Active control method of milling chatter vibration based on electric spindle of magnetic suspension bearing

Abstract

The invention discloses an active control method of milling chatter vibration based on an electric spindle of a magnetic suspension bearing. The method comprises the following steps: collecting a current displacement signal generated when the electric spindle has the milling chatter vibration; obtaining a state vector Q(t) formed by the displacement of the electric spindle and the speed; obtaining harmonic displacement which is shown as the formula in the description according to the electric spindle displacement [Fx Fy]T and a trigonometric function column vector phi(t); obtaining a first self-adaptive weight coefficient which is shown as the formula in the description and a second self-adaptive weight coefficient which is shown as the formula in the description; obtaining a first self-adaptive rate K1 and a second self-adaptive rate K2 according to the harmonic displacement h(t), the first self-adaptive weight coefficient lambda1 and a second self-adaptive weight coefficient lambda2; obtaining self-adaptive control current which is shown as the formula in the description according to the first self-adaptive rate K1, the second self-adaptive rate K2 and the harmonic displacement h(t); and applying the self-adaptive control current Qc(t) on a radial magnetic suspension bearing and generating corresponding magnetic field force so as to restrain the chatter vibration of the spindle. Through the active control method, the chatter vibration in the milling process is eliminated, thereby ensuring the processing quality and improving the processing efficiency.

Description

technical field [0001] The invention belongs to the technical field of numerical control machining, and more specifically relates to an active control method for milling chatter vibration based on a magnetic suspension bearing electric spindle. Background technique [0002] In terms of chatter suppression in five-axis CNC machining of complex curved surface parts, the traditional method is mainly based on passive control. The system works below the lobe effect point, so as to obtain high speed and depth of cut under the premise of ensuring milling stability. Although the design and installation of the passive control method is simple, the stable range it can adjust is very small, and the improvement of the closed-loop dynamics is limited. Therefore, it is necessary to adopt a control method that changes the inherent dynamic characteristics of the spindle unit to suppress the flutter. This control method is based on the active control technology of the magnetic suspension be...

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Problems solved by technology

[0005] In view of the defects of the prior art, the purpose of the present invention is to provide an active control method for milling chatter vibration based on magnetic suspension bearing electric spindle, aiming at solving the problem of workpiece surface quality caused by self-excited chatter vibration phenomenon in the milling process of existing CNC machine tools drop, the problem of low milling efficiency

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