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Właściwości dyskretnego modelu napędu ze sprężystością w części mechanicznej oraz z regulatorem i obserwatorem stanu

Masalski C., Muszyński R.

Przegląd Elektrotechniczny

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2012

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R. 88, nr 4b

151-157

PL

Przedstawiono zagadnienie dyskretnego modelowania napędu z elastycznym połączeniem silnika z obciążeniem, zawierającego w części sterującej regulator i obserwator stanu. Analizuje się dokładność modelowania i symulacji dla dużej i małej dynamiki napędu wyrażającej się częstotliwością rezonansową w części mechanicznej o wartości 17,53 Hz i 124,6 Hz. Dla obydwu przypadków bada się pracę modelu układu otwartego i zamkniętego oraz pracę obserwatora a także wpływ okresu próbkowania i pominięcia opóźnień przy projektowaniu układu regulacji na pracę modelu. Są rekomendacje odnoszące się do wyboru właściwego kroku próbkowania modelu dyskretnego napędu.

EN

The problems of discrete modeling of the drive with elastic coupling the motor and load, containing the state controller and observer in the control structure. The accuracy of modeling and simulation is analyzed for high and low dynamic drive, i. e. for frequency of resonance in the mechanical part equal to 17,53 Hz and 124,6 Hz. For both cases the operation of the model of open- and close-loop system and observer is tested as well as influence of the sampling period and neglecting of the time-delay at designing the controller on the model operation is analyzed. The recommendations related to the choice of the proper sampling period for discrete-time model of the drive are given.

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Identification of continuous-time systems: direct or indirect?

Rao G. P., Garnier H.

Systems Science

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2004

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Vol. 30, no 3

25-50

EN

This paper summarizes and discusses the results of an extensive simulation based exercise in quest of dependable approaches to identification of continuous-time models from sampled input/output data of continuous-time dynamical systems. Two well-established approaches are considered together with several related techniques of parameter estimation. One is an indirect approach in which well-established discrete-time techniques are applied to first estimate a discrete-time model for the original continuous-time system and the model is then transformed into a continuous-time version. The other is a direct approach in which a continuous-time model is estimated straightaway using well-known continuous-time methods. On the surface, the choice between the two approaches may seem trivial but this paper underlines the need to establish dependability of any approach in terms of certain criteria. The results of extensive simulations clearly show that the direct approach is more dependable than the indirect route.

3

Identification of Low-Order Continuous-Time Models Via Discrete-Time Trends of Measurements

Janiszowski K. B.

International Journal of Applied Mathematics and Computer Science

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1999

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Vol. 9, no 4

839-853

EN

The paper deals with the problem of continuous-time (CT) identification of parameters in transfer functions for low-order linear systems, based on recorded discrete-time (DT) data. Algorithms for direct estimation of CT parameters are developed from rules for transformation of a CT transferfunction controlled via a zero-order sampling-and-hold unit into a DT representation.Two schemes are derived and tested: the first is based on the Goodwin transformation and the other is derived from the modified Tustin transformation. Both the approaches result in relations which can be used for direct estimationof CT parameters in a model of the investigated system. The numerical schemes contain some expressions that are reminiscent of DT differences and consequently they may magnify disturbances. Therefore the results of extensively testing both the schemes including different types of disturbances, measurement noise, slow varying drifts, measurement resolution errors together with changes in the sampling time are presented. A model of a pneumatic servomechanism system was used as a test plant.