KR20040067484A - Airplane Test Analysis System - Google Patents

Abstract

PURPOSE: An analysis system for an aircraft test is provided to precisely analyze a stability of an aircraft by obtaining a damping value using a random decrement method and a moving block analysis. CONSTITUTION: An analysis system(100) for an aircraft test includes a signal input section(110), a parameter setting section(120), a random decrement method executing section(130), a moving block analysis executing section(140), a display section(150) and a control unit(101). The signal input section(110) receives signals according to various test conditions of an air craft(200). Various parameters are inputted into the parameter setting section(120) by a user. The random decrement method executing section(130) receives a signal from the signal input section(110) and outputs an attenuated vibration signal in which noise is removed.

Description

Aircraft Test Analysis System

The present invention outputs in the form of attenuated vibration with noise removed by flutter test of aircraft and obtains natural frequency and damping value through moving block analysis, so that user can improve flight stability of the aircraft. The present invention relates to an aircraft test analysis system that enables convenient and accurate identification.

In general, after the manufacture of the aircraft, various tests are conducted to test whether the manufactured aircraft can perform normal flight in various environments that may occur during actual flight.

The flutter test is one of these aircraft tests, and it is possible to stably check whether each part of the aircraft operates normally in each vibration by giving vibration to the aircraft under test according to various conditions. Means to test.

Typically, such a flutter test is applied to shake the aircraft according to the random or predetermined frequency during the flight test flight, and calculate the damping value (Damping Value) based on the input value reflecting the state of each area to determine the stability of the area. do.

In this case, the damping value according to the test means that the calculated value is higher than the reference value to maintain a more stable state, and lower than the reference value means that it represents an unstable state.

In general, there are two methods to obtain the damping value, that is, a random decrement method (RDM) which analyzes an aircraft by giving it a random vibration, and a moving block that analyzes the state by vibration according to a single constant frequency. Analysis (MBA: Moving Block Analysis) is used.

By the way, the random decrement method can attenuate the random noise introduced into the aircraft during the test, but cannot obtain accurate natural frequencies and attenuation coefficients. There is a disadvantage that cannot be used for.

Therefore, there is an urgent need to develop a system that can conveniently perform the flutter test result analysis by accommodating both the above-described random noise method and the moving block analysis during the flutter test.

The present invention has been devised in this background, and the aircraft test analysis system that can accurately determine the flight stability of the aircraft by obtaining a damping value in consideration of the random decrement method and moving block analysis during the flutter test The purpose is to provide.

1 is a block diagram showing the configuration of an aircraft test analysis system according to a preferred embodiment of the present invention;

2 is a flow chart showing the operational flow of the aircraft test analysis system according to a preferred embodiment of the present invention.

<Description of the symbols for the main parts of the drawings>

100: aircraft test analysis system

101: control unit

110: signal input unit

120: parameter setting unit

130: random decrement method execution unit

140: moving block analysis execution unit

150: display unit

200: aircraft

In order to achieve the above object, the present invention provides a signal input unit that performs a function of receiving a signal corresponding to a test situation from an aircraft under test in an analysis system by receiving a signal for a state of each part according to a test from an aircraft under test. And a parameter input unit for performing a function of allowing a user to input various parameters required for analysis, and a random decrement method for receiving a signal input from the signal input unit and outputting attenuated vibration signal from which noise is removed. A random decrement method execution unit that performs a function, and a moving function that converts the attenuation vibration signal output from the random decrement method execution unit into a Fourier transform and outputs a damping value value corresponding to each frequency band. A block analysis execution unit and the signal input unit and random decrement described above It consists in the process execution unit and moving block analysis execution unit in each type and displaying the data to be output in graphical form or in numeric form, and a display unit that controls the interaction and flow of data and the overall operation between the above-mentioned parts the control.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings so that those skilled in the art can easily implement the present invention in detail.

First, in adding reference numerals to the components of each drawing, it should be noted that the same reference numerals are used to refer to the same components, even if displayed on different drawings.

1 is a block diagram showing the configuration of an aircraft test analysis system according to a preferred embodiment of the present invention.

As shown, the aircraft test analysis system 100 according to a preferred embodiment of the present invention includes a signal input unit 110, a parameter setting unit 120, a random decrement method execution unit 130, a moving block The analysis execution unit 140, the display unit 150 and the control unit 101.

The signal input unit 110 performs a function of receiving a signal according to each test situation from the test aircraft 200.

The parameter input unit 120 performs a function of allowing a user to input various parameters required for analysis.

The random decrement method execution unit 130 receives a signal input from the signal input unit 110 and outputs the attenuated vibration signal from which noise is removed according to the random decrement method.

The moving block analysis execution unit 140 converts the attenuation vibration signal output from the random decrement method execution unit 130 through a Fourier transform to output a natural frequency and a damping value.

The display unit 150 displays data input or output from the signal input unit 110, the random decrement method execution unit 130, and the moving block analysis execution unit 140, respectively, in a numerical form or a graph form. Perform the function.

The controller 101 performs a function of controlling the overall operation in the aircraft test analysis system 100, such as the interaction and data flow between the respective units 110 to 150.

2 is a flow chart showing the operation flow of the aircraft test analysis system 100 according to a preferred embodiment of the present invention, the aircraft test analysis system 100 shown in Figure 1 by the control unit 101 the following operation flow Will operate according to

First, the following parameters should be set in the aircraft test analysis system 100 before operation (step: S1).

1. Execution selection parameters (RUN_RANDEC and RUN_MBA): Parameters for determining whether to perform random decrement method and moving block analysis, and may have a value of 'yes' and 'No', and at least one of them is 'Yes'. Must be set to.

2. Averaging unit setting parameter (RMS_MULTIPLIER): A parameter that determines the triggering condition of the random decrement method. The parameter is given as a multiple of the root mean square value (RMSV), which is usually an averaging unit. The value of is used, preferably given so that the averaging in the random decrement method can be 2000 or more.

3. Step parameter (STEP): This parameter determines the movement of a block, which is a calculation unit of moving block analysis. If the data conditions are good, an integer greater than 1 may be given to reduce the calculation time.

4. Sample parameter (SAMPLE): Sample rate of the input signal of the random decrement method, that is, the signal input from the signal input unit, and the unit is Hz.

5. Block parameter (BLOCK): It is the size of the block to be taken at a time by the random decrement method. It is a value that determines the frequency resolution in moving block analysis.

It is preferable to set the frequency resolution to about 0.1 Hz, so that it is about 10 times the sample parameter.

6. Input name parameter (INPUT_NAME): The name of the file where the input signal of the random decrement method is stored. Actually, the file name should have the extension of .m.

7. Run parameter (RUN): A parameter that reads an .m file created by the input name parameter and loads the data into memory.

When the setting of these parameters is completed,

The signal input unit 110 receives a signal according to random vibration from the aircraft under test 200 (step: S2), and the user executes a random decrement method among the selection parameters performed at the prompt of the parameter input unit 120. Enter the parameter RUN_RANDEC (step S3).

When the performance selection parameter is input, the controller 101 transfers the signal input from the signal input unit 110 to the random decrement method execution unit 130, and the random decrement method execution unit 130 receives the input signal. Random decrementation method is applied to remove the noise of the signal which is difficult to analyze due to the mixing of many irregular noises and outputs the attenuated vibration signal (step: S4).

In this case, the user may selectively adjust the calculation condition by inputting a parameter such as an averaging setting unit parameter, a sample parameter, a block parameter, and the like into the parameter input unit 120.

On the other hand, the display unit 150 displays the signal output as the input signal and the attenuation vibration signal in the form of a graph (step: S5), through which the user checks the analysis result according to the random decrement method and the damping value It can be predicted.

Subsequently, the controller 101 transmits the output attenuation vibration signal to the moving block analysis execution unit 140, and the moving block analysis execution unit 140 converts the input attenuation vibration signal into a Fourier transform (step: S6) output the damping value according to each frequency band (step S7).

The display unit 150 displays the damping value output value of each frequency band output through the moving block analysis execution unit 140 in a graph form, and outputs the random decrement method execution result and the moving block analysis execution result that were previously output. The values are compared and output in numerical form (step S8).

Therefore, the user can determine the flight stability of the aircraft 200 through the damping value derived by considering both the random decrement method and the moving block analysis.

As mentioned above, although preferred embodiments of the present invention have been described in detail, those of ordinary skill in the art to which the present invention pertains should realize the present invention without departing from the spirit and scope of the present invention as defined in the appended claims. It will be appreciated that various modifications or changes can be made. Accordingly, modifications to future embodiments of the present invention will not depart from the technology of the present invention.

As described above, according to the present invention, when the flutter test of the aircraft using the random decrement method outputs in the form of attenuated vibrations from which noise is removed, the natural frequency and the damping value can be obtained through moving block analysis. There is an advantage that can conveniently and accurately determine the flight stability of the aircraft.

Claims (3)

In the system for receiving a signal about the state of each part according to the test from the aircraft under test, A signal input unit configured to receive a signal according to the test situation from the test aircraft; A parameter input unit for performing a function of allowing a user to input various parameters required for the analysis; A random decrement method execution unit which receives a signal input from the signal input unit and executes a random decrement method to output attenuated vibration signal from which noise is removed; A moving block analysis execution unit for converting the attenuation vibration signal output from the random decrement method execution unit into a Fourier transform and outputting a damping value value corresponding to each frequency band; Aircraft test analysis system comprising a control unit for controlling the interaction and data flow and overall operation between the respective parts. The aircraft test analysis of claim 1, further comprising a display unit configured to display data input and output from the signal input unit, the random decrement method execution unit, and the moving block analysis execution unit, respectively. system. The aircraft test analysis system of claim 2, wherein the display unit outputs the output data in at least one of a numerical form and a graph form.