CN103344322B - The phase alignment that a kind of mechanical impedance is measured and modification method - Google Patents

Abstract

The present invention relates to phase alignment and the modification method of the measurement of a kind of mechanical impedance, the power and acceleration signal that utilize quality Loading Method to exert oneself to measure when calibrating with acceleration measurement system, and the amplitude between power and acceleration analysis passage and phase place are calibrated, must exert oneself and amplitude and phase deviation between acceleration passage, and in conjunction with correction factor, mechanical impedance be revised.The inventive method is in the amplitude calibration of a consideration sensor in the past, when not doing to further investigate to phase place, by the calibration to whole measuring system amplitude and phase-frequency response, and calibration result is used for mechanical impedance measurement and Data processing, the phase deviation of mechanical impedance is reduced greatly, effectively can reduce the error brought to mechanical impedance measurement by measuring system.

Description

The phase alignment that a kind of mechanical impedance is measured and modification method

Technical field

The present invention relates to the mechanical impedance field tests of flexible member, particularly relate to phase alignment and the modification method of the measurement of a kind of mechanical impedance.

Background technology

Mechanical impedance refers to the Domain Dynamic characteristic parameters of theory of oscillation neutral line stational system, because mechanical impedance is power and the ratio of acceleration complex expression between the two, therefore, in mechanical impedance is measured, the phase equalization of power and acceleration analysis interchannel transitive relation is most important.Existing measurement means is due to the difference of measuring system, and only consider amplitude in measuring process, and phase place is not furtherd investigate, test result is occurred, and phase deviation easily causes the deviation of the mechanical impedance property of tested flexible member, affect the calculating of dissipation factor, the performance that restriction mechanical impedance parameter acts in the quantitative acoustic design of naval vessels mechanical system, also constrains the application of flexible member in Other Engineering field and the raising of flexible member designing technique.

Summary of the invention

The applicant is for above-mentioned existing issue, be studied improvement, the phase alignment providing a kind of mechanical impedance to measure and modification method, the method is repaired being caused the impact of vibration isolation components and parts mechanical impedance measurement result by test macro, specification vibration isolation components and parts mechanical impedance is measured, for the acquisition of vibration isolation components and parts mechanical impedance parameter provides standard.

The technical solution adopted in the present invention is as follows:

The phase alignment that mechanical impedance is measured and a modification method, comprise the following steps:

The first step: the power and acceleration signal that utilize quality Loading Method to exert oneself to measure when calibrating with acceleration measurement system, and the amplitude between power and acceleration analysis passage and phase place are calibrated;

Second step: according to above-mentioned first step resulting force and acceleration signal, the gross mass above adhesion sensor sensing element must be exerted oneself and correction factor between acceleration analysis passage, and its computing formula is:

$K\left(f\right)=\frac{F\left(f\right)}{m_0\·a\left(f\right)}$

Gross mass in above-mentioned formula above force snesor sensitive element is expressed as m ₀;

The power measured during calibration is expressed as F (f);

The acceleration measured during calibration is expressed as a (f);

3rd step: utilize output terminal vibration blocking method to measure the mechanical impedance of tested vibration isolation element, its computing formula is:

$Z_{11}^{\mathrm{mean}}=\mathrm{j\ω}(\frac{F_1^{\mathrm{mean}}\left(f\right)}{a_1\left(f\right)}-m)$

The dynamic force that in above-mentioned formula, tested vibration isolation element records input end by force snesor represents the vibration acceleration that tested vibration isolation element records input end by accelerometer is expressed as a ₁(f); Exciting quality, the quality of connection namely between force snesor and tested vibration isolation element input end is expressed as m; Mechanical impedance refer to the mechanical impedance be not corrected;

4th step: by adjusted coefficient K (f) described in second step to the dynamic force of tested vibration isolation element input end suffered by force snesor in the 3rd step revise, obtain the dynamic ex-citing forces of tested vibration isolator input end by dynamic ex-citing forces revised tested vibration isolation element input mechanical impedance can be drawn its computing formula is:

$Z_{11}^{\mathrm{mean}}=\mathrm{j\ω}(\frac{F_1^{\mathrm{mean}}\left(f\right)}{a_1\left(f\right)}-m)$

In above-mentioned formula, the input mechanical impedance of tested vibration isolation element is expressed as

Force sensor measuring signal is after revising, and the input end dynamic ex-citing forces obtaining tested vibration isolator is expressed as

Its further technical scheme is:

The scope of described quality Loading Method is applicable to calibration frequency lower than system resonance frequency five for the moment;

Described revised mechanical impedance revises power measurement as a reference with accelerometer;

Amplitude between described power and acceleration analysis passage and phase alignment carry out transport function calculating between described power and acceleration signal, must exert oneself and between acceleration signal test channel with the amplitude phase propetry H of frequency change ₁f (), passes through H ₁f () must be exerted oneself and amplitude deviation delta L between acceleration and phase deviation

Beneficial effect of the present invention is as follows:

The inventive method is in the amplitude calibration of a consideration sensor in the past, when not doing to further investigate to phase place, by the calibration to whole measuring system amplitude and phase-frequency response, and calibration result is used for mechanical impedance measurement and Data processing, the phase deviation of mechanical impedance is reduced greatly, effectively can reduce the error brought to mechanical impedance measurement by measuring system.

Accompanying drawing explanation

Fig. 1 is the process schematic utilizing quality Loading Method to calibrate the amplitude between power and acceleration analysis passage and phase place.

The arrangement of vibration isolator axial mechanical impedance test when Fig. 2 is light condition.

Fig. 3 is the structural plan of the first mechanical impedance measuring system.

Fig. 4 is the structural plan of the second mechanical impedance measuring system.

Fig. 5 is the curve map of the axial input mechanical impedance real part tested by the first mechanical impedance measuring system and the second mechanical impedance measuring system under vibration isolator zero load.

Fig. 6 is the curve map of the axial input mechanical impedance imaginary part of being tested by the first mechanical impedance measuring system and the second mechanical impedance measuring system under vibration isolator zero load.

Fig. 7 is the curve map of the axial input mechanical impedance amplitude characteristic tested by the first mechanical impedance measuring system and the second mechanical impedance measuring system under vibration isolator zero load.

Fig. 8 is the curve map of the axial input mechanical impedance phase propetry of being tested by the first mechanical impedance measuring system and the second mechanical impedance measuring system under vibration isolator zero load.

Fig. 9 is the calibration of amplitude and phase result of the first mechanical impedance measuring system.

Figure 10 is the calibration of amplitude and phase result of the second mechanical impedance measuring system.

Figure 11 tests axial input mechanical impedance real part by the first mechanical impedance measuring system and the second mechanical impedance measuring system under revising rear vibration isolator zero load.

Figure 12 tests axial input mechanical impedance imaginary part by the first mechanical impedance measuring system and the second mechanical impedance measuring system under revising rear vibration isolator zero load.

Figure 13 tests axial input mechanical impedance amplitude characteristic by the first mechanical impedance measuring system and the second mechanical impedance measuring system under revising rear vibration isolator zero load.

Figure 14 tests axial input mechanical impedance phase propetry by the first mechanical impedance measuring system and the second mechanical impedance measuring system under revising rear vibration isolator zero load.

Embodiment

Below in conjunction with accompanying drawing, the specific embodiment of the present invention is described.

The inventive method comprises the following steps:

The first step: the power and acceleration signal that utilize quality Loading Method to exert oneself to measure when calibrating with acceleration measurement system, as shown in Figure 1, the scope of quality Loading Method is applicable to calibration frequency lower than system resonance frequency five for the moment, and the concrete steps of quality Loading Method are as follows:

First at the top installing force sensor 3 of standard vibration shaker 4, the mass 2 of known quality is installed at force snesor 3, on mass 2, acceleration transducer 1 is installed simultaneously, force snesor 3 is connected with external equipment with acceleration transducer 1, start standard vibration shaker 4, wideband random signal is adopted to input to standard vibration shaker 4, measure exert oneself and acceleration signal, obtain between force sensor 3 and acceleration transducer 1 test channel with the amplitude phase propetry of the transport function of frequency change through fft algorithm (this fft algorithm is existing known technology), computing formula is as follows:

$H_1\left(f\right)=\frac{F\left(f\right)}{a\left(f\right)}---\left(1\right)$

The power measured during formula (1) alignment is expressed as F (f); The acceleration measured during calibration is expressed as a (f); H ₁f () represents the amplitude phase propetry with frequency change between force snesor 3 and acceleration transducer 1 test channel.

According to the H that formula (1) measures ₁(f), amplitude deviation delta L when can draw calibration between power and acceleration and phase deviation computing formula is as follows:

$\mathrm{\ΔL}=20\lg \frac{\left|H_1\left(f\right)\right|}{m_0}---\left(2\right)$

In formula (2) | H ₁(f) | be expressed as the transport function amplitude with frequency change between force snesor 3 and acceleration transducer 1 test channel, the gross mass above force snesor sensitive element is expressed as m ₀, in formula (3) represent the phasing degree of F (f), represent the phasing degree of a (f), M in above-mentioned formula (2) ₀ingredient as follows:

m ₀=m ₁+m ₂+m ₃+m ₄(4)

As shown in Figure 1, in formula (4), the quality representation of acceleration transducer is m ₁; The effective mass of bolt (not illustrating in Fig. 1) represents m ₂; Effective end quality representation of force snesor is m ₃; The quality of mass is m ₄;

Second step: the measuring system adopted when the measuring system adopted in above-mentioned calibration process is measured with mechanical impedance is identical, when there is the situation that between Measurement channel, phase relation is inconsistent in calibration result, need the correcting process to carrying out amplitude phase place in the test of vibration isolation element mechanical impedance, to eliminate the amplitude and phase deviation brought to mechanical impedance measurement.According to above-mentioned first step resulting force and acceleration signal, gross mass above adhesion sensor sensing element must be exerted oneself and correction factor between acceleration analysis passage, correction factor between power and acceleration analysis passage revises power measurement as a reference with accelerometer, and the computing formula of correction factor is:

$K\left(f\right)=\frac{F\left(f\right)}{m_0\·a\left(f\right)}---\left(5\right)$

Gross mass in above-mentioned formula (5) above force snesor sensitive element is expressed as M ₀; The power measured during calibration is expressed as F; The acceleration measured during calibration is expressed as a;

3rd step: utilize the measurement of output terminal vibration blocking method to draw the mechanical impedance of tested vibration isolation element, concrete method of testing is as follows, as shown in Figure 2, under light condition, the arrangement of the axial mechanical impedance test of vibration isolator comprises the vertical force plate 106 be arranged on impedance platform 107, lower transition element 105 is installed on vertical force plate 106, the tested vibration isolator 104 of device on lower transition element 5, transition element 103 on the top device of tested vibration isolator 104, the surperficial installing force sensor 102 of upper transition element 103, and be connected with the output terminal of electromagnetic actuator 101, be positioned at equal device accelerometer 108. on transition element 103 and lower transition element 105

The mechanical impedance test process of tested vibration isolator 104 is as follows: start electromagnetic actuator 101, the input end of electromagnetic actuator 101 to tested vibration isolator 104 is utilized to encourage, exciting force is recorded by force snesor 102, recorded the vibration acceleration of input end by accelerometer 108, the computing formula of input mechanical impedance is as follows:

$Z_{11}^{\mathrm{mean}}=\mathrm{j\ω}(\frac{F_1^{\mathrm{mean}}\left(f\right)}{a_1\left(f\right)}-m)---\left(6\right)$

In formula (6), tested vibration isolator 102 records input end dynamic force by force snesor 102 and represents the vibration acceleration that tested vibration isolator 102 records input end by accelerometer 108 is expressed as a ₁(f), exciting quality, the quality of connection m namely between force snesor 102 and tested vibration isolator 104 input end; Above-mentioned mechanical impedance be the mechanical impedance be not corrected, ω represents angular frequency, and j represents imaginary part.

4th step: the adjusted coefficient K (f) obtained by above-mentioned second step, recording vibration isolator 102 tested in the 3rd step input end dynamic force by force snesor 102 and represent be converted into real power computing formula is as follows:

${F_1}^{\mathrm{true}}\left(f\right)=\frac{{F_1}^{\mathrm{mean}}\left(f\right)}{K\left(f\right)}---\left(7\right)$

After revising in above-mentioned formula (7), the dynamic force of input end suffered by force snesor of tested vibration isolator is expressed as will substitute in formula (6) and obtain:

$Z_{11}^{\mathrm{mean}}=\mathrm{j\ω}(\frac{F_1^{\mathrm{mean}}\left(f\right)}{a_1\left(f\right)}-m)---\left(8\right)$

Mechanical impedance in formula (8) for the input mechanical impedance after correction.

As shown in Figure 2, when the quality of force snesor in Fig. 2 102 cannot be ignored, so input end excitation quality just comprises effective end mass m of force snesor ₁₀₂, and quality of connection m between force snesor 102 and tested vibration isolator 104 input end, therefore when vibration isolation element mechanical impedance data processing, also need the end mass removing excitation end force snesor, obtain following revised input mechanical impedance formula:

$Z_{11}^{\mathrm{true}}=\mathrm{j\ω}[\frac{F_1^{\mathrm{true}}\left(f\right)}{a_1\left(f\right)}-(m+m_{102}]---\left(9\right)$

In above-mentioned formula (9), the explanation of each parameter is identical with formula (8).

The specific embodiment of the inventive method is as follows:

For the test of BM300 type vibration isolator mechanical impedance, two groups of measuring systems are adopted to measure.As shown in Figure 3, first mechanical impedance measuring system adopts 9341B force snesor and 5015A charge amplifier, 352C68 acceleration transducer and 2694 type signals to fit to adjust instrument and data collecting instrument to measure, as shown in Figure 4, second mechanical impedance measuring system adopts ICP type 288D01 reluctance head and 2694 signals to fit and adjusts instrument, and suitable instrument and the data collecting instrument adjusted of 2694 type signals is measured.

As shown in Fig. 5 to Fig. 8, axial input mechanical impedance test result under the vibration isolator zero load that two kinds of different measuring systems record, wherein there is notable difference in the phase propetry of the mechanical impedance of Fig. 8, in Fig. 5 and Fig. 6, the real part of reflection phase place and imaginary part also there are differences, as shown in Figure 9, the figure shows the calibration of amplitude and phase result of the first mechanical impedance measuring system, in Fig. 9,9-1 represents between force snesor 3 when utilizing the first mechanical impedance measuring system calibration and acceleration transducer 1 test channel with the transport function amplitude of frequency change, 9-2 represent utilize first mechanical impedance measuring system calibration time power and acceleration between amplitude deviation, 9-3 represent utilize first mechanical impedance measuring system calibration time power and acceleration between phase deviation.As shown in Figure 10, the figure shows the calibration of amplitude and phase result of the second mechanical impedance measuring system, wherein in Figure 10,10-1 represents between force snesor 3 when utilizing the second mechanical impedance measuring system calibration and acceleration transducer 1 test channel with the transport function amplitude of frequency change, 10-2 represent utilize second mechanical impedance measuring system calibration time power and acceleration between amplitude deviation, 10-3 represent utilize second mechanical impedance measuring system calibration time power and acceleration between phase deviation.In conjunction with above-mentioned Fig. 5 to Fig. 8, and Fig. 9, Figure 10, can judge to be undertaken measuring between the mechanical impedance that draws by two kinds of measuring systems to there is error, this error be by Measurement channel between amplitude and phase deviation cause, need the correction carrying out amplitude and phase place.

Utilize Fig. 9 and Figure 10 calibration of amplitude and phase result, BM300 vibration isolator mechanical impedance test result is revised, adopt the inventive method, the mechanical impedance property that revised first mechanical impedance measuring system and the second mechanical impedance measuring system draw the results are shown in Figure 11 to Figure 14, visible by contrasting, through the inventive method test mechanical impedance through correction after, the mechanical impedance drawn by the first mechanical impedance measuring system and the second mechanical impedance measuring system relatively, the amplitude of impedance, phase place or real part, imaginary part all reaches unanimity, impedance phase deviation reduces greatly.

More than describing is explanation of the invention, and be not the restriction to invention, limited range of the present invention is see claim, and when without prejudice to basic structure of the present invention, the present invention can do any type of amendment.

Claims (4)

1. mechanical impedance measure phase alignment and a modification method, it is characterized in that comprising the following steps:

The first step: the power and acceleration signal that utilize quality Loading Method to exert oneself to measure when calibrating with acceleration measurement system, and the amplitude between power and acceleration analysis passage and phase place are calibrated;

Second step: according to above-mentioned first step resulting force and acceleration signal, the gross mass above adhesion sensor sensing element must be exerted oneself and correction factor between acceleration analysis passage, and its computing formula is:

Gross mass in above-mentioned formula above force snesor sensitive element is expressed as m ₀;

The power measured during calibration is expressed as F (f);

The acceleration measured during calibration is expressed as a (f);

3rd step: utilize output terminal vibration blocking method to measure the mechanical impedance of tested vibration isolation element, its computing formula is:

The dynamic force that in above-mentioned formula, tested vibration isolation element records input end by force snesor represents F ₁ ^mean(f); The vibration acceleration that tested vibration isolation element records input end by accelerometer is expressed as a ₁(f); Exciting quality, the quality of connection namely between force snesor and tested vibration isolation element input end is expressed as m; Mechanical impedance refer to the mechanical impedance be not corrected;

4th step: by adjusted coefficient K (f) described in second step to the dynamic force F of tested vibration isolation element input end suffered by force snesor in the 3rd step ₁ ^meanf () is revised, described corrected Calculation mode is:

After revising in above-mentioned formula, the dynamic force of input end suffered by force snesor of tested vibration isolation element is expressed as F ₁ ^true; The dynamic force that tested vibration isolation element records input end by force snesor represents F ₁ ^mean(f); Correction factor is expressed as K (f);

Obtain the dynamic force F of tested vibration isolation element input end ₁ ^truef (), by dynamic force F ₁ ^truef () draws revised tested vibration isolation element input mechanical impedance its computing formula is:

In above-mentioned formula, the input mechanical impedance of tested vibration isolation element is expressed as

Force sensor measuring signal is after revising, and the input end dynamic force obtaining tested vibration isolation element is expressed as F ₁ ^true.

2. the phase alignment measured of mechanical impedance as claimed in claim 1 and modification method, is characterized in that: the scope of described quality Loading Method is applicable to calibration frequency lower than system resonance frequency five/for the moment.

3. the phase alignment measured of mechanical impedance as claimed in claim 1 and modification method, is characterized in that: described revised mechanical impedance revises power measurement as a reference with accelerometer.

4. the phase alignment measured of mechanical impedance as claimed in claim 1 and modification method, it is characterized in that: the amplitude between described power and acceleration analysis passage and phase alignment carry out transport function calculating between described power and acceleration signal, must exert oneself and between acceleration analysis passage with the amplitude phase propetry H of frequency change ₁f (), by amplitude phase propetry H ₁f () must be exerted oneself and amplitude deviation delta L between acceleration and phase deviation