Envelope extraction method and system for one-dimensional data

Abstract

The invention relates to an envelope extraction method and system for one-dimensional data. The envelope extraction method comprises the steps of: setting a scale parameter, an envelope amplitude threshold value, a maximum cycle index and a minimum extreme value point parameter; obtaining a primary maximum value point collection with the one-dimensional data amplitude greater than the envelope amplitude threshold value; gradually optimizing to find the maximum point of the one-dimensional data envelope by adopting a plurality of cycles based on the maximum cycle index or the minimum extreme value point which serves as a cycle ending condition, and the primary maximum value point collection which serves as the input; when the distance between the transverse coordinates between any two extreme value points in each cycle is greater than the scale parameter, keeping the two extreme value points and a plurality of extreme value points which are output by the last cycle and have the transverse coordinates located between the two extreme value points as the maximum value points; otherwise, only keeping the two extreme value points as the maximum value points; keeping the end values at two ends of the primary maximum value point collection for each cycle; optimizing the end values at the two ends; and interpolating between the obtained nodes by adopting an interpolation method so as to obtain the envelope of the one-dimensional data.

Description

technical field [0001] The invention proposes an envelope extraction method for one-dimensional data, which is suitable for the envelope extraction of one-dimensional continuous data, and specifically relates to an envelope extraction method and system for one-dimensional data. Background technique [0002] The envelope information of one-dimensional data shows the trend of data changes and reflects the low-frequency information in the data. Envelopes have been widely studied and applied in a large number of engineering fields. [0003] Existing relatively general envelope extraction methods include low-pass filter method, short-time energy method and analytical signal method. [0004] Based on the classic amplitude modulation and demodulation technology, the low-pass filtering method firstly performs half-wave rectification or full-wave rectification on the data, and then low-pass filtering to obtain the envelope of the data. This envelope extraction method is the most co...

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Problems solved by technology

[0007] However, the above methods have their own advantages and disadvantages: the low-pass filtering method can affect the change speed of the envelope by selecting different cut-off frequencies, but it depends on the design of the filter, and the order and form of the filter designed by different designers will be different ;The short-term energy method can affect the change speed of the envelope by choosing different window lengths, and the common disadvantage with the low-pass filtering method is that it cannot ensure accurate capture of the main extreme points of the data, and there is a delay or advance in time; Analysis The signal method has a rigorous expression form in mathematics, but the amplitude of the analytical signal cannot be regarded as an envelope in any case, and the physical meaning is not clear. This method cannot affect the speed of the envelope change by setting parameters

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