CN1987374A - Acceleration meter and its measuring method - Google Patents

Abstract

Lower end of shell is clipped to base. Being composed of symmetrical U shaped butt jointed up and down soft irons, close type cylinder is installed inside shell. U shaped up and down position sleeves are setup at up and down parts inside the cylinder. Permanent magnets with opposite poles are setup on up and down parts of central position of cylinder mouth of butt jointed soft irons. Symmetrical U shaped armatures are installed between up and down permanent magnets. Winding framework with winding being wound is installed on outside armatures. Circular spring leaves on two ends of winding are connected to locking rings. Output connectors of winding are connected to the output socket. Up and low ends of circular ring shaped yoke iron located outside the winding are connected to circular spring leaves respectively. Features are: simple structure, easy of installation, measuring jerk directly, designed closed double magnetic circuit structure, high sensitivity, and shock resistant etc.

Description

A kind of acceleration meter and measuring method thereof

Technical field

The present invention relates to a kind of acceleration meter and measuring method thereof.

Background technology

In recent years in engineering vibration measurement, most displacement meter, velograph, accelerometers of using, it is main (as eddy current type, LVDT formula, photo-electric, stay-supported etc.) that displacement meter generally mostly is relative formula, velograph mainly uses moving-coil type displacement pendulum velograph, and accelerometer mainly uses piezoelectric type, moving-coil speed pendulum-type and force balance type etc.Moving-coil type vibro-pickup commonly used at present mainly contains two kinds: 1. velograph is put in displacement; 2. speed is put accelerometer.The magnetic circuit that adopts is generally single magnetic structure.In recent years, the comfort level of elevator and bullet train, the observation of earthquake, the research of structural seismic mechanism, the mach automatic control of research, high speed that structural damage is surveyed, the anti-seismic performance detection of communication facilities need to measure acceleration, the i.e. rate of change of acceleration.At present, for the measurement of accelerations such as elevator comfort level, all be to utilize accelerometer to obtain acceleration through a subdifferential.In vibration survey, in general can use integration, avoid using differential, this is because integration is to quadrature, differential is to ask slope, and integration can obtain degree of precision, and differential easily brings than mistake, utilize accelerometer easily to bring, and easily lose useful information than mistake through a differential measurement acceleration.The amplitude error expression formula of differentiating circuit is ${\mathrm{\γ}}_d\≈-\frac{1}{2}{\left(\mathrm{\ωRC}\right)}^2,$ ω is the vibration circular frequency of testee, and what obviously the maximum differential error will be at working frequency range is high-end, easily causes high frequency noise.In sum, the moving-coil type vibro-pickup is energy measurement speed and acceleration only, and energy measurement does not add acceleration.In addition, moving-coil type vibro-pickup magnetic circuit system commonly used is single magnet structure, and it is too high that the sensitivity of vibro-pickup is unfit to do.

Moving-coil type vibro-pickup commonly used at present mainly contains two kinds: 1. velograph is put in displacement; 2. speed is put accelerometer.The magnetic circuit that adopts is generally single magnetic structure.

The differential equation of general moving-coil type vibro-pickup is:

$m\stackrel{\·\·}{x}+b\stackrel{\·}{x}+\mathrm{kx}+\mathrm{Gi}=-m\stackrel{\·\·}{X}---\left(1\right)$

M in the formula is the motion parts quality, and k is supporting guide spring rigidity, and b is the damping force coefficient that comprises air damping, and G is the electromechanical coupling factor of moving-coil, and X is the moving displacement of measured point, and x is the moving displacement of quality with respect to shell.

Its circuit equation is

$\left.\begin{array}{c}{R}_{s}i+e=G\stackrel{\·}{x}\\ \frac{1}{R}e=i\end{array}\right\}---\left(2\right)$

In the formula:

When ignoring air damping, solve an equation (1) and (2) from method with calculating, can get

$x\left(s\right)=-\frac{s^{2}X\left(s\right)}{s^2+2D_0{n}_{0}s+{{\mathrm{\ω}}_0}^2}---\left(3\right)$

$e\left(s\right)=-\mathrm{AG}\frac{s^{3}X\left(s\right)}{s^2+2D_0{\mathrm{\ω}}_{0}s+{{\mathrm{\ω}}_0}^2}---\left(4\right)$

In the formula: $D_0=\frac{{\mathrm{<figure-callout\; id="2"\; label="G"\; filenames="A20051012735700121.png"\; state="\{\{state\}\}">G</figure-callout>}}^2}{2m{\mathrm{\&omega;}}_0(R_s+R)}$ Be damping ratio

$A=\frac{R}{R_s+R}$

s＝jω、 $j=\sqrt{-1};$

ω is the self-vibration circular frequency of measured point;

${\mathrm{\&omega;}}_0=2\mathrm{\&pi;}{f}_0=\sqrt{\frac{k}{m}}$ Be pendulum self-vibration circle vibration frequency;

The output voltage of e (s) vibro-pickup;

1. velograph is put in displacement

When ω＞＞ω ₀, D ₀＜1 o'clock, the output voltage signal that vibro-pickup constitutes displacement pendulum velograph velograph was:

$e_1\left(s\right)=G\stackrel{\&CenterDot;}{x}A=A\&CenterDot;G\&CenterDot;H_1\left(s\right)\&CenterDot;\mathrm{sX}\left(s\right)---\left(5\right)$

The sensitivity of velograph is:

$S_{\stackrel{\&CenterDot;}{x}}=\frac{e_1\left(s\right)}{\mathrm{sX}\left(s\right)}=A\&CenterDot;G\&CenterDot;\frac{s^2}{{\mathrm{<figure-callout\; id="2"\; label="s"\; filenames="A20051012735700121.png"\; state="\{\{state\}\}">s</figure-callout>}}^2+2D_0{\mathrm{\&omega;}}_{0}s+{{\mathrm{\&omega;}}_0}^2}---\left(6\right)$

But the sensitivity approximate expression of velograph is:

$S_{\stackrel{\&CenterDot;}{x}}\stackrel{\&CenterDot;}{=}\mathrm{AG}---\left(7\right)$

In the formula:

SX (s) is the speed of measured point.

e ₁(s) be the output voltage of velograph

$H_1\left(s\right)=\frac{s^2}{{\mathrm{<figure-callout\; id="2"\; label="s"\; filenames="A20051012735700121.png"\; state="\{\{state\}\}">s</figure-callout>}}^2+2D_0{\mathrm{\&omega;}}_{0}s+{{\mathrm{\&omega;}}_0}^2}$ Frequency characteristic for velograph;

2. speed is put accelerometer

As ω=ω ₀, D ₀＞＞1 o'clock, the output voltage signal of vibro-pickup formation speed pendulum accelerometer accelerometer was:

$e_2\left(s\right)=G\stackrel{\&CenterDot;}{x}A=A\&CenterDot;G\&CenterDot;H_2\left(s\right)\&CenterDot;s^{2}X\left(s\right)---\left(8\right)$

The sensitivity of accelerometer is:

$S_{\stackrel{\&CenterDot;\&CenterDot;}{x}}=\frac{e_2\left(s\right)}{s^{2}X\left(s\right)}=A\&CenterDot;G\&CenterDot;\frac{s}{{\mathrm{<figure-callout\; id="2"\; label="s"\; filenames="A20051012735700121.png"\; state="\{\{state\}\}">s</figure-callout>}}^2+2D_0{\mathrm{\&omega;}}_{0}s+{{\mathrm{\&omega;}}_0}^2}---\left(9\right)$

But the sensitivity approximate expression of accelerometer is:

$S_{\stackrel{\&CenterDot;}{x}}\stackrel{\&CenterDot;}{=}\frac{\mathrm{AG}}{2D_0{\mathrm{\&omega;}}_0}---\left(10\right)$

In the formula:

e ₂(s) be the output voltage of accelerometer;

$H_2\left(s\right)=\frac{s}{{\mathrm{<figure-callout\; id="2"\; label="s"\; filenames="A20051012735700121.png"\; state="\{\{state\}\}">s</figure-callout>}}^2+2D_0{\mathrm{\&omega;}}_{0}s+{{\mathrm{\&omega;}}_0}^2}$ Frequency characteristic for accelerometer;

s ²X (s) is the acceleration of measured point.

More than two kinds be moving-coil type vibro-pickup commonly used, only energy measurement speed and acceleration.In addition, moving-coil type vibro-pickup magnetic circuit system commonly used is single magnet structure, and it is too high that the sensitivity of vibro-pickup is unfit to do.

Summary of the invention

The objective of the invention is to overcome the weak point that exists in the above-mentioned technology, provide a kind of simple in structure, reasonable in design, easy for installation, can directly measure acceleration.

In order to achieve the above object, the technical solution used in the present invention is: in housing lower end part and base clamping mutually, be equipped with in the housing on the symmetrical U-shaped, following soft iron docks mutually forms the closed cylinder, on in it, following position is provided with on the U-shaped, following locating sleeve, on the soft iron butt joint nozzle centre, the below is respectively equipped with the relative permanent magnet of magnetic pole, on, the cross section that symmetry is housed between the following permanent magnet is a U font armature, coil rack is equipped with in the armature outside, be wound with coil on it, the coil two ends have coil component spring sheet and collar to join, the coil out splice going splice is connected with the accessory power outlet that the middle part setting of loam cake is equipped with at position, housing top, circular yoke is equipped with in the coil outside, on it, the lower end joins with the coil component spring sheet respectively.

Self-vibration circle design f with the moving-coil type vibro-pickup ₀Be 60Hz, 100Hz, 200Hz, 500Hz, 1000Hz, make its ω ₀Greater than the circular frequency ω of the vibration acceleration of measured point, i.e. ω ₀＞＞ω, the damping ratio D of moving-coil type vibro-pickup ₀Be made as 0.707, vibro-pickup constitutes acceleration meter, can directly measure the vibrations acceleration.

ω=2 π f, f are the frequency of the vibration acceleration of measured point, and unit is a hertz

${\mathrm{\&omega;}}_0=2\mathrm{\&pi;}{f}_0=\sqrt{\frac{k}{m}}$

M is the motion parts quality of acceleration meter

K is the supporting guide spring rigidity of acceleration meter

f ₀Be the natural frequency of vibration of acceleration meter, unit for the output voltage signal of hertz acceleration meter is:

$e_3\left(s\right)=G\stackrel{\&CenterDot;}{x}A=A\&CenterDot;G\&CenterDot;H_3\left(s\right)\&CenterDot;s^{3}X\left(s\right)---\left(11\right)$

In the formula: G is the electromechanical coupling factor of acceleration meter;

Be the moving-coil of acceleration meter movement velocity with respect to the vibro-pickup shell;

$A=\frac{R}{R_s+R}$ For adjusting coefficient;

$H_3\left(s\right)=\frac{1}{{\mathrm{<figure-callout\; id="2"\; label="s"\; filenames="A20051012735700121.png"\; state="\{\{state\}\}">s</figure-callout>}}^2+2D_0{\mathrm{\&omega;}}_{0}s+{{\mathrm{\&omega;}}_0}^2}$ Frequency characteristic for acceleration meter; (12)

s ³X (s) is the vibration acceleration of measured point;

s＝jω、 $j=\sqrt{-1};$

e ₃(s) be the output voltage of acceleration meter.

From (11) formula as can be seen, the output voltage e of acceleration meter ₃(s) be proportional to the acceleration s of measured point ³X (s), thus realized the direct measurement of acceleration.

e ₃(s) sensitivity of acceleration meter is the output voltage e of acceleration meter ₃(s) with the acceleration s of measured point ³The ratio of X (s), that is:

$S_{\stackrel{\&CenterDot;\&CenterDot;\&CenterDot;}{x}}=\frac{e_3\left(s\right)}{s^{3}X\left(s\right)}=A\&CenterDot;G\&CenterDot;\frac{1}{{\mathrm{<figure-callout\; id="2"\; label="s"\; filenames="A20051012735700121.png"\; state="\{\{state\}\}">s</figure-callout>}}^2+2D_0{\mathrm{\&omega;}}_{0}s+{{\mathrm{\&omega;}}_0}^2}---\left(13\right)$

But the sensitivity approximate expression of acceleration meter is:

$S_{\stackrel{\&CenterDot;\&CenterDot;\&CenterDot;}{x}}\stackrel{\&CenterDot;}{=}\frac{\mathrm{AG}}{{{\mathrm{\&omega;}}_0}^2}---\left(14\right)$

Advantage of the present invention is:

Simple in structure, reasonable in design, easy for installation, can directly measure acceleration, and design closed two magnetic route structure, have highly sensitive, characteristics such as volume is little, in light weight, range big, shock resistance, anti-electromagnetic interference (EMI).

Description of drawings

Fig. 1 is a structural representation of the present invention;

Embodiment

Below in conjunction with accompanying drawing embodiments of the invention are described in further detail.

As shown in Figure 1, the present invention is in housing 2 lower end parts and base 1 clamping mutually, be equipped with on the symmetrical U-shaped in the housing 2, following soft iron 16,11 dock composition closed cylinder mutually, on in it, following position is provided with on the U-shaped, following locating sleeve 9,3, soft iron 16, on the 11 butt joint letter mouthful centres, the below is respectively equipped with the relative permanent magnet of magnetic pole 10,4, on, following permanent magnet 10, the cross section that symmetry is housed between 4 is a U font armature 7,5, armature 7, coil rack 6 is equipped with in 5 outsides, be wound with coil 13 on it, coil 13 two ends have coil component spring sheet 8 and collar 17 to join, coil 13 out splice going splices are connected with the accessory power outlet 15 that the middle part setting of loam cake 14 is equipped with at position, housing 2 top, circular yoke 12 is equipped with in coil 13 outsides, on it, the lower end joins with coil component spring sheet 8 respectively.

Self-vibration circular frequency ω with the moving-coil type vibro-pickup ₀Enough height of=2 π f design (design f ₀Be 6OHz, 100Hz, 200Hz, 500Hz, 1000Hz), make its ω ₀Greater than the circular frequency ω of the vibration acceleration of measured point, i.e. ω ₀＞＞ω, the damping ratio D of moving-coil type vibro-pickup ₀Be made as 0.707, vibro-pickup constitutes acceleration meter.

ω=2 π f, f are the frequency of the vibration acceleration of measured point, and unit is a hertz

${\mathrm{\&omega;}}_0=2\mathrm{\&pi;}{f}_0=\sqrt{\frac{k}{m}}$

M is the motion parts quality of acceleration meter

K is the supporting guide spring rigidity of acceleration meter

f ₀Be the natural frequency of vibration of acceleration meter, unit for the output voltage signal of hertz acceleration meter is:

$e_3\left(s\right)=G\stackrel{\&CenterDot;}{x}A=A\&CenterDot;G\&CenterDot;H_3\left(s\right)\&CenterDot;s^{3}X\left(s\right)---\left(11\right)$

In the formula: G is the electromechanical coupling factor of acceleration meter;

Be the moving-coil of acceleration meter movement velocity with respect to the vibro-pickup shell;

$A=\frac{R}{R_s+R}$ For adjusting coefficient;

$H_3\left(s\right)=\frac{1}{{\mathrm{<figure-callout\; id="2"\; label="s"\; filenames="A20051012735700121.png"\; state="\{\{state\}\}">s</figure-callout>}}^2+2D_0{\mathrm{\&omega;}}_{0}s+{{\mathrm{\&omega;}}_0}^2}$ Frequency characteristic for acceleration meter; (12)

s ³X (s) is the vibration acceleration of measured point;

s＝jω、 $j=\sqrt{-1};$

e ₃(s) be the output voltage of acceleration meter.

From (11) formula as can be seen, the output voltage e of acceleration meter ₃(s) be proportional to the acceleration s of measured point ³X (s), thus realized the direct measurement of acceleration.

The sensitivity of acceleration meter is the output voltage e of acceleration meter ₃(s) with the acceleration s of measured point ³The ratio of X (s), that is:

$S_{\stackrel{\&CenterDot;\&CenterDot;\&CenterDot;}{x}}=\frac{e_3\left(s\right)}{s^{3}X\left(s\right)}=A\&CenterDot;G\&CenterDot;\frac{1}{{\mathrm{<figure-callout\; id="2"\; label="s"\; filenames="A20051012735700121.png"\; state="\{\{state\}\}">s</figure-callout>}}^2+2D_0{\mathrm{\&omega;}}_{0}s+{{\mathrm{\&omega;}}_0}^2}---\left(13\right)$

But the sensitivity approximate expression of acceleration meter is:

$S_{\stackrel{\&CenterDot;\&CenterDot;\&CenterDot;}{x}}\stackrel{\&CenterDot;}{=}\frac{\mathrm{AG}}{{{\mathrm{\&omega;}}_0}^2}---\left(14\right)$

The present invention is the acceleration meter of a micro component of the direct measuring vibrations acceleration of a kind of energy, in metal shell, becomes to go up magnetic circuit by last permanent magnet, upper armature, last magnetic pole and yoke hook; By permanent magnet, lower armature, lower magnetic pole and yoke hook become magnetic circuit down down; Last magnetic circuit and following magnetic circuit constitute closed double magnetic circuit; By coil former, have mercy on two groups of coils and collar component movement part quality on coil former; This quality and reed constitute high natural frequency of vibration straight line gently to be put, and this light pendulum is to be supported by support ring.When coil moves, produce voltage signal in magnetic circuit.When the shell vibration frequency less than put the natural frequency of vibration, and damping ratio is less than 1 o'clock, the voltage signal direct ratio of coil output and vibration acceleration have been realized the direct measurement of acceleration.It has overcome adopts a series of shortcomings of accelerometer through a differential measurement acceleration existence.

It is made up of the reciprocal oscillator system of moving-coil type and the output regulating networks of housing, closed two magnetic route structure, the high natural frequency of vibration.One closed two magnetic route structure, a high natural frequency of vibration f are housed in housing ₀The straight line of (60Hz, 100Hz, 200Hz, 500Hz, 1000Hz) is gently put, and when coil moves in magnetic circuit, produces voltage signal, and the voltage signal that is produced by coil links to each other with binding post with the sensitivity output network through overdamping, exports through lead then.For from calibration coil, calibrate sensitivity, amplitude versus frequency characte and the linearity of acceleration meter by the fixed ampllitude sinusoidal signal that adds variable frequency.

Constitute double magnetic circuit by U type soft iron, permanent magnet, armature, yoke, by coil former, have mercy on two groups of coils and collar component movement part quality on coil former, this quality and reed constitute the straight line of the high natural frequency of vibration gently to be put, and when coil moves in magnetic circuit, produces voltage signal.The voltage signal that is produced by coil links to each other with binding post with the sensitivity output network through overdamping, links to each other with accessory power outlet then.Natural frequency of vibration ω when the light pendulum of straight line ₀Be far longer than the frequencies omega damping ratio D of measured point swing acceleration ₀＜1 o'clock, its output voltage was proportional to the acceleration of measured point, and vibro-pickup constitutes acceleration meter, can directly carry out acceleration and measure.The invention solves and can't directly measure a vibrations acceleration difficult problem both at home and abroad in special vibrations field, it has highly sensitive, measuring accuracy height, characteristics such as shock resistance.

Claims (2)

1. acceleration meter, comprise shell, base, on, following permanent magnet, it is characterized in that: in housing (2) lower end part and base (1) clamping mutually, be equipped with on the symmetrical U-shaped in the housing (2), following soft iron (16), (11) the closed cylinder is formed in butt joint mutually, on in it, following position is provided with on the U-shaped, following locating sleeve (9), (3), soft iron (16), (11) on the butt joint nozzle centre, the below is respectively equipped with the relative permanent magnet of magnetic pole (10), (4), on, following permanent magnet (10), the cross section that symmetry is housed (4) is a U font armature (7), (5), armature (7), (5) coil rack (6) is equipped with in the outside, be wound with coil (13) on it, coil (13) two ends have coil component spring sheet (8) and collar (17) to join, coil (13) out splice going splice is connected with the accessory power outlet (15) that the middle part setting of loam cake (14) is equipped with at housing (2) position, top, circular yoke (12) is equipped with in coil (13) outside, on it, the lower end joins with coil component spring sheet (8) respectively.

2. one kind adds the measuring method of counting velograph, it is characterized in that: with the self-vibration circular frequency ω of moving-coil type vibro-pickup ₀Enough height of=2 π f design (design f ₀Be 60Hz, 100Hz, 200Hz, 500Hz, 1000Hz), make its ω ₀Greater than the circular frequency ω of the vibration acceleration of measured point, i.e. ω ₀＞＞ω, the damping ratio D of moving-coil type vibro-pickup ₀Be made as 0.707, vibro-pickup constitutes acceleration meter.

ω=2 π f, f are the frequency of the vibration acceleration of measured point, and unit is a hertz

${\mathrm{\&omega;}}_0=2\mathrm{\&pi;}{f}_0=\sqrt{\frac{k}{m}}$

M is the motion parts quality of acceleration meter

K is the supporting guide spring rigidity of acceleration meter

f ₀Be the natural frequency of vibration of acceleration meter, unit is a hertz

The output voltage signal of acceleration meter is:

$e_3\left(s\right)=G\stackrel{\&CenterDot;}{x}A=A\&CenterDot;G\&CenterDot;H_3\left(s\right)\&CenterDot;s^{3}X\left(s\right)---\left(11\right)$

In the formula: G is the electromechanical coupling factor of acceleration meter;

Be the moving-coil of acceleration meter movement velocity with respect to the vibro-pickup shell;

$A=\frac{R}{R_S+R}$ For adjusting coefficient;

$H_3\left(s\right)=\frac{1}{s^2+2D_0{\mathrm{\&omega;}}_{0}s+{\mathrm{\&omega;}}_0^2}$ Frequency characteristic for acceleration meter; (12)

s ³X (s) is the vibration acceleration of measured point;

s＝jω、 $j=\sqrt{-1};$

e ₃(s) be the output voltage of acceleration meter.

From (11) formula as can be seen, the output voltage e of acceleration meter ₃(s) be proportional to the acceleration s of measured point ³X (s), thus realized the direct measurement of acceleration.

The sensitivity of acceleration meter is the output voltage e of acceleration meter ₃(s) with the acceleration s of measured point ³The ratio of X (s), that is:

$s_{\stackrel{\&CenterDot;\&CenterDot;\&CenterDot;}{x}}=\frac{e_3\left(s\right)}{s^{3}X\left(s\right)}=A\&CenterDot;G\&CenterDot;\frac{1}{s^2+2D_0{\mathrm{\&omega;}}_{0}s+{\mathrm{\&omega;}}_0^2}---\left(13\right)$

But the sensitivity approximate expression of acceleration meter is:

$s_{\stackrel{\&CenterDot;\&CenterDot;\&CenterDot;}{x}}\stackrel{\&CenterDot;}{=}\frac{\mathrm{AG}}{{{\mathrm{\&omega;}}_0}^2}---\left(14\right).$

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