CN106596014A - Helicopter in-cabin flight vibration environment simulation test method - Google Patents

Abstract

The invention discloses a helicopter in-cabin flight vibration environment simulation test method. The helicopter in-cabin flight vibration environment simulation test method comprises the following steps: 1) obtaining in-cabin vertical vibration data of a helicopter to be tested in an actual flight condition; 2) carrying out narrow band-pass filtering on the in-cabin vertical vibration data to obtain flight vibration data; 3) generating sinusoidal reference signals according to helicopter in-cabin main oar first-order frequency; 4) calculating a vibration exciter output signal through a recursive least squares adaptive algorithm; and 5) carrying out helicopter in-cabin flight vibration environment simulation test on the helicopter to be tested or a helicopter model to be tested according to the vibration exciter output signal. The helicopter in-cabin flight vibration environment simulation test method can be used for all types of helicopter in-cabin flight vibration environment simulation at present, and provides flight vibration environment for ground test of a helicopter vibration active control system.

Description

Helicopter cabin flight vibration environment simulation test method

Technical Field

The invention relates to the technical field of helicopter vibration simulation, in particular to a helicopter cabin flying vibration environment simulation test method.

Background

The ground test of the helicopter vibration active control system mainly comprises a vibration reduction effect test of the vibration active control system on the position in a helicopter cabin, a vibration reduction robustness test, an adaptability test and a research and development stage. The method realizes that the flight vibration environment at the position in the cabin of the helicopter is the same as the real flight vibration environment, and is related to the key of the ground test of the helicopter vibration active control system.

When simulating the problem of the flying vibration environment at the position in the cabin of the helicopter, the prior art generally adopts a frequency spectrum method to simulate the vibration level under the main vibration frequency. The simulation of the flight vibration environment at the position in the cabin of the helicopter is mainly realized by manually simulating various flight working conditions at the present stage.

Accordingly, a technical solution is desired to overcome or at least alleviate at least one of the above-mentioned drawbacks of the prior art.

Disclosure of Invention

The present invention aims to provide a helicopter cabin flight vibration environment simulation test method which overcomes or at least alleviates at least one of the above-mentioned disadvantages of the prior art.

In order to achieve the purpose, the invention provides a flight vibration environment simulation test method in a helicopter cabin, which comprises the following steps:

step 1: acquiring vertical vibration data of the helicopter to be tested in the cabin in the actual flight state;

step 2: carrying out narrow-band-pass filtering on the vertical vibration data in the cabin obtained in the step 1 by taking the first-order frequency of a main rotor in the cabin of the helicopter as a central frequency, thereby obtaining filtered flight vibration data;

and step 3: generating a sinusoidal reference signal according to the first-order frequency of a main rotor in the cabin of the helicopter;

and 4, step 4: calculating an output signal of a vibration exciter according to the flight vibration data in the step 2 and the sine reference signal in the step 3 by a recursive least square self-adaptive algorithm;

and 5: and outputting a signal to the helicopter to be tested or the helicopter model to be tested through the vibration exciter to perform a flight vibration environment simulation test in the helicopter cabin.

Preferably, the step 1 specifically comprises: according to the position in the cabin of the helicopter, a vibration sensor is arranged on the helicopter to measure the vertical vibration data d of the position of the helicopter under various flight conditions₀。

Preferably, the step 2 specifically comprises: flight vibration data d of the position in the cabin of the helicopter measured according to the step 1₀And carrying out narrow-band-pass filtering by taking the position interest (primary rotor first-order frequency) frequency in the cabin of the helicopter as a central frequency f to obtain filtered flight vibration data d.

Preferably, the step 3 specifically includes generating a sinusoidal reference signal u according to a position interest frequency f in the helicopter cabin by using the following formula;

u ═ sin (ft); wherein t is time; f is the frequency of interest of the position in the cabin of the helicopter; u is a sinusoidal reference signal.

Preferably, the step 4 specifically includes: and calculating the output signal of the vibration exciter by adopting a recursive least square self-adaptive algorithm according to the filtered flight vibration data d obtained in the step 2 and the sinusoidal reference signal u obtained in the step 3.

Preferably, the calculating of the exciter output signal by the recursive least square adaptive algorithm in step 4 specifically includes:

first step algorithm initialization

P(0)＝^-1I

The second step calculates for each time instant n 1,2, …

π(n)＝P(n-1)u(n)

And

P(n)＝λ^-1P(n-1)-λ^-1k(n)u^H(n)P(n-1)

thirdly, outputting a control signal of the vibration exciter

Wherein,

i: a unit diagonal matrix; k (n): at the nth time, a time-varying gain vector is obtained; d (n): secondly, obtaining nth data of the filtered flight vibration data d; p (n): at the nth time, estimateWith respect to noise variance²Normalization of (1);the nth time, tap weight vector estimation, ξ (n), the nth time, a priori estimation error, pi (n), the nth time, an intermediate quantity, n, an iterative computation time, n]^H: matrix conjugate transpose; λ: a step size parameter; y (n): at the nth moment, a vibration exciter control signal is sent;at the initial moment, estimating a tap weight vector; p (0): initial time of day, estimateWith respect to noise variance²Normalization of (1); lambda [ alpha ]^-1: a step size parameter; p (n): at time n-1, estimateWith respect to noise variance²Normalization of (1); u (n) is: inputting the sine reference signal of the nth iteration; h: conjugate transpose;^*: and (5) estimating the quantity.

The helicopter cabin flying vibration environment simulation test method can be used for simulating flying vibration environments in helicopter cabins of all current configurations, provides flying vibration environments for ground tests of helicopter vibration active control systems, and guides the design of helicopter vibration active control systems.

Drawings

Fig. 1 is a schematic flow chart of a flight vibration environment simulation test method in a helicopter cabin according to an embodiment of the present invention.

Detailed Description

In order to make the implementation objects, technical solutions and advantages of the present invention clearer, the technical solutions in the embodiments of the present invention will be described in more detail below with reference to the accompanying drawings in the embodiments of the present invention. In the drawings, the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The described embodiments are only some, but not all embodiments of the invention. The embodiments described below with reference to the drawings are illustrative and intended to be illustrative of the invention and are not to be construed as limiting the invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention. Embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

In the description of the present invention, it is to be understood that the terms "center", "longitudinal", "lateral", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate orientations or positional relationships based on those shown in the drawings, and are used merely for convenience in describing the present invention and for simplifying the description, but do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be construed as limiting the scope of the present invention.

Fig. 1 is a schematic flow chart of a flight vibration environment simulation test method in a helicopter cabin according to an embodiment of the present invention.

The helicopter cabin flight vibration environment simulation test method shown in FIG. 1 comprises the following steps:

step 1: acquiring vertical vibration data of the helicopter to be tested in the cabin in the actual flight state;

step 2: carrying out narrow-band-pass filtering on the vertical vibration data in the cabin obtained in the step 1 by taking the first-order frequency of a main rotor in the cabin of the helicopter as a central frequency, thereby obtaining filtered flight vibration data;

and step 3: generating a sinusoidal reference signal according to the first-order frequency of a main rotor in a helicopter cabin;

and 4, step 4: calculating an output signal of a vibration exciter by a recursive least square self-adaptive algorithm according to the flight vibration data in the step 2 and the sinusoidal reference signal in the step 3;

and 5: and outputting a signal to the helicopter to be tested or the helicopter model to be tested through the vibration exciter to perform a flight vibration environment simulation test in the helicopter cabin.

In this embodiment, step 1 specifically includes: according to helicopter cabinThe inner position is provided with a vibration sensor on the helicopter, and the vertical vibration data d of the helicopter position under various flight working conditions is measured₀。

In this embodiment, step 2 specifically includes: flight vibration data d of the position in the cabin of the helicopter measured according to the step 1₀And carrying out narrow-band-pass filtering by taking the first-order frequency of the main rotor at the position in the cabin of the helicopter as the center frequency f to obtain filtered flight vibration data d.

In this embodiment, the step 3 specifically includes generating a sinusoidal reference signal u according to a first-order frequency f of a main rotor at a position in a cabin of the helicopter by using the following formula;

u＝sin(ft)；

wherein t is time; f is the first-order frequency of a main rotor at the position in the cabin of the helicopter; u is a sinusoidal reference signal.

In this embodiment, step 4 specifically includes: and (3) calculating the output signal of the vibration exciter by adopting a recursive least square self-adaptive algorithm according to the filtered flight vibration data d obtained in the step (2) and the sinusoidal reference signal u obtained in the step (3).

In this embodiment, the calculating of the exciter output signal by the recursive least squares adaptive algorithm in step 4 specifically includes:

first step algorithm initialization

P(0)＝^-1I

The second step calculates for each time instant n 1,2, …

π(n)＝P(n-1)u(n)

And

P(n)＝λ^-1P(n-1)-λ^-1k(n)u^H(n)P(n-1)

thirdly, outputting a control signal of the vibration exciter

Wherein,

i: a unit diagonal matrix; k (n): at the nth time, a time-varying gain vector is obtained; d (n): secondly, obtaining nth data of the filtered flight vibration data d; p (n): at the nth time, estimateWith respect to noise variance²Normalization of (1);the nth time, tap weight vector estimation, ξ (n), the nth time, a priori estimation error, pi (n), the nth time, an intermediate quantity, n, an iterative computation time, n]^H: matrix conjugate transpose; λ: a step size parameter; y (n): at the nth moment, a vibration exciter control signal is sent;at the initial moment, estimating a tap weight vector; p (0): initial time of day, estimateWith respect to noise variance²Normalization of (1); lambda [ alpha ]^-1: a step size parameter; p (n): at time n-1, estimateWith respect to noise variance²Normalization of (1); u (n) is: inputting the sine reference signal of the nth iteration; h: conjugate transpose;^*: and (5) estimating the quantity.

Finally, it should be pointed out that: the above examples are only for illustrating the technical solutions of the present invention, and are not limited thereto. Although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.

Claims (6)

1. A flight vibration environment simulation test method in a helicopter cabin is characterized by comprising the following steps:

step 1: acquiring vertical vibration data of the helicopter to be tested in the cabin in the actual flight state;

step 2: carrying out narrow-band-pass filtering on the vertical vibration data in the cabin obtained in the step 1 by taking the first-order frequency of a main rotor in the cabin of the helicopter as a central frequency, thereby obtaining filtered flight vibration data;

and step 3: generating a sinusoidal reference signal according to the first-order frequency of a main rotor in the cabin of the helicopter;

and 4, step 4: calculating an output signal of a vibration exciter according to the flight vibration data in the step 2 and the sine reference signal in the step 3 by a recursive least square self-adaptive algorithm;

and 5: and outputting a signal to the helicopter to be tested or the helicopter model to be tested through the vibration exciter to perform a flight vibration environment simulation test in the helicopter cabin.

2. The helicopter cabin flying vibration environment simulation test method of claim 1, wherein the step 1 specifically is: according to the position in the cabin of the helicopter, a vibration sensor is arranged on the helicopter to measure the vertical vibration data d of the position of the helicopter under various flight conditions₀。

3. The helicopter cabin flying vibration environment simulation test method of claim 2, wherein said step 2 is specifically: flight vibration data d of the position in the cabin of the helicopter measured according to the step 1₀And carrying out narrow-band-pass filtering by taking the first-order frequency of the main rotor at the position in the cabin of the helicopter as the center frequency f to obtain filtered flight vibration data d.

4. The simulation test method for the flight vibration environment in the helicopter cabin according to claim 3, wherein the step 3 specifically comprises generating a sinusoidal reference signal u according to a first-order frequency f of a main rotor at a position in the helicopter cabin by using the following formula;

u＝sin(ft)；

wherein t is time; f is the frequency of interest of the position in the cabin of the helicopter; u is a sinusoidal reference signal.

5. The helicopter cabin flying vibration environment simulation test method of claim 4, wherein said step 4 is specifically: and calculating the output signal of the vibration exciter by adopting a recursive least square self-adaptive algorithm according to the filtered flight vibration data d obtained in the step 2 and the sinusoidal reference signal u obtained in the step 3.

6. The helicopter cabin flight vibration environment simulation test method according to claim 5, wherein the recursive least squares adaptive algorithm in step 4 calculates the exciter output signal specifically as follows:

first step algorithm initialization

$\hat{w}\left(0\right)=0$

P(0)＝^-1I

The second step calculates for each time instant n 1,2, …

π(n)＝P(n-1)u(n)

$k\left(n\right)=\frac{\mathrm{\π}\left(n\right)}{\mathrm{\λ}+u^H\left(n\right)\mathrm{\π}\left(n\right)}$

$\mathrm{\ξ}\left(n\right)=d\left(n\right)-{\hat{w}}^H(n-1)u\left(n\right)$

$\hat{w}\left(n\right)=\hat{w}(n-1)+k\left(n\right){\mathrm{\ξ}}^{*}\left(n\right)$

And

P(n)＝λ^-1P(n-1)-λ^-1k(n)u^H(n)P(n-1)

thirdly, outputting a control signal of the vibration exciter

$y\left(n\right)={\hat{w}}^H(n-1)u\left(n\right)$

Wherein,

i: a unit diagonal matrix; k (n): at the nth time, a time-varying gain vector is obtained; d (n): secondly, obtaining nth data of the filtered flight vibration data d; p (n): at the nth time, estimateWith respect to noise variance²Normalization of (1);the nth time, tap weight vector estimation, ξ (n), the nth time, a priori estimation error, pi (n), the nth time, an intermediate quantity, n, an iterative computation time, n]^H: matrix conjugate transpose; λ: a step size parameter; y (n): at the nth moment, a vibration exciter control signal is sent;at the initial moment, estimating a tap weight vector; p (0): initial time of day, estimateWith respect to noise variance²Normalization of (1); lambda [ alpha ]^-1: a step size parameter; p (n): at time n-1, estimateWith respect to noise variance²Normalization of (1); u (n) is: inputting the sine reference signal of the nth iteration; h: conjugate transpose;^*: and (5) estimating the quantity.