The Experts below are selected from a list of 20514 Experts worldwide ranked by ideXlab platform

Wenjian Cai - One of the best experts on this subject based on the ideXlab platform.

  • normalized decoupling a new approach for mimo process control system design
    Industrial & Engineering Chemistry Research, 2008
    Co-Authors: Wenjian Cai
    Abstract:

    In this paper, a novel engineering oriented decoupling control system design method for two-input, two-output processes is presented. By employing the concept of integrated error, gain and phase changes of a Transfer Function when other loops are closed can be uniquely determined. Consequently, an equivalent Transfer Function Matrix for a closed-loop control system can be obtained and its relations with the original process Transfer Function Matrix are derived. On the basis of the equivalent Transfer Function Matrix, parameters of a stable, proper, and causal ideal diagonal decoupler can then be easily determined by proper parameter assignments of the decoupled Transfer Function Matrix elements. The method avoids the drawbacks of existing decoupling schemes, is very simple and can be easily understood, and can be implemented by field control engineers. An industrial process is employed to demonstrate its simplicity in design and effectiveness in control system performance.

  • equivalent Transfer Function method for pi pid controller design of mimo processes
    Journal of Process Control, 2007
    Co-Authors: Qiang Xiong, Wenjian Cai, Maojun He
    Abstract:

    Abstract In this paper, a novel engineering oriented control system design method for multivariable processes is presented. By employing the concepts of energy transmission ratio and effective relative gain, an equivalent Transfer Function Matrix for closed loop control system can be obtained. Based on the equivalent Transfer Function Matrix, both off-diagonal decoupling controllers and main loop diagonal controllers can be easily designed using the existing PI/PID tuning rules. The main advantages of the method are that: (1) the overall control system performance is better compared with the existing decoupling control methods; (2) it is very simple which can be easily understood and implemented by field control engineers; and (3) the control system is robust, it can still work with satisfactory performance even under significant model mismatches. Several multivariable industrial processes with different interaction characteristics are employed to demonstrate the simplicity and effectiveness of the design method.

J.s.h. Tsai - One of the best experts on this subject based on the ideXlab platform.

  • digital controller design for analog systems represented by multiple input output time delay Transfer Function matrices with long time delays
    Circuits Systems and Signal Processing, 2012
    Co-Authors: H.p. Wang, L B Xie, Leangsan Shieh, J.s.h. Tsai, Y. Zhang
    Abstract:

    This paper presents a digital controller design methodology for multivariable analog systems represented by minimally realizable multiple input–output time-delay Transfer Function matrices with long time delays. First, the analog Transfer Function Matrix with multiple input–output time delays is minimally realized and represented by a delay-free state-space model and a multiple output-delay Function. For a specific multiple time-delay Transfer Function Matrix with complex poles, a minimal realization scheme is newly proposed. Then the minimized delay-free state-space model is utilized for linear quadratic regulator (LQR) design. Furthermore, the designed analog LQR is digitally redesigned via a predictive state-matching method for finding a low-gain digital controller from the pre-designed high-gain analog controller. For implementation of the digitally redesigned controller, a digital observer is constructed for the multiple time-delay system with long time delays. An illustrative example is given to demonstrate the effectiveness of the proposed method.

  • Minimal realisation of the Transfer Function Matrix with multiple time delays
    IET Control Theory & Applications, 2007
    Co-Authors: H.p. Wang, L.s. Shieh, Y. Zhang, J.s.h. Tsai
    Abstract:

    A minimal realisation scheme for a class of multiple time-delay Transfer Function matrices with distinct poles is presented. Also, a simple minimal realisation method is developed for a specific two-input-two-output multiple time-delay system whose poles can be repeated. In addition, a state-space discretisation technique developed for a multivariable system with a single time delay is extended to a multivariable system with multiple time delays. Finally, it should be mentioned that the proposed approach is restricted to systems where multiple time delays arise only in the input and output, and not in the state. Illustrative examples are given to demonstrate the effectiveness of the proposed method.

Shaoyuan Li - One of the best experts on this subject based on the ideXlab platform.

  • normalized decoupling control for high dimensional mimo processes for application in room temperature control hvac systems
    Control Engineering Practice, 2010
    Co-Authors: Yuling Shen, Shaoyuan Li
    Abstract:

    Abstract A novel decoupling control system design for high-dimensional multi-input, multi-output (MIMO) processes is presented. Based on the Relative Normalized Gain Array (RNGA), an Equivalent Transfer Function (ETF) for each element in the Transfer Function Matrix was derived for the closed-loop control system and was used to approximate the inverse of the process Transfer Function Matrix. The decoupler could be easily determined with each element in the First-Order-plus-Time-Delay (FOPTD) form and resulted in a stable, proper and causal decoupled Matrix. A PI/PID controller could then be designed to meet the performance objectives. The main advantage of this method was its simplicity; it did not require extensive calculation effort. To demonstrate its effectiveness, the decoupling control strategy was applied to control the temperatures of four neighboring rooms in an HVAC process.

Maojun He - One of the best experts on this subject based on the ideXlab platform.

  • equivalent Transfer Function method for pi pid controller design of mimo processes
    Journal of Process Control, 2007
    Co-Authors: Qiang Xiong, Wenjian Cai, Maojun He
    Abstract:

    Abstract In this paper, a novel engineering oriented control system design method for multivariable processes is presented. By employing the concepts of energy transmission ratio and effective relative gain, an equivalent Transfer Function Matrix for closed loop control system can be obtained. Based on the equivalent Transfer Function Matrix, both off-diagonal decoupling controllers and main loop diagonal controllers can be easily designed using the existing PI/PID tuning rules. The main advantages of the method are that: (1) the overall control system performance is better compared with the existing decoupling control methods; (2) it is very simple which can be easily understood and implemented by field control engineers; and (3) the control system is robust, it can still work with satisfactory performance even under significant model mismatches. Several multivariable industrial processes with different interaction characteristics are employed to demonstrate the simplicity and effectiveness of the design method.

H.p. Wang - One of the best experts on this subject based on the ideXlab platform.

  • digital controller design for analog systems represented by multiple input output time delay Transfer Function matrices with long time delays
    Circuits Systems and Signal Processing, 2012
    Co-Authors: H.p. Wang, L B Xie, Leangsan Shieh, J.s.h. Tsai, Y. Zhang
    Abstract:

    This paper presents a digital controller design methodology for multivariable analog systems represented by minimally realizable multiple input–output time-delay Transfer Function matrices with long time delays. First, the analog Transfer Function Matrix with multiple input–output time delays is minimally realized and represented by a delay-free state-space model and a multiple output-delay Function. For a specific multiple time-delay Transfer Function Matrix with complex poles, a minimal realization scheme is newly proposed. Then the minimized delay-free state-space model is utilized for linear quadratic regulator (LQR) design. Furthermore, the designed analog LQR is digitally redesigned via a predictive state-matching method for finding a low-gain digital controller from the pre-designed high-gain analog controller. For implementation of the digitally redesigned controller, a digital observer is constructed for the multiple time-delay system with long time delays. An illustrative example is given to demonstrate the effectiveness of the proposed method.

  • Minimal realisation of the Transfer Function Matrix with multiple time delays
    IET Control Theory & Applications, 2007
    Co-Authors: H.p. Wang, L.s. Shieh, Y. Zhang, J.s.h. Tsai
    Abstract:

    A minimal realisation scheme for a class of multiple time-delay Transfer Function matrices with distinct poles is presented. Also, a simple minimal realisation method is developed for a specific two-input-two-output multiple time-delay system whose poles can be repeated. In addition, a state-space discretisation technique developed for a multivariable system with a single time delay is extended to a multivariable system with multiple time delays. Finally, it should be mentioned that the proposed approach is restricted to systems where multiple time delays arise only in the input and output, and not in the state. Illustrative examples are given to demonstrate the effectiveness of the proposed method.