Journal of Control Science and Engineering The latest articles from Hindawi Publishing Corporation © 2015 , Hindawi Publishing Corporation . 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. Model-Based Development of Control Systems for Forestry Cranes Tue, 02 Jun 2015 09:09:14 +0000 Model-based methods are used in industry for prototyping concepts based on mathematical models. With our forest industry partners, we have established a model-based workflow for rapid development of motion control systems for forestry cranes. Applying this working method, we can verify control algorithms, both theoretically and practically. This paper is an example of this workflow and presents four topics related to the application of nonlinear control theory. The first topic presents the system of differential equations describing the motion dynamics. The second topic presents nonlinear control laws formulated according to sliding mode control theory. The third topic presents a procedure for model calibration and control tuning that are a prerequisite to realize experimental tests. The fourth topic presents the results of tests performed on an experimental crane specifically equipped for these tasks. Results of these studies show the advantages and disadvantages of these control algorithms, and they highlight their performance in terms of robustness and smoothness. Pedro La Hera and Daniel Ortíz Morales Copyright © 2015 Pedro La Hera and Daniel Ortíz Morales. All rights reserved. Observer-Based Robust Passive Control for a Class of Uncertain Neutral Systems: An Integral Sliding Mode Approach Tue, 02 Jun 2015 06:21:40 +0000 The problem of integral sliding mode control (ISMC) with passivity is investigated for a class of uncertain neutral systems with time-varying delay (NTSTD) and external disturbance. The system states are unavailable. An ISMC strategy is proposed based on the state estimate. By employing a novel sliding functional, a new sufficient criterion of robust asymptotic stability and passivity for both the error system and the sliding mode (SM) dynamic system is derived via linear matrix inequality (LMI) technique. Then, a SM controller is synthesized to guarantee the reachability of the sliding surface predefined in the state estimate space. Finally, a numerical example shows the feasibility and superiority of the obtained result. Ruiping Xu, Zhen Liu, Cunchen Gao, and Huimin Xiao Copyright © 2015 Ruiping Xu et al. All rights reserved. Spacecraft Actuator Diagnosis with Principal Component Analysis: Application to the Rendez-Vous Phase of the Mars Sample Return Mission Tue, 26 May 2015 14:21:37 +0000 This paper presents a fault detection and isolation (FDI) approach in order to detect and isolate actuators (thrusters and reaction wheels) faults of an autonomous spacecraft involved in the rendez-vous phase of the Mars Sample Return (MSR) mission. The principal component analysis (PCA) has been adopted to estimate the relationships between the various variables of the process. To ensure the feasibility of the proposed FDI approach, a set of data provided by the industrial “high-fidelity” simulator of the MSR and representing the opening (resp., the rotation) rates of the spacecraft thrusters (resp., reaction wheels) has been considered. The test results demonstrate that the fault detection and isolation are successfully accomplished. Othman Nasri, Imen Gueddi, Philippe Dague, and Kamal Benothman Copyright © 2015 Othman Nasri et al. All rights reserved. In-Flight Self-Alignment Method Aided by Geomagnetism for Moving Basement of Guided Munitions Sun, 24 May 2015 07:11:37 +0000 Due to power-after-launch mode of guided munitions of high rolling speed, initial attitude of munitions cannot be determined accurately, and this makes it difficult for navigation and control system to work effectively and validly. An in-flight self-alignment method aided by geomagnetism that includes a fast in-flight coarse alignment method and an in-flight alignment model based on Kalman theory is proposed in this paper. Firstly a fast in-flight coarse alignment method is developed by using gyros, magnetic sensors, and trajectory angles. Then, an in-flight alignment model is derived by investigation of the measurement errors and attitude errors, which regards attitude errors as state variables and geomagnetic components in navigation frame as observed variables. Finally, fight data of a spinning projectile is used to verify the performance of the in-flight self-alignment method. The satisfying results show that (1) the precision of coarse alignment can attain below 5°; (2) the attitude errors by in-flight alignment model converge to 24′ at early of the latter half of the flight; (3) the in-flight alignment model based on Kalman theory has better adaptability, and show satisfying performance. Shuang-biao Zhang, Xing-cheng Li, and Zhong Su Copyright © 2015 Shuang-biao Zhang et al. All rights reserved. Power Forecasting of Combined Heating and Cooling Systems Based on Chaotic Time Series Tue, 12 May 2015 13:10:56 +0000 Theoretic analysis shows that the output power of the distributed generation system is nonlinear and chaotic. And it is coupled with the microenvironment meteorological data. Chaos is an inherent property of nonlinear dynamic system. A predicator of the output power of the distributed generation system is to establish a nonlinear model of the dynamic system based on real time series in the reconstructed phase space. Firstly, chaos should be detected and quantified for the intensive studies of nonlinear systems. If the largest Lyapunov exponent is positive, the dynamical system must be chaotic. Then, the embedding dimension and the delay time are chosen based on the improved C-C method. The attractor of chaotic power time series can be reconstructed based on the embedding dimension and delay time in the phase space. By now, the neural network can be trained based on the training samples, which are observed from the distributed generation system. The neural network model will approximate the curve of output power adequately. Experimental results show that the maximum power point of the distributed generation system will be predicted based on the meteorological data. The system can be controlled effectively based on the prediction. Liu Hai, Song Yong, and Du Qingfu Copyright © 2015 Liu Hai et al. All rights reserved. Human Simulated Intelligent Control with Double-Direction Dead-Zone Compensation for Joint Motion Control of a Large-Sized Boom System Sun, 10 May 2015 14:32:08 +0000 Joint motion control of a 52-meter-long five-boom system driven by proportional hydraulic system is developed. It has been considered difficult due to strong nonlinearities and parametric uncertainties, the effect of which increases with the size of booms. A human simulated intelligent control scheme is developed to improve control performance by modifying control mode and control parameters. In addition, considering the negative effects caused by frequent and redundant reverse actions of the proportional valve, a double-direction compensation scheme is proposed to deal with the dead-zone nonlinearity of proportional valve. Sinusoidal motions are implemented on a real boom system. The results indicate that HSIC controller can improve control accuracy, and dead-zone nonlinearity is effectively compensated by proposed compensation scheme without introducing frequent reverse actions of proportional valve. Rongsheng Liu, Yingjie Gao, Yulin Yang, and Yanlong Liu Copyright © 2015 Rongsheng Liu et al. All rights reserved. The Exact Linearization and LQR Control of Semiactive Connected Hydropneumatic Suspension System Thu, 30 Apr 2015 07:55:47 +0000 Based on differential geometry theory, the nonlinear system of connected hydropneumatic suspension was transformed to a linear one. What is more, it realized the decoupling and inverter between the control variables and system outputs. With LQR (Linear Quadratic Regulator) control theory, a semiactive system has been developed for connected hydropneumatic suspension in this paper. By AMESim/Simulink cosimulation, the results show that the semiactive connected hydropneumatic suspension decreases the vibration of upper vehicle quickly and reduces the impact acceleration strongly both in displacement and inroll angle. Moreover, the semiactive suspension could increase the suspension dynamic deflection, which would make the system reach balance quickly and keep small vibration amplitude under the effect of disturbance. Xuyang Cao, Linlin Cao, and Dianlong Wang Copyright © 2015 Xuyang Cao et al. All rights reserved. Model Predictive Control of NCS with Data Quantization and Bounded Arbitrary Time Delays Sun, 19 Apr 2015 12:55:12 +0000 The model predictive control for constrained discrete time linear system under network environment is considered. The bounded time delay and data quantization are assumed to coexist in the data transmission link from the sensor to the controller. A novel NCS model is specially established for the model predictive control method, which casts the time delay and data quantization into a unified framework. A stability result of the obtained closed-loop model is presented by applying the Lyapunov method, which plays a key role in synthesizing the model predictive controller. The model predictive controller, which parameterizes the infinite horizon control moves into a single state feedback law, is provided which explicitly considers the satisfaction of input and state constraints. Two numerical examples are given to illustrate the effectiveness of the derived method. Jimin Yu, Yanan Xie, and Xiaoming Tang Copyright © 2015 Jimin Yu et al. All rights reserved. Chaotic Secure Communication Systems with an Adaptive State Observer Tue, 31 Mar 2015 12:29:03 +0000 This paper develops a new digital communication scheme based on using a unified chaotic system and an adaptive state observer. The proposed communication system basically consists of five important elements: signal modulation, chaotic encryption, adaptive state observer, chaotic decryption, and signal demodulation. A sequence of digital signals will be delivered from the transmitter to the receiver through a public channel. It is rather reasonable that if the number of signals delivered on the public channel is fewer, then the security of such communication system is more guaranteed. Therefore, in order to achieve this purpose, a state observer will be designed and its function is to estimate full system states only by using the system output signals. In this way, the signals delivered on the public channel can be reduced mostly. According to these estimated state signals, the original digital sequences are then retrieved completely. Finally, experiment results are provided to verify the applicability of the proposed communication system. Wei-Der Chang, Shun-Peng Shih, and Chih-Yung Chen Copyright © 2015 Wei-Der Chang et al. All rights reserved. Robust Tracking Control for Robotic Manipulator via Fuzzy Logic System and Approaches Mon, 30 Mar 2015 07:09:52 +0000 Based on fuzzy logic system (FLS) and control methodologies, a robust tracking control scheme is proposed for robotic system with uncertainties and external disturbances. FLS is employed to implement the framework of computed torque control (CTC) method via its approximate capability which is used to attenuate the nonlinearity of robotic manipulator. The robust control can guarantee robustness to parametric and dynamics uncertainties and also attenuate the effect of immeasurable external disturbances entering the system. Moreover, a quadratic stability approach is used to reduce the conservatism of the conventional robust control approach. It can be guaranteed that all signals in the closed-loop are bounded by employing the proposed robust tracking control. The validity of the proposed control scheme is shown by simulation of a two-link robotic manipulator. Kun Mu, Cong Liu, and Jinzhu Peng Copyright © 2015 Kun Mu et al. All rights reserved. Reducing Computational Overhead by Improving the CRI and IRI Implication Step Thu, 26 Mar 2015 11:58:04 +0000 In conventional SISO fuzzy expert systems (-element input, -element output), the implication step requires the operations using compositional rule-based inference (CRI) and individual rule-based inference (IRI). However, this introduces excessive complexity. This paper proposes two methods, sort compositional rule-based inference (SCRI) and sort individual rule-based inference (SIRI) aiming at reducing both temporal and spatial complexity by changing the operation of the implication step to log2. We also propose a divide-and-conquer technique, called Quicksort, to verify the accuracy of SCRI and SIRI algorithms deployment to easily outperform the CRI and IRI methods. Thoai Phu Vo and Joy Iong-Zong Chen Copyright © 2015 Thoai Phu Vo and Joy Iong-Zong Chen. All rights reserved. Combining Multiple Strategies for Multiarmed Bandit Problems and Asymptotic Optimality Wed, 25 Mar 2015 09:15:21 +0000 This brief paper provides a simple algorithm that selects a strategy at each time in a given set of multiple strategies for stochastic multiarmed bandit problems, thereby playing the arm by the chosen strategy at each time. The algorithm follows the idea of the probabilistic -switching in the -greedy strategy and is asymptotically optimal in the sense that the selected strategy converges to the best in the set under some conditions on the strategies in the set and the sequence of . Hyeong Soo Chang and Sanghee Choe Copyright © 2015 Hyeong Soo Chang and Sanghee Choe. All rights reserved. Observer Design for a Class of Nonlinear Descriptor Systems: A Takagi-Sugeno Approach with Unmeasurable Premise Variables Wed, 25 Mar 2015 06:54:43 +0000 The Takagi-Sugeno (T-S) fuzzy observer for dynamical systems described by ordinary differential equations is widely discussed in the literature. The aim of this paper is to extend this observer design to a class of T-S descriptor systems with unmeasurable premise variables. In practice, the computation of solutions of differential-algebraic equations requires the combination of an ordinary differential equations (ODE) routine together with an optimization algorithm. Therefore, a natural way permitting to estimate the state of such a system is to design a procedure based on a similar numerical algorithm. Beside some numerical difficulties, the drawback of such a method lies in the fact that it is not easy to establish a rigorous proof of the convergence of the observer. The main result of this paper consists in showing that the state estimation problem for a class of T-S descriptor systems can be achieved by using a fuzzy observer having only an ODE structure. The convergence of the state estimation error is studied using the Lyapunov theory and the stability conditions are given in terms of linear matrix inequalities (LMIs). Finally, an application to a model of a heat exchanger pilot process is given to illustrate the performance of the proposed observer. J. Soulami, A. El Assoudi, M. Essabre, M. Habibi, and E. El Yaagoubi Copyright © 2015 J. Soulami et al. All rights reserved. Discrete Second-Order Sliding Mode Adaptive Controller Based on Characteristic Model for Servo Systems Tue, 17 Mar 2015 08:57:41 +0000 Considering the varying inertia and load torque in high speed and high accuracy servo systems, a novel discrete second-order sliding mode adaptive controller (DSSMAC) based on characteristic model is proposed, and a command observer is also designed. Firstly, the discrete characteristic model of servo systems is established. Secondly, the recursive least square algorithm is adopted to identify time-varying parameters in characteristic model, and the observer is applied to predict the command value of next sample time. Furthermore, the stability of the closed-loop system and the convergence of the observer are analyzed. The experimental results show that the proposed method not only can adapt to varying inertia and load torque, but also has good disturbance rejection ability and robustness to uncertainties. Zhihong Wang, Yifei Wu, Wei Chen, Xiang Wang, Jian Guo, and Qingwei Chen Copyright © 2015 Zhihong Wang et al. All rights reserved. A New Energy-Efficient Data Transmission Scheme Based on DSC and Virtual MIMO for Wireless Sensor Network Wed, 04 Mar 2015 11:06:01 +0000 Energy efficiency in wireless sensor network (WSN) is one of the primary performance parameters. For improving the energy efficiency of WSN, we introduce distributed source coding (DSC) and virtual multiple-input multiple-output (MIMO) into wireless sensor network and then propose a new data transmission scheme called DSC-MIMO. DSC-MIMO compresses the source data using distributed source coding before transmitting, which is different from the existing communication schemes. Data compression can reduce the length of the data and improve the energy efficiency. In addition, DSC-MIMO does not require the cluster heads to collect the data of the source nodes, which reduces the frequencies of data transmission and saves energy. In the simulation, we analyze the energy consumption of DSC-MIMO. The results indicate that DSC-MIMO can effectively reduce the energy consumption and improve the energy efficiency of the whole wireless sensor network. Na Li, Liwen Zhang, and Bing Li Copyright © 2015 Na Li et al. All rights reserved. Design of Internal Model Control Based on an Optimal Control for a Servo System Sun, 01 Mar 2015 14:20:42 +0000 This paper describes a design of internal model control based on an optimal control for a servo system. The control system has the feedback based on the proposed disturbance compensator in the disturbance response. The compensator is designed to become the denominator of the transfer function without a dead time in the disturbance responses. The disturbance response of the proposed method is faster than that of the previous method. Hiromitsu Ogawa, Ryo Tanaka, Takahiro Murakami, and Yoshihisa Ishida Copyright © 2015 Hiromitsu Ogawa et al. All rights reserved.