CN205670160U - Acceleration transducer low-frequency calibration platform - Google Patents

Abstract

The utility model discloses a kind of acceleration transducer low-frequency calibration platform, including disc type precision centrifuge, line slideway and slide unit, described line slideway is fixedly mounted on the rotating disk of described disc type precision centrifuge by rail brackets, and overlap with the diametric(al) of described disc type precision centrifuge rotating disk, described slide unit is arranged on described line slideway and can reciprocatingly slide along described line slideway.This utility model establishes low frequency acceleration calibrating installation centrifuge and slide unit combined, a reference acceleration load is provided to slide unit by centrifuge, then the distance of slide unit distance centrifuge center of rotation is adjusted by the slip of slide unit, thus realize acceleration load by sinusoidal rule change, final on the premise of not increasing slide unit stroke, reach extremely low frequency and big acceleration load simultaneously, improve the signal to noise ratio being calibrated sensor output signal greatly.

Description

Acceleration transducer low-frequency calibration platform

Technical field

This utility model relates to a kind of calibrator (-ter) unit, particularly relates to a kind of acceleration transducer low-frequency calibration platform.

Background technology

The low-frequency calibration equipment of acceleration transducer, the low-frequency vibration tables using special development and two kinds of shapes of low frequency slide unit more Formula, its medium and low frequency slide unit is due to the bigger and more use of stroke.Low frequency slide unit is the shape by driving slide unit on line slideway Formula, will standard transducer and corrected sensor be arranged on slide unit, then drives slide unit to carry out left and right on line slideway past The mode of multiple motion, thus produce an acceleration load in sinusoidal variations in time, act on the sensor on slide unit, enter And sensor is calibrated.

Either low-frequency vibration table or low frequency slide unit, its major defect producing low frequency acceleration load is, due to Square being directly proportional of accekeration produced by it and frequency of vibration, therefore getable acceleration load in the case of low frequency The least.As a example by low frequency slide unit, the currently mainly range of the acceleration transducer calibration low frequency slide unit of manufacturer is 300mm, it is assumed that slide unit starts to do bilateral reciprocation with guideway centreline position for initial point, then its position s is the most such as Shown in lower

S=s₀ sin(ωt)

Then the speed v of slide unit is

$v=\frac{ds}{dt}=s_0\mathrm{\ω}cos\left(\mathrm{\ω}t\right)$

The acceleration a of slide unit is

$a=\frac{dv}{dt}=-s_0{\mathrm{\ω}}^{2}sin\left(\mathrm{\ω}t\right)$

In formula, ω=2 π f, f are the frequencies of acceleration change.

When f is equal to 0.5Hz, for the slide unit of 300mm stroke, its maximum acceleration value that can produce only has 1.48m/s² (0.15g).And if we expect the acceleration load of lower frequency, such as 0.1Hz, then what 300mm slide unit can produce adds Velocity amplitude then only has 0.059m/s²(0.006g), this is a value the least, even if because calibrating installation is through good Base isolation processes, and is affected by ground pulsation and environmental disturbances, and the noise signal calibrating table top under quiescent conditions also about has 0.0001g, say, that signal to noise ratio now only has 35.56dB, when slide unit moves, signal to noise ratio can be lower.

In order to increase signal to noise ratio, acceleration load value during low frequency can be increased by lengthening slide unit stroke.By meter Calculation can obtain, if to obtain 0.1g (0.98m/s under the conditions of 0.1Hz²) acceleration load, the vibration displacement width of needs Value is 2.48m, and slide unit overall length reaches 4.96m, and the distortion factor making vibrational waveform cannot be met requirement by so long stroke. The most no matter low frequency slide unit or low-frequency vibration table, so long stroke does not the most possess realizability in Practical Project.

Utility model content

The purpose of this utility model is that provides a kind of acceleration transducer low-frequency calibration to solve the problems referred to above Platform.

This utility model is achieved through the following technical solutions above-mentioned purpose:

A kind of acceleration transducer low-frequency calibration platform, including disc type precision centrifuge, line slideway and slide unit, described straight line Guide rail is fixedly mounted on the rotating disk of described disc type precision centrifuge by rail brackets, and with described disc type precision centrifuge The diametric(al) of rotating disk overlaps, and described slide unit is arranged on described line slideway and can reciprocatingly slide along described line slideway.

Described slide unit can be electronic slide unit or Pneumatic slid platform, and described centrifuge rotating shaft is hollow axle, the driving of described slide unit The holding wire of circuit, control circuit and calibration is through the hollow rotating shaft of described centrifuge and by electric slip ring and described cunning Platform and be calibrated sensor, standard transducer connect.

As used Pneumatic slid platform, gas circuit may also pass through hollow rotating shaft and provides aerodynamic force by swivel joint for described slide unit. Described centrifuge uses hollow axle can be prevented effectively from when electric slip ring, swivel joint etc. are installed and produces with line slideway interferes.

The beneficial effects of the utility model are:

This utility model one acceleration transducer low-frequency calibration platform establishes one by disc type precision centrifuge and slide unit In conjunction with low frequency acceleration calibrating installation, by centrifuge to slide unit provide a reference acceleration load, then pass through slide unit Slip, adjust the distance of slide unit distance centrifuge center of rotation, thus realize acceleration load by sinusoidal rule change, should Device may be implemented on the premise of not increasing slide unit stroke, reaches extremely low frequency and big acceleration load simultaneously, can greatly carry Height is calibrated the signal to noise ratio of sensor output signal.

Accompanying drawing explanation

Fig. 1 is the structural representation of acceleration transducer low-frequency calibration platform described in the utility model.

Detailed description of the invention

The utility model is described in further detail below in conjunction with the accompanying drawings:

As it is shown in figure 1, this utility model one acceleration transducer low-frequency calibration platform, including disc type precision centrifuge 1, turn Dish 2, line slideway 3 and slide unit 5, line slideway 3 is fixedly mounted on rotating disk 2 by rail brackets 4, and slide unit 5 is arranged on straight line On guide rail 3 and can linearly slide by guide rail 3, line slideway 3 overlaps with the diameter of rotating disk 2, and slide unit 5 is electronic slide unit or aerodynamic slide Platform, the rotating shaft of disc type precision centrifuge 1 is hollow axle, and the holding wire of the driver circuit of slide unit 5, control circuit and calibration passes Centrifuge 1 hollow rotating shaft and by electric slip ring 6 and slide unit 5 be calibrated sensor, standard transducer is connected.

The mair motor of centrifuge 1 uses hollow axle, in the way of facilitating electric slip ring 6 to use lower outlet, thus avoids Electric slip ring 6 and line slideway 3 interference structurally.

Using method based on above-mentioned a kind of acceleration transducer low-frequency calibration platform, comprises the following steps:

1, the acceleration transducer being calibrated and standard transducer are fixed on slide unit, it is ensured that two sensors are respectively positioned on Line slideway is along the same position in disk diameter direction, and the center of line slideway overlaps with the center of rotation of rotating disk；

2, by given acceleration maximum amplitude and frequency values, rotating speed and the motion angular frequency of slide unit of centrifuge is calculated Rate；

3, control centrifuge uniform rotation by calculated rotating speed, control slide unit linearly guide rail by given frequency simultaneously Moving reciprocatingly, reciprocating dead-center position overlaps with the center of rotation of centrifuge rotating disk；

4, the output valve of acceleration transducer it is calibrated by measuring and controlling equipment acquisition, and by itself and the standard sensing on slide unit Device output valve contrasts.

Wherein, the computational methods in step (2) are as follows:

Slide unit linearly guide rail does sinusoidal variable motion, is calibrated acceleration transducer position distance center of rotation Radius is

R=r₀ sin(ω_slit)

In formula: ω_sliAngular frequency when moving for slide unit, r₀Rotate for being calibrated acceleration transducer position distance The maximum radius at center.

The centrifugal acceleration load produced when centrifuge rotates is

$a_{rot}={\mathrm{\ω}}_{rot}^{2}r={\mathrm{\ω}}_{rot}^2{r}_{0}sin\left({\mathrm{\ω}}_{sli}t\right)$

In formula: ω_rotFor angular velocity during turntable rotation.

The linear acceleration load produced when slide unit moves back and forth is

$a_{sli}=-{\mathrm{\ω}}_{sli}^{2}r-{\mathrm{\ω}}_{sli}^2{r}_{0}sin\left({\mathrm{\ω}}_{sli}t\right)$

Being calibrated the total acceleration load that acceleration transducer bears is

$\begin{array}{c}a=a_{rot}+a_{sli}\\ ={\mathrm{\ω}}_{rot}^2{r}_0\sin \left({\mathrm{\ω}}_{sli}t\right)-{\mathrm{\ω}}_{sli}^2{r}_0\sin \left({\mathrm{\ω}}_{sli}t\right)\\ =({\mathrm{\ω}}_{rot}^2-{\mathrm{\ω}}_{sli}^2)r_0\sin \left({\mathrm{\ω}}_{sli}t\right)\end{array}$

Assume that given acceleration maximum amplitude is a_s, given frequency is f_s, then the angular frequency of slide unit_sliFor

ω_sli=2 π f_s

$a_s=({\mathrm{\ω}}_{rot}^2-{\mathrm{\ω}}_{sli}^2)r_0$

The rotating speed n of centrifuge is

$n=\frac{{\mathrm{\ω}}_{rot}}{2\mathrm{\π}}=\frac{1}{2\mathrm{\π}}\sqrt{\frac{a_s}{r_0}+{\mathrm{\ω}}_{sli}^2}$

As can be seen from the above equation, it is calibrated the frequency of acceleration load suffered by acceleration transducer to only have and ω_sliIt is relevant, Amplitude then with ω_rotAnd ω_sliBoth difference correlations, therefore can be by adjusting ω_sliParameter obtains a relatively low frequency, Then ω is adjusted_rotParameter obtains a bigger acceleration load.

The combination using the two kinds of motion modes that rotate and slide produces the acceleration load of needs, and this makes on the one hand can To obtain a acceleration frequency the lowest, on the other hand, the accekeration of this low frequency load depends primarily on turntable Angular velocity of rotation, therefore, sets the angular frequency of slide unit and the angular velocity of centrifuge, it becomes possible to obtain an amplitude sufficiently large respectively And the acceleration load that frequency is of a sufficiently low.

The technical solution of the utility model is not limited to the restriction of above-mentioned specific embodiment, every according to skill of the present utility model The technology deformation that art scheme is made, within each falling within protection domain of the present utility model.

Claims (2)

1. an acceleration transducer low-frequency calibration platform, it is characterised in that: include disc type precision centrifuge, line slideway and cunning Platform, described line slideway is fixedly mounted on the rotating disk of described disc type precision centrifuge by rail brackets, and with described disc type The diametric(al) of the rotating disk of precision centrifuge overlaps, and described slide unit is arranged on described line slideway and can be along described line slideway Reciprocatingly slide.

Acceleration transducer low-frequency calibration platform the most according to claim 1, it is characterised in that: described slide unit is electronic slide unit Or Pneumatic slid platform, the rotating shaft of described disc type precision centrifuge is hollow axle, the driver circuit of described slide unit, control circuit and calibration Holding wire through described disc type precision centrifuge rotating shaft and by electric slip ring and described slide unit and be calibrated sensor, Standard transducer connects.