Device for indicating the vibration level of a vehicle

• US 20060064210A1
• Filed: 12/22/2004
• Published: 03/23/2006
• Est. Priority Date: 12/22/2003
• Status: Active Grant

• Current Assignee: Airbus Helicopters
• Original Assignee: Eurocopter
• Inventors: Aubourg, Pierre-Antoine
• Granted Patent: US 7,225,062 B2
• Time in Patent Office: Days
• US Class Current: 701/3
• CPC Class Codes: G01H 3/08 Analysing frequencies present in complex vibrations, e.g. comparing harmonics present acoustic presence detection G01V1/001

Abstract

A device for indicating at least a first vibration level VIB1 derived from a first acceleration signal γ1 includes:

• • first analysis element FT1 for resolving the first acceleration signal γ1 into a plurality of axial analysis signals γ1_i each occupying an identified frequency band B_i;
  • a first memory RM1 having recorded therein a plurality of axial weighting coefficients KA_i, each corresponding to one of the identified frequency bands B_i; and
  • a first control circuit CC for summing the p^th powers of the axial analysis signals γ1_i weighted by the axial weighting coefficients KA_i, thereby producing the first vibration level VIB1.

Claims

1. A device for indicating the vibration level of a helicopter including a rotor, in order to produce a first vibration level derived from a first acceleration signal, the device comprising:

first analysis means for resolving said first acceleration signal delivered by one or more sensors measuring vibration directed along the axis of the rotor into a plurality of axial analysis signals, each occupying an identified frequency band;

a first memory having recorded therein a plurality of axial weighting coefficients, each corresponding to one of said identified frequency bands; and

a control circuit for summing the p^th powers of said axial analysis signals weighted by said axial weighting coefficients, thereby producing said first vibration level.

2. A device according to claim 1, wherein the control circuits sums the second powers of said axial analysis signals.

3. A device according to claim 1, including a first comparator for producing a first alert signal when said first vibration level exceeds a first predetermined threshold.

4. A device according to claim 1, further comprising a first concentrator member arranged so that said plurality of axial analysis signals come from a plurality of measurement signals each coming from a distinct sensor.

5. A device according to claim 4, wherein said first concentrator member sums said measurement signals.

6. A device according to claim 4, wherein said first concentrator member retains the greatest of said measurement signals.

7. A device according to claim 1, wherein, on receiving a second acceleration signal delivered by one or more sensors measuring vibration directed perpendicularly to the axis of the rotor, the device comprises:

second analysis means for resolving said second acceleration signal into a plurality of radial analysis signals, each occupying an identified frequency band;

a second memory recording a plurality of radial weighting coefficients, each corresponding to one of said identified frequency bands; and

a second control circuit for summing the p^th powers of said radial analysis signals weighted by said radial weighting coefficients in order to produce a second vibration level.

8. A device according to claim 7, wherein the control circuit sums the second powers of said radial analysis signals.

9. A device according to claim 7, including a second comparator for producing a second alert signal when said second vibration level exceeds a second predetermined threshold.

10. A device according to claim 7, including a second concentrator member arranged so that said plurality of radial analysis signals come from a plurality of evaluation signals, each coming from a distinct sensor.

11. A device according to claim 10, wherein said second concentrator member sums said evaluation signals.

12. A device according to claim 10, wherein said second concentrator member retains the greatest of said evaluation signals.

13. A device according to claim 9, including a combiner member for producing a warning signal when a combination of said alert signals exceeds a third predetermined threshold.

14. A device according to claim 13, wherein said combiner member sums the q^th powers of said alert signals.

15. A device according to claim 14, wherein the value of q is equal to 1.