Topic
Transfer function
About: Transfer function is a research topic. Over the lifetime, 14362 publications have been published within this topic receiving 214983 citations. The topic is also known as: system function & network function.
Papers published on a yearly basis
Papers
More filters
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TL;DR: This correspondence considers the robust H/sub 2//H/sub /spl infin// filtering problem for linear perturbed systems with steady-state error variance constraints and presents both the existence conditions and the explicit expression of desired robust filters.
Abstract: In this correspondence, we consider the robust H/sub 2//H/sub /spl infin// filtering problem for linear perturbed systems with steady-state error variance constraints. The purpose of this multiobjective problem is to design a linear filter that does not depend on the parameter perturbations such that the following three performance requirements are simultaneously satisfied. (1) The filtering process is asymptotically stable. (2) The steady-state variance of the estimation error of each state is not more than the individual prespecified value. (3) The transfer function from exogenous noise inputs to error state outputs meets the prespecified H/sub /spl infin// norm upper bound constraint. We show that in both continuous and discrete-time cases, the addressed filtering problem can effectively be solved in terms of the solutions of a couple of algebraic Riccati-like equations/inequalities. We present both the existence conditions and the explicit expression of desired robust filters. An illustrative numerical example is provided to demonstrate the flexibility of the proposed design approach.
124 citations
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01 Apr 2009
TL;DR: In this article, the authors review two commonly adopted methods, namely shaping filter and sinusoidal approximation, for generating one-dimensional random road profiles, that are used in the simulation of a quarter car (or half car) vehicle suspension control system.
Abstract: In this work we review two of the most commonly adopted methods, namely shaping filter and sinusoidal approximation, for generating one-dimensional random road profiles, that are used in the simulation of a quarter car (or half car) vehicle suspension control system. The major contribution of this work is the following: for the shaping filter method, it is found that the time constant of the first order transfer function generating the road profile is independent of the grade of road. While for the sinusoidal approximation method, a detail derivation of the amplitude of each sinusoidal function is re-derived for completeness.
123 citations
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TL;DR: The statistical properties of the transfer function between two points in the power distribution system are deduced from a propagation model that takes into account the complicated structure of the cable bundles.
Abstract: In this paper, we address the problem of power line communication inside a vehicle, focusing on channel characterization and modeling. The statistical properties of the transfer function between two points in the power distribution system are deduced from a propagation model that takes into account the complicated structure of the cable bundles. Theoretical estimates are compared to experimental results. Later on, this theoretical model, together with an impulsive noise model, will be implemented in a software communication tool that is designed to optimize modulation schemes and channel coding.
123 citations
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TL;DR: A novel approach for the auto-tuning of fractional order controllers is proposed, based on a simple experiment that is able to determine the modulus, phase and phase slope of the process required in the computation of the controller parameters.
Abstract: Fractional order PID controllers benefit from an increasing amount of interest from the research community due to their proven advantages. The classical tuning approach for these controllers is based on specifying a certain gain crossover frequency, a phase margin and a robustness to gain variations. To tune the fractional order controllers, the modulus, phase and phase slope of the process at the imposed gain crossover frequency are required. Usually these values are obtained from a mathematical model of the process, e.g. a transfer function. In the absence of such model, an auto-tuning method that is able to estimate these values is a valuable alternative. Auto-tuning methods are among the least discussed design methods for fractional order PID controllers. This paper proposes a novel approach for the auto-tuning of fractional order controllers. The method is based on a simple experiment that is able to determine the modulus, phase and phase slope of the process required in the computation of the controller parameters. The proposed design technique is simple and efficient in ensuring the robustness of the closed loop system. Several simulation examples are presented, including the control of processes exhibiting integer and fractional order dynamics.
122 citations
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TL;DR: In this article, the influence of the nonlinear transfer function of the light-emitting diodes on discrete multitone modulation is studied, and analytical expressions for an idealized link are derived, and these equations allow the estimation of the power of the noise-like, nonlinear crosstalk between the orthogonal subcarriers.
Abstract: Light-emitting diodes constitute a low-cost choice for optical transmitters in medium-bit-rate optical links. An example for the latter is local-area networks. However, one of the disadvantageous properties of light-emitting diodes is their nonlinear characteristic, which may limit the data transmission performance of the system, especially in the case of multiple subcarrier modulation, which is starting to attract attention in various applications, such as visible-light communications and data transmission over polymer optical fibers. In this paper, the influence of the nonlinear transfer function of the light-emitting diodes on discrete multitone modulation is studied. The transfer function describes the dependence of the emitted optical power on the driving current. Analytical expressions for an idealized link were derived, and these equations allow the estimation of the power of the noise-like, nonlinear crosstalk between the orthogonal subcarriers. The crosstalk components of the quadrature and in-phase subcarrier components were found to be independent and approximately normally distributed. Using these results, the influence of light-emitting-diode nonlinearity on the performance of the system was investigated. The main finding was that systems using a small number of subcarriers and/or high QAM level exhibit a large signal-to-noise-ratio penalty due to the nonlinear crosstalk. The model was applied to systems with white and resonant-cavity light-emitting diodes. It is shown that the nonlinearity may severely limit the performance of the system, particularly in the case of resonant-cavity light-emitting diodes, which exhibit a strong nonlinear behavior.
122 citations