Metody symulacji przetwornika z impulsowym sygnałem wyjściowym modulowanym częstotliwościowo

W artykule przedstawiono porównanie zaproponowanych przez autorów metod symulacji wyjściowego sygnału impulsowego przetwornika napięcieczęstotliwość U/F. Pierwsza z analizowanych metod oparta jest na modelu fizycznym przetwornika, druga na jego równaniu matematycznym. Mimo odmiennego podejścia otrzymano zbliżone wyniki. W pierwszej metodzie uzyskano wyniki obarczone błędami kwantowania o rozkładzie jak w rzeczywistym układzie pomiarowym. W drugiej metodzie wyniki są dokładniejsze, ale nie są związane z techniczną realizacją układu pomiarowego.

In measurement engineering, while processing any quantities into digital form, frequency-modulated impulse signals are often used as intermediate signals. During actuation or monitoring of measurement systems with such sensors it is necessary to have an impulse signal correspondent with the signal from the converter during normal operation. That is why there are being developed the methods which allow generating an impulse signal correspondent to the signal from the converter, when taking into account the changes of the measured quantity in accordance with the adopted characteristics. The paper presents a comparison of the methods for simulating the output impulse signal proposed by the authors, on the example of a voltage-to-frequency U/F converter. The first analyzed method, described in Section 2, is based on a physical model of the converter, while the second, presented in Section 3, is based on its mathematical equation. In spite of the difference of approaches, very similar results were obtained - they are given in Section 4. The advantage of the first method is the acquisition of results encumbered with quantization errors of the distribution precisely the same as in an actual measurement system (Fig. 2). The second method allows acquiring more precise results, which reflect the actual location of subsequent impulses. However, they are not related to any specific technical implementation of the measurement system. The selection of the method depends on the purpose of the simulation of the frequency signal, e.g. researching quantization errors, testing algorithms of increasing the effective resolution of the measurement chain or testing the characteristics of the algorithms of digital processing of frequency signals.