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Jie Huang - One of the best experts on this subject based on the ideXlab platform.

  • global robust Servomechanism of a class of nonlinear systems using output feedback
    Asian Journal of Control, 2008
    Co-Authors: Zhiyong Chen, Jie Huang
    Abstract:

    The robust Servomechanism problem (alternatively, output regulation problem) of the class of nonlinear systems in lower triangular form has been extensively studied in recent years. The semi-global solution was first given by either state feedback or output feedback. The global solution by state feedback was given very recently. However, the global solution by output feedback has long been an open problem. In this paper, we present a set of solvability conditions of the global robust Servomechanism problem for this class of nonlinear systems by output feedback.

  • Dissipativity, stabilization, and regulation of cascade-connected systems
    IEEE Transactions on Automatic Control, 2004
    Co-Authors: Zhiyong Chen, Jie Huang
    Abstract:

    This paper presents a technical framework utilizing the dissipativity mechanism that gives rise to the solution of the global regulation problem of the cascade-connected systems subject to both dynamic uncertainty and static uncertainty without knowing the bound of the static uncertainty. Additionally, this paper shows that the nonlinear robust Servomechanism problem for the lower triangular systems can be cast into the regulation problem for the cascade-connected systems, thus leading to a complete solution of the nonlinear robust Servomechanism problem for the lower triangular systems for the most general case where both the uncertain parameters and the exogenous signals can be arbitrarily large.

  • Global Robust Servomechanism Problem of Lower-Triangular Systems in the General Case1
    2003 4th International Conference on Control and Automation Proceedings, 2003
    Co-Authors: Zhiyong Chen, Jie Huang
    Abstract:

    We will show that, for the class of nonlinear lower-triangular systems, the robust Servomechanism problem can be cast into a robust regulation problem for the same class of systems augmented by dynamic uncertainties. Thus, using our recent result on adaptive regulation of lower-triangular systems with both static and dynamic uncertainties, we will solve the robust Servomechanism problem of the lower-triangular systems for the general case where both the uncertain parameter and the exogenous signal can be arbitrarily large.

  • on the discrete time robust nonlinear Servomechanism problem
    Communications in information and systems, 2003
    Co-Authors: Jie Huang
    Abstract:

    The paper addresses the robust Servomechanism problem for nonlinear discrete-time systems. The solvability conditions for the discrete-time k th -order robust Servomechanism prob- lem is first established by using the internal model principle. Then it is further shown that, under an additional assumption on the solution of the discrete regulator equations, the solvability of the discrete-time k th -order robust Servomechanism problem leads to the solvability of the discrete-time robust Servomechanism problem. The results of this paper give a discrete-time counterpart of the results on the continuous-time robust Servomechanism problem.

  • A neural network method for the nonlinear Servomechanism problem
    Proceedings of the 1998 American Control Conference. ACC (IEEE Cat. No.98CH36207), 1998
    Co-Authors: Jie Huang
    Abstract:

    The solution of the nonlinear Servomechanism problem relies on the solvability of a set of mixed nonlinear partial differential and algebraic equations known as the regulator equations. Due to the nonlinear nature, it is difficult to obtain the exact solution of the regulator equations. This paper proposes to solve the regulator equations based on a class of recurrent neural network, leading to an effective approach to approximately solving the nonlinear Servomechanism problem.

E J Davison - One of the best experts on this subject based on the ideXlab platform.

  • Recent Advances in Learning and Control - The Servomechanism Problem for SISO Positive LTI Systems
    Lecture Notes in Control and Information Sciences, 2020
    Co-Authors: Bartek Roszak, E J Davison
    Abstract:

    In this paper, we study the Servomechanism problem for positive LTI systems. In particular, we consider the robust Servomechanism problem of nonnegative constant reference signals for stable SISO positive LTI systems with constant disturbances, for the case when the plant model of the system is not known.

  • The Robust Control of a Servomechanism Problem with Time Delay
    IFAC Proceedings Volumes, 2017
    Co-Authors: A A Goldenberg, E J Davison
    Abstract:

    Abstract In this paper, the Servomechanism problem for a linear, time- invariant multivariable system is extended to systems with time delay. Necessary and sufficient conditions for the existence of a solution to the time delay Servomechanism problem and the structure of compensators required for this problem are obtained. The robust time delay Servomechanism problem is then studied in which plant perturbations are allowed to occur in the system. Necessary and sufficient conditions for the existence of a solution to this robust Servomechanism problem, and a characterization of all compensators which solve the robust Servomechanism problem are obtained.

  • Multivariable Servomechanism Controller for Autonomous Operation of a Distributed Generation Unit: Design and Performance Evaluation
    IEEE Transactions on Power Systems, 2010
    Co-Authors: Houshang Karimi, E J Davison, Reza Iravani
    Abstract:

    A linear time-invariant (LTI) robust Servomechanism controller for islanded (autonomous) operation of a distributed generation (DG) unit and its local load is proposed. The DG unit utilizes a voltage-sourced converter (VSC) as the interface medium. The controller design is obtained by introducing a new optimal controller design procedure, in conjunction with a proposed non-conservative robustness constraint. The proposed controller utilizes 1) an internal oscillator for frequency control and 2) a robust Servomechanism controller (RSC) to regulate the island voltage. Despite uncertainty of the load parameters, the proposed controller guarantees robust stability and pre-specified performance criteria, e.g., fast transient response and zero steady-state error. The theoretical aspects of the proposed robust Servomechanism controller including the existence conditions, design of the controller, and robust stability analysis of the closed-loop system are studied. Moreover, the performance of the robust Servomechanism controller based on 1) simulation studies in the MATLAB software environment, and 2) experiments in a laboratory-scale setup, is presented in this paper. In particular, reference signal tracking and robustness of the closed-loop system with respect to the load parameter uncertainty are investigated. Both computer simulation studies and experimental results confirm that the proposed robust controller provides the specified performance characteristics of the closed-loop system.

  • The Servomechanism Problem for Unknown MIMO LTI Positive Systems: Feedforward and Robust Tuning Regulators
    2008 American Control Conference, 2008
    Co-Authors: Bartek Roszak, E J Davison
    Abstract:

    In this paper we study the Servomechanism problem for unknown MIMO positive LTI systems under constant reference signals and constant measurable disturbances. In particular, we show that in general the Servomechanism problem for standard positive systems is not solvable. Thereafter, we show what subclass of reference and disturbance signals can be considered, and more importantly, we provide the controller structure that solves the problem for the feasible subclass of reference and disturbance signals.

Chung Choo Chung - One of the best experts on this subject based on the ideXlab platform.

  • A modified discrete-time sliding mode control for proximate time-optimal Servomechanisms
    2012 American Control Conference (ACC), 2012
    Co-Authors: Ji Young Jeong, Chung Choo Chung
    Abstract:

    In this paper, a modified discrete-time sliding mode control for proximate time-optimal Servomechanisms is proposed in order to improve the performance of point-to-point motion in a 2nd-order damped linear system. The proposed method consists of a proximate time-optimal control, a time varying sliding mode control, and a variable convergence rate factor in discrete-time. Three sufficient conditions are also proposed to ensure the stability of the suggested scheme. The variable convergence rate factor is implemented in the discrete-time sliding mode control in order to eliminate the overshoot problem and reduce the settling time. The proposed controller was applied to a scanning probe microscope-based data storage system so as to compare its performance to that of a proximate time-optimal Servomechanism and a sliding mode proximate time-optimal Servomechanism.

  • Design of a Servomechanism with sliding mode for a disk drive actuator
    Proceedings of the 38th IEEE Conference on Decision and Control (Cat. No.99CH36304), 1999
    Co-Authors: Sang-fun Baek, Chung Choo Chung
    Abstract:

    Considers a Servomechanism design with sliding mode for disk drives. The proposed Servomechanism consists of suboptimal time control for seek, and sliding mode control for settling and tracking. For fast seek, suboptimal time control with feedforward is used. For settling and tracking, observer based sliding mode control with a fixed linear switching hyperplane is designed in the discrete time domain. Through the results of simulation and experiment, it is shown that the proposed Servomechanism is effective to reduce velocity tracking error during settling.

E J Davison - One of the best experts on this subject based on the ideXlab platform.

  • the positive Servomechanism problem under lqcr control
    Lecture Notes in Control and Information Sciences, 2009
    Co-Authors: Bartek Roszak, E J Davison
    Abstract:

    This paper considers the Servomechanism problem for MIMO positive LTI systems. In particular, the Servomechanism problem of nonnegative constant reference signals for stable MIMO positive LTI systems with unmeasurable unknown constant nonnegative disturbances under strictly nonnegative control inputs is solved using a clamping LQ regulator.

  • the Servomechanism problem for siso positive lti systems
    Lecture Notes in Control and Information Sciences, 2008
    Co-Authors: Bartek Roszak, E J Davison
    Abstract:

    In this paper, we study the Servomechanism problem for positive LTI systems. In particular, we consider the robust Servomechanism problem of nonnegative constant reference signals for stable SISO positive LTI systems with constant disturbances, for the case when the plant model of the system is not known.

  • the Servomechanism problem for unknown siso positive lti systems via tuning regulators and clamping
    IFAC Proceedings Volumes, 2008
    Co-Authors: Bartek Roszak, E J Davison
    Abstract:

    Abstract In this paper we consider the Servomechanism problem for SISO positive LTI systems. In particular, we solve the robust Servomechanism problem of nonnegative constant reference signals for stable SISO positive unknown LTI systems with constant nonnegative unmeasurable disturbances under strictly nonnegative control inputs, using a clamping tuning regulator.

  • Servomechanism controller design of web handling systems
    IEEE Transactions on Control Systems Technology, 2003
    Co-Authors: E J Davison
    Abstract:

    In traditional web handling processes, web tension and speed are typically controlled assuming that the web system consists of a number of single-input-single-output systems. This assumption often results in large interactions occurring in the closed-loop system between the control loops and, hence, results in high-quality control being difficult to achieve. In this paper, the control of the web handling processes is treated as a multivariable Servomechanism problem. Two types of controller design, the "perfect control Servomechanism controller" and the "tuning regulator", are studied and implemented on an industrial web machine. The experimental results obtained show that these controllers provide excellent tension and speed response compared with conventional controllers used in web systems. In particular, it is shown that the "tuning regulator" approach is only marginally worse than the "perfect control Servomechanism controller" approach, despite the fact that it does not require a mathematical model of the web process, and is simpler to implement.

Bartek Roszak - One of the best experts on this subject based on the ideXlab platform.