Device for indicating a beat level
First Claim
Patent Images
1. A device for indicating a beat level (L), the device comprising analyzer means (FT) which, in response to a reference frequency (Ω
- ) and to a harmonic coefficient (B) extracts the following from an evaluation signal (E);
a first acceleration signal (γ
B) at a frequency equal to the product of said reference frequency (Ω
) multiplied by said harmonic coefficient (B); and
a second acceleration signal (γ
B-1) at a frequency equal to the product of said reference frequency (Ω
) multiplied by said harmonic coefficient minus one;
and the device further comprising a control circuit (CC) which receives said first and second acceleration signals (γ
B, γ
B-1) to produce said beat level (L),and wherein said beat level is equal to the ratio of the nth power of said second acceleration signal (γ
B-1) divided by the first acceleration signal (γ
B).
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Abstract
A device for indicating a beat level L, the device including an analyzer which responds to a reference frequency Ω and a harmonic coefficient B to extract from an evaluation signal E a first acceleration signal γB at a frequency equal to the product of reference frequency Ω multiplied by harmonic coefficient B; and a second acceleration signal γB-1 at a frequency equal to the product of reference frequency Ω multiplied by the harmonic coefficient minus one; and it further includes a control circuit CC which receives acceleration signal γB, γB-1 to produce beat level L.
11 Citations
15 Claims
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1. A device for indicating a beat level (L), the device comprising analyzer means (FT) which, in response to a reference frequency (Ω
- ) and to a harmonic coefficient (B) extracts the following from an evaluation signal (E);
a first acceleration signal (γ
B) at a frequency equal to the product of said reference frequency (Ω
) multiplied by said harmonic coefficient (B); anda second acceleration signal (γ
B-1) at a frequency equal to the product of said reference frequency (Ω
) multiplied by said harmonic coefficient minus one;and the device further comprising a control circuit (CC) which receives said first and second acceleration signals (γ
B, γ
B-1) to produce said beat level (L),and wherein said beat level is equal to the ratio of the nth power of said second acceleration signal (γ
B-1) divided by the first acceleration signal (γ
B). - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
- ) and to a harmonic coefficient (B) extracts the following from an evaluation signal (E);
-
9. A device for indicating a beat level (L) of a rotary wing aircraft having a rotor with a plurality of blades, the device comprising:
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a vibration sensor (S1, S2, S3) for measuring vibration on board the aircraft; a speed sensor (T) for measuring the speed of rotation of the rotor, the speed sensor providing a reference signal having a reference frequency (Ω
);a synchronous analysis means (FT) for synchronously analyzing harmonic components of a vibration signal (E) derived from the vibration sensor, the synchronous analysis means (FT) being connected to the vibration sensor and to the speed sensor, the synchronous analysis means (FT) being arranged to extract from the vibration signal (E); i) a first harmonic component (γ
B) of a frequency (BΩ
) equal to the product of said reference frequency (Ω
) multiplied by a harmonic coefficient (B) equal to the number of blades of the rotor, andii) a second harmonic component (γ
B-1) of frequency (B-1) (Ω
) equal to the product of said reference frequency (Ω
) multiplied by said harmonic coefficient minus one (B-1);a control circuit (DC) connected to the synchronous analysis means (FT), the control circuit receiving said first and second harmonic components and outputting a beat level (L). - View Dependent Claims (10, 11, 12, 13, 14, 15)
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Specification