Journal of Control Science and Engineering The latest articles from Hindawi Publishing Corporation © 2016 , Hindawi Publishing Corporation . All rights reserved. Optimal Inversion Feedforward and Robust Feedback Based 2DOF Control Approach for High Speed-Precision Positioning Systems Wed, 27 Jan 2016 10:10:13 +0000 This paper proposed a novel optimal inversion feedforward and robust feedback based two-freedom-of-freedom (2DOF) control approach to address the positioning error caused by system uncertainties in high speed-precision positioning system. To minimize the norm of the positioning error in the presence of model uncertainty, a linear matrix inequality (LMI) synthesis approach for optimal inversion feedforward controller design is presented. The specification of position resolution, control width, robustness, and output signal magnitude imposed on the entire 2DOF control system are taken as optimization objectives of feedback controller design. The robust feedback controller design approach integrates with feedforward controller systematically and is obtained via LMI optimization. The proposed approach was illustrated through a simulation example of nanopositioning control in atomic force microscope (AFM); the experiment results demonstrated that the proposed 2DOF control approach not only achieves the performance specification but also could improve the positioning control performance compared with mixed sensitivity feedback control and inversion-based 2DOF control. Chao Peng, Chongwei Han, Jianxiao Zou, and Guanghui Zhang Copyright © 2016 Chao Peng et al. All rights reserved. Quadcopter Aggressive Maneuvers along Singular Configurations: An Energy-Quaternion Based Approach Mon, 18 Jan 2016 06:49:29 +0000 Automatic aggressive maneuvers with quadcopters are regarded as a highly challenging control problem. The aim is to tackle the singularities that exist in a vertical looping maneuver. Modeling singularities are resolved by writing the equations-of-motion of the quadcopter in quaternion form. Physical singularities due to underactuation are resolved by using an energy-based control. Energy-based control is utilized to overcome the uncontrollability of the quadcopter at physical singular configurations, for instance, when commanding the quadcopter to gain altitude while pitched at . Three looping strategies (circular, clothoidal, and newly developed constant thrust) are implemented on a nonlinear model of the quadcopter. The three looping strategies are discussed along with their advantages and limitations. Ayman A. El-Badawy and Mohamed A. Bakr Copyright © 2016 Ayman A. El-Badawy and Mohamed A. Bakr. All rights reserved. A Robust Control Method for Synchronization between Different Dimensional Integer-Order and Fractional-Order Chaotic Systems Wed, 30 Dec 2015 11:30:57 +0000 A robust control approach is presented to study the problem of Q-S synchronization between Integer-order and fractional-order chaotic systems with different dimensions. Based on Laplace transformation and stability theory of linear integer-order dynamical systems, a new control law is proposed to guarantee the Q-S synchronization between -dimensional integer-order master system and -dimensional fractional-order slave system. This paper provides further contribution to the topic of Q-S chaos synchronization between integer-order and fractional-order systems and introduces a general control scheme that can be applied to wide classes of chaotic and hyperchaotic systems. Illustrative example and numerical simulations are used to show the effectiveness of the proposed method. Adel Ouannas and Raghib Abu-Saris Copyright © 2015 Adel Ouannas and Raghib Abu-Saris. All rights reserved. The Stabilization of Continuous-Time Networked Control Systems with Data Drift Tue, 29 Dec 2015 11:44:15 +0000 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. Qixin Zhu, Kaihong Lu, and Yonghong Zhu Copyright © 2015 Qixin Zhu et al. All rights reserved. Anticollocated Backstepping Observer Design for a Class of Coupled Reaction-Diffusion PDEs Tue, 22 Dec 2015 13:20:20 +0000 The state observation problem is tackled for a system of coupled reaction-diffusion PDEs, possessing the same diffusivity parameter and equipped with boundary sensing devices. Particularly, a backstepping-based observer is designed and the exponential stability of the error system is proven with an arbitrarily fast convergence rate. The transformation kernel matrix is derived in the explicit form by using the method of successive approximations, thereby yielding the observer gains in the explicit form, too. Simulation results support the effectiveness of the suggested design. Antonello Baccoli and Alessandro Pisano Copyright © 2015 Antonello Baccoli and Alessandro Pisano. All rights reserved. Synthesis of Decentralized Variable Gain Robust Controllers with Guaranteed Gain Performance for a Class of Uncertain Large-Scale Interconnected Systems Sun, 20 Dec 2015 11:18:47 +0000 We consider a design problem of a decentralized variable gain robust controller with guaranteed gain performance for a class of uncertain large-scale interconnected systems. For the uncertain large-scale interconnected system, the uncertainties and the interactions satisfy the matching condition. In this paper, we show that sufficient conditions for the existence of the proposed decentralized variable gain robust controller with guaranteed gain performance are given in terms of linear matrix inequalities (LMIs). Finally, simple illustrative examples are shown. Shunya Nagai and Hidetoshi Oya Copyright © 2015 Shunya Nagai and Hidetoshi Oya. All rights reserved. Robust Fault Diagnosis Algorithm for a Class of Nonlinear Systems Sun, 29 Nov 2015 12:05:53 +0000 A kind of robust fault diagnosis algorithm to Lipschitz nonlinear system is proposed. The novel disturbances constraint condition of the nonlinear system is derived by group algebra method, and the novel constraint condition can meet the system stability performance. Besides, the defined robust performance index of fault diagnosis observer guarantees the robust. Finally, the effectiveness of the algorithm proposed is proved in the simulations. Hai-gang Xu, Yue-feng Liao, and Xiao Han Copyright © 2015 Hai-gang Xu et al. All rights reserved. An Improved Optimal Slip Ratio Prediction considering Tyre Inflation Pressure Changes Wed, 25 Nov 2015 13:22:43 +0000 The prediction of optimal slip ratio is crucial to vehicle control systems. Many studies have verified there is a definitive impact of tyre pressure change on the optimal slip ratio. However, the existing method of optimal slip ratio prediction has not taken into account the influence of tyre pressure changes. By introducing a second-order factor, an improved optimal slip ratio prediction considering tyre inflation pressure is proposed in this paper. In order to verify and evaluate the performance of the improved prediction, a cosimulation platform is developed by using MATLAB/Simulink and CarSim software packages, achieving a comprehensive simulation study of vehicle braking performance cooperated with an ABS controller. The simulation results show that the braking distances and braking time under different tyre pressures and initial braking speeds are effectively shortened with the improved prediction of optimal slip ratio. When the tyre pressure is slightly lower than the nominal pressure, the difference of braking performances between original optimal slip ratio and improved optimal slip ratio is the most obvious. Guoxing Li, Tie Wang, Ruiliang Zhang, Fengshou Gu, and Jinxian Shen Copyright © 2015 Guoxing Li et al. All rights reserved. Output Feedback Variable Structure Control Design for Uncertain Nonlinear Lipschitz Systems Mon, 16 Nov 2015 09:34:57 +0000 This paper develops a full-order compensator-based output feedback variable structure control law for uncertain nonlinear Lipschitz systems having matched perturbations. Given that the sufficient condition is satisfied, the developed control scheme, with the observer-like technique incorporated into the design of the compensator, can achieve global exponential stabilization. An illustrative example is provided with simulation results to show the effectiveness of the proposed method. Jeang-Lin Chang and Tsui-Chou Wu Copyright © 2015 Jeang-Lin Chang and Tsui-Chou Wu. All rights reserved. Model Predictive Control for Load Frequency Control with Wind Turbines Sun, 08 Nov 2015 06:44:25 +0000 Reliable load frequency (LFC) control is crucial to the operation and design of modern electric power systems. Considering the LFC problem of a four-area interconnected power system with wind turbines, this paper presents a distributed model predictive control (DMPC) based on coordination scheme. The proposed algorithm solves a series of local optimization problems to minimize a performance objective for each control area. The scheme incorporates the two critical nonlinear constraints, for example, the generation rate constraint (GRC) and the valve limit, into convex optimization problems. Furthermore, the algorithm reduces the impact on the randomness and intermittence of wind turbine effectively. A performance comparison between the proposed controller with and that without the participation of the wind turbines is carried out. Good performance is obtained in the presence of power system nonlinearities due to the governors and turbines constraints and load change disturbances. Yi Zhang, Xiangjie Liu, and Yujia Yan Copyright © 2015 Yi Zhang et al. All rights reserved. MIMO Passive Control Systems Are Not Necessarily Robust Wed, 28 Oct 2015 09:09:15 +0000 Via several cases of study it is shown that a passive multivariable linear control system, contrary to its single input single output counterpart, may not be robust. Moreover, it is shown that lack of robustness can be exposed via the multivariable structure function. Jesús U. Liceaga-Castro, Irma I. Siller-Alcalá, Eduardo Liceaga-Castro, and Luis A. Amézquita-Brooks Copyright © 2015 Jesús U. Liceaga-Castro et al. All rights reserved. A Local Controller for Discrete-Time Large-Scale System by Using Integral Variable Structure Control Thu, 22 Oct 2015 14:28:34 +0000 A new local controller for discrete-time integral variable structure control of a large-scale system with matched and unmatched uncertainty is presented. The local controller is able to bring the large-scale system into stability by using only the states feedback from individual subsystem itself. A new theorem is established and proved that the controller is able to handle the effect of interconnection for the large-scale system with matched and unmatched uncertainty, and the system stability is ensured. The controller is able to control the system to achieve the quasi-sliding surface and remains on it. The results showed a fast convergence to the desired value and the attenuation of disturbance is achieved. C. H. Chai and Johari H. S. Osman Copyright © 2015 C. H. Chai and Johari H. S. Osman. All rights reserved. Wind Characteristics of Three Meteorological Stations in China Thu, 22 Oct 2015 11:04:07 +0000 With rapid economic development of China, demand for energy is growing rapidly. Many experts have begun to pay attention on exploiting wind energy. Wind characteristics of three meteorological stations in China were analyzed to find out if or not it is possible to build a wind farm in this paper. First of all, studies about the wind characteristics and potential wind energy were summarized. Then ways of collecting and manipulating wind data were introduced. Wind-generation potential was assessed by the method of Weibull distribution. Wind shear exponent, extreme wind speed in 50 years, and turbulence intensity were calculated. The wind characteristics were summarized and assessment of wind-generation potential was given. At last, the wind was simulated with autoregressive method by Matlab software. Yang Yang, Yao Gang, Wang Rong, and Wang Hengyu Copyright © 2015 Yang Yang et al. All rights reserved. Predictive Variable Gain Iterative Learning Control for PMSM Thu, 22 Oct 2015 08:59:06 +0000 A predictive variable gain strategy in iterative learning control (ILC) is introduced. Predictive variable gain iterative learning control is constructed to improve the performance of trajectory tracking. A scheme based on predictive variable gain iterative learning control for eliminating undesirable vibrations of PMSM system is proposed. The basic idea is that undesirable vibrations of PMSM system are eliminated from two aspects of iterative domain and time domain. The predictive method is utilized to determine the learning gain in the ILC algorithm. Compression mapping principle is used to prove the convergence of the algorithm. Simulation results demonstrate that the predictive variable gain is superior to constant gain and other variable gains. Huimin Xu, Xuedong Zhang, and Xiangjie Liu Copyright © 2015 Huimin Xu et al. All rights reserved. High-Order Sliding Mode-Based Synchronous Control of a Novel Stair-Climbing Wheelchair Robot Wed, 21 Oct 2015 09:08:38 +0000 For the attitude control of a novel stair-climbing wheelchair with inertial uncertainties and external disturbance torques, a new synchronous control method is proposed via combing high-order sliding mode control techniques with cross-coupling techniques. For this purpose, a proper controller is designed, which can improve the performance of the system under conditions of uncertainties and torque perturbations and also can guarantee the synchronization of the system. Firstly, a robust high-order sliding mode control law is designed to track the desired position trajectories effectively. Secondly, considering the coordination of the multiple joints, a high-order sliding mode synchronization controller is designed to reduce the synchronization errors and tracking errors based on the controller designed previously. Stability of the closed-loop system is proved by Lyapunov theory. The simulation is performed by MATLAB to verify the effectiveness of the proposed controller. By comparing the simulation results of two controllers, it is obvious that the proposed scheme has better performance and stronger robustness. Juanxiu Liu, Yifei Wu, Jian Guo, and Qingwei Chen Copyright © 2015 Juanxiu Liu et al. All rights reserved. A Speed Control Method for Underwater Vehicle under Hydraulic Flexible Traction Sun, 18 Oct 2015 13:05:20 +0000 Underwater vehicle speed control methodology method is the focus of research in this study. Driven by a hydraulic flexible traction system, the underwater vehicle advances steadily on underwater guide rails, simulating an underwater environment for the carried device. Considering the influence of steel rope viscoelasticity and the control system traction structure feature, a mathematical model of the underwater vehicle driven by hydraulic flexible traction system is established. A speed control strategy is then proposed based on the sliding mode variable structure of fuzzy reaching law, according to nonlinearity and external variable load of the vehicle speed control system. Sliding mode variable structure control theory for the nonlinear system allows an improved control effect for movements in “sliding mode” when compared with conventional control. The fuzzy control theory is also introduced, weakening output chattering caused by the sliding mode control switchover while producing high output stability. Matlab mathematical simulation and practical test verification indicate the speed control method as effective in obtaining accurate control results, thus inferring strong practical significance for engineering applications. Yin Zhao, Ying-kai Xia, Ying Chen, and Guo-Hua Xu Copyright © 2015 Yin Zhao et al. All rights reserved. Hybrid Particle Swarm and Differential Evolution Algorithm for Solving Multimode Resource-Constrained Project Scheduling Problem Mon, 05 Oct 2015 12:34:30 +0000 In order to find a feasible solution for the multimode resource-constrained project scheduling problem (MRCPSP), a hybrid of particle swarm optimization (PSO) and differential evolution (DE) algorithm is proposed in this paper. The proposed algorithm uses a two-level coding structure. The upper-level structure is coded for scheduling sequence, which is optimized by PSO algorithm. The lower-level structure is coded for project execution mode, and DE algorithm is used to solve the optimal scheduling model. The effectiveness and advantages of the proposed algorithm are illustrated by using the test function of project scheduling problem library (PSPLIB) and comparing with other scheduling methods. The results show that the proposed algorithm can well solve MRCPSP. Lieping Zhang, Yingxiong Luo, and Yu Zhang Copyright © 2015 Lieping Zhang et al. All rights reserved. Fuzzy Weight Cluster-Based Routing Algorithm for Wireless Sensor Networks Wed, 30 Sep 2015 12:44:40 +0000 Cluster-based protocol is a kind of important routing in wireless sensor networks. However, due to the uneven distribution of cluster heads in classical clustering algorithm, some nodes may run out of energy too early, which is not suitable for large-scale wireless sensor networks. In this paper, a distributed clustering algorithm based on fuzzy weighted attributes is put forward to ensure both energy efficiency and extensibility. On the premise of a comprehensive consideration of all attributes, the corresponding weight of each parameter is assigned by using the direct method of fuzzy engineering theory. Then, each node works out property value. These property values will be mapped to the time axis and be triggered by a timer to broadcast cluster headers. At the same time, the radio coverage method is adopted, in order to avoid collisions and to ensure the symmetrical distribution of cluster heads. The aggregated data are forwarded to the sink node in the form of multihop. The simulation results demonstrate that clustering algorithm based on fuzzy weighted attributes has a longer life expectancy and better extensibility than LEACH-like algorithms. Teng Gao, Jin-Yan Song, Jin-Hua Ding, and De-Quan Wang Copyright © 2015 Teng Gao et al. All rights reserved. Phase Plane Analysis Method of Nonlinear Traffic Phenomena Sun, 20 Sep 2015 11:06:08 +0000 A new phase plane analysis method for analyzing the complex nonlinear traffic phenomena is presented in this paper. This method makes use of variable substitution to transform a traditional traffic flow model into a new model which is suitable for the analysis in phase plane. According to the new model, various traffic phenomena, such as the well-known shock waves, rarefaction waves, and stop-and-go waves, are analyzed in the phase plane. From the phase plane diagrams, we can see the relationship between traffic jams and system instability. So the problem of traffic flow could be converted into that of system stability. The results show that the traffic phenomena described by the new method is consistent with that described by traditional methods. Moreover, the phase plane analysis highlights the unstable traffic phenomena we are chiefly concerned about and describes the variation of density or velocity with time or sections more clearly. Wenhuan Ai, Zhongke Shi, and Dawei Liu Copyright © 2015 Wenhuan Ai et al. All rights reserved. Adaptive Hybrid Visual Servo Regulation of Mobile Robots Based on Fast Homography Decomposition Mon, 07 Sep 2015 09:45:51 +0000 For the monocular camera-based mobile robot system, an adaptive hybrid visual servo regulation algorithm which is based on a fast homography decomposition method is proposed to drive the mobile robot to its desired position and orientation, even when object’s imaging depth and camera’s position extrinsic parameters are unknown. Firstly, the homography’s particular properties caused by mobile robot’s 2-DOF motion are taken into account to induce a fast homography decomposition method. Secondly, the homography matrix and the extracted orientation error, incorporated with the desired view’s single feature point, are utilized to form an error vector and its open-loop error function. Finally, Lyapunov-based techniques are exploited to construct an adaptive regulation control law, followed by the experimental verification. The experimental results show that the proposed fast homography decomposition method is not only simple and efficient, but also highly precise. Meanwhile, the designed control law can well enable mobile robot position and orientation regulation despite the lack of depth information and camera’s position extrinsic parameters. Chunfu Wu, Guodong Li, Qingshun Tang, and Fengyu Zhou Copyright © 2015 Chunfu Wu et al. All rights reserved. Design of Multiregional Supervisory Fuzzy PID Control of pH Reactors Mon, 07 Sep 2015 09:40:33 +0000 This work concerns designing multiregional supervisory fuzzy PID (Proportional-Integral-Derivative) control for pH reactors. The proposed work focuses, mainly, on two themes. The first one is to propose a multiregional supervisory fuzzy-based cascade control structure. It would enable modifying dynamics and enhance system’s stability. The fuzzy system (master loop) has been chosen as a tuner for PID controller (slave loop). It takes into consideration parameters uncertainties and reference tracking. The second theme concerns designing a hybrid neural network-based pH estimator. The proposed estimator would overcome the industrial drawbacks, that is, cost and size, found with conventional methods for pH measurement. The final end-user-interface (EUI) front panel and the results that evaluate the performance of the supervisory fuzzy PID-based control system and hybrid NN-based estimator have been presented using the compatibility found between LabView and MatLab. They lead to conclude that the proposed algorithms are appropriate to systems nonlinearities encountered with pH reactors. Shebel AlSabbah, Mujahed AlDhaifallah, and Mohammad Al-Jarrah Copyright © 2015 Shebel AlSabbah et al. All rights reserved. Robust Control for Lateral and Longitudinal Channels of Small-Scale Unmanned Helicopters Tue, 01 Sep 2015 09:11:17 +0000 Lateral and longitudinal channels are two closely related channels whose control stability influences flight performance of small-scale unmanned helicopters directly. This paper presents a robust control approach for lateral and longitudinal channels in the presence of parameter uncertainties and exogenous disturbances. The proposed control approach is performed by two steps. First, by performing system identification in frequency domain, system model of lateral and longitudinal channels can be accurately identified. Then, a robust state feedback controller is designed to stabilize the helicopter in lateral and longitudinal channels simultaneously under extraneous disturbances situation. The proposed approach takes advantages that it reduces order of the controller by preestimating some parameters (like flapping angles) without sacrificing control accuracy. Numerical results show the reliability and effectiveness of the proposed method. Bao Feng Copyright © 2015 Bao Feng. All rights reserved. A Dynamic Resource Scheduling Method Based on Fuzzy Control Theory in Cloud Environment Mon, 24 Aug 2015 11:35:02 +0000 The resources in cloud environment have features such as large-scale, diversity, and heterogeneity. Moreover, the user requirements for cloud computing resources are commonly characterized by uncertainty and imprecision. Hereby, to improve the quality of cloud computing service, not merely should the traditional standards such as cost and bandwidth be satisfied, but also particular emphasis should be laid on some extended standards such as system friendliness. This paper proposes a dynamic resource scheduling method based on fuzzy control theory. Firstly, the resource requirements prediction model is established. Then the relationships between resource availability and the resource requirements are concluded. Afterwards fuzzy control theory is adopted to realize a friendly match between user needs and resources availability. Results show that this approach improves the resources scheduling efficiency and the quality of service (QoS) of cloud computing. Zhijia Chen, Yuanchang Zhu, Yanqiang Di, and Shaochong Feng Copyright © 2015 Zhijia Chen et al. All rights reserved. Model Predictive Control for Continuous-Time Singular Jump Systems with Incomplete Transition Rates Mon, 17 Aug 2015 11:29:58 +0000 This paper is concerned with model predictive control (MPC) problem for continuous-time Markov Jump Systems (MJSs) with incomplete transition rates and singular character. Sufficient conditions for the existence of a model predictive controller, which could optimize a quadratic cost function and guarantee that the system is piecewise regular, impulse-free, and mean square stable, are given in two cases at each sampling time. Since the MPC strategy is aggregated into continuous-time singular MJSs, a discrete-time controller is employed to deal with a continuous-time plant and the cost function not only refers to the singularity but also considers the sampling period. Moreover, the feasibility of the MPC scheme and the mean square admissibility of the closed-loop system are deeply discussed by using the invariant ellipsoid. Finally, a numerical example is given to illustrate the main results. Xinxin Gu, Jiwei Wen, and Li Peng Copyright © 2015 Xinxin Gu et al. All rights reserved. Nonuniform Polynomial Dichotomy for Noninvertible Linear Discrete-Time Systems in Banach Spaces Mon, 17 Aug 2015 05:47:32 +0000 We study three polynomial dichotomy concepts for linear discrete-time systems in Banach spaces. Our main objective is to give characterizations in terms of Lyapunov functions for nonuniform polynomial dichotomy of nonautonomous and noninvertible linear discrete-time systems. Tian Yue Copyright © 2015 Tian Yue. All rights reserved. Material Selection in Engineering Design Using Choquet Integral-Based Linguistic Operators under Hybrid Environment Sun, 09 Aug 2015 08:24:12 +0000 The performance of phase change materials directly influences the performance and cost of thermal energy storage, and it is the first important task to select the suitable phase change materials for use in a particular kind of applications. Due to the decision maker’s knowledge field and the nature of evaluated attributes, assessments are always with different formats, which were first unified into the linguistic terms in the basic linguistic term set. Two-additive fuzzy measures were used to model criteria interactions by pairs, and the special expressions of Marichal entropy and Choquet integral were derived, more convenient to use in practice. Fuzzy measures were identified based on the maximum of Marichal entropy, and, based on the Choquet integral, the linguistic hybrid weighted geometric averaging with interaction was developed for integrating the individual attributes’ ratings. The detailed decision making procedure was illustrated, with the material 33.2Cu as the optimal solution, which by comparison is reasonable and trustworthy. Anhua Peng, Xiqin Wen, and Kaibo Wu Copyright © 2015 Anhua Peng et al. All rights reserved. Loop Shaping Control of Input Saturated Systems with Norm-Bounded Parametric Uncertainty Mon, 06 Jul 2015 09:03:26 +0000 This paper proposes a gain-scheduling control design strategy for a class of linear systems with the presence of both input saturation constraints and norm-bounded parametric uncertainty. LMI conditions are derived in order to obtain a gain-scheduled controller that ensures the robust stability and performance of the closed loop system. The main steps to obtain such a controller are given. Differently from other gain-scheduled approaches in the literature, this one focuses on the problem of loop shaping control design with input saturation nonlinearity and norm-bounded uncertainty to reduce the effect of the disturbance input on the controlled outputs. Here, the design problem has been formulated in the four-block synthesis framework, in which it is possible to describe the parametric uncertainty and the input saturation nonlinearity as perturbations to normalized coprime factors of the shaped plant. As a result, the shaped plant is represented as a linear parameter-varying (LPV) system while the norm-bounded uncertainty and input saturation are incorporated. This procedure yields a linear parameter-varying structure for the controller that ensures the stability of the polytopic LPV shaped plant from the vertex property. Finally, the effectiveness of the method is illustrated through application to a physical system: a VTOL “vertical taking-off landing” helicopter. Renan Lima Pereira and Karl Heinz Kienitz Copyright © 2015 Renan Lima Pereira and Karl Heinz Kienitz. All rights reserved. LMI Based Fuzzy Control of a Wing Doubled Fractional-Order Chaos Sun, 05 Jul 2015 07:45:27 +0000 This paper investigates a new wing doubled fractional-order chaos and its control. Firstly, a new fractional-order chaos is proposed, replacing linear term x in the second equation by its absolute value; a new improved system is got, which can make the wing of the original system doubled. Then, circuit diagram is presented for the proposed fractional-order chaos. Furthermore, based on fractional-order stability theory and T-S fuzzy model, a more practical stability condition for fuzzy control of the proposed fractional-order chaos is given as s set of linear matrix inequality (LMI) and the strict mathematical norms of LMI are presented. Finally, numerical simulations are given to verify the effectiveness of the proposed theoretical results. Bin Wang, Yuzhu Wang, Hongbo Cao, and Delan Zhu Copyright © 2015 Bin Wang et al. All rights reserved. Linear Feedback Synchronization Used in the Three-Dimensional Duffing System Wed, 24 Jun 2015 06:42:54 +0000 It has been realized that synchronization using linear feedback control method is efficient compared to nonlinear feedback control method due to the less computational complexity and the synchronization error. For the problem of feedback synchronization of Duffing chaotic system, in the paper, we firstly established three-dimensional Duffing system by method of variable decomposition and, then, studied the synchronization of Duffing chaotic system and designed the control law based on linear feedback control and Lyapunov stability theory. It is proved theoretically that the two identical integer order chaotic systems are synchronized analytically and numerically. Jian-qun Han, Xu-dong Shi, and Hong Sun Copyright © 2015 Jian-qun Han et al. All rights reserved. A Novel Stability Analysis of Uncertain Switched Systems with Time-Varying Delays Wed, 10 Jun 2015 07:54:13 +0000 This paper deals with the stability of switched systems with time-varying delay. The time-varying system parameters are assumed to be norm-bounded. Based on a novel switched time-varying Lyapunov functional method, some new LMI-based sufficient conditions have been obtained to ensure the exponential stability for the uncertain switched delays systems. Finally, the proposed method is applied to a numerical example and the simulative results are also given. Ganji Huang, Shixian Luo, Linna Wei, and Wuhua Chen Copyright © 2015 Ganji Huang et al. All rights reserved.