The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Wim Michiels - One of the best experts on this subject based on the ideXlab platform.
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Root Locus for SISO dead-time systems: A continuation based approach
Automatica, 2012Co-Authors: Suat Gumussoy, Wim MichielsAbstract:We present a numerical method to plot the Root Locus of Single-Input-Single-Output (SISO) dead-time systems with respect to the controller gain or the system delay. We compute the trajectories of characteristic Roots of the closed-loop system on a prescribed complex right half-plane. We calculate the starting, branch and boundary crossing Roots of Root-Locus branches inside the region. We compute the Root Locus of each characteristic Root based on a predictor-corrector type continuation method. To avoid the high sensitivity of Roots with respect to the Locus parameter in the neighborhood of branch points, the continuation method relies on a natural parameterization of the Root-Locus trajectory in terms of a distance in the (characteristic Root, Locus parameter)-space. The method is numerically stable for high order SISO dead-time systems.
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technical communique invariance properties in the Root sensitivity of time delay systems with double imaginary Roots
Automatica, 2010Co-Authors: Elias Jarlebring, Wim MichielsAbstract:If i@w@?iR is an eigenvalue of a time-delay system for the delay @t"0 then i@w is also an eigenvalue for the delays @t"k@?@t"0+k2@p/@w, for any k@?Z. We investigate the sensitivity, periodicity and invariance properties of the Root i@w for the case that i@w is a double eigenvalue for some @t"k. It turns out that under natural conditions (the condition that the Root exhibits the completely regular splitting property if the delay is perturbed), the presence of a double imaginary Root i@w for some delay @t"0 implies that i@w is a simple Root for the other delays @t"k, k 0. Moreover, we show how to characterize the Root Locus around i@w. The entire local Root Locus picture can be completely determined from the square Root splitting of the double Root. We separate the general picture into two cases depending on the sign of a single scalar constant; the imaginary part of the first coefficient in the square Root expansion of the double eigenvalue.
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continuation based computation of Root Locus for siso dead time systems
IFAC Proceedings Volumes, 2010Co-Authors: Suat Gumussoy, Wim MichielsAbstract:Abstract We present a numerical method to plot the Root-Locus of Single-Input-Single-Output (SISO) dead-time systems on a given right half-plane up to a predefined controller gain. We compute the starting and intersection points of Root-Locus inside the region and we obtain the Root-loci of each Root based on a predictor-corrector type continuation method. The method is effective for high-order SISO dead-time systems.
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invariance properties in the Root sensitivity of time delay systems with double imaginary Roots
IFAC Proceedings Volumes, 2009Co-Authors: Elias Jarlebring, Wim MichielsAbstract:Abstract If iω ∈ iℝ is an eigenvalue of a time-delay system for the delay τ0 then iω is also an eigenvalue for the delays, for any k ∈ ℤ. We investigate the sensitivity and other properties of the Root iω for the case that iω is a double eigenvalue for some τk. It turns out that under natural conditions, the presence of a double imaginary Root iω for some delay τ0 implies that iω is a simple Root for the other delays τk k ≠ 0. Moreover, we show how to characterize the Root Locus around iω. The entire local Root Locus picture can be determined from the square Root splitting of the double Root. We separate the general picture into two cases depending on the sign of a single scalar constant; the imaginary part of the first coefficient in the square Root expansion of the double eigenvalue.
Lin Tie - One of the best experts on this subject based on the ideXlab platform.
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on near controllability nearly controllable subspaces and near controllability index of a class of discrete time bilinear systems a Root Locus approach
Siam Journal on Control and Optimization, 2014Co-Authors: Lin TieAbstract:This paper studies near-controllability of a class of discrete-time bilinear systems via a Root Locus approach. A necessary and sufficient criterion for the systems to be nearly controllable is given. In particular, by using the Root Locus approach, the control inputs which achieve the state transition for the nearly controllable systems can be computed. Furthermore, for the non-nearly-controllable systems, nearly controllable subspaces are derived and near-controllability index is defined. Accordingly, the controllability properties of such a class of discrete-time bilinear systems are fully characterized. Finally, examples are provided to demonstrate the results of the paper.
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a Root Locus approach to near controllability of a class of discrete time bilinear systems with applications to hermitian matrices
Journal of The Franklin Institute-engineering and Applied Mathematics, 2014Co-Authors: Lin TieAbstract:Abstract In this paper, a Root Locus approach is developed to investigate near-controllability of a class of discrete-time bilinear systems and new representations of Hermitian matrices are derived. The Root Locus approach has three merits: firstly, it makes the proof of near-controllability of the systems more simple; secondly, the control inputs that achieve the state transition can be computed in an explicit way and, meanwhile, the number of the required control inputs can be fixed; and thirdly, it leads to a more general conclusion on near-controllability. A numerical example is given to demonstrate the effectiveness of the Root Locus approach. Finally, the more general conclusion yields new representations of Hermitian matrices.
Maarten M Steinbuch - One of the best experts on this subject based on the ideXlab platform.
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computation of transfer function data from frequency response data with application to data based Root Locus
Control Engineering Practice, 2015Co-Authors: Rob R Hoogendijk, Georgo Zorz Angelis, Van De Rene Rene Molengraft, Den Aj Arjen Hamer, Maarten M SteinbuchAbstract:This paper describes the computation and use of transfer function data (TFD) computed from frequency response data of a system. TFD can be regarded as a sampled, data-based representation of the transfer function. TFD can be computed from frequency response data for stable, lightly damped systems using a Cauchy integral. Computational accuracy and complexity are extensively discussed. As a use-case of TFD it is shown that a Root-Locus can be computed in a data-based way, using only frequency response data of a system. Experiments on a benchmark motion system demonstrate the use of TFD in minimizing the settling time.
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frequency response data based optimal control using the data based symmetric Root Locus
International Conference on Control Applications, 2010Co-Authors: Rob R Hoogendijk, Arjen Den Hamer, Georgo Zorz Angelis, Rene Van De Molengraft, Maarten M SteinbuchAbstract:This paper describes a data-based frequency domain optimal control synthesis method. Plant frequency response data is used to compute the frequency response of the controller using a spectral decomposition of the optimal return difference. The underlying cost function is selected from a databased symmetric Root-Locus, which gives insight in the closed-loop pole locations that will be achieved by the controller. A simulation study shows the abilities of the proposed method.
Suat Gumussoy - One of the best experts on this subject based on the ideXlab platform.
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Root Locus for SISO dead-time systems: A continuation based approach
Automatica, 2012Co-Authors: Suat Gumussoy, Wim MichielsAbstract:We present a numerical method to plot the Root Locus of Single-Input-Single-Output (SISO) dead-time systems with respect to the controller gain or the system delay. We compute the trajectories of characteristic Roots of the closed-loop system on a prescribed complex right half-plane. We calculate the starting, branch and boundary crossing Roots of Root-Locus branches inside the region. We compute the Root Locus of each characteristic Root based on a predictor-corrector type continuation method. To avoid the high sensitivity of Roots with respect to the Locus parameter in the neighborhood of branch points, the continuation method relies on a natural parameterization of the Root-Locus trajectory in terms of a distance in the (characteristic Root, Locus parameter)-space. The method is numerically stable for high order SISO dead-time systems.
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continuation based computation of Root Locus for siso dead time systems
IFAC Proceedings Volumes, 2010Co-Authors: Suat Gumussoy, Wim MichielsAbstract:Abstract We present a numerical method to plot the Root-Locus of Single-Input-Single-Output (SISO) dead-time systems on a given right half-plane up to a predefined controller gain. We compute the starting and intersection points of Root-Locus inside the region and we obtain the Root-loci of each Root based on a predictor-corrector type continuation method. The method is effective for high-order SISO dead-time systems.
Marc Bodson - One of the best experts on this subject based on the ideXlab platform.
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Design of Controllers for Electrical Power Systems Using a Complex Root Locus Method
IEEE Transactions on Industrial Electronics, 2016Co-Authors: Arnau Doria-cerezo, Marc BodsonAbstract:A large class of three-phase electrical power systems possess symmetry conditions that make it possible to describe their behavior using single-input single-output transfer functions with complex coefficients. In such cases, an extended Root Locus method can be used to design control laws, even though the actual systems are multi-input multi-output. In this paper, the symmetric conditions for a large class of power systems are analyzed. Then, the Root Locus method is revisited for systems with complex coeffcients and used for the analysis and control design of power systems. To demonstrate the benefits of the approach, this paper includes two examples: 1) a doubly fed induction machine and 2) a three-phase LCL inverter.
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Root Locus rules for polynomials with complex coefficients
Mediterranean Conference on Control and Automation, 2013Co-Authors: Arnau Doriacerezo, Marc BodsonAbstract:Applications were found recently where the analysis of dynamic systems with a special structure could be simplified considerably by transforming them into equivalent systems having complex coefficients and half the number of poles. The design of controllers for such systems can be simplified in the complex representation, but requires techniques suitable for systems with complex coefficients. In the paper, the extension of the classical Root Locus method to systems with complex coefficients is presented. The results are applied with some advantages to a three-phase controlled rectifier.
