Flutter online monitoring method for machining equipment

Abstract

The invention discloses a flutter online monitoring method for machining equipment. The method comprises the steps that a proper sampling window is selected; empirical mode decomposition is carried out on sampled vibration signals; decomposed eigen modalities are screened to obtain a characteristic eigen modality; Hilbert transformation is carried out on the characteristic eigen modality to obtain a time-frequency spectrum; statistical pattern analysis is carried out on the time-frequency spectrum to obtain characteristic parameters; the statistical characteristic parameters are compared with a set characteristic threshold value and the statistical characteristic parameter of a historical adjacent signal, and the vibration state of a system is judged. The flutter online monitoring method aims to solve the problems that a flutter detecting method is strong in sample dependency and poor in generalization ability, threshold value measurement is difficult, and judgment is not carried out in time, the method combining Hilbert-Huang transformation and statistical pattern recognition is provided, statistical modeling and clustering analysis are carried out on the time-frequency spectrum of the vibration signal based on the aggregation character of energy on frequency in the fluttering process, the characteristic parameters are utilized, the physical characteristic of cutting flutter is represented essentially, the cutting vibration state is effectively monitored in real time, and the judgment result is accurate and visual.

Description

technical field [0001] The invention belongs to the technical field of machine tool processing, and more specifically relates to an online chatter monitoring method of mechanical processing equipment. Background technique [0002] The machine tool is the main carrier of the cutting process, and the vibration is the accompanying phenomenon of the cutting process. When the excitation frequency of the external load on the machine tool reaches a certain natural frequency of the system, the machine tool will vibrate violently, and even cause damage to the machine tool, cutting tool and workpiece in severe cases. According to the different load forms, the vibration generated in cutting process is mainly divided into forced vibration and self-excited vibration. Chatter is the main form of destructive self-excited vibration of machine tools. It is a strong relative vibration between machine tool, workpiece and tool during cutting process. It is a complex dynamic instability phenome...

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Problems solved by technology

[0005] Aiming at the above defects or improvement needs of the prior art, the present invention provides an online chatter monitoring method of mechanical processing equipment, the purpose of which is to realize automatic online monitoring of chatter, thereby solving the problem of strong sample dependence, The technical problems of poor model generalization ability and arbitrary threshold setting

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