CN101520494B - Electromagnetic magnetoelectric-effect type sensor - Google Patents

Abstract

The present invention relates to an electromagnetic magnetoelectric-effect type sensor which comprises electromagnetic energy-release coils and magnetic-energy balance coils. Constant direct current i1 is inputted into a magnetic core of the electromagnetic energy-release coils to generate B1, a stable weak magnetic field B0 of an iron magnetic member generates a correlative magnetic field B and the magnetic-energy balance coils are in a correlative magnetic sensing field. The detecting information contained in the output power of a weak magnetic sensor includes a frequency-selection amplitude mode and a resonance spectrum mode which can be independently used or used in integration. The electromagnetic magnetoelectric-effect type sensor provided by the present invention has reliability, simplicity, economical performance and durability, can be widely used and has high performance and price advantages.

Description

A kind of electromagnetic magnetoelectric-effect type sensor

Technical field

The present invention relates to ferromagnetic component electromagnetic nondestructive device, particularly a kind of electromagnetic magnetoelectric-effect type sensor.

Background technology

At present, the magnetic phenomenon in Magnetic Measurement Technology field is divided into low-intensity magnetic field, high-intensity magnetic field and high-intensity magnetic field very substantially, and as a focus of current new and high technology, the low-intensity magnetic field detection technique is widely used, and development prospect is very wide.

Along with the large-scale application of magnetic material, magnetic effect theory, magneto sensor, data modeling and analysis and computer networking technology, weak magnetic detection technique constantly develops, and arises at the historic moment at the various weak magnetic detection method in different application field.At present according to method classes such as measuring principle existing " magnetic-force method ", " inductive electromagnetic method ", " magnetic saturation method ", " magnetoelectric effect method ", " Pumping Magnetic Resonance Method ", " superconductivity effects method ", " magneto-optic effect methods ".

Wherein, the magnetic saturation method is to utilize the method for being measured magnetic field by the nonlinear relationship of magnetic induction density and magnetic field intensity under the saturation activation of alternating magnetic field of the magnetic core in the measuring magnetic field, be also referred to as " fluxgate " technology, this method can be divided into frequency again to be selected and two kinds of application forms of time encoding, and the field of application is very extensive.For example employing is all arranged at aspects such as space technology, military surveillance, geology detectings.

Ferrimagnet detects, and is by measurement features magnetic field the locus of ferromagnetic component, configuration state, physical property, chemical constitution etc. to be measured, and having can non-contact detection and the characteristics that detect of online in real time.In general, present magnetic material detection mainly adopts " inductive coil+excitation unit ", " Hall element+excitation unit " or technology types such as " inductive coil+Hall elements+excitation unit ".All there is following several big shortcoming in these methods: 1. be overly dependent upon strong magnetic pumping, and the obvious variation of detection performance under the weak magnetic state, even can not detect at all; 2. the magnetic Circuit Design complexity exists the quantitative resolving power of defective very limited to member; 3. skin effect is remarkable, is difficult to the defective of detection means inside; Influenced by Lift-off effect, be difficult under the condition that does not influence member free-running operation and finish detection.

The fluxgate sensor of " magnetic saturation method " principle had highly sensitive, high stable and high response characteristic in the middle of low-intensity magnetic field detected, and obtained certain application in the material tests field in recent years.Adopted the technology type of " fluxgate+inductive coil " as Canadian Rotesco company, China Shanghai Maritime University has adopted the technology type of " multipath magnetic flow door+magnetizing assembly ".But still there is following problem in this series products: the one, and high sensitivity has caused structural leakage field to disturb increase simultaneously; The 2nd, still increased time domain-spatial domain change-over circuit at signal processing, reduction constitutes influence to signal; The 3rd, probe and the still very large heaviness of circuit arrangement are not easy in industry spot practical application and operation.

Summary of the invention

The present invention provides a kind of electromagnetic magnetoelectric-effect type sensor for solving the above-mentioned defective of prior art, and the technical scheme of electromagnetic magnetoelectric-effect type sensor of the present invention is: by electromagnetic energy release coil L ₁With magnetic energy weighing apparatus coil L ₂Constitute electromagnetic magnetoelectric-effect type sensor; Have " galvanomagnetic effect " and " magnetoelectric effect " interlock from know-why, the technical characterictic of the two-way cross complaint of input and output electric weight promptly forms exciting current i by the electromagnetic circuit design ₁With the associated response link of magnetic energy potential difference, releasing by the design formation of magnetoelectricity loop can electromagnetic field (B ₀Or B ₁) and magnetic energy weighing apparatus coil L ₂Output electric weight (u ₀Or i ₀) equivalence induction link; The electromagnetic energy release coil L of described sensor ₁,, magnetic energy weighing apparatus coil L ₂Adjacent parallel is placed, and all adopts high magnetic conduction magnetic core; To electromagnetic energy release coil L ₁Provide by the given steady DC excitation current i of embedded program modulation ₁, magnetic energy weighing apparatus coil L ₂One end (modulated terminal) input frequency modulated oscillations f _i, the other end (output terminal) output electric weight (u ₀Or i ₀).4. ferromagnetic component is placed in contiguous magnetic energy weighing apparatus coil L ₂A side; The magnetic field B of tested ferromagnetic component ₀Direction and electromagnetic energy release coil L ₁, magnetic energy weighing apparatus coil L ₂Direction parallel.

The principle framework of electromagnetic magnetoelectric-effect type sensor of the present invention is: 1. electromagnetic energy release coil L ₁The unsaturation characteristic that provides of magnetic core and be equivalent to a linear element, it is input as permanent constant current i ₁Produce B ₁2. the stable low-intensity magnetic field B of ferromagnetic component ₀With B ₁Produce related magnetic field B during spatial interaction, magnetic energy weighing apparatus coil L ₂Be among the related induced magnetic fields B.3. magnetic energy weighing apparatus coil L ₂, because the saturated luffing characteristic that its magnetic core provides, and being equivalent to a two nonlinear gain link, it is input as related induction magnetic flux Ф _B=constant current magnetic flux Ф _B1+ response magnetic flux Ф _B0, be output as electric weight (u ₀Or i ₀).4. by the 1. 2. 3. system that forms of each link, realized the autocontrol conversion between input variable and the output variable, the output level u of electromagnetic magnetoelectric-effect type sensor ₀Can reflect magnetic uniform magnetic field B a little less than the stable state of corresponding volume unit in space on the ferromagnetic component ₀5. the output electric weight (u of weak magnetic sensor ₀Or i ₀) detection information that comprised comprises frequency-selecting amplitude and two kinds of forms of resonance spectrum, can be by independent employing, but also integrated use.

The invention has the beneficial effects as follows: the present invention and robotization control signal have the compatibility of height, can implement the signal modulation according to plant characteristic, to satisfy the needs that detect; And be suitable for the following low-intensity magnetic field of 1mT and detect, be subjected to the influence of Lift-off effect very little, the distance apart from the magnetic component surface during measurement can reach the 5cm magnitude; The present invention is not subjected to the influence of self time domain dynamic factor, to magnetic uniform magnetic field B a little less than the stable state of space corresponding volume unit ₀Has 0.1Gs (1Gs=10 ^-1MT=10 ^-4T) high resolution can not be subjected to the influence that construction system slightly vibrates and speed of related movement changes when implementing to detect; The present invention adopts low pressure (5V) light current, and (＜0.5A) Constant Electric Current magnetic field does not constitute any remanent magnetism to magnetic component and pollutes; The present invention is reliable, simple and easy, economical, durable, not only can be extensive use of, and have very high performance and price advantage.

Description of drawings

Below in conjunction with accompanying drawing the present invention is described in further detail:

Fig. 1 is a sensor construction synoptic diagram of the present invention.

Fig. 2 is a sensor technology theory diagram of the present invention.

Fig. 3 is a kind of sensor application structural shape of the present invention (pick-up unit) synoptic diagram.

Fig. 4 is the axial view of a kind of sensor application structural shape of the present invention (pick-up unit).

Among Fig. 1, electromagnetic energy release coil L1, magnetic energy weighing apparatus coil L2.

Among Fig. 2, release energy element link 1, magnetic weighing apparatus element link 2.

Among Fig. 3, tested slight ferromagnetic component 1, sensor 2, plastic skeleton 3, folding pivot pin 4.

Embodiment 1:

As shown in fig. 1, a kind of electromagnetic magnetoelectric-effect type sensor of the present invention adopts by electromagnetic energy release coil L ₁With magnetic energy weighing apparatus coil L ₂A kind of electromagnetic magnetoelectric-effect type sensor of being formed; It is characterized in that: 1. described sensor has " the two magnetic of two electricity " loop distribution feature from know-why, i.e. have exciting current and magnetic energy gesture pressure reduction output two-circuit in the electromagnetic circuit design, has on the magnetoelectricity circuit design to release energy electromagnetic field and magnetic energy weighing apparatus coil L ₂The nested two-circuit of related induction, space outerpace magnetic field, the associated response by nested magnetic circuit.2. the electromagnetic energy release coil L of described sensor ₁, magnetic energy weighing apparatus coil L ₂, all adopting high magnetic conduction magnetic core, adjacent parallel is placed.3. to electromagnetic energy release coil L ₁Provide by the given constant direct current stream i of embedded program modulation ₁, magnetic energy weighing apparatus coil L ₂One end (modulated terminal) input frequency modulated oscillations f _i, the other end (output terminal) output electric weight (u ₀Or i ₀).4. magnetic component is placed in adjacent coils L ₂A side.5. tested ferromagnetic component magnetic direction and electromagnetic energy release coil L ₁, magnetic energy weighing apparatus coil L ₂Direction parallel.

Embodiment 2:

As shown in Figure 2, a kind of electromagnetic magnetoelectric-effect type sensor of the present invention: 1. electromagnetic energy release coil L ₁The unsaturation characteristic that provides of magnetic core and be equivalent to a linear element, it is input as permanent constant current i ₁Produce B ₁2. the stable low-intensity magnetic field B of ferromagnetic component ₀With B ₁Produce related magnetic field B during spatial interaction, magnetic energy weighing apparatus coil L ₂Be among the related induced magnetic fields B.3. magnetic energy weighing apparatus coil L ₂, because the saturated luffing characteristic that its magnetic core provides, and being equivalent to a two nonlinear gain link, it is input as related induction magnetic flux Ф _B=constant current magnetic flux Ф _B1+ response magnetic flux Ф _B0, be output as level u ₀4. by the 1. 2. 3. system that forms of each link, realized the autocontrol conversion between input variable and the output variable, the output level u of weak magnetic sensor ₀Can reflect magnetic uniform magnetic field B a little less than the stable state of corresponding volume unit in space on the ferromagnetic component ₀5. the output electric weight (u of weak magnetic sensor ₀Or i ₀) detection information that comprised comprises frequency-selecting amplitude and two kinds of forms of resonance spectrum, can be by independent employing, but also integrated use.

Embodiment 3:

As shown in fig. 1, the electromagnetic energy release coil L of described sensor employing ₁Be 674 circle φ 0.05mm copper wire coils, φ 2.5mm (diameter of section) * 40mm (length) crystallite magnetic core; Magnetic energy weighing apparatus coil L ₂Be 796 circle φ 0.2mm copper wire coils, φ 2mm (diameter of section) * 30mm (length) permalloy magnetic core, electromagnetic energy release coil L ₁, magnetic energy weighing apparatus coil L ₂By the fixing parallel placement of steel frame, centre distance 6.30 ± 0.04mm.

(＜0.5A) Constant Electric Current magnetic field does not constitute any remanent magnetism to magnetic component and pollutes to adopt low pressure (5V) light current; Sensor can be implemented the signal modulation by the robotization control signal according to the detected object characteristic, to satisfy the needs that detect.0.1Gs (1Gs=10 to the detection of the low-intensity magnetic field below the 1mT ^-1MT=10 ^-4T) than high resolution, be subjected to the influence of Lift-off effect very little, during measurement apart from the magnetic component surface can reach 5cm apart from the upper limit, can not be subjected to the slightly influence of vibration and speed of related movement variation of construction system when implement detecting; Have reliable, simple and easy, economic, durable characteristics, not only can be extensive use of, and cheap for manufacturing cost.

The test specimen of accepting weak magnetic detection in the example is one group of equal steel wire, and steel wire quantity is 100 in the group, individual wire diameter phi 1.2mm, and volume element size in intact place is S ₀=113.1mm ², material is material supplies state 45 steel, flush length＞8m.After weak magnetic planning, the even strong and weak magnetic field H that the intact position of the middle effectively section of this test specimen has when implementing to detect ₀=8.4Gs.Steel wire exists two places to concentrate breakpoint in the group, 4 of first place top layer fracture of wires, and all the other steel wires are intact, 10 of second place's central core fracture of wires, all the other steel wires are intact.

For reducing Systematic Errors, 6 sensors of actual employing are worked simultaneously.Shown in Fig. 3,4, evenly arrange electromagnetic energy release coil L according to plastic skeleton coplane annular along external diameter φ 46mm ₁The subtend skeleton outside, magnetic energy weighing apparatus coil L ₂Subtend skeleton inboard.

Described sensor inserts and (respectively contains 16 80C196 single-chip microcomputers by TCK-MZ type industrial microcomputer plate, 12 high speed ad/da converters, the FLASH storer of 16M, RS232 external data communication interface) and the peripheral circuit that constitutes of TCK-PZ type vibration modulation panel (respectively containing 7 road 160MHz crystal oscillators), and adopt the modulation of dedicated custom software control input signal, the mediation sampling input amount of separating of output signal, to each electromagnetic energy release coil L ₁Input is by the constant direct current stream i of embedded program modulation ₁, each magnetic energy weighing apparatus coil L ₂Modulated terminal input higher-order of oscillation f _i=160MHz.Magnetic energy weighing apparatus coil L ₂Output terminal sampled level u ₀According to the demodulation of frequency-selecting amplitude mode, can derive u behind the input microcomputer ₀An active constituent u _Bo, u _BoBe called the demodulation output voltage again, u on Technical Architecture _Bo=f (i ₁, f _i, k, n, H ₀) be one about i ₁, f _i, k, n and B _oDemodulation function.Wherein: k is the peripheral circuit amount of gain, and n is that the frequency of peripheral circuit is selected parameter, and other variable is identical with the implication of corresponding parameter of the present invention.u _BoCan shine upon the related magnetic field of given electromagnetic field and measured object low-intensity magnetic field, therefore as given i ₁, f _i, when k, n, u _BoJust can directly shine upon the internal magnetic field B of tested member ₀Again because B ₀Variable quantity directly shine upon the variable quantity of tested component volume unit (metal normal cross-section), so by u _BoVariable quantity, also just directly shone upon the variable quantity of tested component volume unit

At each sensor when being positioned on the test specimen intact volume element, modulation i ₁=25mA is implemented to detect the demodulation output level u of system to typical case position, test specimen three places by same modulation parameter _B0Actual observation record is as follows:

Sensor number	1	2	3	4	5	6	Average
								The intact u of place of effective section B0(mV)	341	342	340	340	342	341	341.0
4 surperficial fracture of wire u of place B0(mV)	326	328	327	326	327	327	326.8
								10 inner fracture of wire u of place B0(mV)	306	308	307	306	306	307	306.5

The ferromagnetism test specimen main flux of theoretical appraisal through being in weak magnetic state keeps constant (leakage flux is very little), its magnetic field B substantially ₀To be inverse proportion relevant with the volume element size, should be respectively: the effective intact B of place of section ₀=8.4Gs; 4 surperficial fracture of wire B of place ₀=8.75Gs; 10 inner fracture of wire B of place ₀=9.33Gs.

Obviously: $u_{\mathrm{Bo}}=\frac{2864.4}{B_0}+\mathrm{\δ},$ Wherein: u _B0Unit " mV ", B ₀Unit " Gs ", δ comprise outer shifting circuit system error factor in interior total error, and δ ∈ [1,1] mV,

But verificating sensor has been realized the autocontrol conversion between input variable and the output variable, the output level u of weak magnetic sensor ₀Can reflect magnetic uniform magnetic field B a little less than the stable state of corresponding volume unit in space on the ferromagnetic component ₀

Pass through u as desire _BoVariable quantity directly shine upon the variation equivalent of test specimen volume element, can test:

$\frac{\mathrm{\Δ}{u}_{\mathrm{Bo}}}{{\stackrel{\‾}{u}}_{\mathrm{Bo}}}=\frac{\mathrm{\Δs}}{s_0}+\frac{\mathrm{\δ}}{{\stackrel{\‾}{u}}_{B0}}$

Wherein: every unit is " % ", $\frac{\mathrm{\Δ}{u}_{\mathrm{Bo}}}{{\stackrel{\‾}{u}}_{\mathrm{Bo}}}=\frac{u_{\mathrm{Bo}}-{\stackrel{\‾}{u}}_{\mathrm{Bo}}}{{\stackrel{\‾}{u}}_{\mathrm{Bo}}}$ Be u _HoChange equivalent, be the magnetic field B of detection system by the volume element correspondence ₀And variation delta B ₀=B ₀-B ₀Measure the mapping value that converts, $\frac{\mathrm{\Δs}}{s_0}=\frac{s-s_0}{s_0}$ For the test specimen volume element changes equivalent,

Systematic error during for the variation equivalent of detection system mapping test specimen volume element, and $\frac{\mathrm{\δ}}{{\stackrel{\‾}{u}}_{B0}}\∈(-\mathrm{0.5,0.5})\%.$

Claims (4)

1. an electromagnetic magnetoelectric-effect type sensor is by electromagnetic energy release coil L ₁With magnetic energy weighing apparatus coil L ₂Constitute; It is characterized in that: " galvanomagnetic effect " and " magnetoelectric effect " interlock, the technical characterictic of the two-way cross complaint of input and output electric weight promptly forms electromagnetic energy release coil L by the electromagnetic circuit design ₁Import permanent constant current i ₁Releasing with output can electromagnetic field B ₁The associated response link of magnetic energy potential difference, the stable low-intensity magnetic field B of ferromagnetic component to be measured ₀With B ₁Spatial interaction produces related magnetic field B, forms related magnetic field B and magnetic energy weighing apparatus coil L by the design of magnetoelectricity loop then ₂Output electric weight u ₀Or i ₀Equivalence induction link; Electromagnetic energy release coil L ₁Magnetic core adopt the high magnetic conduction magnetic core of unsaturation characteristic, it is input as permanent constant current i ₁, be output as and release energy electromagnetic field B ₁Magnetic energy weighing apparatus coil L ₂Magnetic core adopt the high magnetic conduction magnetic core of saturated luffing characteristic, at magnetic energy weighing apparatus coil L ₂Modulated terminal input frequency modulated oscillations f _iCondition under, be output as magnetic energy weighing apparatus coil L ₂The electric weight u of the other end ₀Or i ₀

2. a kind of electromagnetic magnetoelectric-effect type sensor according to claim 1 is characterized in that: electromagnetic energy release coil L ₁The unsaturation characteristic that provides of magnetic core and be equivalent to a linear element, it is input as permanent constant current i ₁Produce B ₁The stable low-intensity magnetic field B of ferromagnetic component ₀With B ₁Produce related magnetic field B during spatial interaction, magnetic energy weighing apparatus coil L ₂Be among the related induced magnetic fields B; Magnetic energy weighing apparatus coil L ₂, because the saturated luffing characteristic that its magnetic core provides, and being equivalent to a two nonlinear gain link, it is input as related induction magnetic flux Φ _B=constant current magnetic flux Φ _B1+ response magnetic flux Φ _B0, be output as electric weight u ₀Or i ₀By the system that above-mentioned each link is formed, realized the cross complaint formula conversion between input variable and the output variable, the output electric weight u of weak magnetic sensor ₀Or i ₀Can reflect magnetic uniform magnetic field or equivalent uniform magnetic field B a little less than the stable state of corresponding volume unit in space on the ferromagnetic component ₀

3. a kind of electromagnetic magnetoelectric-effect type sensor according to claim 1 is characterized in that: tested ferromagnetic component magnetic field B ₀Direction and electromagnetic energy release coil L ₁With magnetic energy weighing apparatus coil L ₂Direction parallel.

4. a kind of electromagnetic magnetoelectric-effect type sensor according to claim 1 is characterized in that: the output electric weight u of sensor ₀Or i ₀The detection information that is comprised comprises frequency-selecting amplitude and two kinds of forms of resonance spectrum, can be by independent employing, but also integrated use.

Images