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Title: Adaptive vibration control using synchronous demodulation with machine tool controller motor commutation

Abstract

A control system and method for actively reducing vibration in a spindle housing caused by unbalance forces on a rotating spindle, by measuring the force-induced spindle-housing motion, determining control signals based on synchronous demodulation, and provide compensation for the measured displacement to cancel or otherwise reduce or attenuate the vibration. In particular, the synchronous demodulation technique is performed to recover a measured spindle housing displacement signal related only to the rotation of a machine tool spindle, and consequently rejects measured displacement not related to spindle motion or synchronous to a cycle of revolution. Furthermore, the controller actuates at least one voice-coil (VC) motor, to cancel the original force-induced motion, and adapts the magnitude of voice coil signal until this measured displacement signal is brought to a null. In order to adjust the signal to a null, it must have the correct phase relative to the spindle angle. The feedback phase signal is used to adjust a common (to both outputs) commutation offset register (offset relative to spindle encoder angle) to force the feedback phase signal output to a null. Once both of these feedback signals are null, the system is compensating properly for the spindle-induced motion.

Inventors:
 [1]
  1. Livermore, CA
Issue Date:
Research Org.:
Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
981832
Patent Number(s):
7370524
Application Number:
11/205,551
Assignee:
Lawrence Livermore National Security, LLC (Livermore, CA)
Patent Classifications (CPCs):
G - PHYSICS G05 - CONTROLLING G05D - SYSTEMS FOR CONTROLLING OR REGULATING NON-ELECTRIC VARIABLES
G - PHYSICS G05 - CONTROLLING G05B - CONTROL OR REGULATING SYSTEMS IN GENERAL
DOE Contract Number:  
W-7405-ENG48
Resource Type:
Patent
Country of Publication:
United States
Language:
English
Subject:
47 OTHER INSTRUMENTATION

Citation Formats

Hopkins, David James. Adaptive vibration control using synchronous demodulation with machine tool controller motor commutation. United States: N. p., 2008. Web.
Hopkins, David James. Adaptive vibration control using synchronous demodulation with machine tool controller motor commutation. United States.
Hopkins, David James. Tue . "Adaptive vibration control using synchronous demodulation with machine tool controller motor commutation". United States. https://www.osti.gov/servlets/purl/981832.
@article{osti_981832,
title = {Adaptive vibration control using synchronous demodulation with machine tool controller motor commutation},
author = {Hopkins, David James},
abstractNote = {A control system and method for actively reducing vibration in a spindle housing caused by unbalance forces on a rotating spindle, by measuring the force-induced spindle-housing motion, determining control signals based on synchronous demodulation, and provide compensation for the measured displacement to cancel or otherwise reduce or attenuate the vibration. In particular, the synchronous demodulation technique is performed to recover a measured spindle housing displacement signal related only to the rotation of a machine tool spindle, and consequently rejects measured displacement not related to spindle motion or synchronous to a cycle of revolution. Furthermore, the controller actuates at least one voice-coil (VC) motor, to cancel the original force-induced motion, and adapts the magnitude of voice coil signal until this measured displacement signal is brought to a null. In order to adjust the signal to a null, it must have the correct phase relative to the spindle angle. The feedback phase signal is used to adjust a common (to both outputs) commutation offset register (offset relative to spindle encoder angle) to force the feedback phase signal output to a null. Once both of these feedback signals are null, the system is compensating properly for the spindle-induced motion.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {2008},
month = {5}
}

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