http://www.hindawi.com The latest articles from Hindawi Publishing Corporation © 2013 , Hindawi Publishing Corporation . All rights reserved. Tue, 14 May 2013 15:24:21 +0000 http://www.hindawi.com/journals/jcse/2013/432034/ We consider a design problem of a variable gain robust output feedback controller with guaranteed gain performance for a class of Lipschitz uncertain nonlinear systems. The proposed variable gain robust output feedback controller achieves not only robust stability but also a specified gain performance. In this paper, we show that sufficient conditions for the existence of the proposed variable gain robust output feedback controller with guaranteed gain performance are given in terms of linear matrix inequalities (LMIs). Finally, a simple numerical example is included. Hidetoshi Oya and Kojiro Hagino Copyright © 2013 Hidetoshi Oya and Kojiro Hagino. All rights reserved. Mon, 13 May 2013 10:14:14 +0000 http://www.hindawi.com/journals/jcse/2013/491709/ We present a constructive solution to the problem of full output feedback equivalence, of linear, minimal, time-invariant systems. The equivalence relation on the set of systems is transformed to another on the set of invertible block Bezout/Hankel matrices using the isotropy subgroups of the full state feedback group and the full output injection group. The transformation achieving equivalence is calculated solving linear systems of equations. We give a polynomial version of the results proving that two systems are full output feedback equivalent, if and only if they have the same family of generalized Bezoutians. We present a new set of output feedback invariant polynomials that generalize the breakaway polynomial of scalar systems. Aristotle G. Yannakoudakis Copyright © 2013 Aristotle G. Yannakoudakis. All rights reserved. Thu, 02 May 2013 09:07:06 +0000 http://www.hindawi.com/journals/jcse/2013/342949/ At Uppsala University, a research group is investigating a system for converting the power in freely flowing water using a vertical-axis turbine directly connected to a permanent magnet generator. An experimental setup comprising a turbine, a generator, and a control system has been constructed and will be deployed in the Dalälven river in the town of Söderfors in Sweden. The design, construction, simulations, and laboratory tests of the control system are presented in this paper. The control system includes a startup sequence for the turbine and load control. These functions have performed satisfactorily in laboratory tests. Simulations of the system show that the power output is not maximized at the same tip-speed ratio as that which maximizes the turbine power capture. Katarina Yuen, Senad Apelfröjd, and Mats Leijon Copyright © 2013 Katarina Yuen et al. All rights reserved. Tue, 30 Apr 2013 09:53:35 +0000 http://www.hindawi.com/journals/jcse/2013/801237/ This paper focuses on embedded control of a hybrid powertrain concepts for mobile vehicle applications. Optimal robust control approach is used to develop a real-time energy management strategy. The main idea is to store the normally wasted mechanical regenerative energy in energy storage devices for later usage. The regenerative energy recovery opportunity exists in any condition where the speed of motion is in the opposite direction to the applied force or torque. This is the case when the vehicle is braking, decelerating, the motion is driven by gravitational force, or load driven. There are three main concepts for energy storing devices in hybrid vehicles: electric, hydraulic, and mechanical (flywheel). The real-time control challenge is to balance the system power demands from the engine and the hybrid storage device, without depleting the energy storage device or stalling the engine in any work cycle. In the worst-case scenario, only the engine is used and the hybrid system is completely disabled. A rule-based control algorithm is developed and is tuned for different work cycles and could be linked to a gain scheduling algorithm. A gain scheduling algorithm identifies the cycle being performed by the work machine and its position via GPS and maps both of them to the gains. Mohamed Zaher and Sabri Cetinkunt Copyright © 2013 Mohamed Zaher and Sabri Cetinkunt. All rights reserved. Mon, 22 Apr 2013 09:02:58 +0000 http://www.hindawi.com/journals/jcse/2013/498461/ An optimal tracking-based indirect adaptive fuzzy controller for a class of perturbed uncertain affine nonlinear systems without reaching phase is being developed in this paper. First a practical Interval Type-2 (IT2) fuzzy system is used in an adaptive scheme to approximate the system using a nonlinear model and to determine the optimal value of the gain control. Secondly, to eliminate the trade-off between tracking performance and high gain at the control input, a modified output tracking error has been used. The stability is ensured through Lyapunov synthesis and the effectiveness of the proposed method is proved and the simulation is also given to illustrate the superiority of the proposed approach. El Mehdi Mellouli, Siham Massou, and Ismail Boumhidi Copyright © 2013 El Mehdi Mellouli et al. All rights reserved. Mon, 15 Apr 2013 17:35:36 +0000 http://www.hindawi.com/journals/jcse/2013/763165/ This paper studies the application of proper orthogonal decomposition (POD) to reduce the order of distributed reactor models with axial and radial diffusion and the implementation of model predictive control (MPC) based on discrete-time linear time invariant (LTI) reduced-order models. In this paper, the control objective is to keep the operation of the reactor at a desired operating condition in spite of the disturbances in the feed flow. This operating condition is determined by means of an optimization algorithm that provides the optimal temperature and concentration profiles for the system. Around these optimal profiles, the nonlinear partial differential equations (PDEs), that model the reactor are linearized, and afterwards the linear PDEs are discretized in space giving as a result a high-order linear model. POD and Galerkin projection are used to derive the low-order linear model that captures the dominant dynamics of the PDEs, which are subsequently used for controller design. An MPC formulation is constructed on the basis of the low-order linear model. The proposed approach is tested through simulation, and it is shown that the results are good with regard to keep the operation of the reactor. Alejandro Marquez, Jairo José Espinosa Oviedo, and Darci Odloak Copyright © 2013 Alejandro Marquez et al. All rights reserved. Tue, 09 Apr 2013 15:19:04 +0000 http://www.hindawi.com/journals/jcse/2013/678679/ This paper presents a backward differential flow for solving singular optimal control problems. By using Krotov equivalent transformation, the cost functional is converted to a class of global optimization problems. Some properties of the flow are given to reveal the significant relationship between the dynamic of the flow and the geometry of the feasible set. The proposed method is also used in solving a class of variational problems. Some examples are illustrated. Jinghao Zhu, Shangrui Zhao, and Guohua Liu Copyright © 2013 Jinghao Zhu et al. All rights reserved. Sun, 31 Mar 2013 08:33:00 +0000 http://www.hindawi.com/journals/jcse/2013/947428/ This paper discusses the application of a particular fractional-order control scheme, the PDD1/2, to the position control of a micrometric linear axis. The PDD1/2 scheme derives from the classical PD scheme with the introduction of the half-derivative term. The PD and PDD1/2 schemes are compared by adopting a nondimensional approach for the sake of generality. The linear model of the closed-loop system is discussed by analysing the pole location in the σ-plane. Then, different combinations of the derivative and half-derivative terms, characterized by the same settling energy in the step response, are experimentally compared in the real mechatronic application, with nonnegligible friction effects and a position set point with trapezoidal speed law. The experimental results are coherent with the nonlinear model of the controlled system and confirm that the introduction of the half-derivative term is an interesting option for reducing the tracking error in the transient state. Luca Bruzzone and Pietro Fanghella Copyright © 2013 Luca Bruzzone and Pietro Fanghella. All rights reserved. Wed, 06 Mar 2013 09:05:12 +0000 http://www.hindawi.com/journals/jcse/2013/872624/ The new hybrid active filter (HAF) is composed of the larger-capacity passive filter banks and the smaller-capacity active filter. It is difficult to tune the parameters of a PI controller using the DC capacitor voltage control. In this paper, the improved particle swarm optimization (improved PSO) algorithm is proposed to solve the coordinated design problem, and the neural network weights as the particle swarm optimization are adopted to optimize the system parameters. Comparing with the conventional PI controller, the results of PINN controller prove the effectiveness of designed method on both the transient and steady-state performance of the hybrid active filter DC bus voltage (HAFDV) controllers. Bin Huang, Nengling Tai, and Wentao Huang Copyright © 2013 Bin Huang et al. All rights reserved. Mon, 25 Feb 2013 13:51:18 +0000 http://www.hindawi.com/journals/jcse/2013/678016/ The systematic design of automotive control applications is a challenging problem due to lack of understanding of the complex and tight interactions that often manifest during the integration of components from the control design phase with the components from software generation and deployment on actual platform/network. In order to address this challenge, we present a systematic methodology and a toolchain using well-defined models to integrate components from various design phases with specific emphasis on restricting the complex interactions that manifest during integration such as timing, deployment, and quantization. We present an experimental platform for the evaluation and testing of the design process. The approach is applied to the development of an adaptive cruise control, and we present experimental results that demonstrate the efficacy of the approach. Emeka Eyisi, Zhenkai Zhang, Xenofon Koutsoukos, Joseph Porter, Gabor Karsai, and Janos Sztipanovits Copyright © 2013 Emeka Eyisi et al. All rights reserved. Sun, 24 Feb 2013 11:12:21 +0000 http://www.hindawi.com/journals/jcse/2013/719683/ Since smelting process of electro-fused magnesia furnace is a complicated process which has characteristics like complex operation conditions, strong nonlinearities, and strong couplings, traditional linear controller cannot control it very well. Advanced intelligent control strategy is a good solution to this kind of industrial process. However, advanced intelligent control strategy always involves huge programming task and hard debugging and maintaining problems. In this paper, a real-time embedded control system is proposed for the process control of electro-fused magnesia furnace based on intelligent control strategy and model-based design technology. As for hardware, an embedded controller based on an industrial Single Board Computer (SBC) is developed to meet industrial field environment demands. As for software, a Linux based on Real-Time Application Interface (RTAI) is used as the real-time kernel of the controller to improve its real-time performance. The embedded software platform is also modified to support generating embedded code automatically from Simulink/Stateflow models. Based on the proposed embedded control system, the intelligent embedded control software of electro-fused magnesium furnace can be directly generated from Simulink/Stateflow models. To validate the effectiveness of the proposed embedded control system, hardware-in-the-loop (HIL) and industrial field experiments are both implemented. Experiments results show that the embedded control system works very well in both laboratory and industry environments. Fang Zheng, Yang Jie, Tao Shifei, Wu Zhiwei, and Chai Tianyou Copyright © 2013 Fang Zheng et al. All rights reserved. Thu, 21 Feb 2013 10:27:19 +0000 http://www.hindawi.com/journals/jcse/2013/136841/ The paper presents the first experimental results on the control of a prototypal robot designed for the orientation of parts or tools. The innovative machine is a spherical parallel manipulator actuated by 3 linear motors; several position control schemes have been tested and compared with the final aim of designing an interaction controller. The relative simplicity of machine kinematics allowed to test algorithms requiring the closed-loop evaluation of both inverse and direct kinematics; the compensation of gravitational terms has been experimented as well. Massimo Callegari, Luca Carbonari, Giacomo Palmieri, Matteo-Claudio Palpacelli, and Donatello Tina Copyright © 2013 Massimo Callegari et al. All rights reserved. Wed, 20 Feb 2013 11:08:26 +0000 http://www.hindawi.com/journals/jcse/2013/697849/ For a class of Itô stochastic linear systems with the Markov jumping and linear fractional uncertainty, the stochastic stabilization problem is investigated via state feedback and dynamic output feedback, respectively. In order to guarantee the stochastic stability of such uncertain systems, state feedback and dynamic output control law are, respectively, designed by using multiple Lyapunov function technique and LMI approach. Finally, two numerical examples are presented to illustrate our results. Fei Long, Hongmei Huang, and Adan Ding Copyright © 2013 Fei Long et al. All rights reserved. Sun, 30 Dec 2012 09:04:20 +0000 http://www.hindawi.com/journals/jcse/2012/916340/ Alex Poznyak, Isaac Chairez, Haibo He, and Wen Yu Copyright © 2012 Alex Poznyak et al. All rights reserved. Thu, 27 Dec 2012 14:40:49 +0000 http://www.hindawi.com/journals/jcse/2012/923679/ This paper presents the results of quantitative performance evaluation of an authors’ new parabolic sliding mode filter, which is for removing noise from signals in robotics and mechatronics applications, based on the frequency and time domain characteristics. Based on the evaluation results, the paper presents selection guidelines of two parameters of the filter. The evaluation results show that, in the frequency domain, the noise removing capability of the filter is almost the same as that of the second-order Butterworth low-pass filter (2-LPF), but its phase lag is smaller (maximum 150 degree) than that of 2-LPF (maximum 180 degree). Moreover, the filter produces smaller phase lag than a conventional parabolic sliding mode filter with appropriate selection of the parameters. In the time domain, the filter produces smaller overshoot than 2-LPF and the conventional one, while maintaining short transient time, by using an appropriately selected parameter. The presented parameter selection guidelines state that the values of the parameters should be chosen according to some estimated characteristics of the input and some desired characteristics of the output. The effectiveness of the filter and the presented guidelines is validated through numerical examples and their application to a closed-loop, force control of a robot manipulator. Shanhai Jin, Ryo Kikuuwe, and Motoji Yamamoto Copyright © 2012 Shanhai Jin et al. All rights reserved. Tue, 18 Dec 2012 18:40:07 +0000 http://www.hindawi.com/journals/jcse/2012/827479/ Qingsong Xu, Pak-Kin Wong, Minping Jia, Micky Rakotondrabe, and Li Zhang Copyright © 2012 Qingsong Xu et al. All rights reserved. Wed, 21 Nov 2012 10:37:49 +0000 http://www.hindawi.com/journals/jcse/2012/267519/ A continuous fuel level sensor using a side-emitting optical fiber is introduced in this paper. This sensor operates on the modulation of the light intensity in fiber, which is caused by the cladding’s acceptance angle change when it is immersed in fuel. The fiber is bent as a spiral shape to increase the sensor’s sensitivity by increasing the attenuation coefficient and fiber’s submerged length compared to liquid level. The attenuation coefficients of fiber with different bent radiuses in the air and water are acquired through experiments. The fiber is designed as a spiral shape with a steadily changing slope, and its response to water level is simulated. The experimental results taken in water and aviation kerosene demonstrate a performance of 0.9 m range and 10 mm resolution. Chengrui Zhao, Lin Ye, Xun Yu, and Junfeng Ge Copyright © 2012 Chengrui Zhao et al. All rights reserved. Sun, 04 Nov 2012 13:58:04 +0000 http://www.hindawi.com/journals/jcse/2012/923617/ Aimed at portable application, a new integrated process chip for thin film bulk acoustic resonator (FBAR) mass sensor is proposed and verified with 0.18 um CMOS processing in this paper. The longitudinal mode FBAR with back-etched structure is fabricated, which has resonant frequency 1.878 GHz and factor 1200. The FBAR oscillator, based on the current-reuse structure, is designed with Modified Butterworth Van Dyke (MBVD) model. The result shows that the FBAR oscillator operates at 1.878 GHz with a phase noise of −107 dBc/Hz and −135 dBc/Hz at 10 KHz and 100 KHz frequency offset, respectively. The whole process chip size with pads is 1300 μm × 950 μm. The FBAR and process chip are bonded together to sense tiny mass. The measurement results show that this chip precision is 1 KHz with the FBAR frequency gap from 25 kHz to 25 MHz. Pengcheng Jin, Shurong Dong, Hao Jin, and Mengjun Wu Copyright © 2012 Pengcheng Jin et al. All rights reserved. Mon, 08 Oct 2012 11:39:58 +0000 http://www.hindawi.com/journals/jcse/2012/389690/ Polyethylene (PE) pipelines with electrofusion (EF) joining is an essential method of transportation of gas energy. EF joints are weak points for leakage and therefore, Nondestructive testing (NDT) methods including ultrasonic array technology are necessary. This paper presents a practical NDT method of fusion joints of polyethylene piping using intelligent ultrasonic image processing techniques. In the proposed method, to detect the defects of electrofusion joints, the NDT is applied based on an ANN-Wavelet method as a digital image processing technique. The proposed approach includes four steps. First an ultrasonic-phased array technique is used to provide real time images of high resolution. In the second step, the images are preprocessed by digital image processing techniques for noise reduction and detection of ROI (Region of Interest). Furthermore, to make more improvement on the images, mathematical morphology techniques such as dilation and erosion are applied. In the 3rd step, a wavelet transform is used to develop a feature vector containing 3-dimensional information on various types of defects. In the final step, all the feature vectors are classified through a backpropagation-based ANN algorithm. The obtained results show that the proposed algorithms are highly reliable and also precise for NDT monitoring. Reza Bohlouli, Babak Rostami, and Jafar Keighobadi Copyright © 2012 Reza Bohlouli et al. All rights reserved. Wed, 03 Oct 2012 17:31:00 +0000 http://www.hindawi.com/journals/jcse/2012/610160/ Surface acoustic wave device with c-axis-oriented aluminum nitride (AlN) piezoelectric thin films on polymer substrates can be potentially used for development of flexible sensors, flexible microfluidic applications, microsystems, and lab-on-chip systems. In this work, the AlN films have been successfully deposited on polymer substrates using the DC reactive magnetron-sputtering method at room temperature, and the XRD, SEM, and AFM methods reveal that low deposition pressure is beneficial to the highly c-axis-oriented AlN film on polymer substrates. Studies toward the development of AlN thin film-based flexible surface acoustic wave devices on the polymer substrates are initiated and the experimental and simulated results demonstrate the devices showing the acoustic wave velocity of 9000–10000 m/s, which indicate the AlN lamb wave. Jian Zhou, Shurong Dong, Hao Jin, Bing Feng, and Demiao Wang Copyright © 2012 Jian Zhou et al. All rights reserved. Mon, 24 Sep 2012 11:45:17 +0000 http://www.hindawi.com/journals/jcse/2012/634985/ A simple model-free controller is presented for solving the nonlinear dynamic control problems. As an example of the problem, a planetary gear-type inverted pendulum (PIP) is discussed. To control the inherently unstable system which requires real-time control responses, the design of a smart and simple controller is made necessary. The model-free controller proposed includes a swing-up controller part and a stabilization controller part; neither controller has any information about the PIP. Since the input/output scaling parameters of the fuzzy controller are highly sensitive, we use genetic algorithm (GA) to obtain the optimal control parameters. The experimental results show the effectiveness and robustness of the present controller. Huanhuan Mai, Ying-Jeh Huang, Xiaofeng Liao, and Ping-Chou Wu Copyright © 2012 Huanhuan Mai et al. All rights reserved. Wed, 19 Sep 2012 10:40:59 +0000 http://www.hindawi.com/journals/jcse/2012/902576/ We propose a new adaptive gain robust output feedback controller for a class of the Lipschitz nonlinear systems with unknown upper bound of uncertainty. The proposed adaptive gain robust output feedback controller is designed so as to reduce the effect of uncertainties and Lipschitz nonlinearities. In this paper, we show that sufficient conditions for the existence of the proposed adaptive gain robust output feedback controller are reduced to LMI conditions. Finally, the effectiveness of the proposed robust output feedback controller is demonstrated by numerical simulations. Hidetoshi Oya and Kojiro Hagino Copyright © 2012 Hidetoshi Oya and Kojiro Hagino. All rights reserved. Tue, 18 Sep 2012 09:58:48 +0000 http://www.hindawi.com/journals/jcse/2012/827353/ Chengyu Cao, Lili Ma, and Yunjun Xu Copyright © 2012 Chengyu Cao et al. All rights reserved. Mon, 10 Sep 2012 13:40:42 +0000 http://www.hindawi.com/journals/jcse/2012/517157/ The problem of stabilization for a class of neutral-type neural networks with discrete and unbounded distributed delays is investigated. By introducing an appropriate Lyapunov-Krasovskii functional and using Jensen inequality technique to deal with its derivative, delay-range-dependent and rate-dependent stabilization criteria are presented in the form of LMIs with nonlinear constraints. In order to solve the nonlinear problem, a cone complementarity linearization (CCL) algorithm is offered. In addition, several numerical examples are provided to illustrate the applicability of the proposed approach. Yantao Wang, Xue Lin, and Xian Zhang Copyright © 2012 Yantao Wang et al. All rights reserved. Thu, 06 Sep 2012 10:26:32 +0000 http://www.hindawi.com/journals/jcse/2012/564906/ For a class of linear MIMO uncertain systems, a dynamic sliding mode control algorithm that avoids the chattering problem is proposed in this paper. Without using any differentiator, we develop a modified asymptotically stable second-order sliding mode control law in which the proposed controller can guarantee the finite time convergence to the sliding mode and can show that the system states asymptotically approach to zero. Finally, a numerical example is explained for demonstrating the applicability of the proposed scheme. Jeang-Lin Chang Copyright © 2012 Jeang-Lin Chang. All rights reserved. Wed, 18 Jul 2012 13:50:28 +0000 http://www.hindawi.com/journals/jcse/2012/736586/ Due to the uncertainty of wind and because wind energy conversion systems (WECSs) have strong nonlinear characteristics, accurate model of the WECS is difficult to be built. To solve this problem, data-driven control technology is selected and data-driven controller for the WECS is designed based on the Markov model. The neural networks are designed to optimize the output of the system based on the data-driven control system model. In order to improve the efficiency of the neural network training, three different learning rules are compared. Analysis results and SCADA data of the wind farm are compared, and it is shown that the method effectively reduces fluctuations of the generator speed, the safety of the wind turbines can be enhanced, the accuracy of the WECS output is improved, and more wind energy is captured. T. Li, A. J. Feng, and L. Zhao Copyright © 2012 T. Li et al. All rights reserved. Wed, 18 Jul 2012 10:07:52 +0000 http://www.hindawi.com/journals/jcse/2012/964242/ Automatic profiling machine is a movement system that has a high degree of parameter variation and high frequency of transient process, and it requires an accurate control in time. In this paper, the discrete model reference adaptive control system of automatic profiling machine is discussed. Firstly, the model of automatic profiling machine is presented according to the parameters of DC motor. Then the design of the discrete model reference adaptive control is proposed, and the control rules are proven. The results of simulation show that adaptive control system has favorable dynamic performances. Peng Song, Guo-kai Xu, and Xiu-chun Zhao Copyright © 2012 Peng Song et al. All rights reserved. Wed, 18 Jul 2012 08:03:20 +0000 http://www.hindawi.com/journals/jcse/2012/478346/ A fractional-order controller will be proposed to regulate the inlet oxygen into the heart-lung machine. An analytical approach will be explained to satisfy some requirements together with practical implementation of some restrictions for the first time. Primarily a nonlinear single-input single-output (SISO) time-delay model which was obtained previously in the literature is introduced for the oxygen generation process in the heart-lung machine system and we will complete it by adding some new states to control it. Thereafter, the system is linearized using the state feedback linearization approach to find a third-order time-delay dynamics. Consequently classical PID and fractional order 𝑃𝐼𝜆𝐷𝜇 controllers are gained to assess the quality of the proposed technique. A set of optimal parameters of those controllers are achieved through the genetic algorithm optimization procedure through minimizing a cost function. Our design method focuses on minimizing some famous performance criterions such as IAE, ISE, and ITSE. In the genetic algorithm, the controller parameters are chosen as a random population. The best relevant values are achieved by reducing the cost function. A time-domain simulation signifies the performance of 𝑃𝐼𝜆𝐷𝜇 controller with respect to a traditional optimized PID controller. S. J. Sadati, A. Ranjbar Noei, and R. Ghaderi Copyright © 2012 S. J. Sadati et al. All rights reserved. Sun, 15 Jul 2012 11:31:04 +0000 http://www.hindawi.com/journals/jcse/2012/265808/ In this work, it is presented a new contribution to the design of a robust MPC with output feedback, input constraints, and uncertain model. Multivariable predictive controllers have been used in industry to reduce the variability of the process output and to allow the operation of the system near to the constraints, where it is usually located the optimum operating point. For this reason, new controllers have been developed with the objective of achieving better performance, simpler control structure, and robustness with respect to model uncertainty. In this work, it is proposed a model predictive controller based on a nonminimal state space model where the state is perfectly known. It is an infinite prediction horizon controller, and it is assumed that there is uncertainty in the stable part of the model, which may also include integrating modes that are frequently present in the process plants. The method is illustrated with a simulation example of the process industry using linear models based on a real process. J. M. Perez, D. Odloak, and E. L. Lima Copyright © 2012 J. M. Perez et al. All rights reserved. Thu, 05 Jul 2012 12:17:56 +0000 http://www.hindawi.com/journals/jcse/2012/136809/ Ya-Jun Pan, Peter X. Liu, Yang Shi, and Jie Sheng Copyright © 2012 Ya-Jun Pan et al. All rights reserved.