustin Simon,
2015-08-01
Full Text Available The liquid level control system is commonly used in many process control applications. The aim of the process is to keep the liquid level in the tank at the desired value. The conventional proportional-integral-derivative (PID controller is simple, reliable and eliminates the error rate but it cannot handle complex problems. Fuzzy logic controllers are rule based systems which simulates human behavior of the process. The fuzzy controller is combined with the PID controller and then applied to the tank level control system. This paper proposes Inverse fuzzy with fuzzy logic controller for controlling liquid level system for a plant. This paper also compares the transient response as well as error indices of PID, Fuzzy logic controller, inverse fuzzy controllers. The responses of the controllers are verified through simulation. From the simulation results, it is observed that inverse fuzzy-PID controller gives the superior performance than the other controllers. The inverse fuzzy-PID controller gives better performance than the PID and fuzzy controller in terms of overshoot and settling time. Performance analysis is carried out with Liquid Flow Control System Design with Fuzzy logic controller. Results are evaluated by comparing the response time of conventional PID, fuzzy logic and Inverse fuzzy controller. Comparative analysis of the performance of different controllers is done in MATLAB and Simulink.
... Home A-Z Health Topics Birth control methods Birth control methods > A-Z Health Topics Birth control methods ... To receive Publications email updates Enter email Submit Birth control methods Birth control (contraception) is any method, medicine, ...
Hierarchical Control of Thermostatically Controller Loads for Primary Frequency Control
DEFF Research Database (Denmark)
Zhao, Haoran; Wu, Qiuwei; Huang, Shaojun
2016-01-01
This paper proposes a hierarchical control of Thermostatically Controlled Loads (TCLs) to provide primary frequency control support. The control architecture is comprised of three levels. At the high level, an aggregator coordinates multiple distribution substations and dispatches the primary...... respond to the frequency event autonomously. Case studies show that the proposed controller can efficiently respond to frequency events and fulfill the requirement specified by the system operator. The users’ comforts are not compromised and the short cycling of TCLs is largely reduced. Due...
Design of Controllers for Liquid Level Control
Augustin Simon,; Elizabeth Varghese
2015-01-01
The liquid level control system is commonly used in many process control applications. The aim of the process is to keep the liquid level in the tank at the desired value. The conventional proportional-integral-derivative (PID) controller is simple, reliable and eliminates the error rate but it cannot handle complex problems. Fuzzy logic controllers are rule based systems which simulates human behavior of the process. The fuzzy controller is combined with the PID controller and th...
Merrikh-Bayat, Farshad
2017-03-15
In this paper first the Multi-term Fractional-Order PID (MFOPID) whose transfer function is equal to [Formula: see text] , where kj and αj are unknown and known real parameters respectively, is introduced. Without any loss of generality, a special form of MFOPID with transfer function kp+ki/s+kd1s+kd2s(μ) where kp, ki, kd1, and kd2 are unknown real and μ is a known positive real parameter, is considered. Similar to PID and TID, MFOPID is also linear in its parameters which makes it possible to study all of them in a same framework. Tuning the parameters of PID, TID, and MFOPID based on loop shaping using Linear Matrix Inequalities (LMIs) is discussed. For this purpose separate LMIs for closed-loop stability (of sufficient type) and adjusting different aspects of the open-loop frequency response are developed. The proposed LMIs for stability are obtained based on the Nyquist stability theorem and can be applied to both integer and fractional-order (not necessarily commensurate) processes which are either stable or have one unstable pole. Numerical simulations show that the performance of the four-variable MFOPID can compete the trivial five-variable FOPID and often excels PID and TID.
Get the Most from Your Cash Flow.
Bauer, Richard I.
1995-01-01
Provides guidelines for overseeing a school district's cash-flow management program: (1) receipts into cash; (2) types of float; (3) concentration account or controlled-disbursement account; (4) bank-account analysis; and (5) safety. One figure is included. (LMI)
SiCp/Ti6Al4V functionally graded materials produced by laser melt injection
Pei, Y.T.; Ocelik, V.; Hosson, J.Th.M. De
2002-01-01
With a well-controlled laser melt injection (LMI) process, for the first time the feasibility is demonstrated to produce SiC particles (SiCp) reinforced Ti6Al4V functionally graded materials (FGMs). SiCp are injected just behind the laser beam into the extended part of the laser melt pool that is fo
Functionally graded materials produced with high power lasers
de Hosson, J.T.M.; Pei, Y.T.; Kumar, A; Chung, YW; Moore, JJ; Doll, GL; Yatsui, K; Misra, DS
2002-01-01
With a well-controlled laser melt injection (LMI) process, for the first time the feasibility is demonstrated to produce SiC particles (SiCp) reinforced Ti6Al4V functionally graded materials (FGMs). SiCp are injected just behind the laser beam into the extended part of the laser melt pool that is fo
Pinning Synchronization of Delayed Neural Networks with Nonlinear Inner-Coupling
Directory of Open Access Journals (Sweden)
Yangling Wang
2011-01-01
Full Text Available Without assuming the symmetry and irreducibility of the outer-coupling weight configuration matrices, we investigate the pinning synchronization of delayed neural networks with nonlinear inner-coupling. Some delay-dependent controlled stability criteria in terms of linear matrix inequality (LMI are obtained. An example is presented to show the application of the criteria obtained in this paper.
Robust stability of a gyroscope using linear matrix inequalities
Directory of Open Access Journals (Sweden)
Jorge Luis Orozco Mora
2008-01-01
Full Text Available En este artículo se aplican las desigualdades linealesmatriciales al problema de control en tiempo real de un giroscopio con dos grados de libertad. El controlador es diseñado utilizando rutinas de la caja de herramientas LMI de Matlab. Se presentan resultados en tiempo real, mostrando un buen desempeño del controlador de estado retroalimentado.
Robust stability of a gyroscope using linear matrix inequalities
Jorge Luis Orozco Mora; Elvia Ruiz Beltrán
2008-01-01
En este artículo se aplican las desigualdades linealesmatriciales al problema de control en tiempo real de un giroscopio con dos grados de libertad. El controlador es diseñado utilizando rutinas de la caja de herramientas LMI de Matlab. Se presentan resultados en tiempo real, mostrando un buen desempeño del controlador de estado retroalimentado.
Controlling Separation in Turbomachines
Evans, Simon; Himmel, Christoph; Power, Bronwyn; Wakelam, Christian; Xu, Liping; Hynes, Tom; Hodson, Howard
2010-01-01
Four examples of flow control: 1) Passive control of LP turbine blades (Laminar separation control). 2) Aspiration of a conventional axial compressor blade (Turbulent separation control). 3) Compressor blade designed for aspiration (Turbulent separation control). 4.Control of intakes in crosswinds (Turbulent separation control).
1999 American control conference
Energy Technology Data Exchange (ETDEWEB)
NONE
1999-07-01
The technical program reflects the rapid growth and strong interest in the field of control systems engineering. Leaders in the field provide a good balance between control theory and a broad spectrum of practical applications. Topics covered include: nonlinear control using backstepping; adaptive control; vibration control via command shaping; observer based fault detection; control applications; advances in passivity-based control methods; stability and time-delay systems; identification; intelligent systems; robust control; advances in control education.
Controllability of delay systems with restrained controls
Chukwu, E. N.
1979-01-01
Using a geometric growth condition, both the function space and Euclidean controllability of a nonlinear delay system which has a compact and convex control set are characterized. This extends analogous results for ordinary differential systems, and it yields conditions under which perturbed nonlinear delay controllable systems are controllable.
Regulation and controlled synchronization
Huijberts, H.J.C.; Huijberts, H.J.C.; Nijmeijer, Henk; Willems, R.M.A.
1998-01-01
We investigate the problem of controlled synchronization as a regulator problem. In controlled synchronization one is given autonomous transmitter dynamics and controlled receiver dynamics. The question is to find a (output) feedback controller that achieves matching between transmitter and
Energy Technology Data Exchange (ETDEWEB)
2016-07-21
The contact control code is a generalized force control scheme meant to interface with a robotic arm being controlled using the Robot Operating System (ROS). The code allows the user to specify a control scheme for each control dimension in a way that many different control task controllers could be built from the same generalized controller. The input to the code includes maximum velocity, maximum force, maximum displacement, and a control law assigned to each direction and the output is a 6 degree of freedom velocity command that is sent to the robot controller.
DEFF Research Database (Denmark)
Jantzen, Jan
1998-01-01
Control problems in the process industry are dominated by non-linear and time-varying behaviour, many inner loops, and much interaction between the control loops. Fuzzy controllers have in some cases nevertheless mimicked the control actions of a human operator. For high level control and supervi......Control problems in the process industry are dominated by non-linear and time-varying behaviour, many inner loops, and much interaction between the control loops. Fuzzy controllers have in some cases nevertheless mimicked the control actions of a human operator. For high level control...
Are estimated control charts in control?
Albers, W.; Kallenberg, W.C.M.
2001-01-01
Standard control chart practice assumes normality and uses estimated parameters. Because of the extreme quantiles involved, large relative errors result. Here simple corrections are derived to bring such estimated charts under control. As a criterion, suitable exceedance probabilities are used.
Supervisory Control of Networked Control Systems
2006-01-15
REPORT: January 15, 2006 Problem Statement: A networked control system is a control system whose feedback path is realized over a computer...theoretical bounds derived in [Ling03a]. 6. The feedback information in a networked control system is quantized due to the digital nature of
Stabiliser Fault Emergency Control using Reconﬁguration to Preserve Power System Stability
DEFF Research Database (Denmark)
Pedersen, Andreas Søndergaard; Richter, Jan H.; Tabatabaeipour, Mojtaba
2014-01-01
Stabiliser faults in multi-machine power systems are examined in this paper where fault-masking and system reconguration of the nonlinear system is obtained using a virtual actuator approach. Phasor Measurement Units, which can be integrated in wide-area transmission grids to improve...... the performance of power system stabilisers, are utilised when reconguring remaining stabilisers after one has been inoperable by a local failure. A stabilitypreserving reconguration is designed using absolute stability results for Lure type systems: The calculation of the virtual actuator that relies...... on a solution of a linear matrix inequality (LMI) is detailed in the paper. Simulation results of a benchmark transmission system show the ability of the fault-tolerant reconguration strategy to maintain wide-area stability of a power system despite failure in a stabiliser....
PID control with robust disturbance feedback control
DEFF Research Database (Denmark)
Kawai, Fukiko; Vinther, Kasper; Andersen, Palle
2015-01-01
Disturbance Feedback Control (DFC) is a technique, originally proposed by Fuji Electric, for augmenting existing control systems with an extra feedback for attenuation of disturbances and model errors. In this work, we analyze the robustness and performance of a PID-based control system with DFC...... and performance (if such gains exist). Finally, two different simulation case studies are evaluated and compared. Our numerical studies indicate that better performance can be achieved with the proposed method compared with a conservatively tuned PID controller and comparable performance can be achieved when...... compared with an H-infinity controller....
Veterinary practice internal controls.
Catanzaro, T E
1996-02-01
This chapter explores the responsive management requirements critical for effective internal controls. Internal control techniques offered include the application of segregation of function, goal-orientation, performance planning, and training objectives in five veterinary practice areas. These areas are client controls, cash controls, inventory controls, purchase controls, and stock controls. Because only trusted staff members are given access to practice assets, the veterinary leadership must have a responsive management plan to protect the life of the practice while building the practice team. Methods are shared for controlling opportunities that can lead to employee fraud while concurrently building a team approach to internal controls.
Controllability of asynchronous Boolean multiplex control networks.
Luo, Chao; Wang, Xingyuan; Liu, Hong
2014-09-01
In this article, the controllability of asynchronous Boolean multiplex control networks (ABMCNs) is studied. First, the model of Boolean multiplex control networks under Harvey' asynchronous update is presented. By means of semi-tensor product approach, the logical dynamics is converted into linear representation, and a generalized formula of control-depending network transition matrices is achieved. Second, a necessary and sufficient condition is proposed to verify that only control-depending fixed points of ABMCNs can be controlled with probability one. Third, using two types of controls, the controllability of system is studied and formulae are given to show: (a) when an initial state is given, the reachable set at time s under a group of specified controls; (b) the reachable set at time s under arbitrary controls; (c) the specific probability values from a given initial state to destination states. Based on the above formulae, an algorithm to calculate overall reachable states from a specified initial state is presented. Moreover, we also discuss an approach to find the particular control sequence which steers the system between two states with maximum probability. Examples are shown to illustrate the feasibility of the proposed scheme.
Controllability of asynchronous Boolean multiplex control networks
Luo, Chao; Wang, Xingyuan; Liu, Hong
2014-09-01
In this article, the controllability of asynchronous Boolean multiplex control networks (ABMCNs) is studied. First, the model of Boolean multiplex control networks under Harvey' asynchronous update is presented. By means of semi-tensor product approach, the logical dynamics is converted into linear representation, and a generalized formula of control-depending network transition matrices is achieved. Second, a necessary and sufficient condition is proposed to verify that only control-depending fixed points of ABMCNs can be controlled with probability one. Third, using two types of controls, the controllability of system is studied and formulae are given to show: (a) when an initial state is given, the reachable set at time s under a group of specified controls; (b) the reachable set at time s under arbitrary controls; (c) the specific probability values from a given initial state to destination states. Based on the above formulae, an algorithm to calculate overall reachable states from a specified initial state is presented. Moreover, we also discuss an approach to find the particular control sequence which steers the system between two states with maximum probability. Examples are shown to illustrate the feasibility of the proposed scheme.
Adaptive Extremum Control and Wind Turbine Control
DEFF Research Database (Denmark)
Ma, Xin
1997-01-01
This thesis is divided into two parts, i.e., adaptive extremum control and modelling and control of a wind turbine. The rst part of the thesis deals with the design of adaptive extremum controllers for some processes which have the behaviour that process should have as high e ciency as possible...... in parameters, and thus directly lends itself to parameter estimation and adaptive control. The extremum control law is derived based on static optimization of a performance function. For a process with nonlinearity at output the intermediate signal between the linear part and nonlinear part plays an important...... role. If it can be emphasis on control design. The models have beenvalidated by experimental data obtained from an existing wind turbine. The e ective wind speed experienced by the rotor of a wind turbine, which is often required by some control methods, is estimated by using a wind turbine as a wind...
Adaptive Extremum Control and Wind Turbine Control
DEFF Research Database (Denmark)
Ma, Xin
1997-01-01
This thesis is divided into two parts, i.e., adaptive extremum control and modelling and control of a wind turbine. The rst part of the thesis deals with the design of adaptive extremum controllers for some processes which have the behaviour that process should have as high e ciency as possible...... in parameters, and thus directly lends itself to parameter estimation and adaptive control. The extremum control law is derived based on static optimization of a performance function. For a process with nonlinearity at output the intermediate signal between the linear part and nonlinear part plays an important...... role. If it can be emphasis on control design. The models have beenvalidated by experimental data obtained from an existing wind turbine. The e ective wind speed experienced by the rotor of a wind turbine, which is often required by some control methods, is estimated by using a wind turbine as a wind...
Controlling chaos using an exponential control
Gadre, S D; Gadre, Sangeeta D; Varma, V S
1995-01-01
We demonstrate that chaos can be controlled using a multiplicative exponential feedback control. All three types of unstable orbits - unstable fixed points, limit cycles and chaotic trajectories can be stabilized using this control. The control is effective both for maps and flows. The control is significant, particularly for systems with several degrees of freedom, as knowledge of only one variable on the desired unstable orbit is sufficient to settle the system on to that orbit. We find, that in all the cases studied, the transient time is a decreasing function of the stiffness of control. But increasing the stiffness beyond an optimum value can increase the transient time. The control can also be used to create suitable new stable attractors in a map, which did not exist in the original system.
Robust H∞ control for networked control systems
Institute of Scientific and Technical Information of China (English)
Ma Weiguo; Shao Cheng
2008-01-01
The robust H∞ control for networked control systems with both stochastic network-induced delay and data packet dropout is studied.When data are transmitted over network,the stochastic data packet dropout process can be described by a two-state Markov chain.The networked control systems with stochastic network-induced delay and data packet dropout are modeled as a discrete time Markov jump linear system with two operation modes.The sufficient condition of robust H∞ control for networked control systems stabilized by state feedback controller is presented in terms of linear matrix inequality.The state feedback controller can be constructed via the solution of a set of linear matrix inequalities.An example is given to verify the effectiveness of the method proposed.
Alfaro, Víctor M
2007-10-01
In this paper, an index for measuring fragility of proportional integral derivative (PID) controllers is proposed. This index relates the losses of robustness of the control loop when controller parameters change, to the nominal robustness of the control loop. Furthermore, it defines when a PID controller is fragile, nonfragile or resilient.
2013-01-01
Please note this is a short discount publication. In today's manufacturing environment, Motion Control plays a major role in virtually every project.The Motion Control Report provides a comprehensive overview of the technology of Motion Control:* Design Considerations* Technologies* Methods to Control Motion* Examples of Motion Control in Systems* A Detailed Vendors List
Characterization and mapping of a lesion mimicmutant in rice(Oryza sativa L.)
Institute of Scientific and Technical Information of China (English)
无
2003-01-01
A rice initiation-type lesion mimic mutant (imi) was identified, which was isolated from an indica rice Zhongxian 3037 through γ radiation mutagenesis. Trypan blue staining and sterile culture revealed that the mutant spontaneously developed lesions on the leaves in a develop mentally regulated and light-dependent manner. Genetic analysis indicated that the lesion mimic trait was controlled by a single resessive locus. Using public molecular markers and an F2 population derived from lmi and 93-11, we mapped the lmi locus to the short arm of chromosome 8, nearby the centromere, between two SSR markers RM547 and RM331. The genetic distance was 1.2 and 3.2 Cm, respectively. Then according to the public rice genomic sequence between the two SSR markers, lmi was further finely tagged by three CAPS markers: C4135-8, C4135-9 and C4135-10. And lmi locus was a co-segregated with marker C4135-10, providing a starting point for imi gene cloning.
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Gross motor control is the ability to make large, general movements (such as waving an arm or lifting a leg). ... Gross motor control is a milestone in the development of an infant. Infants develop gross motor control before they develop ...
Control System Damps Vibrations
Kopf, E. H., Jr.; Brown, T. K.; Marsh, E. L.
1983-01-01
New control system damps vibrations in rotating equipment with help of phase-locked-loop techniques. Vibrational modes are controlled by applying suitable currents to drive motor. Control signals are derived from sensors mounted on equipment.
Nominal model predictive control
Grüne, Lars
2013-01-01
5 p., to appear in Encyclopedia of Systems and Control, Tariq Samad, John Baillieul (eds.); International audience; Model Predictive Control is a controller design method which synthesizes a sampled data feedback controller from the iterative solution of open loop optimal control problems.We describe the basic functionality of MPC controllers, their properties regarding feasibility, stability and performance and the assumptions needed in order to rigorously ensure these properties in a nomina...
2014-01-01
The basics of remotely controlled sewers [1] are presented focusing on Leipzig Municipality’s sewer control project [2] located in Germany. The consequences of sewer surcharge events are outlined considering possible counter measures. The required data basis, the controllable sewer objects and their relevant control units are pointed out. The presentation is finished exposing the types of control network, possible control algorithms as well as important aspects regarding the decision for / ag...
Nominal Model Predictive Control
Grüne, Lars
2014-01-01
5 p., to appear in Encyclopedia of Systems and Control, Tariq Samad, John Baillieul (eds.); International audience; Model Predictive Control is a controller design method which synthesizes a sampled data feedback controller from the iterative solution of open loop optimal control problems.We describe the basic functionality of MPC controllers, their properties regarding feasibility, stability and performance and the assumptions needed in order to rigorously ensure these properties in a nomina...
Federal Laboratory Consortium — The Test Control Center (TCC) provides a consolidated facility for planning, coordinating, controlling, monitoring, and analyzing distributed test events. ,The TCC...
Dynamic power flow controllers
Divan, Deepakraj M.; Prasai, Anish
2017-03-07
Dynamic power flow controllers are provided. A dynamic power flow controller may comprise a transformer and a power converter. The power converter is subject to low voltage stresses and not floated at line voltage. In addition, the power converter is rated at a fraction of the total power controlled. A dynamic power flow controller controls both the real and the reactive power flow between two AC sources having the same frequency. A dynamic power flow controller inserts a voltage with controllable magnitude and phase between two AC sources; thereby effecting control of active and reactive power flows between two AC sources.
Unfalsified control based on the ? controller parameterisation
Sánchez-Peña, R. S.; Colmegna, P.; Bianchi, F.
2015-11-01
This paper presents an implementation of the unfalsified control (UC) method using the Riccati-based parameterisation of ? controllers. The method provides an infinite controller set to (un)falsify the real-time data streams seeking for the best performance. Different sets may be designed to increase the degrees of freedom of the set of controller candidates to perform UC. In general, a set of m central controllers could be designed, each one seeking different objectives and all with their own parameterisation as a function of a stable and bounded transfer matrix. For example, one controller parameterisation could be designed to solve the robust stability of a model set which covers the physical system, therefore guaranteeing feasibility. The implementation requires the online optimisation of either quadratic fractional or quadratic problems, depending on the selection of the cost function. A multi-input, multi-output (MIMO) time-varying model of a permanent magnet synchronous generator illustrates the use of this technique.
Space Digital Controller for Improved Motor Control
Alves-Nunes, Samuel; Daras, Gaetan; Dehez, Bruno; Maillard, Christophe; Bekemans, Marc; Michel, Raymond
2014-08-01
Performing digital motor control into space equipment is a new challenge. The new DPC (Digital Programmable Controller) is the first chip that we can use as a micro-controller, allowing us to drive motors with digital control schemes. In this paper, the digital control of hybrid stepper motors is considered. This kind of motor is used for solar array rotation and antenna actuation. New digital control technology brings a lot of advantages, allowing an important reduction of thermal losses inside the motor, and a reduction of thermal constraints on power drive electronic components. The opportunity to drive motors with a digital controller also brings many new functionalities like post-failure torque analysis, micro- vibrations and cogging torque reduction, or electro- mechanical damping of solar array oscillations. To evaluate the performance of the system, Field-Oriented Control (FOC) is implemented on a hybrid stepper motor. A test-bench, made of an active load, has been made to emulate the mechanical behaviour of the solar array, by the use of a torsionally-compliant model. The experimental results show that we can drastically reduce electrical power consumption, compared with the currently used open-loop control scheme.
Improving Control of Two Motor Controllers
Toland, Ronald W.
2004-01-01
A computer program controls motors that drive translation stages in a metrology system that consists of a pair of two-axis cathetometers. This program is specific to Compumotor Gemini (or equivalent) motors and the Compumotor 6K-series (or equivalent) motor controller. Relative to the software supplied with the controller, this program affords more capabilities and is easier to use. Written as a Virtual Instrument in the LabVIEW software system, the program presents an imitation control panel that the user can manipulate by use of a keyboard and mouse. There are three modes of operation: command, movement, and joystick. In command mode, single commands are sent to the controller for troubleshooting. In movement mode, distance, speed, and/or acceleration commands are sent to the controller. Position readouts from the motors and from position encoders on the translation stages are displayed in marked fields. At any time, the position readouts can be recorded in a file named by the user. In joystick mode, the program yields control of the motors to a joystick. The program sends commands to, and receives data from, the controller via a serial cable connection, using the serial-communication portion of the software supplied with the controller.
Aircraft Attitude Control by Fuzzy Control
Kato, Akio; Matsuba, Takashi
The fuzzy control law to improve dutch roll characteristics of aircraft was designed and its control performance was evaluated. First, the control law was designed for a small-high speed aircraft at low altitude and low-speed flight conditions. The control law was then applied to flight conditions from minimum speed to supersonic speed and from sea level to high altitude. The control performance for these conditions was evaluated. Furthermore, this control law was adapted to a large transport aircraft with no parameter changes. The evaluation showed good control performance to improve the dutch roll characteristics under all flight conditions for both small high-speed aircraft and large transport aircraft without the parameter changes. This means that the fuzzy control proved to provide effective flexible application to aircraft stability augmentation. If an aircraft in actual flight is in strong air turbulence, inputs to the fuzzy controller may exceed the limit of its effective range. To cope with this problem, the countermeasures were introduced, their methods tested, and their effectiveness proved.
Control and optimal control theories with applications
Burghes, D N
2004-01-01
This sound introduction to classical and modern control theory concentrates on fundamental concepts. Employing the minimum of mathematical elaboration, it investigates the many applications of control theory to varied and important present-day problems, e.g. economic growth, resource depletion, disease epidemics, exploited population, and rocket trajectories. An original feature is the amount of space devoted to the important and fascinating subject of optimal control. The work is divided into two parts. Part one deals with the control of linear time-continuous systems, using both transfer fun
Bifurcation Control, Manufacturing Planning and Formation Control
Institute of Scientific and Technical Information of China (English)
Wei Kang; Mumin Song; Ning Xi
2005-01-01
The paper consists of three topics on control theory and engineering applications, namely bifurcation control, manufacturing planning, and formation control. For each topic, we summarize the control problem to be addressed and some key ideas used in our recent research. Interested readers are referred to related publications for more details. Each of the three topics in this paper is technically independent from the other ones. However, all three parts together reflect the recent research activities of the first author, jointly with other researchers in different fields.
Microprocessor control for standardized power control systems
Green, D. G.; Perry, E.
1978-01-01
The use of microcomputers in space-oriented power systems as a replacement for existing inflexible analog type controllers has been proposed. This study examines multiprocessor systems, various modularity concepts and presents a conceptualized power system incorporating a multiprocessor controller as well as preliminary results from a breadboard model of the proposed system.
Robust control charts in statistical process control
Nazir, H.Z.
2014-01-01
The presence of outliers and contaminations in the output of the process highly affects the performance of the design structures of commonly used control charts and hence makes them of less practical use. One of the solutions to deal with this problem is to use control charts which are robust agains
Controlling neuronal noise using chaos control
Christini, D J; Christini, David J; Collins, James J
1995-01-01
Chaos control techniques have been applied to a wide variety of experimental systems, including magneto-elastic ribbons, lasers, chemical reactions, arrhythmic cardiac tissue, and spontaneously bursting neuronal networks. An underlying assumption in all of these studies is that the system being controlled is chaotic. However, the identification of chaos in experimental systems, particularly physiological systems, is a difficult and often misleading task. Here we demonstrate that the chaos criteria used in a recent study can falsely classify a noise-driven, non-chaotic neuronal model as being chaotic. We apply chaos control, periodic pacing, and anticontrol to the non-chaotic model and obtain results which are similar to those reported for apparently chaotic, {\\em in vitro} neuronal networks. We also obtain similar results when we apply chaos control to a simple stochastic system. These novel findings challenge the claim that the aforementioned neuronal networks were chaotic and suggest that chaos control tech...
Sunan, Huang; Heng, Lee Tong
2002-01-01
The presence of considerable time delays in the dynamics of many industrial processes, leading to difficult problems in the associated closed-loop control systems, is a well-recognized phenomenon. The performance achievable in conventional feedback control systems can be significantly degraded if an industrial process has a relatively large time delay compared with the dominant time constant. Under these circumstances, advanced predictive control is necessary to improve the performance of the control system significantly. The book is a focused treatment of the subject matter, including the fundamentals and some state-of-the-art developments in the field of predictive control. Three main schemes for advanced predictive control are addressed in this book: • Smith Predictive Control; • Generalised Predictive Control; • a form of predictive control based on Finite Spectrum Assignment. A substantial part of the book addresses application issues in predictive control, providing several interesting case studie...
DEFF Research Database (Denmark)
Huusom, Jakob Kjøbsted
2015-01-01
are control objectives and the challenges in obtaining good control of the bioreactor. The objective of this chapter is to discuss the bioreactor control problems and to highlight some general traits that distinguish operation of bioprocesses from operation of processes in the conventional chemical process......The purpose of bioprocess control is to ensure that the plant operates as designed. This chapter presents the fundamental principles for control of biochemical processes. Through examples, the selection of manipulated and controlled variables in the classical reactor configurations is discussed, so...... industries. It also provides a number of typical control loops for different objectives. A brief introduction to the general principles of process control, the PID control algorithm is discussed, and the design and effect of tuning are shown in an example. Finally, a discussion of novel, model-free control...
DEFF Research Database (Denmark)
Jantzen, Jan
as any PID controller. In the nonlinear domain, the stability of four standard control surfaces is analysed by means of describing functions and Nyquist plots. The self-organizing controller (SOC) is shown to be a model reference adaptive controller. There is a possibility that a nonlinear fuzzy PID......The objective of this textbook is to acquire an understanding of the behaviour of fuzzy logic controllers. Under certain conditions a fuzzy controller is equivalent to a proportional-integral-derivative (PID) controller. Using that equivalence as a link, the book applies analysis methods from...... linear and nonlinear control theory. In the linear domain, PID tuning methods and stability analyses are transferred to linear fuzzy controllers. The Nyquist plot shows the robustness of different settings of the fuzzy gain parameters. As a result, a fuzzy controller is guaranteed to perform as well...
DEFF Research Database (Denmark)
Jantzen, Jan
linear and nonlinear control theory. In the linear domain, PID tuning methods and stability analyses are transferred to linear fuzzy controllers. The Nyquist plot shows the robustness of different settings of the fuzzy gain parameters. As a result, a fuzzy controller is guaranteed to perform as well......The objective of this textbook is to acquire an understanding of the behaviour of fuzzy logic controllers. Under certain conditions a fuzzy controller is equivalent to a proportional-integral-derivative (PID) controller. Using that equivalence as a link, the book applies analysis methods from...... as any PID controller. In the nonlinear domain, the stability of four standard control surfaces is analysed by means of describing functions and Nyquist plots. The self-organizing controller (SOC) is shown to be a model reference adaptive controller. There is a possibility that a nonlinear fuzzy PID...
CONTROLLING AND BUSINESS EFFICIENCY
Directory of Open Access Journals (Sweden)
Tina Vuko
2013-02-01
Full Text Available Managing business successfully in dynamic environment requires effective controlling system. Controlling is the process of defining objectives, planning and management control so that every decision maker can act in accordance with agreed objectives. Controlling function as a separate department contributes business efficiency trough ensuring transparency of business result and business processes. Controlling takes place when manager and controller cooperate. The aim of this paper is to investigate the effectiveness of controlling function (i.e. controlling department in Croatian companies and to address the specific features of the function that contribute significantly to overall business performance. The research is conducted on the sample of companies listed on the Regulated market of the Zagreb Stock Exchange. Survey is used as a method to collect the data regarding the controlling function, while financial data necessary for the research are extracted from the published financial statements. Results of the research indicate that controlling department has positive effects on the business performance.
Bieńkowska Agnieszka; Zabłocka-Kluczka Anna
2016-01-01
The purpose of this study is to discuss the trust within and towards an organisation in the context of implementation of controlling therein. In this context the essence of trust and its importance in organisation management was presented, as well as trust in the contemporary management methods and concepts. Controlling as a trust-building factor inside an organisation was pointed out. Especially controlling and control were described. Moreover management by considering deviations in controll...
Bernal Muñoz, Ferran
2015-01-01
ARDUINO is a vey usefull platform for prototypes. In this project ARDUINO will be used for controling a Semiconductor Tuneable Laser. [ANGLÈS] Diode laser for communications control based on an Arduino board. Temperature control implementation. Software and hardware protection for the laser implementation. [CASTELLÀ] Control de un láser de comunicaciones ópticas desde el ordenador utilizando una placa Arduino. Implementación de un control de temperatura y protección software y hardware ...
Bieńkowska Agnieszka; Zabłocka-Kluczka Anna
2016-01-01
The purpose of this study is to discuss the trust within and towards an organisation in the context of implementation of controlling therein. In this context the essence of trust and its importance in organisation management was presented, as well as trust in the contemporary management methods and concepts. Controlling as a trust-building factor inside an organisation was pointed out. Especially controlling and control were described. Moreover management by considering deviations in controll...
Bernal Muñoz, Ferran
2015-01-01
ARDUINO is a vey usefull platform for prototypes. In this project ARDUINO will be used for controling a Semiconductor Tuneable Laser. [ANGLÈS] Diode laser for communications control based on an Arduino board. Temperature control implementation. Software and hardware protection for the laser implementation. [CASTELLÀ] Control de un láser de comunicaciones ópticas desde el ordenador utilizando una placa Arduino. Implementación de un control de temperatura y protección software y hardware ...
Naumann, H D; Armstrong, S A; Lambert, B D; Muir, J P; Tedeschi, L O; Kothmann, M M
2014-01-17
The effect of molecular weight of condensed tannins (CT) from a variety of warm-season perennial legumes commonly consumed by sheep and goats on anthelmintic activity has not been previously explored. The objectives of this study were to determine if molecular weight of CT from warm-season perennial legumes could predict the biological activity of CT relative to anthelmintic activity against ivermectin resistant L3 stage Haemonchus contortus (HC) using a larval migration inhibition (LMI) assay. A second objective was to determine if CT from warm-season perennial legumes possess anthelmintic properties against L3 stage (HC). Lespedeza stuevei had the greatest concentration of total condensed tannin (TCT; 11.7%), whereas, with the exception of Arachis glabrata, a CT-free negative control, Leucaena retusa had the least TCT (3.3%). Weight-average molecular weight of CT ranged from 552 Da for L. stuevei to 1483 Da for Lespedeza cuneata. The treatments demonstrating the greatest percent LMI were L. retusa, L. stuevei and Acacia angustissima var. hirta (65.4%, 63.1% and 42.2%, respectively). The ivermectin treatment had the smallest percent LMI (12.5%) against ivermectin resistant L3 HC. There was a weak correlation (R(2)=0.34; P=0.05) between CT MW and percent LMI, suggesting that molecular weight of CT is a weak contributing factor to CT biological activity as it relates to LMI of L3 stage HC. L. stuevei, L. retusa and A. angustissima var. hirta STP5 warrant further evaluation of anthelmintic properties in vivo.
Generic device controller for accelerator control systems
Energy Technology Data Exchange (ETDEWEB)
Mariotti, R.; Buxton, W.; Frankel, R.; Hoff, L.
1987-01-01
A new distributed intelligence control system has become operational at the AGS for transport, injection, and acceleration of heavy ions. A brief description of the functionality of the physical devices making up the system is given. An attempt has been made to integrate the devices for accelerator specific interfacing into a standard microprocessor system, namely, the Universal Device Controller (UDC). The main goals for such a generic device controller are to provide: local computing power; flexibility to configure; and real time event handling. The UDC assemblies and software are described. (LEW)
Rajamani, Rajesh
2012-01-01
Vehicle Dynamics and Control provides a comprehensive coverage of vehicle control systems and the dynamic models used in the development of these control systems. The control system applications covered in the book include cruise control, adaptive cruise control, ABS, automated lane keeping, automated highway systems, yaw stability control, engine control, passive, active and semi-active suspensions, tire-road friction coefficient estimation, rollover prevention, and hybrid electric vehicle. In developing the dynamic model for each application, an effort is made to both keep the model simple enough for control system design but at the same time rich enough to capture the essential features of the dynamics. A special effort has been made to explain the several different tire models commonly used in literature and to interpret them physically. In the second edition of the book, chapters on roll dynamics, rollover prevention and hybrid electric vehicles have been added, and the chapter on electronic stability co...
DEFF Research Database (Denmark)
Jagd, Søren
This paper focuses on the leadership challenge of balancing trust and control. The relation between trust and control has for a long time been a puzzling issue for management researchers. In the paper I first show that there has been a dramatic change in the way the relation between trust...... and control has been conceptualized in trust research. While the relation between trust and control earlier was conceptualized as a more or less stable balance between trust and control, more recent research conceptualizes the relation between trust and control more as a dynamical process that involves...... an ongoing process of balancing the relation between trust and control. Second, taking the departure in the recent conceptualization of the balance between trust and control as an interactive process I discuss the challenges for management in handling this more subtle balancing of trust and control...
Digital Optical Control System
Jordan, David H.; Tipton, Charles A.; Christmann, Charles E.; Hochhausler, Nils P.
1988-09-01
We describe the digital optical control system (DOGS), a state-of-the-art controller for electrical feedback in an optical system. The need for a versatile optical controller arose from a number of unique experiments being performed by the Air Force Weapons Laboratory. These experiments use similar detectors and actuator-controlled mirrors, but the control requirements vary greatly. The experiments have in common a requirement for parallel control systems. The DOGS satisfies these needs by allowing several control systems to occupy a single chassis with one master controller. The architecture was designed to allow upward compatibility with future configurations. Combinations of off-the-shelf and custom boards are configured to meet the requirements of each experiment. The configuration described here was used to control piston error to X/80 at a wavelength of 0.51 Am. A peak sample rate of 8 kHz, yielding a closed loop bandwidth of 800 Hz, was achieved.
Wilson, David G [Tijeras, NM; Robinett, III, Rush D.
2012-02-21
A control system design method and concomitant control system comprising representing a physical apparatus to be controlled as a Hamiltonian system, determining elements of the Hamiltonian system representation which are power generators, power dissipators, and power storage devices, analyzing stability and performance of the Hamiltonian system based on the results of the determining step and determining necessary and sufficient conditions for stability of the Hamiltonian system, creating a stable control system based on the results of the analyzing step, and employing the resulting control system to control the physical apparatus.
Institute of Scientific and Technical Information of China (English)
ZhangShuochengt; WangDan; QiaoWeimin; JingLan
2003-01-01
All kinds of step motors and servomotors are widely used in CSR control system, such as many vacuum valves control that set on the HIRFL-CSR; all kinds of electric switches and knobs of ECR Ion Source; equipment of CSR Beam Diagnostics and a lot of large equipment like Inside Gun Toroid and Collector Toroid of HIRFL. A typical control system include up to 32 16-I/O Control boards, and each 16-I/O Control board can control 4 motors at the same time (including 8 Limit Switches).
Control integral systems; Sistemas integrales de control
Energy Technology Data Exchange (ETDEWEB)
Burgos, Estrella [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)
1998-12-31
Almost two third of the electric power generation in Mexico are obtained from hydrocarbons, for that reasons Comision Federal de Electricidad (CFE) dedicated special commitment in modernizing the operation of fossil fuel central stations. In attaining this objective the control systems play a fundamental roll, from them depend a good share of the reliability and the efficiency of the electric power generation process, as well as the extension of the equipment useful life. Since 1984 the Instituto de Investigaciones Electricas (IIE) has been working, upon the request of CFE, on the development of digital control systems. To date it has designed and implemented a logic control system for gas burners, which controls 32 burners of the Unit 4 boiler of the Generation Central of Valle de Mexico and two systems for distributed control for two combined cycle central stations, which are: Dos Bocas, Veracruz Combined cycle central, and Gomez Palacio, Durango combined cycle central. With these two developments the IIE enters the World tendency of implementing distributed control systems for the fossil fuel power central update [Espanol] Casi las dos terceras partes de la generacion electrica en Mexico se obtienen a partir de hidrocarburos, es por eso que la Comision Federal de Electricidad (CFE) puso especial empeno en modernizar la operacion de las centrales termoelectricas de combustibles fosiles. En el logro de este objetivo los sistemas de control desempenan un papel fundamental, de ellos depende una buena parte la confiabilidad y la eficiencia en el proceso de generacion de energia electrica, asi como la prolongacion de la vida util de los equipos. Desde 1984 el Instituto de Investigaciones Electricas (IIE) ha trabajado, a solicitud de la CFE, en el desarrollo de sistemas digitales de control. A la fecha se han disenado e implantado un sistema de control logico de quemadores de gas, el cual controla 32 quemadores de la caldera de la unidad 4 de la central de generacion
Modeling and control of thermostatically controlled loads
2011-01-01
As the penetration of intermittent energy sources grows substantially, loads will be required to play an increasingly important role in compensating the fast time-scale fluctuations in generated power. Recent numerical modeling of thermostatically controlled loads (TCLs) has demonstrated that such load following is feasible, but analytical models that satisfactorily quantify the aggregate power consumption of a group of TCLs are desired to enable controller design. We develop such a model for...
Guaranteed cost control for networked control systems
Institute of Scientific and Technical Information of China (English)
Linbo XIE; Huajing FANG; Ying ZHENG
2004-01-01
The guaranteed cost control problem for networked control systems (NCSs) is addressed under communication constraints and varying sampling rate. First of all, a simple information-scheduling scheme is presented to describe the scheduling approach of system signals in NCSs. Then, based on such a scheme and given sampling method, the design procedure in dynamic output feedback manner is also derived which renders the closed loop system to be asymptotically stable and guarantees an upper bound of the LQ performance cost function.
Embedded controllers for local board-control
Neufeld, Niko; Mini, Giuseppe; Sannino, Mario; Guzik, Zbigniew; Jacobsson, Richard; Jost, Beat
2005-01-01
The LHCb experiment at CERN has a large number of custom electronic boards performing high-speed data-processing. Like in any large experiment the control and monitoring of these crate-mounted boards must be integrated into the overall control-system. Traditionally this has been done by using buses like VME on the back-plane of the crates. LHCb has chosen to equip every board with an embedded micro-controller and connecting them in a large Local Area Network. The intelligence of these devices allows complex (soft) real-time control and monitoring, required for modern powerful FPGA driven electronics. Moreover each board has its own, isolated control access path, which increases the robustness of the entire system. The system is now in pre-production at several sites and will go into full production during next year. The hardware and software will be discussed and experiences from the R&D and pre-production will be reviewed, with an emphasis on advantages and difficulties of this approach to board-control.
Prevention and Control of Cryptosporidiosis
... Email Address Submit Button What's this? Parasites Home Prevention & Control Recommend on Facebook Tweet Share Compartir Prevention & Control Topics Prevention & Control - General Public Prevention & Control - ...
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Scabies: Prevention and Control
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Birth control pill - slideshow
... page: //medlineplus.gov/ency/presentations/100108.htm Birth control pill - series—Normal female anatomy To use the ... produce a successful pregnancy. To prevent pregnancy, birth control pills affect how these organs normally function. Review ...
Cholera Prevention and Control
... name="commit" type="submit" value="Submit" /> Prevention & Control Recommend on Facebook Tweet Share Compartir Prevention of ... of cholera and other diarrheal disease prevention. Prevention Control Topics Six Basic Cholera Prevention Messages I nfection ...
These Nutrient Control Seminars will present an extensive state-of-the-technology review of the engineering design and operation of nitrogen and phosphorous control technologies and techniques applied at municipal wastewater treatment plants (WWTPs). These seminars will present ...
National Oceanic and Atmospheric Administration, Department of Commerce — The NGS Survey Control Map provides a map of the US which allows you to find and display geodetic survey control points stored in the database of the National...
Insensitive control technology development
Harvey, C. A.; Pope, R. E.
1978-01-01
THe investigation of two insensitive controller synthesis techniques was reported. The finite dimensional inverse approach produces a time varying insensitive controller and/or parameter identifier by constructing inverse functions derived from a finite number of input output pair relationships. The MD/IM concept relies on the information matrix theory that was developed in the estimation and identification field. The MD/IM synthesis technique is based on the hypothesis that minimizing the information matrix will reduce system identifiability and consequently system sensitivity to uncertain parameters. The controllers designed with both techniques were evaluated on a realistic C-5A aircraft flight control problem. Results indicate that the FDI controller is more suited to trajectory type problems because of its time varying nature. The MD/IM controller performed as well as the top-rated controllers of the initial effort and has direct application to aircraft flight control problems.
Directory of Open Access Journals (Sweden)
Özgü CAN
2010-02-01
Full Text Available As computer technologies become pervasive, the need for access control mechanisms grow. The purpose of an access control is to limit the operations that a computer system user can perform. Thus, access control ensures to prevent an activity which can lead to a security breach. For the success of Semantic Web, that allows machines to share and reuse the information by using formal semantics for machines to communicate with other machines, access control mechanisms are needed. Access control mechanism indicates certain constraints which must be achieved by the user before performing an operation to provide a secure Semantic Web. In this work, unlike traditional access control mechanisms, an "Ontology Based Access Control" mechanism has been developed by using Semantic Web based policies. In this mechanism, ontologies are used to model the access control knowledge and domain knowledge is used to create policy ontologies.
King, Q
2015-01-01
Reliable powering of accelerator magnets requires reliable power converters and controls, able to meet the powering specifications in the long term. In this paper, some of the issues that will challenge a power converter controls engineer are discussed.
Distributed computer control systems
Energy Technology Data Exchange (ETDEWEB)
Suski, G.J.
1986-01-01
This book focuses on recent advances in the theory, applications and techniques for distributed computer control systems. Contents (partial): Real-time distributed computer control in a flexible manufacturing system. Semantics and implementation problems of channels in a DCCS specification. Broadcast protocols in distributed computer control systems. Design considerations of distributed control architecture for a thermal power plant. The conic toolset for building distributed systems. Network management issues in distributed control systems. Interprocessor communication system architecture in a distributed control system environment. Uni-level homogenous distributed computer control system and optimal system design. A-nets for DCCS design. A methodology for the specification and design of fault tolerant real time systems. An integrated computer control system - architecture design, engineering methodology and practical experience.
Gosline, R. M.
1988-02-01
Three data controllers developed for the SETI project are described. Two are used primarily for recording and playback of SETI data from the Radio Science Surveillance System (RSSS). The third is used as a SETI station controller for DSS 13.
Vacuum controls and interlocks
Strubin, P
2007-01-01
The vacuum control system is, in most cases, a subset of the general control system of an accelerator. As such, it shares the architecture and communication infrastructure of the main control system. Considered as a ‘slow process’ to control in the frame of accelerators, the vacuum control system can be built using commercial industrial controllers (PLCs). A data driven approach allows for changes in configuration without changing the software code but at the expense of a solid database. Modelling the equipment allows for easy adaptation of a variety of control units with the same functionality but different physical interfaces. It also allows for a uniform display of the available data and status values. Interlocks are required to protect the vacuum equipment itself against abnormal conditions, but also to protect other systems, like RF, which need a good vacuum to operate. They are an integral part of any vacuum control system.
DEFF Research Database (Denmark)
Dotoli, M.; Jantzen, Jan
1999-01-01
The tutorial concerns automatic control of an inverted pendulum, especially rule based control by means of fuzzy logic. A ball balancer, implemented in a software simulator in Matlab, is used as a practical case study. The objectives of the tutorial are to teach the basics of fuzzy control......, and to show how to apply fuzzy logic in automatic control. The tutorial is distance learning, where students interact one-to-one with the teacher using e-mail....
2015-04-29
Luke J. Schaub Chief, GPS Control Segment Division 29 Apr 15 GPS Control Segment Report Documentation Page Form ApprovedOMB No. 0704-0188...00-2015 4. TITLE AND SUBTITLE GPS Control Segment 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT...Center, GPS Control Segment Division,Los Angeles AFB, El Segundo,CA,90245 8. PERFORMING ORGANIZATION REPORT NUMBER 9. SPONSORING/MONITORING AGENCY NAME(S
DEFF Research Database (Denmark)
Dotoli, M.; Jantzen, Jan
1999-01-01
The tutorial concerns automatic control of an inverted pendulum, especially rule based control by means of fuzzy logic. A ball balancer, implemented in a software simulator in Matlab, is used as a practical case study. The objectives of the tutorial are to teach the basics of fuzzy control, and t......, and to show how to apply fuzzy logic in automatic control. The tutorial is distance learning, where students interact one-to-one with the teacher using e-mail....
DSP controlled power converter
Chan, CH; Pong, MH
1995-01-01
A digital controller is designed and implemented by a Digital Signal Processor (DSP) to replace the Pulse Width Modulator (PWM) and error amplifier compensation network in a two wheeler forward converter. The DSP controller is designed in three approaches: a) Discretization of analog controller - the design is based on the transfer function of the error amplifier compensation network. b) Digital PID controller design - the design is based on the general form of the pulse transfer function of ...
DEFF Research Database (Denmark)
Jantzen, Jan
1998-01-01
Design of a fuzzy controller requires more design decisions than usual, for example regarding rule base, inference engine, defuzzification, and data pre- and post processing. This tutorial paper identifies and describes the design choices related to single-loop fuzzy control, based...... on an international standard which is underway. The paper contains also a design approach, which uses a PID controller as a starting point. A design engineer can view the paper as an introduction to fuzzy controller design....
DEFF Research Database (Denmark)
Krause Hansen, Hans; Tang-Jensen, Morten Hove
2015-01-01
Contemporary scholarship on corruption control lacks an analytical focus on anti-corruption in practice. We examine corruption control at the micro-level as exemplified by the use of anti-corruption due diligence in a Danish law firm. Building on concepts from studies of the cultural economy, anti...... control work. By providing also an extended view on the operations of due diligence in the wider corruption control regime the paper problematizes clear-cut distinctions and categories used in established literatures....
Robust Self Tuning Controllers
DEFF Research Database (Denmark)
Poulsen, Niels Kjølstad
1985-01-01
The present thesis concerns robustness properties of adaptive controllers. It is addressed to methods for robustifying self tuning controllers with respect to abrupt changes in the plant parameters. In the thesis an algorithm for estimating abruptly changing parameters is presented. The estimator...... has several operation modes and a detector for controlling the mode. A special self tuning controller has been developed to regulate plant with changing time delay....
Holzrichter, John F
2015-05-05
An implanted stimulation device or air control device are activated by an external radar-like sensor for controlling apnea. The radar-like sensor senses the closure of the air flow cavity, and associated control circuitry signals (1) a stimulator to cause muscles to open the air passage way that is closing or closed or (2) an air control device to open the air passage way that is closing or closed.
Mehrmann, Volker; Xu, Hongguo
2000-11-01
We study classical control problems like pole assignment, stabilization, linear quadratic control and H[infinity] control from a numerical analysis point of view. We present several examples that show the difficulties with classical approaches and suggest reformulations of the problems in a more general framework. We also discuss some new algorithmic approaches.
Optimal magnetic attitude control
DEFF Research Database (Denmark)
Wisniewski, Rafal; Markley, F.L.
1999-01-01
because control torques can only be generated perpendicular to the local geomagnetic field vector. This has been a serious obstacle for using magnetorquer based control for three-axis stabilization of a low earth orbit satellite. The problem of controlling the spacecraft attitude using only magnetic...
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... Surgery? A Week of Healthy Breakfasts Shyness Birth Control Patch KidsHealth > For Teens > Birth Control Patch Print A A A What's in this ... Does It Cost? What Is It? The birth control patch is a thin, beige, 1¾-inch (4½- ...
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Survivability via Control Objectives
Energy Technology Data Exchange (ETDEWEB)
CAMPBELL,PHILIP L.
2000-08-11
Control objectives open an additional front in the survivability battle. A given set of control objectives is valuable if it represents good practices, it is complete (it covers all the necessary areas), and it is auditable. CobiT and BS 7799 are two examples of control objective sets.
Controllability of Quantum Systems
Schirmer, S G; Solomon, A I
2003-01-01
An overview and synthesis of results and criteria for open-loop controllability of Hamiltonian quantum systems obtained using Lie group and Lie algebra techniques is presented. Negative results for open-loop controllability of dissipative systems are discussed, and the superiority of closed-loop (feedback) control for quantum systems is established.
Contraception and Birth Control
... to the NICHD Staff Directory Skip sharing on social media links Rollup Image Home > Health & Research > A-Z Topics > Contraception and Birth Control > About Page Content About Contraception and Birth Control Contraception is the prevention of pregnancy. Contraception, or birth control, also allows couples to ...
Switching Between Multivariable Controllers
DEFF Research Database (Denmark)
Niemann, H.; Stoustrup, Jakob; Abrahamsen, R.B.
2004-01-01
A concept for implementation of multivariable controllers is presented in this paper. The concept is based on the Youla-Jabr-Bongiorno-Kucera (YJBK) parameterization of all stabilizing controllers. By using this architecture for implementation of multivariable controllers, it is shown how...
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Distributed Power Flow Controller
Yuan, Z.
2010-01-01
In modern power systems, there is a great demand to control the power flow actively. Power flow controlling devices (PFCDs) are required for such purpose, because the power flow over the lines is the nature result of the impedance of each line. Due to the control capabilities of different types of P
Energy Technology Data Exchange (ETDEWEB)
Koponen, P. [VTT Energy, Espoo (Finland)
1998-08-01
Electricity cannot be stored in large quantities. That is why the electricity supply and consumption are always almost equal in large power supply systems. If this balance were disturbed beyond stability, the system or a part of it would collapse until a new stable equilibrium is reached. The balance between supply and consumption is mainly maintained by controlling the power production, but also the electricity consumption or, in other words, the load is controlled. Controlling the load of the power supply system is important, if easily controllable power production capacity is limited. Temporary shortage of capacity causes high peaks in the energy price in the electricity market. Load control either reduces the electricity consumption during peak consumption and peak price or moves electricity consumption to some other time. The project Optimisation of Load Control is a part of the EDISON research program for distribution automation. The following areas were studied: Optimization of space heating and ventilation, when electricity price is time variable, load control model in power purchase optimization, optimization of direct load control sequences, interaction between load control optimization and power purchase optimization, literature on load control, optimization methods and field tests and response models of direct load control and the effects of the electricity market deregulation on load control. An overview of the main results is given in this chapter
Ilarraza-Lomelí, A C; Salas-Brito, A L; Ilarraza-Lomelí, Aquiles
1999-01-01
We apply the Ott, Grebogy and Yorke mechanism for the control of chaos to the analytical oscillator model of a leaky tap obtaining good results. We exhibit the robustness of the control against both dynamical noise and measurement noise.A possible way of controlling experimentally a leaky tap using magnetic-field-produced variations in the viscosity of a magnetorheological fluid is suggested.
Bergstra, Jan A
2010-01-01
General definitions as well as rules of reasoning regarding control code production, distribution, deployment, and usage are described. The role of testing, trust, confidence and risk analysis is considered. A rationale for control code testing is sought and found for the case of safety critical embedded control code.
DEFF Research Database (Denmark)
Knudsen, Torben; Bak, Thomas; Svenstrup, Mikael
2013-01-01
for the research part than for the practice part. It is however not the intention to do company interviews or similar. This report is structured into a section for each WF control objective. These sections then includes the important control project issues: choice of input and output, control method, and modelling...
Distributed Power Flow Controller
Yuan, Z.
2010-01-01
In modern power systems, there is a great demand to control the power flow actively. Power flow controlling devices (PFCDs) are required for such purpose, because the power flow over the lines is the nature result of the impedance of each line. Due to the control capabilities of different types of P
Switching Between Multivariable Controllers
DEFF Research Database (Denmark)
Niemann, Hans Henrik; Stoustrup, Jakob; Abrahamsen, Rune
2004-01-01
it is possible to smoothly switch between multivariable controllers with guaranteed closed-loop stability. This includes also the case where one or more controllers are unstable. The concept for smooth online changes of multivariable controllers based on the YJBK architecture can also handle the start up...
... Loss Surgery? A Week of Healthy Breakfasts Shyness Birth Control Patch KidsHealth > For Teens > Birth Control Patch A A A What's in this article? ... Much Does It Cost? What Is It? The birth control patch is a thin, beige, 1¾-inch (4½- ...
... Loss Surgery? A Week of Healthy Breakfasts Shyness Birth Control Pill KidsHealth > For Teens > Birth Control Pill A A A What's in this article? ... español La píldora anticonceptiva What Is It? The birth control pill (also called "the Pill") is a daily ...
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... Loss Surgery? A Week of Healthy Breakfasts Shyness Birth Control Shot KidsHealth > For Teens > Birth Control Shot A A A What's in this article? ... español La inyección anticonceptiva What Is It? The birth control shot is a long-acting form of progesterone, ...
Power oscillation damping controller
DEFF Research Database (Denmark)
2012-01-01
A power oscillation damping controller is provided for a power generation device such as a wind turbine device. The power oscillation damping controller receives an oscillation indicating signal indicative of a power oscillation in an electricity network and provides an oscillation damping control...
Intelligent Distributed Control
2012-08-10
Transactions on Automatic Control , 2012. in preparation. [19] C. Yu, B. D. O. Anderson, and A. S. Morse. Gossiping periodically. IEEE Transactions on Automatic Control , 2011...Adaptive Control and Signal Processing, 2011. submitted. [18] J. Liu and A. S. Morse. Distributed averaging via double linear iterations. IEEE
Rafaely, Boaz
This thesis is concerned with the development an application of feedback control techniques for active sound control. Both fixed and adaptive controllers are considered. The controller design problem for active sound control is formulated as a constrained optimisation problem with an H2 performance objective, of minimising the variance of the control error, and H2 and H∞ design constraints involving control power output, disturbance enhancement, and robust stability. An Internal Model Controller with an FIR control filter is assumed. Conventional H2 design methods for feedback controllers are studied first. Although such controllers can satisfy the design constraints by employing effort terms in the quadratic cost function, they do not achieve the best possible performance, and when adapted using LMS-based algorithms, they suffer from instabilities if the plant response varies significantly. Improved H2/H∞ design methods for fixed and adaptive controllers are then developed, which achieve the best H2 performance under the design constraints, offer an improved stability when made adaptive, and in general outperform the conventional H2 controllers. The H2/H∞ design problems employ convex programming to ensure a unique solution. The Sequential Quadratic Programming methods is used for the off-line design of fixed controllers, and penalty and barrier function methods, together with frequency domain LMS-based algorithms are employed in the H2/H∞ adaptive controllers. The controllers studied and developed here were applied to three active sound control systems: a noise-reducing headset, an active headrest, and a sound radiating panel. The emphasis was put on developing control strategies that improve system performance. First, a high performance controller for the noise-reducing headset was implemented in real-time, which combines analogue and adaptive digital controllers, and can thus reject disturbances which has both broad-band and periodic components. Then
Control of wastewater using multivariate control chart
Nugraha, Jaka; Fatimah, Is; Prabowo, Rino Galang
2017-03-01
Wastewater treatment is a crucial process in industry cause untreated or improper treatment of wastewater may leads some problems affecting to the other parts of environmental aspects. For many kinds of wastewater treatments, the parameters of Biological Oxygen Demand (BOD), Chemical Oxygen Demand (COD), and the Total Suspend Solid (TSS) are usual parameters to be controlled as a standard. In this paper, the application of multivariate Hotteling T2 Individual was reported to control wastewater treatment. By using wastewater treatment data from PT. ICBP, east Java branch, while the fulfillment of quality standards are based on East Java Governor Regulation No. 72 Year 2013 on Standards of Quality of Waste Water Industry and / or Other Business Activities. The obtained results are COD and TSS has a correlation with BOD values with the correlation coefficient higher than 50%, and it is is also found that influence of the COD and TSS to BOD values are 82% and 1.9% respectively. Based on Multivariate control chart Individual T2 Hotteling, it is found that BOD-COD and BOD-TSS are each one subgroup that are outside the control limits. Thus, it can be said there is a process that is not multivariate controlled, but univariately the variables of BOD, COD and TSS are within specification (standard quality) that has been determined.
Approximate controllability of distributed systems by distributed controllers
Directory of Open Access Journals (Sweden)
Benzion Shklyar
2005-04-01
Full Text Available Approximate controllability problem for a linear distributed control system with possibly unbounded input operator, connected in a series to another distributed system without control is investigated. An initial state of the second distributed system is considered as a control parameter. Applications to control partial equations governed by hyperbolic controller, and to control delay systems governed by hereditary controller are considered.
Fault Tolerant Feedback Control
DEFF Research Database (Denmark)
Stoustrup, Jakob; Niemann, H.
2001-01-01
An architecture for fault tolerant feedback controllers based on the Youla parameterization is suggested. It is shown that the Youla parameterization will give a residual vector directly in connection with the fault diagnosis part of the fault tolerant feedback controller. It turns out...... that there is a separation be-tween the feedback controller and the fault tolerant part. The closed loop feedback properties are handled by the nominal feedback controller and the fault tolerant part is handled by the design of the Youla parameter. The design of the fault tolerant part will not affect the design...... of the nominal feedback con-troller....
[Controlling instruments in radiology].
Maurer, M
2013-10-01
Due to the rising costs and competitive pressures radiological clinics and practices are now facing, controlling instruments are gaining importance in the optimization of structures and processes of the various diagnostic examinations and interventional procedures. It will be shown how the use of selected controlling instruments can secure and improve the performance of radiological facilities. A definition of the concept of controlling will be provided. It will be shown which controlling instruments can be applied in radiological departments and practices. As an example, two of the controlling instruments, material cost analysis and benchmarking, will be illustrated.
Induction motor control design
Marino, Riccardo; Verrelli, Cristiano M
2010-01-01
""Nonlinear and Adaptive Control Design for Induction Motors"" is a unified exposition of the most important steps and concerns in the design of estimation and control algorithms for induction motors. A single notation and modern nonlinear control terminology is used to make the book accessible to readers who are not experts in electric motors at the same time as giving a more theoretical control viewpoint to those who are. In order to increase readability, the book concentrates on the induction motor, eschewing the much more complex and less-well-understood control of asynchronous motors. The
Control and optimization system
Xinsheng, Lou
2013-02-12
A system for optimizing a power plant includes a chemical loop having an input for receiving an input parameter (270) and an output for outputting an output parameter (280), a control system operably connected to the chemical loop and having a multiple controller part (230) comprising a model-free controller. The control system receives the output parameter (280), optimizes the input parameter (270) based on the received output parameter (280), and outputs an optimized input parameter (270) to the input of the chemical loop to control a process of the chemical loop in an optimized manner.
Varma, Subir
2015-01-01
Internet Congestion Control provides a description of some of the most important topics in the area of congestion control in computer networks, with special emphasis on the analytical modeling of congestion control algorithms. The field of congestion control has seen many notable advances in recent years and the purpose of this book, which is targeted towards the advanced and intermediate reader, is to inform about the most important developments in this area. The book should enable the reader to gain a good understanding of the application of congestion control theory to a number of applic
Directory of Open Access Journals (Sweden)
Mentor Gashi
2015-11-01
Full Text Available Customs control, is regulated by law in different countries. Different countries define through the law, the control of goods.. Main purpose of this paper is to analyze two types of customs controls, and their effect in reducing avoidance of duty or tax evasion which may be caused by the import of goods of certain companies. For this reason we researched which model is implemented in developing countries and what results were reached through questionnaires. In this sense the next research question, consists in defining the moment of customs control pre or post-clearance control of goods.
Controlling the intelligent building
Energy Technology Data Exchange (ETDEWEB)
LeBlanc, R.J.
1985-08-01
Companies will be able to locate in intelligent buildings that offer access to a variety of sophisticated communications equipment, at the heart of which are building controls that ensure a comfortable and safe working environment for the occupants. Future buildings will include advanced telephones or workstations with built-in building control sensors for temperature, light level, and security. Advanced telecommunication systems may have telephone cabinets with built-in control functions which eliminate the need for discrete control systems. The owners and tenants will both enjoy benefits if the controls are carefully selected and designed so that they integrate into a single building package.
Integration of Fire Control, Flight Control and Propulsion Control Systems.
1983-08-01
system, the answer was by a comprehensive programme of simulation and rig testing. ix In the only paper in the programme deailing with systems for civil ...be used otherwise. At one time there was an explosive growth in the application of automatic flight control to civil transport aircraft, culminating in...nombre at l’ampleur des 6quipesenta de maintenance extgrieurs a lavion, 11 faut s’efforcer I ce qua 1. mayan privil~gif pareattant lea 6changss
Modeling and control of thermostatically controlled loads
Energy Technology Data Exchange (ETDEWEB)
Backhaus, Scott N [Los Alamos National Laboratory; Sinitsyn, Nikolai [Los Alamos National Laboratory; Kundu, S. [UNIV OF MICHIGAN; Hiskens, I. [UNIV OF MICHIGAN
2011-01-04
As the penetration of intermittent energy sources grows substantially, loads will be required to play an increasingly important role in compensating the fast time-scale fluctuations in generated power. Recent numerical modeling of thermostatically controlled loads (TCLs) has demonstrated that such load following is feasible, but analytical models that satisfactorily quantify the aggregate power consumption of a group of TCLs are desired to enable controller design. We develop such a model for the aggregate power response of a homogeneous population of TCLs to uniform variation of all TCL setpoints. A linearized model of the response is derived, and a linear quadratic regulator (LQR) has been designed. Using the TCL setpoint as the control input, the LQR enables aggregate power to track reference signals that exhibit step, ramp and sinusoidal variations. Although much of the work assumes a homogeneous population of TCLs with deterministic dynamics, we also propose a method for probing the dynamics of systems where load characteristics are not well known.
Directory of Open Access Journals (Sweden)
Salas-Auvert, Jesús A.
2008-09-01
Full Text Available En resumen, a pesar de que en algunas circunstancias, la exagerada percepción o necesidad de control es contraproducente para la adaptación y crecimiento psicológico, la aceptación general es que, al menos en grado moderado, el control percibido y control real son beneficios para las personas y un recurso valioso para enfrentar las dificultades en la vida. Por ello, las personas, grupos y naciones buscan sentirse dueñas de sus destinos y no víctimas de las circunstancias. Las personas y los pueblos con control son las que moldean y transforman las circunstacias, los que construyen un futuro mejor. Por ello, con objetivos preventivos y remediativos, los profesionales de la salud mental debemos promover el desarrollo y optimizacion de un control moderado y flexible como nutriente del crecimiento psicológico y bienestar biopsicosocial individual y colectivo. El trabajo aborda el significado del control, el desarrollo del control real y percibido, la relación entre control, salud y enfermedad, control, bienestar y psicopatología, la renuncia a los intentos de control, y control y terapia cognitivo-conductual.
Sabanovic, Asif
2011-01-01
"Presents a unified approach to the fundamental issues in motion control, starting from the basics and moving through single degree of freedom and multi-degree of freedom systems In Motion Control Systems, Šabanovic and Ohnishi present a unified approach to very diverse issues covered in motion control systems, offering know-how accumulated through work on very diverse problems into a comprehensive, integrated approach suitable for application in high demanding high-tech products. It covers material from single degree of freedom systems to complex multi-body non-redundant and redundant systems. The discussion of the main subject is based on original research results and will give treatment of the issues in motion control in the framework of the acceleration control method with disturbance rejection technique. This allows consistent unification of different issues in motion control ranging from simple trajectory tracking to topics related to haptics and bilateral control without and with delay in the measure...
Directory of Open Access Journals (Sweden)
Bieńkowska Agnieszka
2016-12-01
Full Text Available The purpose of this study is to discuss the trust within and towards an organisation in the context of implementation of controlling therein. In this context the essence of trust and its importance in organisation management was presented, as well as trust in the contemporary management methods and concepts. Controlling as a trust-building factor inside an organisation was pointed out. Especially controlling and control were described. Moreover management by considering deviations in controlling and the teamwork in controlling were described. The role of controlling in process of trust-building to an organisation was presented. Establishing relations with the environment and systems of measurement of organisation’s achievements were presented, too.
Energy Technology Data Exchange (ETDEWEB)
Kazmierkowski, M.P. [Institute of Control and Industrial Electronics, Warsaw University of Technology, Warszawa (Poland)
1997-12-31
In this paper a review of control methods for high performance PWM inverter-fed induction motor drives is presented. Starting from the description of an induction motor by the help of the space vectors, three basic control strategic are discussed. As first, the most popular Field Oriented Control (FOC) is described. Secondly, the Direct Torque and Flux vector Control (DTFC) method, which - in contrast to FOC - depart from idea of coordinate transformation and analogy with DC motor, is briefly characterized. The last group is based on Feedback Linearization Control (FLC) and can be easy combined with sliding mode control. The simulation and experimental oscillograms that illustrate the performance of the discussed control strategies are shown. (orig.) 35 refs.
Energy Technology Data Exchange (ETDEWEB)
Bick, Christian [Network Dynamics, Max Planck Institute for Dynamics and Self-Organization (MPIDS), 37077 Göttingen (Germany); Bernstein Center for Computational Neuroscience (BCCN), 37077 Göttingen (Germany); Institute for Mathematics, Georg–August–Universität Göttingen, 37073 Göttingen (Germany); Kolodziejski, Christoph [Network Dynamics, Max Planck Institute for Dynamics and Self-Organization (MPIDS), 37077 Göttingen (Germany); III. Physical Institute—Biophysics, Georg–August–Universität Göttingen, 37077 Göttingen (Germany); Timme, Marc [Network Dynamics, Max Planck Institute for Dynamics and Self-Organization (MPIDS), 37077 Göttingen (Germany); Institute for Nonlinear Dynamics, Georg–August–Universität Göttingen, 37077 Göttingen (Germany)
2014-09-01
Predictive feedback control is an easy-to-implement method to stabilize unknown unstable periodic orbits in chaotic dynamical systems. Predictive feedback control is severely limited because asymptotic convergence speed decreases with stronger instabilities which in turn are typical for larger target periods, rendering it harder to effectively stabilize periodic orbits of large period. Here, we study stalled chaos control, where the application of control is stalled to make use of the chaotic, uncontrolled dynamics, and introduce an adaptation paradigm to overcome this limitation and speed up convergence. This modified control scheme is not only capable of stabilizing more periodic orbits than the original predictive feedback control but also speeds up convergence for typical chaotic maps, as illustrated in both theory and application. The proposed adaptation scheme provides a way to tune parameters online, yielding a broadly applicable, fast chaos control that converges reliably, even for periodic orbits of large period.
The Parrot UAV Controlled by PID Controllers
Directory of Open Access Journals (Sweden)
Koszewnik Andrzej
2014-08-01
Full Text Available The paper presents the process of modeling and designing control laws for four-rotor type of the Parrot UAV. The state space model is obtained by using several phenomena like gyroscopic effects for rigid bodies, propellers and rotors. The obtained model has been used to design PID control laws for roll, pitch, yaw angle and altitude, respectively. The numerical simulations of the closed loop model are shown that system in satisfy way stabilize flight of the quadro-rotor in all considered directions.
New robust stable MPC using linear matrix inequalities
Directory of Open Access Journals (Sweden)
M.A. Rodrigues
2000-03-01
Full Text Available This paper addresses the stability of Model Predictive Control (MPC with output feedback. The proposed controller uses a new state-space formulation of the system, and the control problem is presented as an LMI optimization problem. The stability condition for the closed loop is included as a Lyapunov inequality. The resulting optimization problem becomes nonlinear with the inclusion of the stabilizing condition. A suboptimal solution is developed and the problem reduces to a pair of coupled LMI problems. An iterative solution that converges to a stable output feedback gain is proposed. A polytopic set of process models can be considered. A simulation example is included in the paper and shows that the proposed strategy eliminates the usual practice of enforcing robustness by detuning the MP controller.
Robust Control Design for Flight Control
1989-07-01
to achieve desired performance over the full flight envelope when linear feedback is employed. Exact linearization methods [48] provide means for...designing nonlinear feedback laws which satisfy these requirements. However, exact linearization is not always compatible with control authority...specific situations. The most promising approaches appear to be those associated with methods of exact linearization . This procedure is based on some
Price control and macromarketing
Directory of Open Access Journals (Sweden)
Kancir Rade
2003-01-01
Full Text Available Price control at macro level is part of integral macro marketing strategic control system, or more precisely, part of social marketing mix control. Price impact is direct, if it is regarded in the context of needs satisfaction, and indirect, within the context of resource allocation. These two patterns of price impact define control mechanism structuring. Price control in sense of its direct impact at process of need satisfaction should comprise qualitative and quantitative level of needs satisfaction at a given price level and its structure, informational dimension of price and different disputable forms of corporate pricing policies. Control of price allocation function is based at objectives of macro marketing system management in the area of resource allocation and the role of price as allocator in contemporary market economies. Control process is founded, on one hand, at theoretical models of correlation between price and demand in different market structures, and on the other hand, at complex limits that price as allocator has, and which make whole control process even more complex because of reduction of the degree of determinism in functioning of contemporary economic systems. Control of price allocation function must be continuous and dynamic process if it is to provide for convergence with environmental changes and if it is to provide for placing control systems at micro marketing levels in the function of socially valid objectives.
MULTIPLE OSCILLATION STABILIZING CONTROL.
Energy Technology Data Exchange (ETDEWEB)
YUE,M.; SCHLUETER,R.; AZARM,M.; BARI,R.
2004-07-23
This paper presents a strategy that may be used to guide stabilizing control design for multiple oscillations, which are difficult to control using conventional control design procedures. A multiple oscillation phenomena is observed in an example power system. A local bifurcation and an interarea bifurcation develop in an example power system due to multiple bifurcation parameter variations. The dynamic behaviors of the bifurcating system are complex due to the overlapping of the two different bifurcation subsystems and are shown to be difficult to control. The double bifurcations are studied in this paper and in order to stabilize them, three kind of {mu}-synthesis robust controls are designed, (a) {mu}-synthesis power system stabilizer (MPSS); (b) {mu}-synthesis SVC control (MSVC); and (c) a mixed MPSS/MSVC control. Based on the bifurcation subsystem analysis, the measurement signals and locations of the controls are selected. The control performances of three kind of controls are evaluated and compared. The conclusions are given according to the analysis and time simulation results.
DEFF Research Database (Denmark)
Achtziger, Anja; Hubert, Marco; Kenning, Peter
2015-01-01
In a representative sample of the German population (n = 946), we explored the links between self-control, compulsive buying, and debts. Participants completed the self-control scale (Tangney, Boone, & Baumeister, 2004) and the German Addictive Buying Scale (Raab, Neuner, Reisch, & Scherhorn, 2005......). Additionally, they gave information about their real debts. It was observed that self-control was negatively related to debts while compulsive buying was positively related to debts. Detailed analyses revealed that the link between self-control and debts was fully mediated by compulsive buying. Finally......, there was a gender effect on compulsive buying: women were more prone to compulsive buying than men. Age also was significantly negatively related to compulsive buying and positively linked to self-control. Household income was not linked to self-control, compulsive buying, and debts. Implications for practice...
Control in Complex Organizations
DEFF Research Database (Denmark)
Rennstam, Jens; Kärreman, Dan
The extant research on organizational control builds on the assumption of vertical control – managers are thought to develop orders, rules and norms to control the operating core. Yet it is claimed that work becomes increasingly “knowledge intensive” and that organizations rely heavily...... for their productivity on the knowledge and creativity of their work force. In this type of “knowledge work,” the strong focus on vertical control is insufficient as it fails to account for the important operative and horizontal interactions upon which many contemporary organizations depend. Drawing on practice theory...... and an ethnographic study of engineering work, this paper theorizes control as a form of work that does not only belong to formal management, but is dispersed among various work activities, including horizontal ones. The article introduces the idea of control work as a key practice in contemporary organizations...
Lewis, Andrew D
2014-01-01
This brief presents a description of a new modelling framework for nonlinear/geometric control theory. The framework is intended to be—and shown to be—feedback-invariant. As such, Tautological Control Systems provides a platform for understanding fundamental structural problems in geometric control theory. Part of the novelty of the text stems from the variety of regularity classes, e.g., Lipschitz, finitely differentiable, smooth, real analytic, with which it deals in a comprehensive and unified manner. The treatment of the important real analytic class especially reflects recent work on real analytic topologies by the author. Applied mathematicians interested in nonlinear and geometric control theory will find this brief of interest as a starting point for work in which feedback invariance is important. Graduate students working in control theory may also find Tautological Control Systems to be a stimulating starting point for their research.
Applied Control Systems Design
Mahmoud, Magdi S
2012-01-01
Applied Control System Design examines several methods for building up systems models based on real experimental data from typical industrial processes and incorporating system identification techniques. The text takes a comparative approach to the models derived in this way judging their suitability for use in different systems and under different operational circumstances. A broad spectrum of control methods including various forms of filtering, feedback and feedforward control is applied to the models and the guidelines derived from the closed-loop responses are then composed into a concrete self-tested recipe to serve as a check-list for industrial engineers or control designers. System identification and control design are given equal weight in model derivation and testing to reflect their equality of importance in the proper design and optimization of high-performance control systems. Readers’ assimilation of the material discussed is assisted by the provision of problems and examples. Most of these e...
Spacecraft momentum control systems
Leve, Frederick A; Peck, Mason A
2015-01-01
The goal of this book is to serve both as a practical technical reference and a resource for gaining a fuller understanding of the state of the art of spacecraft momentum control systems, specifically looking at control moment gyroscopes (CMGs). As a result, the subject matter includes theory, technology, and systems engineering. The authors combine material on system-level architecture of spacecraft that feature momentum-control systems with material about the momentum-control hardware and software. This also encompasses material on the theoretical and algorithmic approaches to the control of space vehicles with CMGs. In essence, CMGs are the attitude-control actuators that make contemporary highly agile spacecraft possible. The rise of commercial Earth imaging, the advances in privately built spacecraft (including small satellites), and the growing popularity of the subject matter in academic circles over the past decade argues that now is the time for an in-depth treatment of the topic. CMGs are augmented ...
Lee, Taeyoung; McClamroch, N Harris
2007-01-01
Discrete control systems, as considered here, refer to the control theory of discrete-time Lagrangian or Hamiltonian systems. These discrete-time models are based on a discrete variational principle, and are part of the broader field of geometric integration. Geometric integrators are numerical integration methods that preserve geometric properties of continuous systems, such as conservation of the symplectic form, momentum, and energy. They also guarantee that the discrete flow remains on the manifold on which the continuous system evolves, an important property in the case of rigid-body dynamics. In nonlinear control, one typically relies on differential geometric and dynamical systems techniques to prove properties such as stability, controllability, and optimality. More generally, the geometric structure of such systems plays a critical role in the nonlinear analysis of the corresponding control problems. Despite the critical role of geometry and mechanics in the analysis of nonlinear control systems, non...
DEFF Research Database (Denmark)
Jagd, Søren
2010-01-01
The purpose of this paper is to show that conceptualizing trust and control as interactively related processes, as opposed to more static conceptualizations of the two concepts and the relations between them, adds importantly towards understanding the challenges involved in balancing of trust...... and control in organizations. The paper examines recent literature on the conceptualization of the relation between trust and control in and between organizations. The literature review shows that trust and control has been conceptualized as either substituting or complementing each other. Further......, it is found that the complementary/substitution debate calls for an explicit conceptualization of the relation between trust and control as an interactive process, in contrast to earlier conceptualizations of trust and control as two relatively static and isolated concepts. While the static perspective...
[Controlling in clinical management].
Bähr, K; Ellinger, K
1999-02-01
Managers of industrial enterprises strive continually to improve the efficiency of production, distribution and service for their customers in order to be able to compete on the market. In socially orientated non-profit-organisations this is not universe practice. Relating to section 17 Abs. 1 KHG and section 13 BPfIV of German social legislation hospital charges are refunded only, if the hospital is working efficiently and economically. Controlling is a tool to achieve these goals. Controlling coordinates the flow of information for planning and evaluation. Strategic and operative controlling are closely interrelated: Strategic controlling is directed towards new and promising activities, operative controlling supports decision--making--including future-oriented aspects-by providing and condensing information. Controlling is definitely not intended to dictate or "command" any action. Its object is to serve as an instrument or tool supporting result-oriented planning, regulating and evaluation.
Chorafas, Dimitris N
2013-01-01
Quality control is a constant priority in electrical, mechanical, aeronautical, and nuclear engineering – as well as in the vast domain of electronics, from home appliances to computers and telecommunications. Quality Control Applications provides guidance and valuable insight into quality control policies; their methods, their implementation, constant observation and associated technical audits. What has previously been a mostly mathematical topic is translated here for engineers concerned with the practical implementation of quality control. Once the fundamentals of quality control are established, Quality Control Applications goes on to develop this knowledge and explain how to apply it in the most effective way. Techniques are described and supported using relevant, real-life, case studies to provide detail and clarity for those without a mathematical background. Among the many practical examples, two case studies dramatize the importance of quality assurance: A shot-by-shot analysis of the errors made ...
Institute of Scientific and Technical Information of China (English)
Duan Li; Fucai Qian; Peilin Fu
2005-01-01
This paper summarizes recent progress by the authors in developing two solution frameworks for dual control. The first solution framework considers a class of dual control problems where there exists a parameter uncertainty in the observation equation of the LQG problem. An analytical active dual control law is derived by a variance minimization approach. The issue of how to determine an optimal degree of active learning is then addressed, thus achieving an optimality for this class of dual control problems. The second solution framework considers a general class of discrete-time LQG problems with unknown parameters in both state and observation equations. The best possible (partial) closed-loop feedback control law is derived by exploring the future nominal posterior probabilities, thus taking into account the effect of future learning when constructing the optimal nominal dual control.
DEFF Research Database (Denmark)
Achtziger, Anja; Hubert, Marco; Kenning, Peter
2015-01-01
In a representative sample of the German population (n = 946), we explored the links between self-control, compulsive buying, and debts. Participants completed the self-control scale (Tangney, Boone, & Baumeister, 2004) and the German Addictive Buying Scale (Raab, Neuner, Reisch, & Scherhorn, 2005......). Additionally, they gave information about their real debts. It was observed that self-control was negatively related to debts while compulsive buying was positively related to debts. Detailed analyses revealed that the link between self-control and debts was fully mediated by compulsive buying. Finally......, there was a gender effect on compulsive buying: women were more prone to compulsive buying than men. Age also was significantly negatively related to compulsive buying and positively linked to self-control. Household income was not linked to self-control, compulsive buying, and debts. Implications for practice...
Baños, Alfonso
2012-01-01
Reset Control Systems addresses the analysis for reset control treating both its basic form which requires only that the state of the controller be reinitialized to zero (the reset action) each time the tracking error crosses zero (the reset condition), and some useful variations of the reset action (partial reset with fixed or variable reset percentage) and of the reset condition (fixed or variable reset band and anticipative reset). The issues regarding reset control – concepts and motivation; analysis tools; and the application of design methodologies to real-world examples – are given comprehensive coverage. The text opens with an historical perspective which moves from the seminal work of the Clegg integrator and Horowitz FORE to more recent approaches based on impulsive/hybrid control systems and explains the motivation for reset compensation. Preliminary material dealing with notation, basic definitions and results, and with the definition of the control problem under study is also included. The fo...
Microprocessor controlled static converter
Directory of Open Access Journals (Sweden)
Stefan Szabo
2005-10-01
Full Text Available This paper wants to demonstrate a way of implementing a microcontroller into an DC motor speed control loop. The static power converter is a fully controlled rectifier bridge, using standard SCR's. The bridge's control signals are supplied by the microcontroller and are phase-angle or burst types. The automation loop contains a software PI-style regulator. All the experimental results shows that this aproach is flexibile enough to be used on a large scale.
Tagging vs. Controlled Vocabulary
DEFF Research Database (Denmark)
Bogers, Toine; Petras, Vivien
2015-01-01
elements like core bibliographic data, controlled vocabulary terms, reviews, and tags to the retrieval performance. Our comparison is done using a test collection of over 2 million book records with information elements from Amazon, the British Library, the Library of Congress, and LibraryThing. We find...... that tags and controlled vocabulary terms do not actually outperform each other consistently, but seem to provide complementary contributions: some information needs are best addressed using controlled vocabulary terms whereas other are best addressed using tags....
Temperature measurement and control
Leigh, JR
1988-01-01
This book treats the theory and practice of temperature measurement and control and important related topics such as energy management and air pollution. There are no specific prerequisites for the book although a knowledge of elementary control theory could be useful. The first half of the book is an application oriented survey of temperature measurement techniques and devices. The second half is concerned mainly with temperature control in both simple and complex situations.
1979-12-01
with Uncertain Components 44 13 Component Uncertainty Representation of Uncertain Pole-Zero Locations 46 12 A Feedback Control System 60 i 1 I vii €in...OF FEEDBACK SYSTEM ROBUSTNESS A feedback control system design is said to be robust if it is able to meet design specifications despite differences... feedback control system design problems, the design specifications usually demand that the system be "robust" against the effects of deviations within
Key to Network Controllability
Banerjee, Soumya Jyoti; Roy, Soumen
2012-01-01
Liu et al recently proposed a minimum number of driver nodes needed to obtain full structural controllability over a directed network. Driver nodes are unmatched nodes, from which there are directed paths to all matched nodes. Their most important assertion is that a system's controllability is to a great extent encoded by the underlying network's degree distribution, $P(k_{in}, k_{out})$. Is the controllability of a network decided almost completely by the immediate neighbourhood of a node, ...
Fliess, Michel; Join, Cédric
2008-01-01
International audience; Intelligent PID controllers, or i-PID controllers, are PID controllers where the unknown parts of the plant, which might be highly nonlinear and/or time-varying, are taken into account without any modeling procedure. Our main tool is an online numerical differentiator, which is based on easily implementable fast estimation and identification techniques. Several numerical experiments demonstrate the efficiency of our method when compared to more classic PID regulators.