Method of monitoring the operation of a machine tool

• US 20050055125A1
• Filed: 08/02/2004
• Published: 03/10/2005
• Est. Priority Date: 08/02/2003
• Status: Abandoned Application

• Current Assignee: Dr Ing hc F Porsche AG (Volkswagen AG)
• Original Assignee: Dr Ing hc F Porsche AG (Volkswagen AG)
• Inventors: Kappich, Joachim, Stankewitz, Britta
• Application Number:
  US10/903,482
• Publication Number:
  US 20050055125A1
• Time in Patent Office: Days
• US Class Current: 700/175
• CPC Class Codes: A01D 41/127 Control or measuring arrangements specially adapted for combines
• CPC Class Codes: A01D 69/00 Driving mechanisms or parts thereof for harvesters or mowers driving mechanisms for the cutters of mowers or harvesters A01D34/00
• CPC Class Codes: G01H 1/003 of rotating machines G01H1/10 takes precedence
• CPC Class Codes: G01N 29/12 by measuring frequency or resonance of acoustic waves measuring frequency or resonant frequency of mechanical vibrations or acoustic waves in general G01H1/06, G01H3/04, G01H13/00; acoustic resonators G10K11/04; vibration or shock testing of structures G01M7/00
• CPC Class Codes: G01N 29/14 using acoustic emission techniques echo of particles G01N29/046; measuring mechanical vibrations or acoustic waves in solids in general G01H1/00
• CPC Class Codes: H03H 17/0263 Rank order filters

Abstract

A method of monitoring the operation of machine tools, wherein at least one sensor for detecting the vibrations and a predefinable number of sensors for detecting the rotational speed of the individual assemblies of a machine tool are provided. The rotational speed sensors or the rotational speeds determined from the CAN determine the center frequency of an order filter, and the vibration sensors are analyzed by way of a rotational-speed-dependent order filter.

Claims

1. A method of monitoring operation of a machine tool using at least one sensor for detecting vibrations and a plurality of sensors for detecting rotational speed of individual assemblies of the machine tool, said method comprising the steps of:

detecting rotational speed of an assembly;

determining a center frequency of an order filter as a function of said detected rotational speed;

detecting vibration signals of said machine tool; and

analyzing said vibration signal by means of a rotational-speed dependent order filter.

2. The method according to claim 1, further comprising the step of providing a fault report when a filter signal of the vibration sensors is outside a predefined band with.

3. The method according to claim 2, wherein an amplitude of the filter vibration signal is reduced by a desired value.

5. The method according to claim 1, providing a fault indication as a function of the comparing step.

4. A method for monitoring operation of a machine tool comprising the steps of:

detecting vibration of said machine tool and outputting a vibration signal;

detecting rotational speed values related to rotating components of said machine and outputting a plurality of speed signals;

determining a center frequency of an order filter as a function of said rotational speed signals;

filtering said detected vibration signals as a function of said center frequency; and

comparing said filter vibration signal with at least one predetermined value.

6. The method according to claim 4, wherein an amplitude of the vibration signal is reduced by a predetermined value prior to a comparing step.