Search Results

Now showing 1 - 10 of 57
  • Article
    Citation - WoS: 1
    Citation - Scopus: 1
    Novel Frequency-Domain Criterion for Elimination of Limit Cycles in a Class of Digital Filters With Single Saturation Nonlinearity
    (Pergamon-elsevier Science Ltd, 2008) Singh, Vimal
    A frequency-domain criterion for the elimination of limit cycles in a class of digital filters utilizing single saturation nonlinearity is presented. The criterion is derived by exploiting the structural properties of the system under consideration in a greater detail. A novel feature of the criterion is that it takes the form of a matrix inequality, despite the fact that there is single nonlinearity in the system. An example showing the effectiveness of the criterion is given. (c) 2006 Elsevier Ltd. All rights reserved.
  • Article
    Citation - WoS: 13
    Citation - Scopus: 12
    Novel Global Robust Stability Criterion for Neural Networks With Delay
    (Pergamon-elsevier Science Ltd, 2009) Singh, Vimal; Sıngh, Vımal; Sıngh, Vımal; Department of Mechatronics Engineering; Department of Mechatronics Engineering
    A novel criterion for the global robust stability of Hopfield-type interval neural networks with delay is presented. An example illustrating the improvement of the present criterion over several recently reported criteria is given. (C) 2008 Elsevier Ltd. All rights reserved.
  • Article
    Citation - WoS: 30
    Citation - Scopus: 30
    New approach to stability of 2-D discrete systems with state saturation
    (Elsevier, 2012) Singh, Vimal
    A new criterion for the global asymptotic stability of 2-D discrete systems described by the Roesser model using saturation arithmetic is presented. The criterion is a generalization over an earlier criterion due to Liu and Michel. The generalized criterion has the feature that Lyapunov matrix P is not restricted to be symmetric, i.e., P can be even unsymmetric. A modified form of the criterion is also presented. Two examples showing the effectiveness of the generalized approach to yield new 2-D stability results are provided. To the best of author's knowledge, the use of unsymmetric P to obtain new 2-D stability conditions (i.e., conditions which are outside the scope of symmetric P) is demonstrated, for first time, in this paper. (C) 2011 Elsevier B.V. All rights reserved.
  • Article
    Citation - WoS: 14
    Citation - Scopus: 15
    Global asymptotic stability of 2-D state-space digital filters with saturation arithmetic: Modified approach
    (Elsevier Science Bv, 2008) Singh, Vimal
    A criterion for the global asymptotic stability of 2-D state-space digital filters described by the Roesser model employing state saturation arithmetic is presented. The criterion is a modified form of a recently reported criterion. An example shows the effectiveness of the modified criterion. (C) 2007 Elsevier B.V. All rights reserved.
  • Article
    Citation - WoS: 42
    Citation - Scopus: 47
    A Novel Global Robust Stability Criterion for Neural Networks With Delay
    (Elsevier Science Bv, 2005) Singh, V
    A criterion based on the intervalised network parameters for the global robust stability of Hopfield-type neural networks with delay is presented. The criterion is compared with an earlier criterion. (c) 2005 Elsevier B.V. All rights reserved.
  • Article
    Citation - WoS: 34
    Citation - Scopus: 38
    Discussion on Barkhausen and Nyquist Stability Criteria
    (Springer, 2010) Singh, Vimal
    Most textbooks on analog circuits and signal processing describe the Barkhausen criterion pertaining to the determination of sinusoidal oscillations in a closed-loop system. On the other hand, the Nyquist stability criterion is well known, as discussed in most textbooks on control systems. Recently, some examples in which the Barkhausen criterion fails to produce the correct condition for startup of oscillations have been reported. In the present paper, an explanation of oscillation startup based on the Nyquist stability criterion is given and the close relationship between the Barkhausen and the Nyquist criteria highlighted. It is shown that the Nyquist criterion (which is a rigorous technique) is a more robust approach than the Barkhausen criterion concerning the determination of sinusoidal oscillations in a closed-loop system and that the Barkhausen criterion (whenever it yields the correct result) is subsumed by the Nyquist criterion as a special case. The textbooks usually describe the Barkhausen criterion as a separate topic, i.e., do not discuss the relationship of this criterion with the Nyquist criterion. It is, therefore, felt that the present discussion will go a long way to put the subject in a broader perspective.
  • Letter
    Citation - WoS: 22
    Citation - Scopus: 24
    A Note on Determination of Oscillation Startup Condition
    (Springer, 2006) Singh, Vimal
    There prevails a widespread notion that, given a closed-loop system, oscillation will commence and build up therein if the magnitude of loop gain is greater than unity at the frequency at which the angle of loop gain is zero degree. Three novel examples in which this notion fails are presented.
  • Article
    Citation - WoS: 26
    Citation - Scopus: 31
    New Lmi Condition for the Nonexistence of Overflow Oscillations in 2-D State-Space Digital Filters Using Saturation Arithmetic
    (Academic Press inc Elsevier Science, 2007) Singh, Vimal
    A new criterion for the nonexistence of overflow oscillations in 2-D state-space digital filters described by Roesser model using saturation arithmetic is presented. The criterion is in the form of a linear matrix inequality (LMI) and hence computationally tractable. The criterion is compared with an earlier LMI-based criterion due to Xiao and Hill. It turns out that the present criterion may uncover some new A (i.e., other than those arrived at via Xiao-Hill's criterion) for which the absence of overflow oscillations is assured. (c) 2006 Elsevier Inc. All rights reserved.
  • Article
    Citation - WoS: 13
    Citation - Scopus: 14
    Improved Global Robust Stability for Interval-Delayed Hopfield Neural Networks
    (Springer, 2008) Singh, Vimal
    A modified form of a recent criterion for the global robust stability of interval-delayed Hopfield neural networks is presented. The effectiveness of the modified criterion is demonstrated with the help of an example.
  • Article
    Citation - WoS: 5
    Citation - Scopus: 5
    2-D Digital Filter Realization Without Overflow Oscillations
    (Pergamon-elsevier Science Ltd, 2013) Singh, Vimal
    A novel criterion for the elimination of overflow oscillations in 2-D state-space digital filters described by the Roesser model employing two's complement overflow arithmetic is presented. The criterion takes the form of linear matrix inequality (LMI) and, hence, is computationally tractable. The criterion is a generalization and improvement over an earlier criterion. An example shows the effectiveness of the new criterion. (C) 2012 Elsevier Ltd. All rights reserved.