interpolationsverfahren and high-resolution digital interpolationseinrichtung

摘要

The method provides interpolation of at least two analog signals obtained by sampling a division carrier. The analog signals are sinusoidal, position dependent, periodic signals shifted by 90 deg. relative to each other. Noise is superimposed on each analog signal by means of sigma-delta modulation. Signal trains are generated from the resulting trains by a simultaneous low pass filtering of the noise component above the max. input frequency of the analog signals. A stream of angle values is obtained from the signal trains. After a second low pass filtering of the noise component above the max. frequency of the input analog signals, a stream of output values are allocated to the angle values. The method may be carried out by a high resolution, digital interpolation device. This has two sigma-delta modulators (4). A conversion device (6) for converting the angle values is connected to each modulator (4) via a digital low pass filter (5) to convert the signal trains. The conversion device (6) is connected to an analyser circuit (7) to convert the angle values to output values.