CN103528668A - Physical-simulation test processing system for microvibration of refrigerating machine and test method thereof - Google Patents

Abstract

The invention discloses a physical-simulation test processing system for microvibration of a refrigerating machine and a test method thereof. The physical-simulation test processing system comprises a compressor, a compressor bracket, a Z-shaped patch board, a hexagonal patch board, a six-component and eight-sensor perturbation-vibration force testing platform, distributed acceleration sensors, a laser displacement measuring system and a data acquisition and processing system, wherein the refrigerating machine device is arranged on the six-component and eight-sensor testing platform by the patch board, and simultaneously the accelerator sensors are distributed on the refrigerating machine according to the testing requirement. When in working, the refrigerating machine can generate micro-perturbation to the six-component and eight-sensor perturbation-vibration force testing platform. The data acquisition system acquires signals of the eight sensors of the six-component and eight-sensor perturbation-vibration force testing platform, obtains the perturbation-vibration force by a series of calculations and also acquires the signals of the acceleration sensors to obtain acceleration.

Description

The micro-vibration physical simulation of a kind of refrigeration machine test processes system and method for testing thereof

Technical field

The present invention relates to the micro-method for testing vibration of a kind of refrigeration machine, can be used for the vibration signal on six-freedom degree to spacecraft refrigerator device tiny perturbation load and carry out kinetic measurement.

Background technology

Refrigeration machine is the main devices on satellite, for regulating inside satellite temperature variation.Due to reasons such as the manufacturing defect of the compressor in refrigeration machine and noise of motor, refrigeration machine produces periodically and the small power of shaking of disturbing in broadband celestial body, these disturb the power of shaking through modulation and the amplification of their internal dynamic characteristics, can produce considerable influence to the light path pointing accuracy of remote sensing satellite (GF-4) and degree of stability.Consider that refrigeration machine is arranged near imaging device, it is particularly important that this impact just seems.

Because the disturbance of spacecraft disturbing source is very little, indivedual useful load are as momenttum wheel three faint disturbances that direction can only produce even a few milli newton of tens milli newton in space, want to measure this type of disturbance very difficult in the ground experiment chamber with relatively strong jamming pattern noise, and the accuracy requirement of its respective sensor is very high.

At present, there is not yet the reported in literature of relevant this type of microvibration measuring system both at home and abroad.

Summary of the invention

The technical matters that the present invention solves is: overcome the deficiencies in the prior art, provide a kind of refrigeration machine micro-method for testing vibration, measure and analyze the dynamic perfromance of spacecraft refrigerator device on the six-freedom degree of space, for improving the attitude control accuracy of spacecraft, provide reliable test data with the safe design of strengthening spacecraft.

Technical scheme of the present invention is: the micro-vibration physical simulation of a kind of refrigeration machine test processes system, comprises that refrigerator system, zigzag card extender, hexagon card extender, six component eight sensors disturb the power test board that shakes, data acquisition and processing (DAP) system; Described refrigerator system comprises compressor, compressor bracket, infrared probe support, infrared probe; Hexagon card extender is fixedly connected on six component eight sensors and disturbs and shake on power test board; Zigzag card extender is fixedly connected on hexagon card extender; Compressor is fixedly connected on one end of zigzag card extender by compressor bracket, infrared probe support is fixedly connected on the other end of zigzag card extender by infrared probe; Data acquisition and processing (DAP) system is disturbed with six component eight sensors the power test board of shaking and is connected, by six component eight sensors, disturb micro-vibration data that refrigerator system was measured and obtained to the power test board of shaking, and transfer data to data acquisition and processing (DAP) system and carry out the power of shaking of disturbing that analyzing and processing obtains refrigerator system.

Also comprise acceleration transducer, for measuring refrigerator system, disturb the acceleration while shaking.

Also comprise laser non-contact testing system; Laser non-contact testing system Emission Lasers, to refrigerator system, and is delivered to data acquisition and processing (DAP) system by the feedback signal reflecting and is processed, and obtains the displacement of shaking of disturbing of infrared probe; Described laser non-contact testing system is produced by German Polytec company, and model is: D-76337.

A micro-vibration physical simulation test processes system detection method, step is as follows:

1) demarcation dish is arranged on to six component eight sensors and disturbs and shake on power test board, with bolt, tightened; Demarcation dish is a square aluminium dish, and described demarcation dish is evenly equipped with 3 beating points on four sides separately, is furnished with 4 beating points on upper surface, and lower surface is disturbed with six component eight sensors the power test board of shaking and is connected;

2) firmly hammer knocks 16 beating points on demarcation dish successively, and gather the time-domain signal of power hammer, six component eight sensors are disturbed the power test board that shakes while knocking each point output voltage signal, obtain frequency response function;

3) by step 2) frequency response function that obtains obtains calibration matrix;

4) pull down demarcation dish;

5) refrigerator system is arranged on to six component eight sensors by zigzag card extender and hexagon card extender and disturbs and shake on power test board, and with bolt tightening;

6) refrigerator system energising is started working;

7) six component eight sensors are disturbed the power test board that shakes refrigerator system are tested, and the voltage time-domain signal while working by data acquisition and processing (DAP) system acquisition refrigeration machine;

8) voltage time-domain signal step 7) being obtained carries out the frequency-region signal that Fourier transform obtains voltage;

9) voltage frequency-region signal step 8) being obtained and calibration matrix multiply each other and obtain the frequency-region signal of refrigeration machine disturbing force;

10) frequency-region signal of refrigeration machine disturbing force step 9) being obtained carries out the time-domain signal that inversefouriertransform can obtain disturbing force, completes the processing to micro-vibration signal.

The present invention compared with prior art has the following advantages:

(1) the present invention is by the reasonable Arrangement of eight common piezoelectric sensors, thereby the micro-disturbing signal that makes six-freedom degree can utilize existing one-way piezoelectric power sensor to measure, overcome the problem that lacks high precision three-dimensional sensor, measuring accuracy is improved greatly.Meanwhile, the present invention adopts high precision acceleration transducer can improve acceleration test precision.

(2) measurement mechanism of the present invention is separated with measured test specimen, optional equipment and sensor need to be installed on test specimen, does not affect the dynamic perfromance of test specimen, does not damage test specimen structure, and after test, test specimen can also normally be used.

(3) the present invention is by the pretightning force of reasonable adjusting bolt, realized the amplification of signal and can have the accurate measurement under the actual motion condition in larger quality disturbance source, improved the reliability of measuring.

(4) disturbing source of the present invention can be placed in measuring system inside or outside, has improved the adaptability of measuring system.

Accompanying drawing explanation

Fig. 1 is test macro schematic diagram;

Fig. 2 is calibration point position view of the present invention;

Fig. 3 is the inventive method process flow diagram.

Embodiment

As shown in Figure 1, the micro-vibration physical simulation of native system refrigeration machine disposal system, comprises that refrigerator system, zigzag card extender 3, hexagon card extender 4, six component eight sensors disturb the power test board 5 that shakes, data acquisition and processing (DAP) system 9, laser non-contact testing system 10; Described refrigerator system comprises compressor 1, compressor bracket 2, infrared probe support 6, infrared probe 7, acceleration transducer 8, data acquisition and processing (DAP) system 9; Hexagon card extender 4 is fixedly connected on six component eight sensors and disturbs and shake on power test board 5; Zigzag card extender 3 is fixedly connected on hexagon card extender 4; Compressor 1 is fixedly connected on one end of zigzag card extender 3 by compressor bracket 2, infrared probe support 6 is fixedly connected on the other end of zigzag card extender 3 by infrared probe 7; Acceleration transducer 8 is fixedly connected on zigzag card extender 3; Data acquisition and processing (DAP) system 9 is disturbed with six component eight sensors the power test board 5 that shakes with acceleration transducer 8 by wire and is connected, six component eight sensors are disturbed the power test board 5 that shakes and are measured and obtain the micro-vibration data of refrigeration machine and be transferred to data acquisition and processing (DAP) system 9 analyzing and processing, finally obtain the power of shaking of disturbing of refrigerator system.

A plurality of acceleration transducers 8 can be arranged micro-Vibration Condition of test focus as required, and each acceleration transducer 8 is connected with data acquisition and processing (DAP) system 9 by wire.

In the course of work, the signal output of laser non-contact testing system 10 control signal generators, and control vibration measurement with laser camera test specimen is tested, vibration measurement with laser camera is tested the vibration signal of test specimen by laser beam, and received simulating signal is passed to laser vibration measurer, laser vibration measurer receives the simulating signal that vibration measurement with laser camera transmits, and convert it into digital signal, digital signal is transferred to computing machine by data line, thereby realize the non-cpntact measurement of infrared probe, after the digital signal processing recording, by data acquisition and processing (DAP) system 9, gather digital signal, obtain the displacement of shaking of disturbing of infrared probe.

As shown in Figure 3, the invention provides refrigeration machine micro-vibration signal disposal route, step is as follows:

1) demarcation dish is arranged on to six component eight sensors and disturbs and shake on power test board 5, with bolt, tightened; Demarcation dish is a square aluminium dish, and as shown in Figure 2, demarcation dish is evenly equipped with 3 beating points on four sides separately, is furnished with 4 beating points on upper surface, and lower surface is disturbed with six component eight sensors the power test board 5 that shakes and is connected; Six component eight sensors are disturbed the power test board 5 that shakes and are comprised of eight one-way piezoelectric sensors, and wherein four piezoelectric sensor along continuous straight runs are arranged, guarantee to test two disturbing forces of along continuous straight runs and around the disturbing moment of vertical direction; Other four piezoelectric sensors vertically arrange, guarantee disturbing force vertically of test and around two disturbing moments of horizontal direction.

2) firmly hammer knocks 16 beating points on demarcation dish successively, and gather the time-domain signal of power hammer, six component eight sensors are disturbed the power test board 5 that shakes while knocking each point output voltage signal, obtain frequency response function;

3) by step 2) frequency response function that obtains calculates calibration matrix;

4) pull down demarcation dish;

5) refrigerator system is arranged on to six component eight sensors and disturbs and shake on power test board 5, with bolt tightening;

6) refrigerator system energising is started working;

7) six component eight sensors are disturbed the 5 pairs of refrigerator systems of power test board that shake and are tested, and the voltage time-domain signal while gathering refrigeration machines work by data acquisition and processing (DAP) system 9;

8) voltage time-domain signal step 7) being obtained carries out the frequency-region signal that Fourier transform obtains voltage;

9) voltage frequency-region signal step 8) being obtained and calibration matrix multiply each other and obtain the frequency-region signal of refrigeration machine disturbing force;

10) frequency-region signal of refrigeration machine disturbing force step 9) being obtained carries out the time-domain signal that inversefouriertransform can obtain disturbing force, completes the processing to micro-vibration signal.

First should try to achieve corresponding calibration matrix W (ω), integral calibrating matrix is actually the response signal of eight piezoelectric force transducers and acts on the frequency response function matrix between the load of equivalent center point.In the method, equivalent center is the central point of the loading disk upper surface of eight component sensor devices, heart point directly applies three translation power and three moments are had any problem hereinto, on the basis that is rigid body at hypothesis loading disk herein, a calibrating table that rigidity is very high is installed, and is selected 16 load(ing) points as shown in the figure.Known according to space force system level theory, utilize 16 load(ing) points selecting can equivalent go out to act on three translation power and three moments of loading disk geometric center; In Fig. 2, O point is the central point of loading disk upper surface, and table 1 has been listed the value of each parameter in figure.

Table 1 calibration point location parameter

Lx/m	Ly/m	Lz/m
			0.042	0.042	0.04

In test, by 16, demarcate power F ₁～F ₁₆obtain the calibration matrix W (ω) of system, the loading matrix of the expression actual loaded in test and the transition matrix between equivalent load matrix are that the expression formula of the Matrix C in formula (5) is:

C ₁=[0 1 0 -Lz 0 -Lx] ^T

C ₂=[0 1 0 -Lz 0 0] ^T

C ₃=[0 1 0 -Lz 0 Lx] ^T

C ₄=[-1 0 0 0 -Lz -Ly] ^T

C ₅=[-1 0 0 0 -Lz 0] ^T

C ₆=[-1 0 0 0 -Lz Ly] ^T

C ₇=[0 -1 0 Lz 0 -Lx] ^T

C ₈=[0 -1 0 Lz 0 0] ^T

C ₉=[0 -1 0 Lz 0 Lx] ^T

C ₁₀=[1 0 0 0 Lz -Ly] ^T

C ₁₁=[1 0 0 0 Lz 0] ^T

C ₁₂=[1 0 0 0 Lz Ly] ^T

C ₁₃=[0 0 -1 Ly -Lx 0] ^T

C ₁₄=[0 0 -1 Ly Lx 0] ^T

C ₁₅=[0 0 -1 -Ly Lx 0] ^T

C ₁₆=[0 0 -1 -Ly -Lx 0] ^T

C in above formula _irepresent the load of the i time loading and the transition matrix between the equivalent load of center.

Secondly, according to Modal Analysis Theory, for N degree of freedom linear system, have:

X(ω)=H(ω)F(ω) (1)

In above formula, X (ω) is response spectra vector (voltage signal), and dimension is N * 1; H (ω) is frequency response function matrix, and dimension is N * N; F (ω) is loading spectrum vector, and dimension is N * 1.

Generally, real system is continuous structure particularly, and its number of degrees of freedom, N is very large, and the response that can not record in all degree of freedom solves the load that structure is subject to.Generally, because charge number P to be determined can be very not large, so wish to determine load to be identified by few response data of trying one's best, namely by the partial response of structure, identify load.Suppose that charge number undetermined is P, the measuring point number of response is L, and both are all less than total number of degrees of freedom, N of system, therefore:

X(ω) _L×1=H(ω) _L×PF(ω) _P×1 (2)

By above formula is known, as long as determine the frequency spectrum of frequency response function matrix and response vector, just can solves and carry spectrum, and then with inverse fourier transform, obtain the time-domain signal of load, be i.e. the identification of load in Modal Analysis Theory inverse matrix of frequency response.If charge number P undetermined counts L with the measuring point of response and equates to be L=P in formula (2), frequency response function matrix H (ω) is square formation, and now loading spectrum vector F (ω) can be tried to achieve by following formula:

F(ω)=H ^-1(ω)X(ω) (3)

If it is unequal that the measuring point of charge number P undetermined and response is counted L, L >=P normally, frequency response function matrix H (ω) is no longer just square formation, must ask generalized inverse to frequency response function, like this, the formula of load identification is:

F(ω)=[H ^H(ω)H(ω)] ^-1H ^H(ω)X(ω) (4)

In formula, the conjugate transpose of subscript H representing matrix.Conventionally dynamic response X (ω) becomes more readily available, and frequency response function matrix H (ω) really rule be not easy, because each element reflection is the point of excitation of various discrete and the relation between response point in H (ω) matrix, response point is mutually different for each different point of excitation and point of excitation for the frequency response function between each different response point, that is to say, H in above formula (ω) and F (ω) are closely connected together, if do not know each component F in load vectors F (ω) _j(ω) active position, also just cannot determine each element in H (ω).Therefore, inverse matrix of frequency response can only, for identifying the dynamic load of known action position, can not be identified for active position the unknown or time dependent situation in this way.

For refrigeration machine, its disturbing force application point can not accurately be determined.At this moment when the foregoing inverse matrix of frequency response of application, can run into two problems: 1) how to define disturbing force application point; 2) due to the direct imposed load often of the disturbing force application point for definition, how this application point is carried out to transfer matrix demarcation.

For above-mentioned two problems, solution of the present invention is:

1) process a relatively firm disturbing source mounting disc, the natural frequency of mounting disc own is greater than and detects frequency more than 3 times, at this moment can think that mounting disc relative system other parts are rigid body;

2) all disturbing forces are equivalent to six the external force load of application point in mounting disc, i.e. three translation power, two moments of flexure and a moment of torsion;

3) establish between demarcation power point of excitation in mounting disc and its central point O as being rigidly connected, directly the different application points of this dish and different directions are applied to demarcation power and demarcate.

According to foregoing description, first will demarcate load transfer to the mounting disc centre of form, that is:

${\mathrm{<figure-callout\; id="6"\; label="F"\; filenames="HDA00003880310900011.png"\; state="\{\{state\}\}">F</figure-callout>}}_{6\&times;n}\left(\mathrm{\&omega;}\right)={\mathrm{<figure-callout\; id="6"\; label="C"\; filenames="HDA00003880310900011.png"\; state="\{\{state\}\}">C</figure-callout>}}_{6\&times;n}{F}_{n\&times;n}^{\&prime;}\left(\mathrm{\&omega;}\right)---\left(5\right)$

In above formula, the n in matrix subscript represents the number of times loading in test; F represents that equivalence is to the load of the centre of form, and dimension is 6 * n; The load of F ' expression actual loaded, is a diagonal matrix, in matrix equal the load value loading for the ii time; C represents the loading matrix of actual loaded and the transition matrix between equivalent load matrix, and dimension is 6 * n.

Pass between equivalent load and force sensor signals is:

W _6×8(ω)T _8×n(ω)=F _6×n(ω) (6)

Wherein the n in matrix subscript represents the number of times loading in test; W is the contrary of system frequency response function matrix; T is the response signal of eight power sensors, and dimension is 8 * n; F is the equivalent load obtaining in formula (3.2.5).Known in formula (6), when response matrix there is the inverse time in T, has:

W _6×8(ω)=F _6×n(ω)T ^-1 _n×8(ω) (7)

The passage of considering response signal only has 8, and in order to improve measuring accuracy, the number of load(ing) point should be greater than response channel number, i.e. n > 8, at this moment response matrix T is no longer a square formation, but the matrix of a row full rank, application Generalized Inverses Theory, has:

W _6×8(ω)=F _6×n(ω)T ^H(ω)[T(ω)T ^H(ω)] ^-1 (8)

By (5) formula substitution (8), have:

${\mathrm{<figure-callout\; id="6"\; label="W"\; filenames="HDA00003880310900011.png"\; state="\{\{state\}\}">W</figure-callout>}}_{6\&times;8}\left(\mathrm{\&omega;}\right)={\mathrm{<figure-callout\; id="6"\; label="C"\; filenames="HDA00003880310900011.png"\; state="\{\{state\}\}">C</figure-callout>}}_{6\&times;n}{F}_{n\&times;n}^{\&prime;}\left(\mathrm{\&omega;}\right)T^T\left(\mathrm{\&omega;}\right){\left[T\left(\mathrm{\&omega;}\right)T^T\left(\mathrm{\&omega;}\right)\right]}^{-1}---\left(9\right)$

The generalized inverse of frequency response function matrix H (ω) in T (ω) the difference expression (4) that the matrix W (ω) of in test, formula (9) being tried to achieve and test record and response X (ω), just can determine the equivalent external applied load of system, realize the force signal that the center equivalence demarcation voltage signal that soon sensor will obtain is converted to actual needs,

F _6×1(ω)=W _6×8(ω)T _8×1(ω) (10)

Measuring error check, the employing power hammer transient state method of inspection.

The method of inspection of measuring error is impulse load check, utilizes F1, F5, and the actual measurement load of F13 compares with the load going out by response and calibration matrix reverse, the accuracy of checking calibration matrix.(during standby measurement momenttum wheel, using)

Each hammer point comprises 0 and non-zero to the actual measurement equivalent load component of center calibration point, uses respectively

represent, corresponding inverse value is used

represent i=1～6, the corresponding Fx of difference, Fy, Fz, Mx, My, Mz.The error of hammer force 0 component and non-zero component is used respectively

represent, error calculation formula is:

$e_i^0=\widetilde{F_i^0}/F_j^1,e_i^1=|\widetilde{F_i^1}-F_i^1|/F_i^1---\left(11\right)$

The content not being described in detail in instructions of the present invention belongs to those skilled in the art's known technology.

Claims (4)

1. the micro-vibration physical simulation of a refrigeration machine test processes system, is characterized in that: comprise that refrigerator system, zigzag card extender (3), hexagon card extender (4), six component eight sensors disturb the power test board (5) that shakes, data acquisition and processing (DAP) system (9); Described refrigerator system comprises compressor (1), compressor bracket (2), infrared probe support (6), infrared probe (7); Hexagon card extender (4) is fixedly connected on six component eight sensors and disturbs and shake on power test board (5); Zigzag card extender (3) is fixedly connected on hexagon card extender (4); Compressor (1) is fixedly connected on one end of zigzag card extender (3) by compressor bracket (2), infrared probe support (6) is fixedly connected on the other end of zigzag card extender (3) by infrared probe (7); Described data acquisition and processing (DAP) system (9) comprises data acquisition module and computing machine; Six component eight sensors are disturbed the power test board (5) that shakes and are measured micro-vibration data of refrigerator system, and transfer data to data acquisition and processing (DAP) system (9) and carry out analyzing and processing, obtain the power of shaking of disturbing of refrigerator system.

2. the micro-vibration physical simulation of a kind of refrigeration machine according to claim 1 test processes system, is characterized in that: also comprise acceleration transducer (8), for measuring refrigerator system, disturb the acceleration while shaking.

3. the micro-vibration physical simulation of a kind of refrigeration machine according to claim 1 test processes system, is characterized in that: also comprise laser non-contact testing system (10); Laser non-contact testing system (10) Emission Lasers, to refrigerator system, and is delivered to data acquisition and processing (DAP) system (9) by the feedback signal reflecting and is processed, and obtains the displacement of shaking of disturbing of infrared probe (7); Described laser non-contact testing system (10) is produced by German Polytec company, and model is: D-76337.

4. the micro-vibration physical simulation of a refrigeration machine test processes system detection method, is characterized in that step is as follows:

1) demarcation dish is arranged on to six component eight sensors and disturbs on the power test board (5) that shakes, with bolt, tightened; Demarcation dish is a square aluminium dish, and described demarcation dish is evenly equipped with 3 beating points on four sides separately, is furnished with 4 beating points on upper surface, and lower surface is disturbed with six component eight sensors the power test board (5) that shakes and is connected;

2) firmly hammer knocks 16 beating points on demarcation dish successively, and gather the time-domain signal of power hammer, six component eight sensors are disturbed power test board (5) that shake while knocking each point output voltage signal, obtain frequency response function;

3) by step 2) the frequency response function meter that obtains obtains calibration matrix;

4) pull down demarcation dish;

5) refrigerator system being arranged on to six component eight sensors by zigzag card extender (3) and hexagon card extender (4), to disturb the power test board (5) that shakes upper, and with bolt tightening;

6) refrigerator system energising is started working;

7) six component eight sensors are disturbed the power test board (5) that shakes refrigerator system are tested, and the voltage time-domain signal while gathering refrigeration machine work by data acquisition and processing (DAP) system (9);

8) voltage time-domain signal step 7) being obtained carries out the frequency-region signal that Fourier transform obtains voltage;

9) voltage frequency-region signal step 8) being obtained and calibration matrix multiply each other and obtain the frequency-region signal of refrigeration machine disturbing force;

10) frequency-region signal of refrigeration machine disturbing force step 9) being obtained carries out the time-domain signal that inversefouriertransform can obtain disturbing force, completes the processing to micro-vibration signal.

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