Vibration detection system and method for aircraft brake based on composite parameters

Abstract

To provide a vibration detection system and method capable of improving detection accuracy without receiving interference of machine body vibration.SOLUTION: The present invention relates to a field of aviation detection, in particular to a vibration detection system and method of an aircraft brake based on composite parameters, which is used for brake inspection during static maintenance of an aircraft, and comprises a vibration exciter, a vibration excitation controller, a fan-shaped array sensing assembly, a sensor processor and a central data processor. The fan-shaped array sensing assembly includes one vibration excitation area with one vibration excitation frequency sensor, where a plurality of detection shafts are distributed at equal included angles, with the vibration excitation area defined as a circle center, and a plurality of amplitude sensors are distributed on the detection shafts at equal intervals. Detection precision is higher, intersection processing is carried out on a plurality of dangerous areas by adopting Boolean operation, prediction precision of the dangerous areas is improved, subsequent flaw detection processing steps are simplified, and detection efficiency is improved.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention is in the field of aviation sensing, and more particularly, a system and method for vibration detection of aircraft brakes based on multiple parameters. [Background technology]

[0002] The landing brake of an airplane is a process of converting kinetic energy into thermal energy from motion to rest. Taking the A380, which weighs 500 tons and has a landing speed of 270 km / h, as an example, it has about 1700 megajoules of kinetic energy during landing, and most of the kinetic energy is converted into thermal energy due to friction of the brake material and absorbed by the brake material. At this time, the temperature of the brake material quickly exceeds 1000 degrees Celsius, which is a severe test of the high temperature resistance and heat dissipation of the brake material. Under the action of ultra-high braking force, the high-rigidity airplane brake will generate different vibrations, and when the structural equipment is weakened, the vibration mode of the brake will change, which in many cases is a sign of the occurrence of failure. How to predict the failure of the brake based on the vibration signal and avoid safety risks during descent is a problem that is being focused on in this field.

[0003] In the prior art, there are technical solutions that are specialized in detecting vibrations of aircraft brakes.

[0004] (1) CN112078826A discloses an aircraft wheel and brake assembly, specifically, a wheel, a brake configured to brake the wheel, and a measuring device configured to measure the rotational speed of the wheel, the brake comprising at least one friction member, a brake support, and at least one brake carried by the brake support and configured to selectively apply a braking force to the friction member, the measuring device comprising an object and a sensing component for generating a measurement signal representative of the rotational speed of the object, the aircraft wheel and brake assembly is configured such that, when the aircraft wheel and brake assembly is assembled, the object is constrained to rotate with the wheel, and the sensing component is attached to the brake support, and the object and sensing component are configured such that the sensing component detects the rotation of the object.

[0005] (2) CN110816887A discloses an airplane wheel brake system test bench and a test method, specifically, the airplane wheel brake system test bench has three test units, and the brake test of three wheels can be performed simultaneously. The present invention uses the drum surface in the drive system to simulate the airplane runway, the drum rotation speed to simulate the ground running speed and running kinetic energy of the airplane, the load system to simulate the ground load of the airplane, and integrates the drive system and the load system, and simulates the takeoff and landing process of the whole airplane on the test bench, and the braking system performs the wheel brake system ground runway test on the airplane runway. In addition, the ground runway test of the takeoff and landing braking system of the whole airplane on the airplane runway may be simulated under extreme conditions. The risk in the test process is reduced, the large test cost and test difficulty caused by the test using the airplane are reduced, and the control and collection of the test data are realized more easily and accurately.

[0006] (3) CN107310750A discloses a vibration test method for an aircraft brake system, specifically, the test time is determined according to the vibration time in the life requirement, the test maximum vibration value is determined according to the maximum vibration value within the life period, all products of the brake system are attached to the extension head according to the system connection method, the extension head is attached to the moving coil of the electric vibration table, and the vibration test section is determined according to the test time and the vibration value. The section has a low-value vibration required to indicate the failure risk stimulated by the maximum vibration value, and the vibration time is determined according to the life of the brake system, so that the present invention can stimulate the vibration failure risk within the life period of the brake system in principle.

[0007] Although the above technical proposals have put forward improvements, the prior art still has the following problems:

[0008] 1. The sensor-based detection method cannot judge the stiffness change of the aircraft brake. Under the assumption of high stiffness, acceleration sensors and Amplitude Sensor However, because it is easily affected by external vibrations, it is difficult to quickly determine the degree of deterioration of the brake. 2. Traditional vibration detection methods can only detect dynamic vibrations, but cannot detect quickly under static maintenance conditions. The detection conditions for aviation equipment are strict, and the detection accuracy is not high. 3. Traditional detection methods mainly rely on detecting G values, which cannot determine the differences in vibration at different positions on the brake, and cannot quickly find weak points within the brake structure. 4. Traditional brake life detection must rely on destructive fatigue testing, that is, one or more brakes are mounted on a fatigue testing machine and loaded until they are destroyed, their fatigue life is measured, and then compared with brake products in the same batch. In this way, there are often orders of magnitude differences in fatigue tests, that is, the difference in fatigue life of products in the same batch can be as much as tens or even hundreds of times, so the evaluation accuracy is very low, and there is a problem that products with long life are discarded early. Summary of the Invention

[0009] The system is used for brake inspection during static maintenance of an aircraft, and includes a vibration exciter, a vibration controller, a sector array sensing assembly, a sensor processor, and a central data processor. The sector array sensing assembly has an excitation area with one excitation frequency sensor, the excitation area is a circle center, a plurality of detection axes are distributed at equal angles, and a plurality of amplitude sensors are distributed at equal intervals on the detection axes; The sensor processor receives the vibration signals generated by the sector array sensing assembly and generates a set of vibration signals {Q ij (F;t,A)| i=1,2,…,n;j=1,2,…,m} and transmit it to said central data processor; In the figure, i represents the detection axis symbol, n represents a total of n detection axes, and j represents the number of detection axes arranged along the excitation region in the detection axis. Amplitude Sensor m represents the number of the detection axes, and m represents the number of detection axes. Amplitude Sensor F represents the vibration frequency actually measured by the vibration frequency sensor, t represents the detection time, and A represents the Amplitude Sensor represents the measured vibration amplitude, The vibrator applies vibrations to the brake disc that have a constant amplitude and a gradually increasing frequency, The central data processor first detects the distance between the distal end of the sector array sensing assembly and the Amplitude Sensor Based on the average value of the amplitude of G Determine, JPEG2025068582000013.jpg2577, of which f t represents the actual measured value of the excitation frequency given by the excitation frequency sensor at time t, JPEG2025068582000014.jpg1164 is represents the excitation frequency when the maximum amplitude appears at the end of the damper, resonance frequency f G After determining, the resonance frequency f G The vibration signal set {Q ij (F;t,A)| i=1,2,…,n;j=1,2,…,m}, perform curve fitting, and take the maximum point of change in slope of the fitted curve as the danger region.

[0010] Furthermore, after the initial determination of the danger zone, the exciter and the sector array sensing assembly are deflected at a given angle along the center of the damper to obtain the resonant frequency f G The vibration is then applied and the critical area is measured again, and a "Boolean intersection" calculation is performed with the initially determined critical area.

[0011] In addition, the exciter and sector array sensing assembly are deflected multiple times along the center of the damper to obtain multiple danger regions and perform a "Boolean intersection" calculation.

[0012] Furthermore, the deflection angle is between 30° and 90°.

[0013] Furthermore, the deflection angle is one of 30°, 45°, 60°, and 90°.

[0014] Further, the vibration exciter is one of inertial, electric, electromagnetic, electro-hydraulic, pneumatic and hydraulic.

[0015] Implemented based on the vibration detection system, In a static maintenance state of the aircraft equipment, a vibration exciter is installed at a position other than the center of the brake disc, and the sector array sensing assembly has one excitation area, and the vibration head of the vibration exciter is attached to the excitation area; a resonance frequency determination step S2 in which the vibrator applies vibration to the brake disc with a constant amplitude and a gradually increasing frequency, detects the amplitude of the end sensor, and takes the vibration frequency at the maximum amplitude as the resonance frequency; A vibration is applied to the brake disk with a vibration frequency equal to the resonant frequency, and the sensor processor detects the vibration signal set {Q ij (F;t,A)| i=1,2,…,n;j=1,2,…,mand step S3 of generating {}, transmitting it to a central data processor, performing curve fitting, and taking the maximum point of change in slope of the fitting curve as the danger region.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] 1. In the present invention, a vibration exciter is used to detect dangerous points on the aircraft braking disk during static maintenance. Amplitude Sensor Compared with mounting a sensor on a ground vehicle and detecting vibrations during landing, the detection method of the present invention is more convenient to implement, is not affected by vibrations of the aircraft, and has higher detection accuracy.

[0018] 2. In the present invention, a fan-shaped sensor array is used to detect the amplitude of each point on the brake disc. If an area where the amplitude increases sharply appears, it means that the area is weakened and may be a sign of internal damage, and therefore detection such as X-ray inspection is necessary.

[0019] 3. The present invention adopts Boolean operations to perform cross processing for multiple dangerous areas, which improves the accuracy of dangerous area prediction, simplifies the subsequent steps of flaw detection processing, and improves the detection efficiency. [Brief description of the drawings]

[0020] [Figure 1] FIG. 2 is a schematic diagram of one sector array sensing assembly of the present invention. [Diagram 2] FIG. 2 is a schematic diagram of another sector array sensing assembly of the present invention. [Diagram 3] FIG. 2 is a schematic diagram of curve fitting according to the present invention, in which the four curves represent the fitting results of detection data from four detection axes. [Figure 4] FIG. 2 is a schematic diagram of the Boolean intersection calculation of critical regions of the present invention; [Diagram 5] FIG. 2 is a schematic diagram of an equivalent structure of a defective braking disc. [Explanation of symbols]

[0021] In the figure, 1··· braking disk, 2··· excitation area, 3··· sector array sensing assembly, 4··· danger area, 5··· first danger area, 6··· second danger area, 7··· Boolean intersection area, 8··· perfect braking disk, 9··· defective braking disk, 10··· equivalent structure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0022] Hereinafter, the technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the drawings in the embodiments of the present invention, but of course, the described embodiments are only some of the embodiments of the present invention, and are not all of the embodiments. All other embodiments obtained based on the embodiments of the present invention without creative labor by those skilled in the art are all within the scope of protection of the present invention.

[0023] Example 1 It is used for brake inspection during static maintenance of an aircraft, and is equipped with a vibration exciter, a vibration controller, a sector array sensing assembly 3, a sensor processor, and a central data processor. The sector array sensing assembly 3 has one excitation area 2 with one excitation frequency sensor, and as shown in FIG. 1, the excitation area 2 is the center of a circle, and multiple detection axes are distributed at equal angles, and multiple amplitude sensors are distributed at equal intervals on the detection axes; The sensor processor receives the vibration signals generated by the sector array sensing assembly 3 and calculates a set of vibration signals {Q ij (F;t,A)| i=1,2,…,n;j=1,2,…,m} and transmit it to said central data processor; In the figure, i represents the detection axis symbol, n represents a total of n detection axes, and j represents the number of detection axes arranged along the excitation region 2 in the detection axis. Amplitude Sensor m represents the number of the detection axes, and m represents the number of detection axes. Amplitude Sensor F represents the vibration frequency actually measured by the vibration frequency sensor, t represents the detection time, and A represents the Amplitude Sensor represents the measured vibration amplitude, The vibrator applies vibrations to the brake disc 1 that have a constant amplitude and a gradually increasing frequency, The central data processor first detects the end of the sector array sensing assembly 3. Amplitude Sensor Based on the average value of the amplitude of G Determine, JPEG2025068582000015.jpg2577, of which f t represents the actual measured value of the excitation frequency given by the excitation frequency sensor at time t, JPEG2025068582000016.jpg1164 is represents the excitation frequency when the maximum amplitude appears at the end of the damper, resonance frequency f G After determining, the resonance frequency f G The vibration signal set {Q ij (F;t,A)| i=1,2,…,n;j=1,2,…,m} is generated, curve fitting is performed, and the fitting result is as shown in FIG. 3, and the maximum point of the slope change of the fitting curve is taken as the danger area 4.

[0024] Specifically, when the braking disc 1 is intact, its side view may be equivalent to a rectangular bar, as shown in FIG. 5. When an invisible crack appears in the braking disc 1, a weak point appears in its middle, which may be equivalent to two bars connected by a spring. When one bar is vibrated, a "whiplash effect" appears at the far end of the weak point, i.e., the other bar, resulting in an increased amplitude. From the curve, the amplitude near the weak point is small, and the amplitude far from the weak point is large, and the curve has an inflection point near the weak point. In this way, the approximate location of the weak point can be detected, and the weak point can be quickly located by detecting and Boolean calculation many times, and the flaw detection can be performed using X-rays, which makes the detection fast, efficient and accurate.

[0025] Example 2 Implemented based on the vibration detection system, In the static maintenance state of the aircraft, the brake disc 1 is removed or the brake caliper is loosened to the maximum position to ensure that the brake disc 1 is not interfered with during the vibration process; The vibrator is mounted at a position other than the center of the brake disc 1, and it is possible to ensure that the excitation area 2 is located at the axis of the brake disc 1 and the excitation area 2 is located on the outside, as shown in FIG. The sector array sensing assembly 3 has one excitation area 2, and the excitation head of the excitation device is attached to the excitation area 2; an equipment installation step S1, in which the vibrator is one of an inertial type, an electric type, an electromagnetic type, an electrohydraulic type, a pneumatic type, and a hydraulic type; a resonance frequency determination step S2 in which the vibrator applies vibration to the brake disc 1 with a constant amplitude and a gradually increasing frequency, detects the amplitude of the end sensor, and takes the vibration frequency at the maximum amplitude as the resonance frequency; A vibration is applied to the brake disk 1 with a vibration frequency equal to the resonant frequency, and the sensor processor detects a vibration signal set {Q ij (F;t,A)| i=1,2,…,n;j=1,2,…,m}, and send it to a central data processor, and perform curve fitting, as shown in FIG. 4, the x-axis in FIG. 4 represents the distance from the excitation region, the y-axis represents the amplitude, and the curve in FIG. 4 is a fitting curve, and the maximum point of the change in slope of the fitting curve is taken as the danger region 4, After the first danger zone 5 is determined, the excitation zone 2 is deflected by an angle of 30°, 45°, 60°, or 90°, and the danger zone 4 is determined again and marked as the second danger zone 6. Through Boolean intersection calculation, it is found that the overlapping zone, i.e., the Boolean intersection zone 7, is more likely to have invisible damage, which can be subsequently identified and detected by ultrasonic testing or X-ray testing.

[0026] As shown in FIG. 5, the complete brake disk 8 is a homogenous bar, and when broken, the broken area is weakened to become a thin bar with low stiffness, as shown in FIG. 5 as the defective brake disk 9, and may be equivalent to two rigid bars connected by a spring, for example, the equivalent structure 10 in FIG. 5. When vibrated, a "whiplash effect" occurs in which the ends shake. Although the embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations may be made to these embodiments without departing from the principles and spirit of the present invention, and the scope of the present invention is limited by the appended claims and their equivalents.

Claims

1. The system is used for brake inspection during static maintenance of an aircraft, and includes a vibration exciter, a vibration controller, a sector array sensing assembly (3), a sensor processor, and a central data processor; The sector array sensing assembly (3) has one excitation region (2) provided with one excitation frequency sensor, the excitation region (2) is the center of a circle, a plurality of detection axes are distributed at equal included angles, and a plurality of amplitude sensors are distributed at equal intervals on the detection axes; The sensor processor receives the vibration signals generated by the sector array sensing assembly (3) and generates a set of vibration signals {Q ij (F;t,A)| i=1,2,…,n;j=1,2,…,m } and transmit it to said central data processor; In the above, i represents the detection axis symbol, n represents a total of n detection axes, j represents the number of the vibrator arranged along the excitation region (2) on the detection axis, m represents that each detection axis has m vibration sensors, F represents the vibration frequency actually measured by the excitation frequency sensor, t represents the detection time, and A represents the actually measured vibration amplitude of the vibrator. The vibrator applies vibrations to the brake disc (1) that have a constant amplitude and a gradually increasing frequency, The central data processor first calculates the resonant frequency f of the brake to be measured based on the average amplitude of the vibration sensors at the ends of the sector array sensing assembly (3). G Determine, Among them, f t represents the actual measured value of the excitation frequency given by the excitation frequency sensor at time t, teeth, represents the excitation frequency when the maximum amplitude appears at the end of the damper, resonance frequency f G After determining, the resonance frequency f G The vibration signal set {Q ij (F;t,A)| i=1,2,…,n;j=1,2,…,m }, perform curve fitting, and take the maximum point of change in slope of the fitted curve as the critical region (4); 13. A vibration detection system for an aircraft brake based on a composite parameter, comprising:

2. After the danger zone (4) is first determined, the exciter and sector array sensing assembly (3) are deflected at a given angle along the center of the damper to obtain the resonant frequency f G The critical area (4) is then measured again and a "Boolean intersection" operation is performed with the first determined critical area (4).

2. The composite parameter based aircraft brake vibration detection system according to claim 1.

3. The actuator and sector array sensing assembly (3) are deflected multiple times along the center of the damper to obtain multiple danger zones (4) and perform a "Boolean intersection" calculation.

3. The composite parameter based aircraft brake vibration detection system according to claim 2.

4. The deflection angle is between 30° and 90°.

4. The composite parameter based aircraft brake vibration detection system according to claim 3.

5. The deflection angle is one of 30°, 45°, 60°, and 90°.

5. The composite parameter based aircraft brake vibration detection system according to claim 4.

6. The vibrator is one of an inertial type, an electric type, an electromagnetic type, an electrohydraulic type, a pneumatic type, and a hydraulic type.

6. The vibration detection system for aircraft brakes based on multiple parameters as claimed in claim 5.

7. The vibration detection system according to any one of claims 1 to 6, In a static maintenance state of an aircraft equipment, an excitation device is attached to a position other than the center of a brake disk (1), a sector array sensing assembly (3) has one excitation area (2), and an excitation head of the excitation device is adhered to the excitation area (2); a resonance frequency determination step S2 in which the vibrator applies vibration to the brake disc (1) with a constant amplitude and a gradually increasing frequency, detects the amplitude of the end sensor, and takes the vibration frequency at the maximum amplitude as the resonance frequency; A vibration is applied to the brake disk (1) with a vibration frequency equal to the resonant frequency, and the sensor processor detects a set of vibration signals {Q ij (F;t,A)| i=1,2,…,n;j=1,2,…,m }, sending it to a central data processor, performing curve fitting, and taking the maximum point of change in slope of the fitted curve as the critical region (4).

23. A method for vibration detection of an aircraft brake based on a composite parameter, comprising:

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