CN102759752A - Metal detection device and detection method - Google Patents

Abstract

The invention provides a metal detection device, which includes a power supply, an emitter coil and a current sensor, that are connected in series to form a loop, wherein a first receiving coil and a second receiving coil are connected with a processor respectively; the power supply outputs alternating current, so as to enable the emitter coil connected with the power supply to generate an alternating magnetic field; the current sensor collects current signals flowing through the emitter coil in a real-time manner; and the real-time current signals are obtained by the processor, the real-time current signals of the emitter coil and the real-time differential voltage signals of the first and the second receiving coils under the action of the alternating magnetic field are calculated according to the pre-arranged computation rule, so as to obtain the detection value, and the detection value is analyzed as per the pre-arranged analysis rule to judge that whether metal is detected. According to the metal detection device provided by the invention, the processor is used for calculation and judgment as per the real-time differential voltage between the two receiving coils and the real-time current signals of the emitter coil, the calculation result is free from the influences of the consistency of the receiving coils and symmetry degree in installation, therefore, the obtained judgment result is high in accuracy.

Description

A kind of metal detecting device and detection method

Technical field

The invention belongs to detection of electrons and technical field of detection, relate in particular to a kind of metal detecting device and detection method.

Background technology

Metal detection is widely used in fields such as food and medicine processing and manufacturing, military equipment, safety precaution, criminal investigation.Existing technological sniffer can be divided into generally based on eddy current principle: based on frequency detecting, based on impedance and phase-detection, based on several types of differential voltage detections etc.

Referring to the structural representation of using the metal detecting device that detects based on differential voltage at present always shown in Fig. 1; Comprise power supply 001, transmitting coil 002, first receiving coil 003, second receiving coil 004 and analyzer 005; Power supply 001 is formed the transmission loop with transmitting coil 002; First receiving coil 003 and second receiving coil 004 are identical and be arranged symmetrically in the both sides of transmitting coil 002; Analyzer 005 links to each other with second receiving coil 004 with first receiving coil 003 respectively; First receiving coil 003, second receiving coil 004 and analyzer 005 are formed receiving loop, and analyzer 005 is gathered the inductive voltage value of first receiving coil 003 and second receiving coil 004 respectively.Its metal detection principle is: analyzer 005 gather the inductive voltage value of first receiving coil 003 and second receiving coil 004 respectively and calculate first receiving coil 003 and second receiving coil 004 between differential voltage; When not having metal near sniffer; Differential voltage between first receiving coil 003 and second receiving coil 004 is zero; When receiving coil of metal distance nearer; When far away apart from another receiving coil, the differential voltage between first receiving coil 003 and second receiving coil 004 is non-vanishing.

In the practical application; Because two receiving coil parameters can not be in full accord; Also symmetry is installed in the both sides of transmitting coil fully, and therefore, the mutual inductance between two receiving coils and transmitting coil is unequal; Differential voltage when not having metal near sniffer between two receiving coils is still bigger, causes the sensitivity of detection lower.

Summary of the invention

In view of this; The object of the present invention is to provide a kind of metal detecting device and detection method; In order to solve in the prior art because the parameter of two receiving coils is not quite identical and two receiving coils not exclusively are symmetricly set on the problem of transmitting coil both sides to the influence of metal detection sensitivity, its technical scheme is following:

A kind of metal detecting device comprises: power supply, transmitting coil, first receiving coil, second receiving coil, current sensor and processor;

Said power supply, said transmitting coil and said current sensor are concatenated into the loop; Said first receiving coil, second receiving coil link to each other with said processor respectively, and said first receiving coil and said second receiving coil are arranged at the both sides of said transmitting coil respectively;

Said power supply output exchange current is so that connected said transmitting coil produces alternating magnetic field;

The real-time acquisition stream of said current sensor is crossed the current signal of said transmitting coil, and said real-time current signal is sent to said processor;

Said processor receives said real-time current signal; Detect said first receiving coil in real time at first induced potential under the said action of alternating magnetic field and second induced potential of said second receiving coil under said action of alternating magnetic field; Obtain the real time differential voltage signal according to said first induced potential and second induced potential; Computation rule according to preset calculates detected value to said real-time current signal and real time differential voltage signal; And according to preset analysis rule said detected value is analyzed, whether output detects the information of metal.

Said detected value is specially strides the active power value, and said preset computation rule comprises: averaging after said real-time current signal and said real time differential voltage signal are multiplied each other obtains striding the active power value.

The preset analysis rule of said foundation is analyzed said detected value, and the information whether output detects metal is specially:

Analyze and saidly stride the active power value, if the said active power value of striding changes, judge then and detect metal that output detects the information of metal, if the said active power of striding does not change, judge then and do not detect metal that output does not detect the information of metal.

Said metal detecting device also comprises:

Optional, alarm is used for when said processor judgement detects metal, giving the alarm.

A kind of metal detecting device comprises: power supply, transmitting coil, first receiving coil, second receiving coil, current sensor and processor;

Said power supply, said transmitting coil and said current sensor are concatenated into the loop; One end of said first receiving coil links to each other with an end of said second receiving coil; The other end of said first receiving coil links to each other with said processor; The other end of said second receiving coil links to each other with said processor, and said first receiving coil and said second receiving coil are arranged at the both sides of said transmitting coil respectively;

Said power supply output exchange current is so that connected transmitting coil produces alternating magnetic field;

The real-time acquisition stream of said current sensor is crossed the current signal of said transmitting coil, and said real-time current signal is sent to said processor;

Said processor receives said real-time current signal; Detect said first receiving coil and the real time differential voltage signal of said second receiving coil under said action of alternating magnetic field in real time; Computation rule according to preset calculates detected value to said real-time current signal and real time differential voltage signal; And according to preset analysis rule said detected value is analyzed, whether output detects the information of metal.

Said detected value is specially strides the active power value, and said preset computation rule is: averaging after said real-time voltage signal and said real time differential voltage signal are multiplied each other obtains striding the active power value.

The preset analysis rule of said foundation is analyzed said detected value, and the information whether output detects metal is specially:

Analyze and saidly stride the active power value, if the said active power value of striding changes, judge then and detect metal that output detects the information of metal, if the said active power of striding does not change, judge then and do not detect metal that output does not detect the information of metal.

Optional, said metal detecting device also comprises:

Alarm is used for when said processor judgement detects metal, giving the alarm.

A kind of metal probing method comprises:

Power supply output exchange current is so that transmitting coil produces alternating magnetic field;

The real-time acquisition stream of current sensor is crossed the current signal of said transmitting coil, and said real-time current signal is sent to processor;

Processor receives said real-time current signal; Detect said first receiving coil in real time at first induced potential under the said action of alternating magnetic field and second induced potential of said second receiving coil under said action of alternating magnetic field; Obtain the real time differential voltage signal according to said first induced potential and second induced potential; Computation rule according to preset calculates detected value to said real-time current signal and real time differential voltage signal; And according to preset analysis rule said detected value is analyzed, whether output detects the information of metal.

A kind of metal probing method comprises:

Power supply output exchange current is so that transmitting coil produces alternating magnetic field;

The real-time acquisition stream of current sensor is crossed the current signal of said transmitting coil, and said real-time current signal is sent to processor;

Processor receives said real-time current signal; Detect said first receiving coil and the real time differential voltage signal of said second receiving coil under said action of alternating magnetic field in real time; Computation rule according to preset calculates detected value to said real-time current signal and real time differential voltage signal; And according to preset analysis rule said detected value is analyzed, whether output detects the information of metal.

A kind of metal detecting device provided by the invention and detection method, power supply output exchange current makes connected transmitting coil produce alternating magnetic field; The real-time acquisition stream of current sensor is crossed the current signal of transmitting coil, and the real-time current signal is sent to processor; Processor receives the real-time current signal; Detect first induced potential and second receiving coil second induced potential under action of alternating magnetic field of first receiving coil under action of alternating magnetic field in real time; Obtain the real time differential voltage signal according to first induced potential and second induced potential; Perhaps directly detect the real time differential voltage signal of first receiving coil and second receiving coil; According to preset computation rule real-time current signal and real time differential voltage signal are calculated detected value then, and according to preset analysis rule detected value is analyzed, whether output detects the information of metal.Metal detecting device provided by the invention and method; The real time differential voltage between two receiving coils of processor foundation and the real-time current signal of transmitting coil calculate and obtain to stride active power value or transimpedance value of real part; And whether change to survey and have or not metal according to striding active power value or transimpedance value of real part; Metal detection sensitivity does not receive the parameter consistency and symmetric influence of installation of receiving coil, and the metal detection accuracy that obtains in view of the above is high.

Description of drawings

In order to be illustrated more clearly in the embodiment of the invention or technical scheme of the prior art; To do to introduce simply to the accompanying drawing of required use in embodiment or the description of the Prior Art below; Obviously, the accompanying drawing in describing below is some embodiments of the present invention, for those of ordinary skills; Under the prerequisite of not paying creative work, can also obtain other accompanying drawing according to these accompanying drawings.

Fig. 1 is the structural representation of the metal detecting device that differential voltage detects in the prior art;

Fig. 2 is the structural representation of the metal detecting device that provides of the embodiment of the invention one;

Fig. 3 is another structural representation of the metal detecting device that provides of the embodiment of the invention one;

Fig. 4 is the schematic flow sheet of the metal probing method that provides of the embodiment of the invention one;

Fig. 5 is the structural representation of the metal detecting device that provides of the embodiment of the invention two;

Fig. 6 is another structural representation of the metal detecting device that provides of the embodiment of the invention two;

Fig. 7 is the schematic flow sheet of the metal probing method that provides of the embodiment of the invention two.

Embodiment

For the purpose, technical scheme and the advantage that make the embodiment of the invention clearer; To combine the accompanying drawing in the embodiment of the invention below; Technical scheme in the embodiment of the invention is carried out clear, intactly description; Obviously, described embodiment is the present invention's part embodiment, rather than whole embodiment.Based on the embodiment among the present invention, those of ordinary skills are not making the every other embodiment that is obtained under the creative work prerequisite, all belong to the scope of the present invention's protection.

Embodiment one

The embodiment of the invention one provides a kind of metal detecting device, and Fig. 2 is the structural representation of this device, and this device can comprise: power supply 101, transmitting coil 102, first receiving coil 103, second receiving coil 104, current sensor 105 and processor 106.

Wherein, Power supply 101, transmitting coil 102 and current sensor 105 are concatenated into the loop; First receiving coil 103, second receiving coil 104 link to each other with processor 106 respectively, and first receiving coil 103 and second receiving coil 104 are arranged at the both sides of transmitting coil 102 respectively.In the present embodiment, first receiving coil 103 and second receiving coil 104 are preferably the both sides that are symmetricly set in transmitting coil 102.

Power supply 101 output exchange current are so that connected transmitting coil 102 produces alternating magnetic field, and current sensor 105 real-time acquisition stream are crossed the current signal of transmitting coil 102, and the real-time current signal is sent to processor 106.

Processor 106 receives the real-time current signal; Detect first induced potential and second receiving coil 104 second induced potential under action of alternating magnetic field of first receiving coil 103 under action of alternating magnetic field in real time; Obtain the real time differential voltage signal according to first induced potential and second induced potential; Computation rule according to preset calculates detected value to real-time current signal and real time differential voltage signal; And according to preset analysis rule detected value is analyzed, whether output detects the information of metal.

One end of transmitting coil 102 links to each other with power supply 101, and the other end links to each other with the first test side S1 of current sensor 105; The second test side S2 of current sensor 105 links to each other with power supply 101, and power supply 101, transmitting coil 102 and current sensor 105 are formed a launching circuit; First receiving coil 103 is formed receiving loop respectively with processor 106, second receiving coil 104 and processor 106; The output terminal S3 of current sensor 105 is connected with processor 106.

In the present embodiment, detected value is specially strides the active power value, and preset computation rule is: averaging after said real-time current signal and said real time differential voltage signal are multiplied each other obtains striding the active power value.Striding the active power value is that transmitting coil 102 current instantaneous values are real-time current i _cAnd first receiving coil 103 and 104 differential voltage instantaneous values of second receiving coil are the mean value of the product of real time differential magnitude of voltage e:

$P_g=\stackrel{\‾}{i_c\×e}---(1-1)$

In the present embodiment, active power value P is striden in the processor analysis _gIf, P _gChange, then judge and detect metal, output detects the information of metal, like P _gDo not change, then judge and do not detect metal, output does not detect the information of metal, certainly, when not detecting metal, also output information not.

Detect the effective value of real-time current signal, obtain the transimpedance value of real part with striding the square value of active power value divided by the effective value of real-time current signal, i.e. transimpedance value of real part is: R _g=P _g/ I ², when knowing transmitting coil 102 real-time current i _cEffective value I and stride active power value P _gThe time, also can analyze whether detect metal according to the transimpedance value of real part.

Provide below according to striding active power value P _gOr R _gVariation judge the principle whether detect metal: establish transmitting coil 102 no metal near with air dielectric in inductance be L ₁, Δ L ₃For ferromagnetic metal during near transmitting coil 102 because of magnetic permeability increases the inductance increase that causes, the loop resistance that excitation power supply 101, transmitting coil 102, current sensor 105 constitute is R ₁, eddy current inductance, the eddy current resistance of being surveyed metal are respectively L ₂, R ₂, the voltage effective value of excitation power supply 101, angular frequency, current effective value are respectively E ₁, ω, I ₁, surveyed the eddy current effective value I of metal ₂, transmitting coil 102 is M with the mutual inductance of being surveyed metal.

The electric equation of excitation power supply 101, transmitting coil 102, current sensor 105 series loops is:

E ₁+jMωI ₂=I ₁R ₁+j(L ₁+ΔL ₃)ωI ₁ （1-2）

The electric equation in metal electric eddy current loop is:

jMωI ₁=I ₂R ₂+jL ₂ωI ₂ （1-3）

If M ₁Be the mutual inductance of the transmitting coil 102 and first receiving coil 103, M _1WBe the mutual inductance of the metal and first receiving coil 103, M ₂Be the mutual inductance of the transmitting coil 102 and second receiving coil 104, M _2WMutual inductance for the metal and second receiving coil 104.

The induced potential effective value of first receiving coil 103 is:

E _r1＝jω(M ₁I ₁+M _1WI ₂) （1-4）

The induced potential effective value of second receiving coil 104 is:

E _r2＝jω(M ₂I ₁+M _2WI ₂) （1-5）

Then the differential voltage effective value between first receiving coil 103 and second receiving coil 104 is:

E _r=jω[(M ₁-M ₂)I ₁+(M _1W-M _2W)I ₂] （1-6）

Obtain by formula (1-2), (1-3), (1-6):

$E_r=I_1\{-\frac{M(M_{1W}-M_{2W}){\mathrm{<figure-callout\; id="2"\; label="R"\; filenames="HDA00001930187800021.png"\; state="\{\{state\}\}">R</figure-callout>}}_2{\mathrm{\&omega;}}^2}{{\mathrm{<figure-callout\; id="2"\; label="L"\; filenames="HDA00001930187800021.png"\; state="\{\{state\}\}">L</figure-callout>}}_2^2{\mathrm{\&omega;}}^2+{\mathrm{<figure-callout\; id="2"\; label="R"\; filenames="HDA00001930187800021.png"\; state="\{\{state\}\}">R</figure-callout>}}_2^2}+\mathrm{j\&omega;}[(M_1-M_2)+\frac{M-(M_{1W}-M_{2W}){\mathrm{\&omega;}}^2{L}_2}{{\mathrm{<figure-callout\; id="2"\; label="L"\; filenames="HDA00001930187800021.png"\; state="\{\{state\}\}">L</figure-callout>}}_2^2{\mathrm{\&omega;}}^2+{\mathrm{<figure-callout\; id="2"\; label="R"\; filenames="HDA00001930187800021.png"\; state="\{\{state\}\}">R</figure-callout>}}_2^2}\left]\right\}---(1-7)$

(1-7) obtains differential voltage E by formula _rWith transmitting coil 102 electric current I ₁Between transimpedance be:

$Z_g=-\frac{M(M_{1W}-M_{2W}){\mathrm{<figure-callout\; id="2"\; label="R"\; filenames="HDA00001930187800021.png"\; state="\{\{state\}\}">R</figure-callout>}}_2{\mathrm{\&omega;}}^2}{{\mathrm{<figure-callout\; id="2"\; label="L"\; filenames="HDA00001930187800021.png"\; state="\{\{state\}\}">L</figure-callout>}}_2^2{\mathrm{\&omega;}}^2+{\mathrm{<figure-callout\; id="2"\; label="R"\; filenames="HDA00001930187800021.png"\; state="\{\{state\}\}">R</figure-callout>}}_2^2}+\mathrm{j\&omega;}[(M_1-M_2)+\frac{M(M_{1W}-M_{2W}){\mathrm{\&omega;}}^2{L}_2}{{\mathrm{<figure-callout\; id="2"\; label="L"\; filenames="HDA00001930187800021.png"\; state="\{\{state\}\}">L</figure-callout>}}_2^2{\mathrm{\&omega;}}^2+{\mathrm{<figure-callout\; id="2"\; label="R"\; filenames="HDA00001930187800021.png"\; state="\{\{state\}\}">R</figure-callout>}}_2^2}]---(1-8)$

The real part that is obtained transimpedance by formula (1-8) is:

$R_g=-\frac{M(M_{1W}-M_{2W}){\mathrm{<figure-callout\; id="2"\; label="R"\; filenames="HDA00001930187800021.png"\; state="\{\{state\}\}">R</figure-callout>}}_2{\mathrm{\&omega;}}^2}{{\mathrm{<figure-callout\; id="2"\; label="L"\; filenames="HDA00001930187800021.png"\; state="\{\{state\}\}">L</figure-callout>}}_2^2{\mathrm{\&omega;}}^2+{\mathrm{<figure-callout\; id="2"\; label="R"\; filenames="HDA00001930187800021.png"\; state="\{\{state\}\}">R</figure-callout>}}_2^2}---(1-9)$

Striding the active power value is:

$P_g=I_1^2{R}_g---(1-10)$

So formula (1-1) can be expressed as:

$P_g=\stackrel{\&OverBar;}{i_c\&times;e}=I_1^2{R}_g---(1-11)$

Can know the said active power P that strides by formula (1-9), (1-10) _gOr said transimpedance value of real part R _gMutual inductance M with the transmitting coil 102 and first receiving coil 103 ₁And the mutual inductance M of the transmitting coil 102 and second receiving coil 104 ₂Irrelevant, the promptly said active power P that strides _gOr said transimpedance value of real part R _gWith the parameter of first receiving coil 103, second receiving coil 104 and to be installed in the symmetry of transmitting coil 102 both sides irrelevant.

When not having metal near sniffer, M, M _1W, M _2WBe zero, transimpedance value of real part R _gBe zero, then stride active power value P _gAlso be zero; When metal distance second receiving coil 104 is nearer, M _2WGreater than M _1W, transimpedance value of real part R _gFor just, then stride active power value P _gAlso for just; When certain position between first receiving coil 103 and second receiving coil 104 of metal, M _2WEqual M _1W, transimpedance value of real part R _gBe zero, then stride active power value P _gAlso be zero; When metal distance first receiving coil 103 is nearer, M _2WLess than M _1W, transimpedance value of real part R _gFor negative, then stride active power value P _gAlso for negative.From the above, when metal did not get into effective investigative range of metal detecting device provided by the invention, what calculate in the processor 106 strode active power value P _gOr transimpedance value of real part R _gPerseverance is zero; When metal got into effective investigative range of metal detecting device provided by the invention, what calculate strode active power value P _gOr transimpedance value of real part R _gBecome non-zero, when this metal when the metal detecting device, what calculate strides active power value P _gOr transimpedance value of real part R _gBecome non-zero vanishing again by zero, stride active power value P according to what calculate _gOr transimpedance value of real part R _gChange, just can judge and detect metal, if the said active power value P that strides _gOr transimpedance value of real part R _gDo not change, then judge and do not detect metal.

In addition, as shown in Figure 3, the metal detecting device that present embodiment provides also comprises: the alarm 107 that when processor 106 judgements detect metal, gives the alarm.When processor 106 judgements obtained detecting metal, alarm 107 was sounded a buzzer or is glistened and detects metal with prompting.

The embodiment of the invention one also provides a kind of metal probing method, is applied to above-mentioned metal detecting device, and Fig. 4 is the process flow diagram of this method, comprising:

S101: power supply output exchange current is so that transmitting coil produces alternating magnetic field;

S102: the real-time acquisition stream of current sensor is crossed the current signal of transmitting coil, and the real-time current signal is sent to processor;

S103: processor receives the real-time current signal; Detect first induced potential and second receiving coil second induced potential under action of alternating magnetic field of first receiving coil under action of alternating magnetic field in real time; Obtain the real time differential voltage signal according to first induced potential and second induced potential; Computation rule according to preset calculates detected value to real-time current signal and real time differential voltage signal; And according to preset analysis rule detected value is analyzed, whether output detects the information of metal.

A kind of metal detecting device and detection method that the embodiment of the invention one provides, power supply output exchange current makes connected transmitting coil produce alternating magnetic field; The real-time acquisition stream of current sensor is crossed the current signal of transmitting coil, and the real-time current signal is sent to processor; Processor receives the real-time current signal; Detect first induced potential and second receiving coil second induced potential under action of alternating magnetic field of first receiving coil under action of alternating magnetic field in real time; Obtain the real time differential voltage signal according to first induced potential and second induced potential; According to preset computation rule real-time current signal and real time differential voltage signal are calculated detected value then; And according to preset analysis rule detected value is analyzed, whether output detects the information of metal.A kind of metal detecting device provided by the invention; Processor calculates said detected value according to the real time differential voltage between two receiving coils and the real-time current signal of transmitting coil; And survey metal according to said detected value; Metal detection sensitivity does not receive the consistance and the influence that symmetry is installed of receiving coil, and the metal detection accuracy that obtains in view of the above is high.

Embodiment two

The embodiment of the invention two provides a kind of metal detecting device, and Fig. 5 is the structural representation of this device, and this device comprises: power supply 201, transmitting coil 202, first receiving coil 203, second receiving coil 204, current sensor 205 and processor 206.

Wherein, power supply 201, transmitting coil 202 and current sensor 205 are concatenated into the loop; One end of first receiving coil 203 links to each other with an end of second receiving coil 204; The other end of first receiving coil 203 links to each other with processor 206; The other end of second receiving coil 204 links to each other with processor 206, and first receiving coil 203 and second receiving coil 204 are arranged at the both sides of transmitting coil 202 respectively.

Power supply 201 output exchange current are so that connected transmitting coil 202 produces alternating magnetic field, and current sensor 205 real-time acquisition stream are crossed the current signal of transmitting coil 202, and the real-time current signal is sent to processor 206.

Processor 206 receives the real-time current signal; Detect first receiving coil 203 and the real time differential voltage signal of second receiving coil 204 under action of alternating magnetic field in real time; Computation rule according to preset calculates detected value to real-time current signal and real time differential voltage signal; And according to preset analysis rule detected value is analyzed, whether output detects the information of metal.

One end of transmitting coil 202 links to each other with power supply 201, and the other end links to each other with the first test side S1 of current sensor 205; The second test side S2 of current sensor 205 links to each other with power supply 201, and power supply 201, transmitting coil 202 and current sensor 205 are formed a launching circuit; First receiving coil, 203 1 ends link to each other with second receiving coil, 204 1 ends, and the other end links to each other with processor 206 respectively, and first receiving coil 203, second receiving coil 204 and processor 206 are formed a receiving loop.

Power supply 201 output exchange current make connected transmitting coil 202 produce alternating magnetic field; Because electromagnetic induction effect; First receiving coil 203 and second receiving coil 204 produce induced potential; Processor 206 collects is the real time differential voltage signal at the two ends of the integral body formed of first receiving coil 203 and second receiving coil 204, and current sensor 205 detects the real-time current signal of transmitting coils 201, and exports processor 206 to through output terminal S3.

Be preset with computation rule in the processor 206; First receiving coil 203 that receives and the real time differential voltage signal between second receiving coil 204 and the real-time current signal of transmitting coil 202 are calculated detected value; And the analysis rule according to preset is analyzed said detected value, judges whether to detect metal.

In present embodiment two, detected value is specially strides the active power value, and preset computation rule is: averaging after real-time current signal and real time differential voltage signal are multiplied each other obtains striding the active power value.Striding the active power value is that transmitting coil 202 current instantaneous values are real-time current i _cAnd first receiving coil 203 and 204 differential voltage instantaneous values of second receiving coil are the mean value of the product of real time differential magnitude of voltage e:

$P_g=\stackrel{\&OverBar;}{i_c\&times;e}---(2-1)$

In the present embodiment, active power value P is striden in the processor analysis _gIf, P _gChange, then judge and detect metal, output detects the information of metal, like P _gDo not change, then judge and do not detect metal, output does not detect the information of metal, certainly, when not detecting metal, also output information not.

Detect the effective value of real-time current signal, obtain the transimpedance value of real part with striding the square value of active power value divided by the effective value of real-time current signal, i.e. transimpedance value of real part is: R _g=P _g/ I ², when knowing transmitting coil 102 real-time current i _cEffective value I with stride active power value P _gThe time, also can analyze whether detect metal according to the transimpedance value of real part.

In present embodiment two, active power value P is striden in the processor analysis _gOr transimpedance value of real part R _gIf, P _gOr R _gChange, then judge and detect metal, output detects the information of metal, if P _gOr R _gDo not change, then judge and do not detect metal, output does not detect the information of metal, certainly, when not detecting metal, also output information not.

Basis is striden active power value P in the present embodiment two _gOr R _gVariation judge that the principle whether detect metal is identical with embodiment one, do not give unnecessary details at this.

In addition, as shown in Figure 6, the metal detecting device that present embodiment two provides also comprises: the alarm 207 that when processor 206 judgements detect metal, gives the alarm.When processor 206 judgements obtained detecting metal, alarm 207 can be sounded a buzzer or glisten and detected metal with prompting.

The embodiment of the invention two also provides a kind of metal probing method, is applied to above-mentioned metal detecting device, and Fig. 7 is the process flow diagram of this method, comprising:

S201: power supply output exchange current is so that transmitting coil produces alternating magnetic field;

S202: the real-time acquisition stream of current sensor is crossed the current signal of transmitting coil, and the real-time current signal is sent to processor;

S203: processor receives the real-time current signal; Detect first receiving coil and the real time differential voltage signal of second receiving coil under action of alternating magnetic field in real time; Computation rule according to preset calculates detected value to real-time current signal and real time differential voltage signal; And according to preset analysis rule detected value is analyzed, whether output detects the information of metal.

A kind of metal detecting device and detection method that the embodiment of the invention two provides, power supply output exchange current makes connected transmitting coil produce alternating magnetic field; The real-time acquisition stream of current sensor is crossed the current signal of transmitting coil, and the real-time current signal is sent to processor; Processor receives the real-time current signal; And detect the real time differential voltage signal of first receiving coil and second receiving coil; According to preset computation rule real-time current signal and real time differential voltage signal are calculated detected value then; And according to preset analysis rule detected value is analyzed, whether output detects the information of metal.A kind of metal detecting device provided by the invention; Processor calculates said detected value according to the real time differential voltage between two receiving coils and the real-time current signal of transmitting coil; And survey metal according to said detected value; Metal detection sensitivity does not receive the consistance and the influence that symmetry is installed of receiving coil, and the metal detection accuracy that obtains in view of the above is high.

What each embodiment stressed in this instructions all is and the difference of other embodiment that identical similar part is mutually referring to getting final product between each embodiment.

To the above-mentioned explanation of the disclosed embodiments, make this area professional and technical personnel can realize or use the present invention.Multiple modification to these embodiment will be conspicuous concerning those skilled in the art, and defined General Principle can realize under the situation that does not break away from the spirit or scope of the present invention in other embodiments among this paper.Therefore, the present invention will can not be restricted to these embodiment shown in this paper, but will meet and principle disclosed herein and features of novelty the wideest corresponding to scope.

Claims (10)

1. a metal detecting device is characterized in that, comprising: power supply, transmitting coil, first receiving coil, second receiving coil, current sensor and processor;

Said power supply, said transmitting coil and said current sensor are concatenated into the loop; Said first receiving coil, second receiving coil link to each other with said processor respectively, and said first receiving coil and said second receiving coil are arranged at the both sides of said transmitting coil respectively;

Said power supply output exchange current is so that connected said transmitting coil produces alternating magnetic field;

The real-time acquisition stream of said current sensor is crossed the current signal of said transmitting coil, and said real-time current signal is sent to said processor;

Said processor receives said real-time current signal; Detect said first receiving coil in real time at first induced potential under the said action of alternating magnetic field and second induced potential of said second receiving coil under said action of alternating magnetic field; Obtain the real time differential voltage signal according to said first induced potential and second induced potential; Computation rule according to preset calculates detected value to said real-time current signal and said real time differential voltage signal; And according to preset analysis rule said detected value is analyzed, whether output detects the information of metal.

2. metal detecting device according to claim 1; It is characterized in that; Said detected value is specially strides the active power value, and said preset computation rule is: averaging after said real-time current signal and said real time differential voltage signal are multiplied each other obtains striding the active power value.

3. metal detecting device according to claim 2 is characterized in that, the preset analysis rule of said foundation is analyzed said detected value, and the information whether output detects metal is specially:

Analyze and saidly stride the active power value, if the said active power value of striding changes, judge then and detect metal that output detects the information of metal, if the said active power of striding does not change, judge then and do not detect metal that output does not detect the information of metal.

4. metal detecting device according to claim 1 is characterized in that, also comprises:

Alarm is used for when said processor judgement detects metal, giving the alarm.

5. a metal detecting device is characterized in that, power supply, transmitting coil, first receiving coil, second receiving coil, current sensor and processor;

Said power supply, said transmitting coil and said current sensor are concatenated into the loop; One end of said first receiving coil links to each other with an end of said second receiving coil; The other end of said first receiving coil links to each other with said processor; The other end of said second receiving coil links to each other with said processor, and said first receiving coil and said second receiving coil are arranged at the both sides of said transmitting coil respectively;

Said power supply output exchange current is so that connected said transmitting coil produces alternating magnetic field;

The real-time acquisition stream of said current sensor is crossed the current signal of said transmitting coil, and said real-time current signal is sent to said processor;

Said processor receives said real-time current signal; Detect said first receiving coil and the real time differential voltage signal of said second receiving coil under said action of alternating magnetic field in real time; Computation rule according to preset calculates detected value to said real-time current signal and said real time differential voltage signal; And according to preset analysis rule said detected value is analyzed, whether output detects the information of metal.

6. metal detecting device according to claim 5; It is characterized in that; Said detected value is specially strides the active power value, and said preset computation rule comprises: averaging after said real-time current signal and said real time differential voltage signal are multiplied each other obtains striding the active power value.

7. metal detecting device according to claim 6 is characterized in that, the preset analysis rule of said foundation is analyzed said detected value, and the information whether output detects metal is specially:

Analyze and saidly stride the active power value, if the said active power value of striding changes, judge then and detect metal that output detects the information of metal, if the said active power of striding does not change, judge then and do not detect metal that output does not detect the information of metal.

8. metal detecting device according to claim 5 is characterized in that, also comprises:

Alarm is used for when said processor judgement detects metal, giving the alarm.

9. a metal probing method is characterized in that, is applied to comprise like any described metal detecting device among the claim 1-4:

Power supply output exchange current is so that transmitting coil produces alternating magnetic field;

The real-time acquisition stream of current sensor is crossed the current signal of said transmitting coil, and said real-time current signal is sent to processor;

Processor receives said real-time current signal; Detect said first receiving coil in real time at first induced potential under the said action of alternating magnetic field and second induced potential of said second receiving coil under said action of alternating magnetic field; Obtain the real time differential voltage signal according to said first induced potential and second induced potential; Computation rule according to preset calculates detected value to said real-time current signal and real time differential voltage signal; And according to preset analysis rule said detected value is analyzed, whether output detects the information of metal.

10. a metal probing method is characterized in that, is applied to comprise like any described metal detecting device among the claim 5-8:

Power supply output exchange current is so that transmitting coil produces alternating magnetic field;

The real-time acquisition stream of current sensor is crossed the current signal of said transmitting coil, and said real-time current signal is sent to processor;

Processor receives said real-time current signal; Detect said first receiving coil and the real time differential voltage signal of said second receiving coil under said action of alternating magnetic field in real time; Computation rule according to preset calculates detected value to said real-time current signal and real time differential voltage signal; And according to preset analysis rule said detected value is analyzed, whether output detects the information of metal.

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