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Control Applications, 2004. Proceedings of the 2004 IEEE International Conference on

Date 2-4 Sept. 2004

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Displaying Results 1 - 25 of 175
  • Model gain scheduling and reporting for ethylene plant on-line optimizer

    Page(s): 1085 - 1089 Vol.2
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (590 KB) |  | HTML iconHTML  

    An ethylene plant is one of the largest chemical plants. As such, there are frequent changes in hydrocarbon feed mix, individual feed quality and demand for its olefin products. This makes it difficult to operate an ethylene plant in an optimal way. Showa Denko K.K. (SDK) has applied on-line optimization software packages of Honeywell Process Solutions to its ethylene plant. The software packages consist of large-scale model predictive control (MPC) controllers and optimization systems. As a function of the software, furnace yield model gains of MPC are scheduled by using a rigorous first principle model to cope with the strong non-linearity of the reactions in the furnace. In addition, non-linearity of consumption of fuel and steam is important, especially when user demand or storage tank room is limited and productions rates are kept constant. In that case, the direction of optimization of fuel and steam users could be wrong if non-linearity is ignored. The software, however, cannot cope with that non-linearity. Therefore, the achievable performance of the original software is limited. To cope with non-linearity, SDK developed a function of gain scheduling for utility models. As a result, both throughput and efficiency were improved more than expected. Since the on-line optimizer copes with many constraints and checks benefits, it is difficult for operators to intuitively understand the optimization results. Therefore, SDK also developed user interfaces and daily reporting systems for the on-line optimizer. The user interfaces indicate the operating condition and the bottlenecks in the ethylene plant every minute. Thus, operators can recognize the operation determined by the on-line optimizer. In daily reports, process trends of bottleneck points and manipulated variables of the on-line optimizer are reported. The daily reports are automatically generated and sent to members in associated sections by e-mail. With the report, the operation of the ethylene plant can be monitored and fine-tuning of the on-line optimizer can be performed. View full abstract»

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  • Robust stability of nonlinear polynomial systems by LMI

    Page(s): 1017 - 1019 Vol.2
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (510 KB) |  | HTML iconHTML  

    The use of modern results from real algebraic geometry has led to new approaches to the problem of positivity of polynomials. This manuscript shows how these results can be applied in order to ensure robust stability for uncertain polynomial systems. Due to the mentioned results from real algebra we are able to derive sufficient conditions for asymptotic stability in the form of linear matrix inequalities (LMI) and to estimate a subset of the robust region of attraction. View full abstract»

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  • Reconstruction based sensor fault identification in chemical processes

    Page(s): 1096 - 1100 Vol.2
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (610 KB) |  | HTML iconHTML  

    This paper discusses the reconstruction based sensor fault identification in a chemical process. Many approaches to monitor chemical processes have been developed and modified to isolate various abnormal operating conditions. One of those methods is the reconstruction based approach which has been developed from the missing data estimation to treat incomplete data obtained from a chemical process. We focus on the sensor fault identification using the principal component analysis based on reconstruction and propose new identification indices, FIIM and FIIR, which can distinguish an abnormal sensor from the others in both of model and residual spaces. In addition, a problem of reconstruction based sensor fault identification and identification performances using different reconstruction methods are discussed in this paper. The proposed indices are applied to a simulated nonisothermal continuous stirred tank reactor. View full abstract»

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  • Adaptive inverse control for piezoelectric actuator with dominant hysteresis

    Page(s): 973 - 976 Vol.2
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (560 KB) |  | HTML iconHTML  

    Piezoelectric actuator controlled by voltage shows serious hysteresis phenomena, which severely degrades the positioning accuracy. Based on Prandtle-Ishlinskii hysteresis operator, an adaptive inverse control approach is presented for reducing hysteresis. The weights of the model are identified by using LMS algorithm. The realization of an inverse feedforward controller for the linearization of a piezoelectric actuator is formulated. Experiments were performed on a micro-positioning system driven by piezoelectric actuators. The results show that the presented adaptive inverse control lowers the non-linearity error from about 17.3 to about 2% in comparison to the conventionally open-loop control. View full abstract»

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  • A time frequency distribution and ART2 network approach in non destructive evaluation, fault localization proposal

    Page(s): 1242 - 1247 Vol.2
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (764 KB) |  | HTML iconHTML  

    Nowadays the use of pattern recognition for signal processing presents a novel approach in order to determine the position and number of flaws within a tested material. The aim of this work is to propose a pattern recognition technique in order to determine different types of flaws based upon pulse echoes using ultrasonic measurements. This approach is performed by the processing of an ultrasonic measurement using time frequency distribution technique and ART2 network. This approach is focused to understand how pattern recognition can be pursued into fault diagnosis. View full abstract»

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  • Visual servo tracking control of a wheeled mobile robot with a monocular fixed camera

    Page(s): 1061 - 1066 Vol.2
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (740 KB) |  | HTML iconHTML  

    A visual servo tracking controller for a wheeled mobile robot (WMR) is developed that utilizes feedback from a monocular camera system that is mounted with a fixed position and orientation (i.e., the eye-to-hand problem). A prerecorded image sequence (e.g., a video) of four target points is used to define a desired trajectory for the WMR. By comparing the target points from the prerecorded sequence with the corresponding target points in the live image, projective geometric relationships are exploited to construct a Euclidean homography. The information obtained by decomposing the Euclidean homography is used to develop a kinematic controller. A Lyapunov-based analysis is used to develop an adaptive update law to actively compensate for the lack of depth information required for the translation error system. In contrast to previous WMR visual servo controllers using a fixed camera configuration, the controller in this paper does not require the camera to be mounted so that the optical axis is perpendicular to the WMR plane of motion. View full abstract»

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  • A combined geometric-volumetric calibration of inclined cylindrical underground storage tanks using the regularized least-squares method

    Page(s): 1515 - 1520 Vol.2
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (691 KB) |  | HTML iconHTML  

    Due to some technical and economical factors, the conventional geometric calibration cannot be completely applied to inclined underground storage tanks (UST), nor can the regular volumetric calibration. We propose a novel calibration method called combined geometric-volumetric calibration. The method is based on the data fitting of a level-volume (LV) characteristic curve where LV data are acquired through partially volumetric calibration. The approach aims to find the inclination of UST in order to generate the LV table. The calibrating problem is formulated as a series of standard regularized least-squares (RLS) problem. A computer program with user-friendly GUIs has also been implemented, on the basis of MATLAB, for the ease of the calibrating operation. The numerical example verifies that the presented method could determine the amount of inclination, and return the LV curve that satisfactorily matched the LV data. The result suggests that the presented method as well as the program can be realized with actual applications in industrial sections. View full abstract»

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  • Implementation of dual redundant CAN module based on IEEE 1451 in in-vehicle network

    Page(s): 1558 - 1563 Vol.2
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (736 KB) |  | HTML iconHTML  

    Drive-by-wire systems are consists of bus systems, microprocessors, electrical actuators, and sensors. Replacing rigid mechanical components with dynamically configurable electronic elements triggers an almost organic system wide level of integration. For the safety design, integration methods including reliability and fault-tolerance are required. In general, the fault-tolerance function is realized by redundancy of the communication module. In this paper, we introduced the concept and design methodology of an IEEE 1451 based dual redundant module as one method for realization of the redundancy in CAN network. Also, we implemented the experimental model for the brake-by-wire system to observe feasibility of the dual redundancy module. View full abstract»

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  • Engine modeling based on projection method and conservation laws

    Page(s): 1420 - 1424 Vol.2
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (597 KB) |  | HTML iconHTML  

    To realize the concurrent development of engine hardware and control software, a rapid modeling method has been proposed based on "projection method" for mechanical portions and conservation laws for the other portions. Those methods can preserve the assembling model components of the actual engine represented by the visual image. In order to realize the rapid modeling environment, the concept of "base model" and "model library" has been also introduced. The base model defines partitioning of engine model and the interfaces among the model components. It can be used as the template for the required engine model. The model of a targeted subsystem control, an actuator control as an example, can be rapidly developed abstracting the necessary portions which are revised or simplified according to the required fidelity. View full abstract»

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  • Development of fault detection and diagnosis schemes for industrial refrigeration systems - lessons learned

    Page(s): 1248 - 1253 Vol.2
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (692 KB) |  | HTML iconHTML  

    The success of a fault detection and diagnosis (FDD) scheme depends not alone on developing an advanced detection scheme. To enable successful deployment in industrial applications, an economically optimal development of FDD schemes are required. This paper reviews and discusses the gained experiences achieved by employing a combination of various techniques, methods, and algorithms, which are proposed by academia, on an industrial application. The main focus is on sharing the "lessons learned" from developing and employing fault-tolerant functionalities to a controlled process in order to meet the industrial needs while satisfying economically motivated constraints. View full abstract»

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  • Development of a new hydraulic cylinder with built-in compound control function of displacement and thrust

    Page(s): 1177 - 1182 Vol.2
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (716 KB) |  | HTML iconHTML  

    A novel actuator with built-in compound control function of displacement and thrust is developed. This actuator is a kind of compact hydraulic cylinder system, which consists of a stepping motor, a control valve with a spool and a slide sleeve, a hydraulic cylinder and a mechanical feedback mechanism. In the proposed actuator, with a mechanical displacement feedback and a mechanical pressure feedback, displacement and thrust control can be realized. Also the flexible compliance control could be realized by adjusting the feedback weights in the actuator. The basic characteristics of this actuator are investigated theoretically. Through the prototype experiments, it is confirmed that the actuator is very effective in the compound control and compliance control. Furthermore, it is proved that the precision of this actuator can be improved by introducing a dither, and the system dynamic performance can be improved by adding damping orifices. View full abstract»

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  • Optimal posture control for object on active vision robot

    Page(s): 1141 - 1146 Vol.2
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (674 KB) |  | HTML iconHTML  

    The paper describes way of determining the optimal posture of active vision robot (AVRobot) for recognizing unidentified objects. In the object recognition with visual information by the AVRobot, it is required to measure the accurate positions of feature points of a target object. For the precise measurement, it is preferable, for example, that several feature points exist in a captured image for calculation of relative positions and distances among them and that the position of feature point on the image moves boldly in small motion of the camera attached on the robot. In this paper, the motion control law based on visual servoing and posture design technique with -space vector is proposed so as to satisfy such requirements. The control law simultaneously achieves two control requirement in our approach; the first one is to make the position of primary feature point of the target locate center of the image, and the second to induce the camera position where let the image transition sensitive to the infinitesimal change of the camera motion referring the positions of the secondary features, so as to suppress the measurement errors of the feature positions. View full abstract»

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  • Defining a model-based calibration process for a twin-independent valve timing engine

    Page(s): 1431 - 1436 Vol.2
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (744 KB) |  | HTML iconHTML  

    Model-based calibration tools can be used to prototype a process for an advanced engine type, reducing the burden of developing optimal calibrations for complex modern engines. This paper is a practical example of using simulation to prototype a calibration process before the engine hardware is available. We produce optimized tables for spark and cam timings for a 2.2 L naturally aspirated 4-valve overhead-cam spark ignition engine with twin-independent variable valve timing. We use design of experiments techniques to minimize testing, and a novel boundary modeling technique to describe the surface of the engine operating envelope and to constrain optimizations to realistic bounds. Testing simulated prototypes rather than the real hardware can save time and money by catching process errors and clearly defining measurement data requirements early in the design cycle. Offline optimization can be carried out independently of the test bench, limiting expenditure. This can help obtain consistent results faster, strengthen the predictive capability of the design process, and increase test bed productivity. View full abstract»

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  • Estimation of vehicle loading state

    Page(s): 1260 - 1265 Vol.2
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (638 KB) |  | HTML iconHTML  

    In the area of dynamic driving control and sensor monitoring, the parameters, which characterize the vehicle loading state, play an important role. In practice, the vehicle loading state and therefore the parameters change permanently. This fact influences the quality of both the control and the sensor monitoring. To ensure the efficiency of such control and sensor monitoring systems, there exist several possibilities. One possibility is to estimate the parameters on-line and insert them into the related models continuously. The estimated parameters can be regarded as available vehicle parameters for the total electronic control system. The contribution of this paper is to develop a concept for estimating these parameters. View full abstract»

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  • Robust performance and transient response of the Hμ DIA control for magnetic suspension systems

    Page(s): 1020 - 1025 Vol.2
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (675 KB) |  | HTML iconHTML  

    This paper deals with robust performance and transient response of H/μ DIA control for magnetic suspension systems. H DIA control is an H control problem which treats a mixed disturbance and an initial-state uncertainty attenuation (DIA) and supplies H controls with good transients. H DIA controller has a good initial response property, however its robust performance might be improved. We propose H/μ DIA control which is to find a multi-objective controller to achieve both the H DIA condition for good initial responses/transient responses and the structured singular value μ condition for robust performance. We apply this proposed approach to magnetic suspension systems, and design a robust controller, which has both good properties. Finally simulation and experimental results show effectiveness of the proposed control system design framework. View full abstract»

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  • A collision avoidance control for multi-vehicle using PWA/MLD hybrid system representation

    Page(s): 872 - 877 Vol.2
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (630 KB) |  | HTML iconHTML  

    This paper considers a collision avoidance control for multi-vehicle systems which are modeled as a class of hybrid systems, piecewise affine (PWA) systems. Using an equivalence between piecewise affine systems and mixed logical dynamical (MLD) systems, the collision avoidance problem is formulated as mixed integer programming for a trajectory generation problem. We propose an optimal trajectory path which guarantees that the vehicle moves to the objective point without collision. The closed loop system is constructed by two parts: a trajectory generation part and a local control part. Finally, simulation results and the experimental results are shown. View full abstract»

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  • RobSin: a new tool for robust design of PID and three-term controllers based on singular frequencies

    Page(s): 1546 - 1551 Vol.2
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (648 KB) |  | HTML iconHTML  

    This paper introduces a new Matlab Toolbox called RobSin, which for a given plant (multi-) model provides a fast computation of the stabilizing region in the coordinates of PID parameters. The algorithms use the concept of singular frequencies for computation of convex polygonal slices on planes kp = const. In addition to time-continuous systems, the method described in this paper is especially convenient for the design of time-discrete PID and three-term controllers and time-delay systems. View full abstract»

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  • AC induction motor sensorless control using Lyapunov function based flux and speed observer implemented on Motorola DSP

    Page(s): 1744 - 1750 Vol.2
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (690 KB) |  | HTML iconHTML  

    AC induction motors become very popular for motion control applications due to their simple and reliable construction. Control of drives based on AC induction motors is a quite complex task. Provided the vector control algorithm is used we need to know not only the rotor speed but also the position of the magnetic flux inside the motor during the control process. In most applications the flux sensors are omitted and the magnetic flux phasor position has to be calculated. But there are also applications in which even speed sensors should be omitted. In such a situation, we have to solve the task of state reconstruction only from voltage and currents measurements. In the current paper, we present a method based on deterministic evaluation of measurement using the state observer based on Lyapunov function. The method has been proven in testing on real AC induction machine. View full abstract»

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  • Unified PID design for load frequency control

    Page(s): 1627 - 1632 Vol.2
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (617 KB) |  | HTML iconHTML  

    This work presents a new PID controller for power system load-frequency control. A systematic tuning method is developed. The method is mainly based on a maximum peak-resonance specification that is graphically supported by the Nichols chart. The proposed controller is simple, effective and can ensure that the overall system performance is desirable. Comparative results of this new load-frequency controller and a conventional PI one show the improvement in system damping remarkably. View full abstract»

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  • Fixed order controller design via generalized KYP lemma

    Page(s): 1527 - 1532 Vol.2
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (648 KB) |  | HTML iconHTML  

    This paper proposes methods for fixed-order controller synthesis based on the generalized KYP (GKYP) lemma that provides a unified LMI characterization of frequency domain inequalities in (semi) finite frequency ranges for both continuous and discrete-time systems. We first show the GKYP lemma and how to use it for control system design including PID controller synthesis and controller order reduction with fixed poles. We then propose a recursive algorithm for fixed structure controller synthesis, where both the numerator and denominator are design parameters. We also provide a robust GKYP lemma to encompass the practical situations. The effectiveness of the proposed methods is verified by several numerical examples which include a practical application of tracking controller design for laser-driven micro-airplanes. View full abstract»

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  • A robust controller for an electro-mechanical fin actuator

    Page(s): 1448 - 1453 Vol.2
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (607 KB) |  | HTML iconHTML  

    The objective of this paper is to realize a robust controller for an electro-mechanical fin servo system of a missile. We design the robust controller using an H optimization method and a disturbance observer, in order to improve the overall performance of the fin servo system. The H controller is designed using the mixed sensitivity H control method, based on the 2-Riccati state-space approach of Glover and Doyle. The newly proposed disturbance observer is applied to the fin servo system and it consists of three elements: a time delay estimation algorithm part, an anti-filtering compensator (AFC) part and a low pass filter (LPF) part. The effectiveness of this control scheme is verified through simulations. View full abstract»

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  • System identification and LQG control of variable-compression HCCI engine dynamics

    Page(s): 1442 - 1447 Vol.2
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (669 KB) |  | HTML iconHTML  

    The homogenous charge compression ignition (HCCI) combustion engine has potential to replace the spark ignition and compression ignition engines of today. One of the main problems in making the engine commercially attractive is the lack of direct means of controlling the ignition phasing. We investigate the potential of inlet air temperature as a means to ignition actuation. This article describes a method for system identification of the HCCI process, and development of an effective LQG regulator for the combustion process, Matlab and Simulink being used in computations and simulations. View full abstract»

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  • Design of a control law for a semiactive suspension system using a solenoid valve damper

    Page(s): 1467 - 1472 Vol.2
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (762 KB) |  | HTML iconHTML  

    We present a design procedure for semiactive suspension systems using a solenoid valve damper as a shock absorber. We first derive a target active control law that takes the form of a feedback control law. Then, we approximate the target law by controlling the damper coefficient f of the semiactive suspension. The nonlinear characteristics force-velocity of the solenoid valve damper is used to approximate the target law. To improve the efficiency of the proposed system, we take into account the updating frequency of the coefficient f and compute the expected value of f using a predictive procedure. View full abstract»

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  • H DIA control of magnetic suspension systems

    Page(s): 1697 - 1702 Vol.2
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (691 KB) |  | HTML iconHTML  

    This paper deals with the H DlA control system design attenuating initial-state uncertainties and its application to magnetic suspension systems. Here the H DlA control means a mixed disturbance and an initial state uncertainty attenuation (DlA) control for linear time-invariant systems in the infinite-horizon case. The H DIA control problem supplies H controls with good transients and assures H controls of robustness against initial-state uncertainties. We derived a necessary and sufficient condition of the generalized H DlA problem. We apply this H DIA approach to magnetic suspension systems, and evaluate a mixed attenuation property of the proposed approach via experiments. We investigate a role of the weighting matrix N for the initial state uncertainty in the control system design. View full abstract»

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  • Robust stability and control of nonlinear reheat power systems

    Page(s): 1479 - 1484 Vol.2
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (625 KB) |  | HTML iconHTML  

    In this paper, the dynamic behavior of reheat power systems is represented by a class of nonlinear time delay models. Both robust stability and state feedback control problems are considered. A convex programming approach is developed to establish tractable conditions expressed by linear matrix inequalities. The effect of finite feedback gains is cast into the analysis. Simulation results of a typical reheat power system are provided to illustrate the theoretical developments. View full abstract»

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