A New Method for Extraction of Process Differential Signal Based on Single-frequency-pass Filter

Abstract

Aimed at the severely amplified disturbance in the traditional differential operators and non-linear differential methods, a novel linear differential method is proposed. In this paper, the inter-relationship between step response and sine response of plants is analyzed. It is pointed out that under certain conditions, the differential component of the step response of a plant could be extracted from the sinusoidal excitation signal upon the same plant. And a new method is proposed that step excitations of a plant could be transformed to sinusoidal excitations through single-frequency-pass filter. Furthermore, a logic structure to extract the differential component of process signals is constructed via single-frequency-pass filters and a new type sinusoid tracking filter. Superior anti-noise characteristics could be obtained with the proposed method, which is the development and extension of linear filters, and possesses good theoretical significance and practical application prospect. Mathematical analysis, simulation experiment, and practical application results have shown that the new method is correct and valid.