Software-based method of increasing the effective resolution of a measurement chain for a transducer with a pulse frequency output

摘要

The article covers the problems of digital signal processing in a measurement chain that uses a measuring transducer with a pulse frequency output. Such a measurement chain arrangement presents numerous advantages, particularly due to the high accuracy of frequency conversion to digital form, and the high immunity of a frequency signal to interference. However, the assessment of the metrological characteristics of such a measurement chain, especially in dynamic states, presents a challenge. This problem stems from the fact that digital frequency measurement is always a mean value measurement, which introduces a greater dynamic error for longer averaging times. At the same time, a quantization error occurs, which also depends on the averaging time and measurement method. The work presents the possibility of increasing the effective resolution of a measurement chain with a frequency signal by using software methods of reciprocal counting. An algorithm developed for this purpose and the results of conducted simulation studies are presented.