Weak fault identification method of underwater robot thruster based on wavelet packet energy and FFT

Abstract

The invention relates to a weak fault identification method of an underwater robot thruster based on wavelet packet energy and FFT, and belongs to the technical field of weak fault identification of the underwater robot thruster. The method comprises: performing noise reduction on controller and sensor data based on a wavelet packet noise reduction method; based on an empirical mode decomposition(EMD) method and a mutual-correlation criterion, extracting energy characteristics of the data subjected to noise reduction; and at the same time, performing frequency-domain analysis on the data subjected to noise reduction based on an FFT method, to obtain improved frequency-domain characteristics; performing contrast calculation on a fault matrix composed of energy and the improved frequency-domain characteristics and a sample matrix based on a grey correlation analysis method, to realize weak fault identification. The weak fault identification method can effectively solve the problem thatwhen weak fault identification is performed by only adopting a single time domain or energy characteristic, the weak fault identification accuracy is lower because characteristic changes are non-single and it is easy to lose some important information, thereby improving the weak fault identification accuracy. The method is applicable to the fields such as weak fault identification of the underwater robot thruster, and has broad application prospects.

Description

technical field [0001] The invention relates to a method for identifying weak faults of thrusters of underwater robots based on wavelet packet energy and FFT, and belongs to the technical field of weak faults identification of thrusters of underwater robots. Background technique [0002] With the dwindling land resources, the pace of human development of the ocean is getting faster and faster. Autonomous underwater robot is currently the only carrier that can detect and develop in the deep sea without human beings, and has been highly valued by researchers at home and abroad. The thruster is its key component and also the part with the heaviest load, so it is of great significance to study the fault diagnosis technology of the thruster to improve the safety. Many scholars have achieved good research results in propeller fault diagnosis technology, but most of them focus on hard faults of propellers and faults with greater output loss, and less research on faults with output...

AI Technical Summary

Problems solved by technology

[0006] The purpose of the present invention is to provide a weak fault identification method for underwater robot thrusters based on wavelet packet energy and FFT in order to solve the problem of low identification accuracy of weak faults of underwater robots in weak fault diagnosis

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