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Jp h09 237399 Jp h09 237399 Document Transcript

  • JP,09-237399,A(1997) PATENT ABSTRACTS OF JAPAN (11)Publication number : 09-237399 (43)Date of publication of application : 09.09.1997(51)Int.Cl. G08G 1/042 B60R 21/00 G01R 33/02 G01V 3/08 G01V 3/10 // G01C 21/00(21)Application number : 08-0439 (71)Applicant : CANON ELECTRON 33 INC(22)Date of filing : 01.03.19 (72)Inventor : KAWASE MASAHIRO 96 TAZAKI SHINICHI(54) METHOD, DEVICE AND SYSTEM FOR VEHICLE DETECTION (57)Abstract: PROBLEM TO BE SOLVED: To improve reliability by making the magnetic detection of an vehicle highly precise through the use of a magnetic sensor consisting of plural small magnetic detection elements. SOLUTION: The magnetic sensor 12 plurally arranging along the longitudinal direction of the vehicle the magnetic detection elements 1A to 11N with magnetic field detecting sensitivity in a direction vertical to the ground is installed on or in the ground within the passing width of the vehicle. Through the use of aselector 21, a timer counter 20 and RAM 26 storing the early value ofexternal magnetic intensity, a control part 19 measures each change ofexternal magnetic field intensity basing on the state of no vehicle with
  • respect to each magnetic detection element as a reference based on theintensity of external magnetic field detected by each magnetic detectionelement. Then the part 19 judges vehicle detection depending on whetherthe total sum of the respective absolute values of the measured valuesexceeds a prescribed combined threshold values.CLAIMS[Claim(s)][Claim 1]In a vehicle detecting method which detects a magnetic fieldgenerated from vehicles with a magnetic sensor, and detects vehiclesmagnetically, A magnetic sensor which put in order two or moremagnetism detecting elements which have magnetic field detectionsensitivity in the direction vertical to a ground surface along with a vehicleslongitudinal direction is installed in a ground surface in a band pass ofvehicles, or underground, A vehicle detecting method detecting vehicles bythe judgment of whether external magnetic field intensity change as on thebasis of the state where each of two or more of said magnetism detectingelements detects external magnetic field intensity, and there are novehicles is measured, and total of an absolute value of two or moremeasurement values of this measuring result exceeds predetermined jointthreshold S.[Claim 2]The vehicle detecting method according to claim 1 setting saidjoint threshold S as a value of a product which hung threshold s in thecase of one magnetism detecting element, and a square root of theaddition numbers n of said measurement value added in order to ask forsaid total.[Claim 3]An absolute value of two or more measurement values of ameasuring result of the aforementioned external magnetic field intensitychange is arranged in descending, it is considered as |deltaH(k) | (k= 1,2, ordinal number of --), and they are the following expression about thisvalue, threshold s in the case of one magnetism detecting element, and asquare root of said addition numbers n. [Mathematical formula 1]
  • The vehicle detecting method according to claim 2 judging with havingdetected vehicles when it compared whether it is alike, it would set, wouldsubstitute one by one from k= 1, and the above-mentioned expressionwould be satisfied and the above-mentioned expression was satisfied.[Claim 4]The vehicle detecting method according to claim 2 or 3 settingthreshold s in the case of said one magnetism detecting element as therange of 0.05-0.1 gauss.[Claim 5]It is a vehicle detecting device which detects a magnetic fieldgenerated from vehicles with a magnetic sensor, and detects vehiclesmagnetically, A magnetic sensor which consists of two or more magnetismdetecting elements arranged so that it may have magnetic field detectionsensitivity in the direction vertical to a ground surface and may rank with aground surface in a band pass of vehicles, or underground along with avehicles longitudinal direction, A measurement means which measureseach of external magnetic field intensity change as on the basis of thestate where there are no vehicles to each magnetism detecting element,based on external magnetic field intensity detected by each of two or moreof said magnetism detecting elements, A vehicle detecting device having ajudging means which judges vehicle detection by whether total of eachabsolute value of a measurement value of external magnetic field intensitychange measured by this measurement means exceeds predeterminedjoint threshold S.[Claim 6]It has a memory measure which memorizes a value of externalmagnetic field intensity detected by said two or more magnetism detectingelements in the state where said measurement means does not havevehicles as an initial value used as a standard, The vehicle detectingdevice according to claim 5 measuring the aforementioned externalmagnetic field intensity change on the basis of an initial value memorizedto this memory measure.[Claim 7]A Colpitts oscillator in which said magnetism detecting elementincorporated a magnetic impedance component which attached a coil, Itcomprises a comparator [ predetermined comparison voltage / output / of
  • a detector circuit which detects an output of this oscillator and thisdetector circuit ], By detecting external magnetic field intensity, applyingan AC bias magnetic field to said magnetic impedance component withsaid coil, A Pulse-Density-Modulation output in which a pulse which is twokinds from which pulse width differs according to external magnetic fieldintensity in an output of said comparator appears by turns is obtained, Thevehicle detecting device according to claim 5 or 6, wherein saidmeasurement means measures external magnetic field intensity change ason the basis of the state where ask for data of a difference of pulse widthof two kinds of said pulses as external magnetic field strength data, andsaid vehicles cannot be found based on this data.[Claim 8]It is a vehicle detection system which carries out vehicledetection to any 1 clause from Claim 5 to 7 using a vehicle detectingdevice of a description, A judging means which judges whether whethervehicles advanced on a magnetic sensor, whether it stopped on amagnetic sensor based on a decided result of vehicle detection by ajudging means of said vehicle detecting device, and on a magnetic sensorwere left, Car presence information on a purport that vehicles havestopped on a magnetic sensor based on a decided result of this judgingmeans, And a vehicle detection system characterized by having an outputmeans to which vehicles output **** information on a purport that on amagnetic sensor was left, and enabling it to manage parking vehicles withthe output of said car presence information and **** information.DETAILED DESCRIPTION[Detailed Description of the Invention][0001][Field of the Invention]This invention detects the magnetic field generatedfrom vehicles, such as a car, with a magnetic sensor, and detects vehiclesmagnetically, namely, relates to the vehicle detecting method whichdetects the existence of vehicles thru/or passage, a vehicle detectingdevice, and a vehicle detection system.[0002][Description of the Prior Art]Conventionally, the sensor which detectsvehicles, such as a car, is used in the use of measuring the distinction of
  • the existence of parking in the managerial system of a motor pool, and thetraffic of the vehicles in a traffic control system.[0003]Usually, since vehicles, such as a car, are tinged with magnetismusing the metallic material which is easy to be tinged with magnetism, suchas a steel plate, it is detecting the magnetic field generated from vehicleswith a magnetic sensor, and it is possible to recognize existence ofvehicles or passage.[0004]Conventionally, in the motor pool, the loop coil type magneticsensor was buried in the earth, and it has been used for vehicle detectionin it. A loop coil type magnetic sensor is that generate a magnetic field byan eddy current in the metal part of the body of vehicles to the alternatingcurrent sent through a coil, or the magnetic field from the bodys ownmagnetization interlinks with a loop coil, A coils own inductance changes,it is changed as change of oscillating frequency or amplitude in a circuit,and vehicle detection is performed by the existence of the change.[0005]However, although the loop coil type magnetic sensor is spreadingby detection of vehicles, it has the following problems.[0006]- Since a loop coil opens an interval a little with vehicles and isinstalled, in order to detect the inductance variation in vehicles existence,there is the necessity of enlarging size of a sensitivity secured upper coil(about 1mx1m).[0007]- If metal bodies, such as a steel rod, are in the neighborhood, S/Ncannot be taken enough.[0008]- Since a loop coil is large and power consumption is large, it is notfit for continuous energization use.[0009]- A coil is a size which is about 1mx1m, and the burden ofconstruction expense is heavy in subterranean installation.[0010]Then, although the small magnetic sensor was used and thesubstitution was considered, When the magnetic field generated from avehicles pars basilaris ossis occipitalis was measured, near the zerocrossing point which remarkable unevenness is made to distribution ofmagnetic field strength, and magnetic field polarity reverses by the localmagnetization of Body Manufacturing Division article each which it has, itturned out that the dead point which does not exceed a threshold requiredfor the judgment of vehicle detection arises.[0011]
  • [Problem to be solved by the invention]Then, a reliable vehicle detectingmethod in which SUBJECT of this invention can perform magneticdetection of vehicles with high precision using the magnetic sensor whichconsists of two or more small magnetism detecting elements, And it is inproviding the vehicle detection system which is a vehicle detecting devicewhich performs vehicle detection by the method, can attain aminiaturization and can be used effective in management of parkingvehicles using the vehicle detecting device of low power consumption, andthis vehicle detecting device.[0012][Means for solving problem]In the vehicle detecting method whichaccording to this invention detects the magnetic field generated fromvehicles with a magnetic sensor, and detects vehicles magnetically in orderto solve above-mentioned SUBJECT, The magnetic sensor which put inorder two or more magnetism detecting elements which have magneticfield detection sensitivity in the direction vertical to a ground surface alongwith the vehicles longitudinal direction is installed in the ground surface inthe band pass of vehicles, or underground, The external magnetic fieldintensity change as on the basis of the state where each of two or more ofsaid magnetism detecting elements detects external magnetic fieldintensity, and there are no vehicles was measured, and the method ofdetecting vehicles by the judgment of whether total of the absolute valueof two or more measurement values of this measuring result exceedspredetermined joint threshold S was adopted.[0013]According to such a vehicle detecting method, the influence of thezero crossing point which the magnetic field polarity looked at bydistribution of the magnetic field strength in the case of measuring themagnetic field generated from a vehicles pars basilaris ossis occipitalisreverses can be avoided, and highly precise and reliable vehicle detectioncan be performed.[0014]According to this invention, it is a vehicle detecting device whichdetects the magnetic field generated from vehicles with a magnetic sensor,and detects vehicles magnetically, The magnetic sensor which consists oftwo or more magnetism detecting elements arranged so that it may havemagnetic field detection sensitivity in the direction vertical to a groundsurface and may rank with the ground surface in the band pass of
  • vehicles, or underground along with a vehicles longitudinal direction, Themeasurement means which measures each of external magnetic fieldintensity change as on the basis of the state where there are no vehicles toeach magnetism detecting element, based on the external magnetic fieldintensity detected by each of two or more of said magnetism detectingelements, Total of each absolute value of the measurement value ofexternal magnetic field intensity change measured by this measurementmeans adopted the composition of the vehicle detecting device which hasa judging means which judges vehicle detection by whether predeterminedjoint threshold S is exceeded.[0015]While being able to perform reliable vehicle detection with highdegree of accuracy with the vehicle detecting method of this inventionaccording to such composition, the magnetic sensor can consist of smallsize which consists of plurality of the small magnetism detecting elementconstituted, for example using the magnetic impedance component as amagnetic sensor of low power consumption.[0016]It is a vehicle detection system which performs vehicle detectionusing the vehicle detecting device by above-mentioned this inventionaccording to this invention, The judging means which judges whetherwhether vehicles advanced on the magnetic sensor, whether it stopped onthe magnetic sensor based on the decided result of the vehicle detectionby the judging means of said vehicle detecting device, and on themagnetic sensor were left, The car presence information on the purportthat vehicles have stopped on a magnetic sensor based on the decidedresult of this judging means, And it has an output means to which vehiclesoutput the **** information on the purport that on the magnetic sensor wasleft, and the composition of the vehicle detection system which enabled itto manage parking vehicles with the output of said car presenceinformation and **** information was adopted.[0017]According to such composition, the advantage of the vehicledetecting device of this invention can be enjoyed, exact car presenceinformation and **** information can be outputted based on highly preciseand reliable vehicle detection, and it can use effective in management ofparking vehicles.[0018][Mode for carrying out the invention]Hereafter, an embodiment of the
  • invention is described with reference to figures.[0019][Embodiment of a vehicle detecting method] Drawing 1 - 3 explainthe embodiment of the vehicle detecting method by this invention first.[0020]In this embodiment, as shown in drawing 1, to the ground surface14 in the width which the vehicles (car) 10 pass, or underground. Themagnetic sensor 12 which has arranged two or more magnetism detectingelements 11A, 11B, and 11C which have magnetic field detectionsensitivity in the direction (Z direction) vertical to a ground surface so thatit may stand in a line along with the longitudinal direction of the vehicles 10is installed, and vehicle detection is performed.[0021]The external magnetic field intensity change as on the basis of thestate where each magnetism detecting element of the magnetic sensor 12detects external magnetic field intensity, and there are no vehicles 10 ismeasured, and total of the absolute value of two or more measuredmagnetic-field-strength change detects vehicles by the judgment ofwhether to exceed a predetermined joint threshold.[0022]This method was drawn from the following examining results.[0023]First, on the ground surface 14 in the width which the vehicles 10pass as shown in drawing 2, The magnetic sensor 12 which comprisedone magnetism detecting element which has magnetic field detectionsensitivity in the Z direction which is a vertical direction to the groundsurface 14 is arranged, the vehicles 10 were moved on the sensor 12, themagnetic sensor 12 detected external magnetic field intensity, externalmagnetic field intensity change was measured, and the situation of thechange was investigated. The variation of external magnetic field intensitymade the measurement value in the state where there are no vehicles 10the initial value used as a standard, and displayed a changed part from it.The element using the magnetic impedance component mentioned later asa magnetic sensing device was used for the magnetism detecting element.Two or more vehicles performed the sampling. Four data measuring of acharacteristic example is shown in drawing 2 (a) - (d) in it.[0024]Generally, magnetic field distribution of the cross direction of a barmagnet has a peak of reverse polarity at both ends of the bar magnet 16like drawing 3, and has a tendency which carries out a zero cross in thecenter section. On the other hand, it can guess that the body of a carconstitutes a roughly big bar magnet from a vehicles longitudinal direction
  • from it being in agreement with how of data measuring of drawing 2 tolengthen the skirt near the both-ends peak of magnetic field distribution ofdrawing 3 by (c) and (d), especially, if it observes near the both ends of amagnetic field change. However, attitude of a peak has dispersionconsiderably by overall magnetic-field-strength distribution, and it doesnot become a beautiful form like a bar magnet because localmagnetization exists by part each of a body pars basilaris ossis occipitalis.[0025]Since detection of vehicles will detect a magnetic field of a bodycenter section if detection of parking vehicles is taken into consideration,for example, it observes a magnetic field of a center of the body by widthof the length of a half of the body shown in the range of H seal in a figureof each data measuring of drawing 2. It is because movement speed of adifference in the length of each body and the body at the time ofMeasurement Division had dispersion that the length of H seal differs.[0026]Also when unevenness is looked at by magnetic-field-strengthchange within the limits of H seal of data of four examples and a zerocross exists, an absolute value of a measurement value may go into aDETTO point on which it is less than threshold s, and one magnetismdetecting element is not enough as it for vehicle detection at a certainthing.[0027]When threshold s of one magnetism detecting element considersresolution of a magnetism detecting element, and S/N of a circuit, 0.05gauss of a minimum is a limit, and considering that a maximum has about0.1 gauss vehicles like drawing 2 (c) in the maximum of a magnetic fieldchange by vehicles, it is difficult to set up exceeding 0.1 gauss.[0028]Then, two or more magnetism detecting elements are arrangedalong with a vehicles longitudinal direction, and if vehicle detection iscarried out by whether either exceeds threshold s, detection probability willincrease.[0029]However, in a case of vehicles of drawing 2 (d), when fourmagnetism detecting elements have been arranged to each of a positioncorresponding to four points, a in a figure, b, c, and d, a measurementvalue by which element will also be less than 0.05 gauss. If such a case istaken into consideration, a device which raises detection probability furtheris required.
  • [0030]Then, an absolute value of a measurement value of two or moremagnetic-field-strength change which detected external magnetic fieldintensity by each of two or more magnetism detecting elements, and wasmeasured is added, A value of a product which, on the other hand, hungsaid number (addition numbers of a measurement value) n of a magnetismdetecting element of added square roots on threshold s at the time ofdetection by an independent magnetism detecting element is set up asjoint threshold S, If vehicle detection is judged by whether total of anadded result of said absolute value exceeds joint threshold S, it isdetectable by high probabilities.[0031]A noise component serves as a mean square to addition of anoutput of each magnetism detecting element, and if it is considered as anoise component of the respectively same size, this will use that a productof a noise for one element and a square root of the addition numbers nserves as a noise at the time of combination, and will try to earn the wholeS/N.[0032]For example, magnetic-field-strength change, a of the datameasuring of the vehicles of drawing 2 (d), b, c, and d, of four points, Itwill be 0.03G-0.04G-0.02G-0.03G, and if threshold s of independentdetection is set to 0.05G, when these are added, it will be 0.12G, and0.05xroot4=0.1 gauss is set to joint threshold S, total of the added resultof an output will exceed joint threshold S, and detection of it will beattained.[0033]Therefore, when the magnetic field component of a directionvertical to the ground surface of the magnetic field generated fromvehicles is detected by two or more Magnetism detecting elementn and themagnetic-field-strength change by vehicles existence is measured, Itturned out that it is suitable that the total adding each of the absolute valueof magnetic-field-strength change measured based on the detection resultof n magnetism detecting elements of a result performs vehicle detectionby whether joint threshold S as independent threshold sxrootn is exceeded.[0034]By the way, since a magnetic-field-detection output may becomenear a zero cross with a certain element and total of the above-mentionedadded result may become low when detecting as mentioned above by twoor more magnetism detecting elements, the method explained below can
  • also be chosen as a method of raising vehicle detection efficiency further.[0035]Arrange in descending each absolute value of the measurementvalue of the external magnetic field intensity change from the initial valuewhich detected external magnetic field intensity by two or more magnetismdetecting elements of the magnetic sensor mentioned above, and wasmeasured, consider it as |deltaH(k) | (k= 1, 2, ordinal number of --), andNamely, this value, They are [ threshold s in the case of one magnetismdetecting element, and ] the following expression about said additionnumbers n.[0036][Mathematical formula 2][0037]It compares whether it is alike, it sets, substitutes one by one fromk= 1, and the above-mentioned expression is satisfied, and when theabove-mentioned expression is satisfied, it judges with having detectedvehicles.[0038]According to this method, vehicle detection efficiency can be raisedby adding the measurement value of two or more external magnetic fieldintensity change to descending one by one, and using for the judgment ofvehicle detection.[0039]In above-mentioned explanation, the "ground surface of"underground" meaning the inside of those fields including all the fieldsthat vehicles, such as a floor line in the building of not only the groundsurface of the ground, and the road surface of a road and the groundsurface of an outdoor parking lot but a multi-level car parking tower, runfields thru/or park" of 14 is natural.[0040][Embodiment of a vehicle detecting device] Next, the embodimentof a vehicle detecting device which enforces concretely the vehicledetecting method mentioned above, and performs vehicle detection isdescribed.[0041]First, the magnetism detecting element of the magnetic sensor usedfor a vehicle detecting device is explained. Being required of thismagnetism detecting element should be 10 or more milligauss in (1)magnetic field detection sensitivity.
  • [0042](2) There is two or more dispersion [ little ] of the performance ofan element for use.[0043](3) Considering ground surface installation, the height of an elementshould be several millimeters.[0044](4) The detector circuit of an element is excellent in a noise-proofand temperature characteristics, and be low power consumption.[0045]Although there is a flux gate type magnetism detecting element aswhat satisfies the conditions of (1), if it is going to raise detectionsensitivity with this element, several 10 mm of the length of an element willbe needed, and it will not be satisfied with it of the conditions of (3).[0046]Since it is easy to come out of dispersion in performance, aproblem produces a flux gate type magnetism detecting element also oncondition of (2).[0047]Then, the magnetism detecting element constituted using amagnetic impedance component is seemed that it is the optimal by it.[0048]The magnetic impedance component is indicated byJP,H7-181239,A and the element body as a magnetic body is constitutedfrom an amorphous wire or these days by the magnetic thin film etc. If thehigh frequency current of an MHz band is impressed to this element body,according to a magnetic impedance effect, according to an externalmagnetic field, the impedance of an element body changes several 10%,and can detect an external magnetic field using this.[0049]Sensitivity of a magnetic impedance component has the sensitivityof a 10-5 gauss stand, and number milligauss is securable and it issatisfied also with practical resolution in a case where it connects with acircuit of a magnetism detecting element of conditions of (1).[0050]From there being little influence of a demagnetizing field, it is easyfor the length of an element to be 5 mm or less, and conditions of (3) arealso cleared.[0051]About dispersion in performance, when supplied with an amorphouswire, since it is easy to control thickness, dispersion in performanceresulting from an outside dimension of a magnetic body of an elementbody is pressed down, and is satisfied with that there is little dispersion ina path of a wire, and a magnetic film of conditions of (2).[0052]Although application was considered according to contentsreported at a society etc. about magnetic field detection which uses the
  • Colpitts oscillating circuit about conditions of (4), there is a problempractically.[0053]For example, an application of a magnetic field sensor as anazimuth sensor is shown by an "amorphous wire MI Colpitts oscillation typemicro magnetic sensor" announced at the 18th Maganetics Society ofJapan academic lecture meeting (14pB-7).[0054]In composition of this azimuth sensor, an amorphous wire isincluded in a Colpitts type oscillator, and since change of an externalmagnetic field turns into change of oscillation amplitude and it appears, anoutput is obtained through a detector circuit. While sending a direct currentthrough a coil directly twisted around a wire of an element, applying a DCbias magnetic field and making it operate in a field where sensitivity ishigh, he is trying to know the polarity of the direction of north and south.[0055]However, in minute magnetic field detection, such asgeomagnetism (about 0.3 gauss) by this method. Change of an outputafter a detector circuit is as small as several percent, and in order to treatabsolute value change of oscillation amplitude as an output as it is,sufficient S/N is not obtained from it being easy to be influenced bychange of power supply voltage, the temperature characteristics of anelement, etc. by amplitude fluctuation, and it is unreliable.[0056]So, in this embodiment, circuitry of a magnetism detecting elementshown in drawing 4 was adopted.[0057]Circuitry of a magnetism detecting element shown in drawing 4consists of a Colpitts oscillator, a detector circuit, and a comparator, themagnetic impedance component 1 mentioned above is included in aColpitts oscillator, it direct-winds, or the magnetic impedance component1 is approached, and the coil 2 for bias is formed.[0058]In this composition, AC bias current Ib is sent through the coil 2,and an about **1-**2 gauss AC bias magnetic field is impressed to themagnetic impedance component 1. As shown in (a), amplitude modulationof the oscillation output which appears like the after-mentioned by this atan A point in a figure of a Colpitts oscillator according to intensity of theexternal magnetic field Hex for [ which is impressed to the magneticimpedance component 1 ] detection is carried out, A ripple waveformcorresponding to a bias magnetic field which has the difference ofelevation of an adjacent peak corresponding to intensity of the external
  • magnetic field Hex by detecting this in a detector circuit at a B point asshown in (b) is acquired, By carrying out a party rate with the comparisonvoltage Vref which crosses a voltage waveform of said ripple with acomparator, a Pulse-Density-Modulation output corresponding to intensityof the external magnetic field Hex can be obtained at C point.[0059]A signal of AC bias current Ib carries out dividing of the clock froma microcomputer judgment part mentioned later, with a low pass filter, itmay be made into a sine wave or the shape of a triangular wave, and itmay throw it in, or may provide and throw in an oscillator individually.[0060]Next, details of operation of circuitry of a magnetism detectingelement of drawing 4 mentioned above are explained.[0061]the characteristic of a magnetic impedance component issymmetrical with the direction of +- in several gauss to the externalmagnetic field Hex, as shown in drawing 5 -- a V character-likeimpedance change is shown in general. As shown in drawing 5 (a) as aprinciple of operation of the magnetic impedance component 1 of drawing4, when there is no external magnetic field, an AC bias magnetic field is +.- It touches symmetrically, In change of impedance to it, an impedancechange which the difference of elevation does not have in peaks on aripple breaks out by a magnetic field twice the frequency of AC bias.[0062]Since an AC bias magnetic field and an unsymmetrical magneticfield which an external magnetic field superimposed will start the magneticimpedance component 1 like drawing 5 (b) there if an external magneticfield is impressed to a longitudinal direction of the magnetic impedancecomponent 1, An impedance change (ripple waveform) from which heightof a peak differs by turns on an impedance change arises.[0063]The ripple waveform in an impedance change as showed the outputafter detection of drawing 4 (b) which appeared as amplitude modulationin the oscillation amplitude characteristic of the Colpitts oscillator aschange of this impedance was shown in drawing 4 (a), and detected thatoscillation output in the detector circuit by drawing 5 (b), and a similarsignal are acquired. The size of an external magnetic field is changed intothe output of a digital signal by which Pulse Density Modulation wascarried out by carrying out a party rate with the comparison voltage Vrefwhich crosses a ripple waveform as the signal is shown in drawing 6 in acomparator. That is, the Pulse-Density-Modulation output in which the
  • pulse which is two kinds from which pulse width differs according toexternal magnetic field intensity appears by turns is obtained.[0064]Thus, pulse width [ of two kinds of pulses ] A which appears byturns, and B can be measured and evaluated using the timer counter of amicrocomputer, and the digital data in which external magnetic fieldintensity is shown can be obtained by asking for the digital data ofdifference A-B of pulse width by an operation after that. Although themeasurement data of pulse width to a actual external magnetic field isshown in drawing 7, in **0.5 gauss shows an almost linear change. Thenumerical input value of joint threshold S mentioned above can be decidedby transposing the magnetic field strength of magnetism detecting elementindependent threshold s to the math-processing value of pulse widthbased on this data, and hanging the several n square root of a magnetismdetecting element on it.[0065]And the digital data of difference A-B of the pulse width measuredin the state where there are no vehicles, in detection of vehicles ismemorized as data of the initial value of the external magnetic fieldintensity used as a standard, Then, the absolute value of the difference ofdifference A-B of pulse width and the initial value according to themeasured external magnetic field intensity is calculated as datacorresponding to the absolute value of intensity change of an externalmagnetic field, It can ask for total of the data of said absolute value calledfor by further two or more magnetism detecting elements, and theexistence of vehicles can be judged by whether the figure exceeded thenumerical value of joint threshold S.[0066]Next, drawing 8 explains the composition of the vehicle detectingdevice using the magnetism detecting element of drawing 4.[0067]Colpitts oscillator 3 incorporating the magnetic impedancecomponent 1 which wound the coil 2 for bias which 12 is a magneticsensor and was mentioned above in the composition of the vehicledetecting device shown in drawing 8, They are the marks 11A and 11Babout the magnetism detecting element of drawing 4 which consists of thedetector circuit 4 and the comparator 5. -- As shown in 11N, N pieces areprovided and it is constituted. Magnetism detecting elements 11A and 11B-- 11N is arranged so that it may rank with the ground surface in the bandpass of vehicles, or underground along with the longitudinal direction of
  • vehicles as mentioned above, and each element can be giving magneticfield detection sensitivity in the direction vertical to a ground surface.[0068]18 is a microcomputer judgment part which comprises amicrocomputer, analyzes the Pulse-Density-Modulation output of eachmagnetism detecting element of the magnetic sensor 12, and judges theexistence of vehicles. The microcomputer judgment part 18, Either thetimer counter 20 which counts pulse width [ of the control section 19which performs whole control and various data processing, and the Pulse-Density-Modulation output mentioned above ] A, and B or magnetismdetecting elements 11A-11N are chosen. It consists of the selector 21which inputs the output pulse into the timer counter 20 and the clockgenerator 22, the clock divider 23, the low pass filter 24, and the biascircuit (amplifier) 25.[0069]Dividing is carried out so that the clock signal which the clockgenerator 22 oscillates may become the range of 1 kHz - 100 kHz by theclock divider 23 in this composition, The low pass filter 24 and the biascircuit 25 let this signal by which dividing was carried out pass, the signalof the AC bias current of a sine wave or the shape of a triangular wave isformed, and it is impressed by the coil 2 for bias which are eachmagnetism detecting elements 11A-11N of the magnetic sensor 12. Thefeed zone of this bias current may be provided in the magnetic sensor 12side.[0070]Next, the vehicle detection operation by the composition of drawing8 is explained. First, the initial value of the external magnetic field intensityused as the standard for asking for external magnetic field intensity changein the state where there are no vehicles is measured. For this reason, withthe magnetic sensor 12, the pulse signal which detected external magneticfield intensity by two or more magnetism detecting elements 11A-11N, andcarried out Pulse Density Modulation is outputted as mentioned above, andit sends to the selector 21 of the microcomputer judgment part 18.[0071]With the command from the control section 19, the selector 21chooses and sends two kinds of pulses A and B further mentioned abovewhile it chooses the output pulse signal of two or more magnetismdetecting elements 11A-11N which should be sent to the timer counter 20one by one and sends it.[0072]In the timer counter 20, the pulse width of two kinds of said pulses
  • A and B of two or more magnetism detecting elements sent one by one iscounted and evaluated, and the data is sent to the control section 19.[0073]In the control section 19, difference A-B of the pulse width data ofA pulse and B pulse evaluated with the timer counter 20 is computed forevery magnetism detecting element, and the measured value of externalmagnetic field intensity is calculated. The measured data is recorded onmemory storage, such as RAM26 in the control section 19, as initial valuedata used as a standard.[0074]Then, in order to detect vehicles, the detection and theMeasurement Division of external magnetic field intensity by eachmagnetism detecting element are performed in the same procedure as theabove, In the control section 19, it asks separately, absolute-value-izes byusing the difference of said measurement data and initial value data asexternal magnetic field intensity change data, and asks for the total, andthe existence of vehicles is judged by whether it is over predetermined jointthreshold S which the total mentioned above. And in the case of thevehicle detection system mentioned later, car presence information etc.are taken out based on the result of said judgment.[0075]In order not to treat the amplitude of a Colpitts oscillator as anabsolute value in the circuitry of the magnetism detecting element ofdrawing 4 as an advantage of the equipment of these above embodimentsprobably but to treat a changed part of amplitude, a low change of thefrequency by change, temperature characteristics, etc. of power supplyvoltage can be disregarded.[0076]Since the detect output of the external magnetic field intensity in themagnetic sensor 12 is digitized-output-ized by the Pulse DensityModulation by a comparator, The magnetic sensor 12 and themicrocomputer judgment part 18 connect two or more magnetic sensors12 to the microcomputer judgment part 18, and can carry out common useof the microcomputer judgment part 18 to two or more magnetic sensors12 while also being able to perform installation to isolate and obtaining theflexibility of installation.[0077]Since the whole equipment which constituted the magnetismdetecting element very small, could constitute the magnetic sensor 12small, and includes the microcomputer judgment part 18 can be madesmall, The burden of installation cost is small, and it is low power
  • consumption, and since the prolonged energization use which was poor atconventional loop coil type equipment is possible, the use of vehicledetection is expandable.[0078][An embodiment of a vehicle detection system] Next, drawing 9and drawing 10 explain an embodiment of a vehicle detection system forparking-vehicles management in a motor pool using a vehicle detectingdevice of drawing 8 mentioned above. As for this vehicle detection system,it is needless to say that a portion of the magnetic sensor 12 is provided ina ground surface of a motor pool or underground at least, and it carriesout of a vehicle detecting device of drawing 8.[0079]Drawing 9 is a block diagram showing functional composition of avehicle detection system of this embodiment. Composition of those otherthan magnetic sensor 12 is specifically realized in drawing 9 by hardwareand software of the microcomputer judgment part 18 of drawing 8.[0080]In drawing 9, it realizes from the control section 19 of drawing 8,the timer counter 20, and the selector 21, and the measurement means 27measures external magnetic field intensity change as on the basis of thestate where there are no vehicles based on a detection result of externalmagnetic field intensity by the magnetism detecting elements 11A-11N ofthe magnetic sensor 12 as mentioned above. This measurement means 27has the initial value memory measure 28 which memorizes a value ofexternal magnetic field intensity detected by the magnetism detectingelements 11A-11N in the state where there are no vehicles as an initialvalue used as a standard, and measures external magnetic field intensitychange on the basis of an initial value memorized to this memory measure28. The memory measure 28 is specifically constituted as RAM26 ofdrawing 8.[0081]It realizes as a function of the control section 19, and the vehicledetection judging means 29 judges vehicle detection as mentioned abovebased on the measuring result of the measurement means 27.[0082]Penetration, a stop, and the **** judging means 30 are realized asa function of processing of Step S3 of below-mentioned drawing 10 by thecontrol section 19, S6, and S9, Based on the decided result of the vehicledetection by the vehicle detection judging means 29. [ whether vehiclesadvanced into the motor pool, and ] It is judged whether on whether itadvanced on the magnetic sensor 12 formed in the motor pool, whether
  • whether whether it having stopped in the motor pool and a motor poolhaving been left and vehicles stopped on the magnetic sensor 12, and themagnetic sensor 12 was left.[0083]Car presence and the **** information output means 31 are realizedas a function of Step S7 of drawing 10 by the control section 19, andprocessing of S10, Based on the decided result of penetration, a stop, andthe **** judging means 30, vehicles have stopped at the motor pool, thecar presence information on the purport that vehicles have stopped on themagnetic sensor 12, and vehicles left the motor pool, namely, vehiclesoutput the **** information on the purport that on the magnetic sensor 12was left.[0084]External magnetic field intensity is detected by the basis of suchcomposition by the magnetism detecting elements 11A-11N of themagnetic sensor 12, The external magnetic field intensity change on thebasis of the state where there are no vehicles by the measurement means27 based on the detection result is measured, and the judgment of vehicledetection is performed by the vehicle detection judging means 29 basedon the measuring result. And based on the decided result of vehicledetection, penetration of the vehicles in a motor pool, a stop, and **** arejudged by the judging means 30, and car presence information thru/or ****information are outputted by the output means 31 based on the decidedresult.[0085]Next, drawing 10 explains the details of vehicle detection operationof this system. Drawing 10 is a flow chart which shows the procedure ofthe vehicle detection processing by the control section 19 of drawing 8which realizes each means 27, 29, 30, and 31 of drawing 9.[0086]On vehicle detection processing and first in Step S1 of drawing 10the control section 19, External magnetic field intensity by each magnetismdetecting element of the magnetic sensor 12 is made to detect asmentioned above in the state where there are no vehicles, It asks formeasurement data of external magnetic field intensity of A-B mentionedabove based on the detection result, this is set up as initial value dataused as a standard which asks for external magnetic field intensity change,and it memorizes to recording equipment of RAM26 grade. Since there areno vehicles into a motor pool at this time, the control section 19 checks**** information.
  • [0087]Next, in order to judge penetration of vehicles to the magneticsensor 12 top formed in penetration of vehicles into a motor pool, i.e., aground surface of a motor pool, and underground, Detection andMeasurement Division of external magnetic field intensity from vehicles byeach magnetism detecting element are performed in a procedurementioned above (Step S2), It judges with vehicles having advanced into amotor pool, when it absolute-value-ized in quest of a difference of eachmeasurement data A-B and initial value data separately and the total wasover predetermined joint threshold S, and when not having progressed andexceeded for the following procedure, it returns to Step S2 (Step S3).[0088]When vehicles enter in a motor pool even in a front procedure, canjudge that, but. Since it thinks when passing without stopping then, afterjudging penetration of vehicles at Step S3, detection and MeasurementDivision of the external magnetic field intensity from the vehicles by eachmagnetism detecting element are performed again (step S4), and itcompares with total of the absolute value of data A-B measured last time(Step S5). When this measurement value is changing from the lastmeasurement value, it judges with vehicles moving in the inside of a motorpool, and returns to step S4.[0089]Since it will be either when vehicles stop in a motor pool or apassing car comes out out of a motor pool as it is if change of measuredvalue is lost, In order to carry out that judgment which is the any, in questof the difference of an initial value and measured-value-data A-B, itabsolute-value-izes separately by all the magnetism detecting elements, Itjudges that the total is in the car presence state which vehicles havestopped in a motor pool when total exceeds joint threshold S as comparedwith the above-mentioned predetermined joint threshold S (that is, it hasstopped on the magnetic sensor 12) (Step S6), and car presenceinformation is taken out (Step S7). On the other hand, when total of theabsolute value of aforementioned difference A-B is not over joint thresholdS, it judges with the passing car having come out out of the motor pool asit is, and returns to Step S2.[0090]Next, detection of the magnetic field of the vehicles by eachmagnetism detecting element in order to detect **** of the parkedvehicles, Measure (Step S8) and it absolute-value-izes in quest of thedifference of measurement data A-B and the data of an initial value
  • separately, When the total is over predetermined joint threshold S, vehiclesare judged continuously to be under parking, It returns to Step S8, andwhen it repeated and is not over measurement, vehicles judge with havingleft the inside of a motor pool (that is, on the magnetic sensor 12 was left),take out **** information (Step S10), return to Step S2, and are againrepeated from detection of penetration of vehicles.[0091]Thus, based on the detection result of the magnetic field fromvehicles, a stop and **** can be judged during penetration of the vehiclesin a motor pool, and movement, and car presence information and ****information can be outputted. And the advantage of the vehicle detectingdevice of this invention can be enjoyed, a stop and **** can be correctlyjudged during penetration of vehicles, and movement by highly precise andreliable vehicle detection, and exact car presence information and ****information can be outputted. Therefore, the vehicle detection system ofthis embodiment is effectively [ as management of parking vehicles /because of management of parking duration, the empty area display in ascale parking lot, vehicle guiding, etc. ] available.[0092][Effect of the Invention]According to the vehicle detecting method of thisinvention, so that clearly from the above explanation to the ground surfacein the band pass of vehicles, or underground. The magnetic sensor whichput in order two or more magnetism detecting elements which havemagnetic field detection sensitivity in the direction vertical to a groundsurface along with the vehicles longitudinal direction is installed, Theexternal magnetic field intensity change as on the basis of the state whereeach of a magnetism detecting element detects external magnetic fieldintensity, and there are no vehicles is measured, Since total of the absolutevalue of two or more measurement values of this measuring result wasmade to detect vehicles by the judgment of whether to exceedpredetermined joint threshold S, The influence of the zero crossing pointwhich the magnetic field polarity looked at by distribution of the magneticfield strength in the case of measuring the magnetic field generated from avehicles pars basilaris ossis occipitalis reverses can be avoided, and highlyprecise and reliable vehicle detection can be performed.[0093]While being able to perform reliable vehicle detection with highdegree of accuracy with the vehicle detecting method of this invention
  • according to the vehicle detecting device of this invention, a magneticsensor, For example, it can constitute from small size which consists ofplurality of the small magnetism detecting element constituted using themagnetic impedance component as a magnetic sensor of low powerconsumption, Compared with the equipment using the conventional loopcoil type sensor, prolonged continuous use is possible, installation canalso be easily performed by low cost, and the use of vehicle detection canbe expanded.[0094]According to the vehicle detection system using the vehicledetecting device of this invention. By vehicle detection enjoy theadvantage of the vehicle detecting device of this invention, highly preciseand reliable, exact car presence information, **** information can beoutputted and the outstanding effect of being available is acquiredeffectively [ because of management of parking duration, the empty areadisplay in a scale parking lot, vehicle guiding, etc. ] as management ofparking vehicles.TECHNICAL FIELD[Field of the Invention]This invention detects the magnetic field generatedfrom vehicles, such as a car, with a magnetic sensor, and detects vehiclesmagnetically, namely, relates to the vehicle detecting method whichdetects the existence of vehicles thru/or passage, a vehicle detectingdevice, and a vehicle detection system.PRIOR ART[Description of the Prior Art]Conventionally, the sensor which detectsvehicles, such as a car, is used in the use of measuring the distinction ofthe existence of parking in the managerial system of a motor pool, and thetraffic of the vehicles in a traffic control system.[0003]Usually, since vehicles, such as a car, are tinged with magnetismusing the metallic material which is easy to be tinged with magnetism, suchas a steel plate, it is detecting the magnetic field generated from vehicleswith a magnetic sensor, and it is possible to recognize existence ofvehicles or passage.
  • [0004]Conventionally, in the motor pool, the loop coil type magneticsensor was buried in the earth, and it has been used for vehicle detectionin it. A loop coil type magnetic sensor is that generate a magnetic field byan eddy current in the metal part of the body of vehicles to the alternatingcurrent sent through a coil, or the magnetic field from the bodys ownmagnetization interlinks with a loop coil, A coils own inductance changes,it is changed as change of oscillating frequency or amplitude in a circuit,and vehicle detection is performed by the existence of the change.[0005]However, although the loop coil type magnetic sensor is spreadingby detection of vehicles, it has the following problems.[0006]- Since a loop coil opens an interval a little with vehicles and isinstalled, in order to detect the inductance variation in vehicles existence,there is the necessity of enlarging size of a sensitivity secured upper coil(about 1mx1m).[0007]- If metal bodies, such as a steel rod, are in the neighborhood, S/Ncannot be taken enough.[0008]- Since a loop coil is large and power consumption is large, it is notfit for continuous energization use.[0009]- A coil is a size which is about 1mx1m, and the burden ofconstruction expense is heavy in subterranean installation.[0010]Then, although the small magnetic sensor was used and thesubstitution was considered, When the magnetic field generated from avehicles pars basilaris ossis occipitalis was measured, near the zerocrossing point which remarkable unevenness is made to distribution ofmagnetic field strength, and magnetic field polarity reverses by the localmagnetization of Body Manufacturing Division article each which it has, itturned out that the dead point which does not exceed a threshold requiredfor the judgment of vehicle detection arises.EFFECT OF THE INVENTION[Effect of the Invention]According to the vehicle detecting method of thisinvention, so that clearly from the above explanation to the ground surfacein the band pass of vehicles, or underground. The magnetic sensor whichput in order two or more magnetism detecting elements which havemagnetic field detection sensitivity in the direction vertical to a ground
  • surface along with the vehicles longitudinal direction is installed, Theexternal magnetic field intensity change as on the basis of the state whereeach of a magnetism detecting element detects external magnetic fieldintensity, and there are no vehicles is measured, Since total of the absolutevalue of two or more measurement values of this measuring result wasmade to detect vehicles by the judgment of whether to exceedpredetermined joint threshold S, The influence of the zero crossing pointwhich the magnetic field polarity looked at by distribution of the magneticfield strength in the case of measuring the magnetic field generated from avehicles pars basilaris ossis occipitalis reverses can be avoided, and highlyprecise and reliable vehicle detection can be performed.[0093]While being able to perform reliable vehicle detection with highdegree of accuracy with the vehicle detecting method of this inventionaccording to the vehicle detecting device of this invention, a magneticsensor, For example, it can constitute from small size which consists ofplurality of the small magnetism detecting element constituted using themagnetic impedance component as a magnetic sensor of low powerconsumption, Compared with the equipment using the conventional loopcoil type sensor, prolonged continuous use is possible, installation canalso be easily performed by low cost, and the use of vehicle detection canbe expanded.[0094]According to the vehicle detection system using the vehicledetecting device of this invention. By vehicle detection enjoy theadvantage of the vehicle detecting device of this invention, highly preciseand reliable, exact car presence information, **** information can beoutputted and the outstanding effect of being available is acquiredeffectively [ because of management of parking duration, the empty areadisplay in a scale parking lot, vehicle guiding, etc. ] as management ofparking vehicles.TECHNICAL PROBLEM[Problem to be solved by the invention]Then, a reliable vehicle detectingmethod in which SUBJECT of this invention can perform magneticdetection of vehicles with high precision using a magnetic sensor whichconsists of two or more small magnetism detecting elements, And it is in
  • providing a vehicle detection system which is a vehicle detecting devicewhich performs vehicle detection by the method, can attain aminiaturization and can be used effective in management of parkingvehicles using a vehicle detecting device of low power consumption, andthis vehicle detecting device.MEANS[Means for solving problem]In a vehicle detecting method which accordingto this invention detects a magnetic field generated from vehicles with amagnetic sensor, and detects vehicles magnetically in order to solveabove-mentioned SUBJECT, A magnetic sensor which put in order two ormore magnetism detecting elements which have magnetic field detectionsensitivity in the direction vertical to a ground surface along with a vehicleslongitudinal direction is installed in a ground surface in a band pass ofvehicles, or underground, External magnetic field intensity change as onthe basis of the state where each of two or more of said magnetismdetecting elements detects external magnetic field intensity, and there areno vehicles was measured, and a method of detecting vehicles by thejudgment of whether total of an absolute value of two or moremeasurement values of this measuring result exceeds predetermined jointthreshold S was adopted.[0013]According to such a vehicle detecting method, influence of a zerocrossing point which magnetic field polarity looked at by distribution ofmagnetic field strength in a case of measuring a magnetic field generatedfrom a vehicles pars basilaris ossis occipitalis reverses can be avoided,and highly precise and reliable vehicle detection can be performed.[0014]According to this invention, it is a vehicle detecting device whichdetects a magnetic field generated from vehicles with a magnetic sensor,and detects vehicles magnetically, A magnetic sensor which consists oftwo or more magnetism detecting elements arranged so that it may havemagnetic field detection sensitivity in the direction vertical to a groundsurface and may rank with a ground surface in a band pass of vehicles, orunderground along with a vehicles longitudinal direction, A measurementmeans which measures each of external magnetic field intensity change ason the basis of the state where there are no vehicles to each magnetism
  • detecting element, based on external magnetic field intensity detected byeach of two or more of said magnetism detecting elements, Total of eachabsolute value of a measurement value of external magnetic field intensitychange measured by this measurement means adopted composition of avehicle detecting device which has a judging means which judges vehicledetection by whether predetermined joint threshold S is exceeded.[0015]While being able to perform reliable vehicle detection with highdegree of accuracy with a vehicle detecting method of this inventionaccording to such composition, the magnetic sensor can consist of smallsize which consists of plurality of a small magnetism detecting elementconstituted, for example using a magnetic impedance component as amagnetic sensor of low power consumption.[0016]It is a vehicle detection system which performs vehicle detectionusing a vehicle detecting device by above-mentioned this inventionaccording to this invention, A judging means which judges whetherwhether vehicles advanced on a magnetic sensor, whether it stopped on amagnetic sensor based on a decided result of vehicle detection by ajudging means of said vehicle detecting device, and on a magnetic sensorwere left, Car presence information on a purport that vehicles havestopped on a magnetic sensor based on a decided result of this judgingmeans, And it has an output means to which vehicles output ****information on a purport that on a magnetic sensor was left, andcomposition of a vehicle detection system which enabled it to manageparking vehicles with the output of said car presence information and ****information was adopted.[0017]According to such composition, an advantage of a vehicledetecting device of this invention can be enjoyed, exact car presenceinformation and **** information can be outputted based on highly preciseand reliable vehicle detection, and it can use effective in management ofparking vehicles.[0018][Mode for carrying out the invention]Hereafter, an embodiment of theinvention is described with reference to figures.[0019][Embodiment of a vehicle detecting method] Drawing 1 - 3 explainthe embodiment of the vehicle detecting method by this invention first.[0020]In this embodiment, as shown in drawing 1, to the ground surface
  • 14 in the width which the vehicles (car) 10 pass, or underground. Themagnetic sensor 12 which has arranged two or more magnetism detectingelements 11A, 11B, and 11C which have magnetic field detectionsensitivity in the direction (Z direction) vertical to a ground surface so thatit may stand in a line along with the longitudinal direction of the vehicles 10is installed, and vehicle detection is performed.[0021]The external magnetic field intensity change as on the basis of thestate where each magnetism detecting element of the magnetic sensor 12detects external magnetic field intensity, and there are no vehicles 10 ismeasured, and total of the absolute value of two or more measuredmagnetic-field-strength change detects vehicles by the judgment ofwhether to exceed a predetermined joint threshold.[0022]This method was drawn from the following examining results.[0023]First, on the ground surface 14 in the width which the vehicles 10pass as shown in drawing 2, The magnetic sensor 12 which comprisedone magnetism detecting element which has magnetic field detectionsensitivity in the Z direction which is a vertical direction to the groundsurface 14 is arranged, the vehicles 10 were moved on the sensor 12, themagnetic sensor 12 detected external magnetic field intensity, externalmagnetic field intensity change was measured, and the situation of thechange was investigated. The variation of external magnetic field intensitymade the measurement value in the state where there are no vehicles 10the initial value used as a standard, and displayed a changed part from it.The element using the magnetic impedance component mentioned later asa magnetic sensing device was used for the magnetism detecting element.Two or more vehicles performed the sampling. Four data measuring of acharacteristic example is shown in drawing 2 (a) - (d) in it.[0024]Generally, magnetic field distribution of the cross direction of a barmagnet has a peak of reverse polarity at both ends of the bar magnet 16like drawing 3, and has a tendency which carries out a zero cross in thecenter section. On the other hand, it can guess that the body of a carconstitutes a roughly big bar magnet from a vehicles longitudinal directionfrom it being in agreement with how of data measuring of drawing 2 tolengthen the skirt near the both-ends peak of magnetic field distribution ofdrawing 3 by (c) and (d), especially, if it observes near the both ends of amagnetic field change. However, attitude of a peak has dispersion
  • considerably by overall magnetic-field-strength distribution, and it doesnot become a beautiful form like a bar magnet because localmagnetization exists by part each of a body pars basilaris ossis occipitalis.[0025]Since detection of vehicles will detect the magnetic field of a bodycenter section if detection of parking vehicles is taken into consideration,for example, it observes the magnetic field of the center of the body by thewidth of the length of the half of the body shown in the range of H seal ina figure of each data measuring of drawing 2. It is because the movementspeed of the difference in the length of each body and the body at thetime of Measurement Division had dispersion that the length of H sealdiffers.[0026]Also when unevenness is looked at by magnetic-field-strengthchange within the limits of H seal of the data of four examples and a zerocross exists, the absolute value of a measurement value may go into theDETTO point on which it is less than threshold s, and one magnetismdetecting element is not enough as it for vehicle detection at a certainthing.[0027]When threshold s of one magnetism detecting element considersthe resolution of a magnetism detecting element, and S/N of a circuit, 0.05gauss of a minimum is a limit, and considering that a maximum has about0.1 gauss vehicles like drawing 2 (c) in the maximum of the magnetic fieldchange by vehicles, it is difficult to set up exceeding 0.1 gauss.[0028]Then, two or more magnetism detecting elements are arrangedalong with a vehicles longitudinal direction, and if vehicle detection iscarried out by whether either exceeds threshold s, detection probability willincrease.[0029]However, in the case of the vehicles of drawing 2 (d), when fourmagnetism detecting elements have been arranged to each of the positioncorresponding to four points, a in a figure, b, c, and d, the measurementvalue by which element will also be less than 0.05 gauss. If such a case istaken into consideration, the device which raises detection probabilityfurther is required.[0030]Then, the absolute value of the measurement value of two or moremagnetic-field-strength change which detected external magnetic fieldintensity by each of two or more magnetism detecting elements, and was
  • measured is added, The value of the product which, on the other hand,hung said number (addition numbers of a measurement value) n of amagnetism detecting element of added square roots on threshold s at thetime of detection by an independent magnetism detecting element is setup as joint threshold S, If vehicle detection is judged by whether total ofthe added result of said absolute value exceeds joint threshold S, it isdetectable by high probabilities.[0031]A noise component serves as a mean square to addition of theoutput of each magnetism detecting element, and if it is considered as thenoise component of the respectively same size, this will use that theproduct of the noise for one element and the square root of the additionnumbers n serves as a noise at the time of combination, and will try toearn the whole S/N.[0032]For example, magnetic-field-strength change, a of the datameasuring of the vehicles of drawing 2 (d), b, c, and d, of four points, Itwill be 0.03G-0.04G-0.02G-0.03G, and if threshold s of independentdetection is set to 0.05G, when these are added, it will be 0.12G, and0.05xroot4=0.1 gauss is set to joint threshold S, total of the added resultof an output will exceed joint threshold S, and detection of it will beattained.[0033]Therefore, when the magnetic field component of a directionvertical to the ground surface of the magnetic field generated fromvehicles is detected by two or more Magnetism detecting elementn and themagnetic-field-strength change by vehicles existence is measured, Itturned out that it is suitable that the total adding each of the absolute valueof magnetic-field-strength change measured based on the detection resultof n magnetism detecting elements of a result performs vehicle detectionby whether joint threshold S as independent threshold sxrootn is exceeded.[0034]By the way, since a magnetic-field-detection output may becomenear a zero cross with a certain element and total of the above-mentionedadded result may become low when detecting as mentioned above by twoor more magnetism detecting elements, the method explained below canalso be chosen as a method of raising vehicle detection efficiency further.[0035]Arrange in descending each absolute value of the measurementvalue of the external magnetic field intensity change from the initial value
  • which detected external magnetic field intensity by two or more magnetismdetecting elements of the magnetic sensor mentioned above, and wasmeasured, consider it as |deltaH(k) | (k= 1, 2, ordinal number of --), andNamely, this value, They are [ threshold s in the case of one magnetismdetecting element, and ] the following expression about said additionnumbers n.[0036][Mathematical formula 2][0037]It compares whether it is alike, it sets, substitutes one by one fromk= 1, and the above-mentioned expression is satisfied, and when theabove-mentioned expression is satisfied, it judges with having detectedvehicles.[0038]According to this method, vehicle detection efficiency can be raisedby adding the measurement value of two or more external magnetic fieldintensity change to descending one by one, and using for the judgment ofvehicle detection.[0039]In above-mentioned explanation, the "ground surface of"underground" meaning the inside of those fields including all the fieldsthat vehicles, such as a floor line in the building of not only the groundsurface of the ground, and the road surface of a road and the groundsurface of an outdoor parking lot but a multi-level car parking tower, runfields thru/or park" of 14 is natural.[0040][Embodiment of a vehicle detecting device] Next, the embodimentof a vehicle detecting device which enforces concretely the vehicledetecting method mentioned above, and performs vehicle detection isdescribed.[0041]First, the magnetism detecting element of the magnetic sensor usedfor a vehicle detecting device is explained. Being required of thismagnetism detecting element should be 10 or more milligauss in (1)magnetic field detection sensitivity.[0042](2) There is two or more dispersion [ little ] of the performance ofan element for use.[0043](3) Considering ground surface installation, the height of an element
  • should be several millimeters.[0044](4) The detector circuit of an element is excellent in a noise-proofand temperature characteristics, and be low power consumption.[0045]Although there is a flux gate type magnetism detecting element aswhat satisfies the conditions of (1), if it is going to raise detectionsensitivity with this element, several 10 mm of the length of an element willbe needed, and it will not be satisfied with it of the conditions of (3).[0046]Since it is easy to come out of dispersion in performance, aproblem produces a flux gate type magnetism detecting element also oncondition of (2).[0047]Then, the magnetism detecting element constituted using amagnetic impedance component is seemed that it is the optimal by it.[0048]The magnetic impedance component is indicated byJP,H7-181239,A and the element body as a magnetic body is constitutedfrom an amorphous wire or these days by the magnetic thin film etc. If thehigh frequency current of an MHz band is impressed to this element body,according to a magnetic impedance effect, according to an externalmagnetic field, the impedance of an element body changes several 10%,and can detect an external magnetic field using this.[0049]The sensitivity of a magnetic impedance component has thesensitivity of a 10-5 gauss stand, and number milligauss is securable and itis satisfied also with the practical resolution in the case where it connectswith the circuit of a magnetism detecting element of the conditions of (1).[0050]From there being little influence of a demagnetizing field, it is easyfor the length of an element to be 5 mm or less, and the conditions of (3)are also cleared.[0051]About dispersion in performance, when supplied with an amorphouswire, since it is easy to control thickness, dispersion in the performanceresulting from the outside dimension of the magnetic body of an elementbody is pressed down, and is satisfied with that there is little dispersion inthe path of a wire, and a magnetic film of the conditions of (2).[0052]Although application was considered according to the contentsreported at the society etc. about the magnetic field detection which usesthe Colpitts oscillating circuit about the conditions of (4), there is aproblem practically.[0053]For example, the application of the magnetic field sensor as an
  • azimuth sensor is shown by the "amorphous wire MI Colpitts oscillationtype micro magnetic sensor" announced at the 18th Maganetics Society ofJapan academic lecture meeting (14pB-7).[0054]In the composition of this azimuth sensor, an amorphous wire isincluded in a Colpitts type oscillator, and since change of an externalmagnetic field turns into change of oscillation amplitude and it appears, anoutput is obtained through a detector circuit. While sending a direct currentthrough the coil directly twisted around the wire of the element, applying aDC bias magnetic field and making it operate in the field where sensitivityis high, he is trying to know the polarity of the direction of north and south.[0055]However, in minute magnetic field detection, such asgeomagnetism (about 0.3 gauss) by this method. Change of the outputafter a detector circuit is as small as several percent, and in order to treatabsolute value change of oscillation amplitude as an output as it is,sufficient S/N is not obtained from it being easy to be influenced bychange of power supply voltage, the temperature characteristics of anelement, etc. by amplitude fluctuation, and it is unreliable.[0056]So, in this embodiment, the circuitry of the magnetism detectingelement shown in drawing 4 was adopted.[0057]The circuitry of the magnetism detecting element shown in drawing4 consists of a Colpitts oscillator, a detector circuit, and a comparator, themagnetic impedance component 1 mentioned above is included in theColpitts oscillator, it direct-winds, or the magnetic impedance component1 is approached, and the coil 2 for bias is formed.[0058]In this composition, AC bias current Ib is sent through the coil 2,and an about **1-**2 gauss AC bias magnetic field is impressed to themagnetic impedance component 1. As shown in (a), amplitude modulationof the oscillation output which appears like the after-mentioned by this atthe A point in a figure of a Colpitts oscillator according to the intensity ofthe external magnetic field Hex for [ which is impressed to the magneticimpedance component 1 ] detection is carried out, The ripple waveformcorresponding to the bias magnetic field which has the difference ofelevation of the adjacent peak corresponding to the intensity of theexternal magnetic field Hex by detecting this in a detector circuit at a Bpoint as shown in (b) is acquired, By carrying out a party rate with the
  • comparison voltage Vref which crosses the voltage waveform of said ripplewith a comparator, the Pulse-Density-Modulation output corresponding tothe intensity of the external magnetic field Hex can be obtained at C point.[0059]The signal of AC bias current Ib carries out dividing of the clockfrom the microcomputer judgment part mentioned later, with a low passfilter, it may be made into a sine wave or the shape of a triangular wave,and it may throw it in, or may provide and throw in an oscillatorindividually.[0060]Next, the details of operation of the circuitry of the magnetismdetecting element of drawing 4 mentioned above are explained.[0061]the characteristic of a magnetic impedance component issymmetrical with the direction of +- in several gauss to the externalmagnetic field Hex, as shown in drawing 5 -- a V character-likeimpedance change is shown in general. As shown in drawing 5 (a) as aprinciple of operation of the magnetic impedance component 1 of drawing4, when there is no external magnetic field, an AC bias magnetic field is +.- It touches symmetrically, In change of impedance to it, an impedancechange which the difference of elevation does not have in peaks on aripple breaks out by a magnetic field twice the frequency of AC bias.[0062]Since an AC bias magnetic field and the unsymmetrical magneticfield which the external magnetic field superimposed will start the magneticimpedance component 1 like drawing 5 (b) there if an external magneticfield is impressed to the longitudinal direction of the magnetic impedancecomponent 1, The impedance change (ripple waveform) from which theheight of a peak differs by turns on an impedance change arises.[0063]The ripple waveform in an impedance change as showed the outputafter detection of drawing 4 (b) which appeared as amplitude modulationin the oscillation amplitude characteristic of the Colpitts oscillator aschange of this impedance was shown in drawing 4 (a), and detected thatoscillation output in the detector circuit by drawing 5 (b), and a similarsignal are acquired. The size of an external magnetic field is changed intothe output of a digital signal by which Pulse Density Modulation wascarried out by carrying out a party rate with the comparison voltage Vrefwhich crosses a ripple waveform as the signal is shown in drawing 6 in acomparator. That is, the Pulse-Density-Modulation output in which thepulse which is two kinds from which pulse width differs according to
  • external magnetic field intensity appears by turns is obtained.[0064]Thus, pulse width [ of two kinds of pulses ] A which appears byturns, and B can be measured and evaluated using the timer counter of amicrocomputer, and the digital data in which external magnetic fieldintensity is shown can be obtained by asking for the digital data ofdifference A-B of pulse width by an operation after that. Although themeasurement data of pulse width to a actual external magnetic field isshown in drawing 7, in **0.5 gauss shows an almost linear change. Thenumerical input value of joint threshold S mentioned above can be decidedby transposing the magnetic field strength of magnetism detecting elementindependent threshold s to the math-processing value of pulse widthbased on this data, and hanging the several n square root of a magnetismdetecting element on it.[0065]And the digital data of difference A-B of the pulse width measuredin the state where there are no vehicles, in detection of vehicles ismemorized as data of the initial value of the external magnetic fieldintensity used as a standard, Then, the absolute value of the difference ofdifference A-B of pulse width and the initial value according to themeasured external magnetic field intensity is calculated as datacorresponding to the absolute value of intensity change of an externalmagnetic field, It can ask for total of the data of said absolute value calledfor by further two or more magnetism detecting elements, and theexistence of vehicles can be judged by whether the figure exceeded thenumerical value of joint threshold S.[0066]Next, drawing 8 explains the composition of the vehicle detectingdevice using the magnetism detecting element of drawing 4.[0067]Colpitts oscillator 3 incorporating the magnetic impedancecomponent 1 which wound the coil 2 for bias which 12 is a magneticsensor and was mentioned above in the composition of the vehicledetecting device shown in drawing 8, They are the marks 11A and 11Babout the magnetism detecting element of drawing 4 which consists of thedetector circuit 4 and the comparator 5. -- As shown in 11N, N pieces areprovided and it is constituted. Magnetism detecting elements 11A and 11B-- 11N is arranged so that it may rank with the ground surface in the bandpass of vehicles, or underground along with the longitudinal direction ofvehicles as mentioned above, and each element can be giving magnetic
  • field detection sensitivity in the direction vertical to a ground surface.[0068]18 is a microcomputer judgment part which comprises amicrocomputer, analyzes a Pulse-Density-Modulation output of eachmagnetism detecting element of the magnetic sensor 12, and judgesexistence of vehicles. The microcomputer judgment part 18, Either thetimer counter 20 which counts pulse width [ of the control section 19which performs whole control and various data processing, and a Pulse-Density-Modulation output mentioned above ] A, and B or magnetismdetecting elements 11A-11N are chosen. It consists of the selector 21which inputs the output pulse into the timer counter 20 and the clockgenerator 22, the clock divider 23, the low pass filter 24, and the biascircuit (amplifier) 25.[0069]Dividing is carried out so that a clock signal which the clockgenerator 22 oscillates may become the range of 1 kHz - 100 kHz by theclock divider 23 in this composition, The low pass filter 24 and the biascircuit 25 let this signal by which dividing was carried out pass, a signal ofAC bias current of a sine wave or the shape of a triangular wave is formed,and it is impressed by the coil 2 for bias which are each magnetismdetecting elements 11A-11N of the magnetic sensor 12. A feed zone ofthis bias current may be provided in the magnetic sensor 12 side.[0070]Next, vehicle detection operation by composition of drawing 8 isexplained. First, an initial value of external magnetic field intensity used asa standard for asking for external magnetic field intensity change in thestate where there are no vehicles is measured. For this reason, with themagnetic sensor 12, a pulse signal which detected external magnetic fieldintensity by two or more magnetism detecting elements 11A-11N, andcarried out Pulse Density Modulation is outputted as mentioned above, andit sends to the selector 21 of the microcomputer judgment part 18.[0071]With the command from the control section 19, the selector 21chooses and sends two kinds of pulses A and B further mentioned abovewhile it chooses the output pulse signal of two or more magnetismdetecting elements 11A-11N which should be sent to the timer counter 20one by one and sends it.[0072]In the timer counter 20, the pulse width of two kinds of said pulsesA and B of two or more magnetism detecting elements sent one by one iscounted and evaluated, and the data is sent to the control section 19.
  • [0073]In the control section 19, difference A-B of the pulse width data ofA pulse and B pulse evaluated with the timer counter 20 is computed forevery magnetism detecting element, and the measured value of externalmagnetic field intensity is calculated. The measured data is recorded onmemory storage, such as RAM26 in the control section 19, as initial valuedata used as a standard.[0074]Then, in order to detect vehicles, the detection and theMeasurement Division of external magnetic field intensity by eachmagnetism detecting element are performed in the same procedure as theabove, In the control section 19, it asks separately, absolute-value-izes byusing the difference of said measurement data and initial value data asexternal magnetic field intensity change data, and asks for the total, andthe existence of vehicles is judged by whether it is over predetermined jointthreshold S which the total mentioned above. And in the case of thevehicle detection system mentioned later, car presence information etc.are taken out based on the result of said judgment.[0075]In order not to treat the amplitude of a Colpitts oscillator as anabsolute value in the circuitry of the magnetism detecting element ofdrawing 4 as an advantage of the equipment of these above embodimentsprobably but to treat a changed part of amplitude, a low change of thefrequency by change, temperature characteristics, etc. of power supplyvoltage can be disregarded.[0076]Since the detect output of the external magnetic field intensity in themagnetic sensor 12 is digitized-output-ized by the Pulse DensityModulation by a comparator, The magnetic sensor 12 and themicrocomputer judgment part 18 connect two or more magnetic sensors12 to the microcomputer judgment part 18, and can carry out common useof the microcomputer judgment part 18 to two or more magnetic sensors12 while also being able to perform installation to isolate and obtaining theflexibility of installation.[0077]Since the whole equipment which constituted the magnetismdetecting element very small, could constitute the magnetic sensor 12small, and includes the microcomputer judgment part 18 can be madesmall, The burden of installation cost is small, and it is low powerconsumption, and since the prolonged energization use which was poor atconventional loop coil type equipment is possible, the use of vehicle
  • detection is expandable.[0078][Embodiment of a vehicle detection system] Next, drawing 9 anddrawing 10 explain the embodiment of the vehicle detection system for theparking-vehicles management in the motor pool using the vehicledetecting device of drawing 8 mentioned above. As for this vehicledetection system, it is needless to say that the portion of the magneticsensor 12 is provided in the ground surface of a motor pool orunderground at least, and it carries out of the vehicle detecting device ofdrawing 8.[0079]Drawing 9 is a block diagram showing the functional composition ofthe vehicle detection system of this embodiment. Composition of thoseother than magnetic sensor 12 is specifically realized in drawing 9 by thehardware and software of the microcomputer judgment part 18 of drawing8.[0080]In drawing 9, it realizes from the control section 19 of drawing 8,the timer counter 20, and the selector 21, and the measurement means 27measures the external magnetic field intensity change as on the basis ofthe state where there are no vehicles based on the detection result of theexternal magnetic field intensity by the magnetism detecting elements11A-11N of the magnetic sensor 12 as mentioned above. Thismeasurement means 27 has the initial value memory measure 28 whichmemorizes the value of the external magnetic field intensity detected bythe magnetism detecting elements 11A-11N in the state where there are novehicles as an initial value used as a standard, and measures externalmagnetic field intensity change on the basis of the initial value memorizedto this memory measure 28. The memory measure 28 is specificallyconstituted as RAM26 of drawing 8.[0081]It realizes as a function of the control section 19, and the vehicledetection judging means 29 judges vehicle detection as mentioned abovebased on the measuring result of the measurement means 27.[0082]Penetration, a stop, and the **** judging means 30 are realized asa function of processing of Step S3 of below-mentioned drawing 10 by thecontrol section 19, S6, and S9, Based on the decided result of the vehicledetection by the vehicle detection judging means 29. [ whether vehiclesadvanced into the motor pool, and ] It is judged whether on whether itadvanced on the magnetic sensor 12 formed in the motor pool, whether
  • whether whether it having stopped in the motor pool and a motor poolhaving been left and vehicles stopped on the magnetic sensor 12, and themagnetic sensor 12 was left.[0083]Car presence and the **** information output means 31 are realizedas a function of Step S7 of drawing 10 by the control section 19, andprocessing of S10, Based on the decided result of penetration, a stop, andthe **** judging means 30, vehicles have stopped at the motor pool, thecar presence information on the purport that vehicles have stopped on themagnetic sensor 12, and vehicles left the motor pool, namely, vehiclesoutput the **** information on the purport that on the magnetic sensor 12was left.[0084]External magnetic field intensity is detected by the basis of suchcomposition by the magnetism detecting elements 11A-11N of themagnetic sensor 12, The external magnetic field intensity change on thebasis of the state where there are no vehicles by the measurement means27 based on the detection result is measured, and the judgment of vehicledetection is performed by the vehicle detection judging means 29 basedon the measuring result. And based on the decided result of vehicledetection, penetration of the vehicles in a motor pool, a stop, and **** arejudged by the judging means 30, and car presence information thru/or ****information are outputted by the output means 31 based on the decidedresult.[0085]Next, drawing 10 explains the details of vehicle detection operationof this system. Drawing 10 is a flow chart which shows the procedure ofthe vehicle detection processing by the control section 19 of drawing 8which realizes each means 27, 29, 30, and 31 of drawing 9.[0086]On vehicle detection processing and first in Step S1 of drawing 10the control section 19, The external magnetic field intensity by eachmagnetism detecting element of the magnetic sensor 12 is made to detectas mentioned above in the state where there are no vehicles, It asks for themeasurement data of the external magnetic field intensity of A-Bmentioned above based on the detection result, this is set up as initialvalue data used as the standard which asks for external magnetic fieldintensity change, and it memorizes to the recording equipment of RAM26grade. Since there are no vehicles into a motor pool at this time, thecontrol section 19 checks **** information.
  • [0087]Next, in order to judge penetration of the vehicles to the magneticsensor 12 top formed in penetration of the vehicles into a motor pool, i.e.,the ground surface of a motor pool, and underground, Detection andMeasurement Division of the external magnetic field intensity from thevehicles by each magnetism detecting element are performed in theprocedure mentioned above (Step S2), It judges with vehicles havingadvanced into the motor pool, when it absolute-value-ized in quest of thedifference of each measurement data A-B and initial value data separatelyand the total was over predetermined joint threshold S, and when nothaving progressed and exceeded for the following procedure, it returns toStep S2 (Step S3).[0088]When vehicles enter in a motor pool even in a front procedure, canjudge that, but. Since it thinks when passing without stopping then, afterjudging penetration of vehicles at Step S3, detection and MeasurementDivision of the external magnetic field intensity from the vehicles by eachmagnetism detecting element are performed again (step S4), and itcompares with total of the absolute value of data A-B measured last time(Step S5). When this measurement value is changing from the lastmeasurement value, it judges with vehicles moving in the inside of a motorpool, and returns to step S4.[0089]Since it will be either when vehicles stop in a motor pool or apassing car comes out out of a motor pool as it is if change of measuredvalue is lost, In order to carry out that judgment which is the any, in questof the difference of an initial value and measured-value-data A-B, itabsolute-value-izes separately by all the magnetism detecting elements, Itjudges that the total is in the car presence state which vehicles havestopped in a motor pool when total exceeds joint threshold S as comparedwith the above-mentioned predetermined joint threshold S (that is, it hasstopped on the magnetic sensor 12) (Step S6), and car presenceinformation is taken out (Step S7). On the other hand, when total of theabsolute value of aforementioned difference A-B is not over joint thresholdS, it judges with the passing car having come out out of the motor pool asit is, and returns to Step S2.[0090]Next, detection of the magnetic field of the vehicles by eachmagnetism detecting element in order to detect **** of the parkedvehicles, Measure (Step S8) and it absolute-value-izes in quest of the
  • difference of measurement data A-B and the data of an initial valueseparately, When the total is over predetermined joint threshold S, vehiclesare judged continuously to be under parking, It returns to Step S8, andwhen it repeated and is not over measurement, vehicles judge with havingleft the inside of a motor pool (that is, on the magnetic sensor 12 was left),take out **** information (Step S10), return to Step S2, and are againrepeated from detection of penetration of vehicles.[0091]Thus, based on the detection result of the magnetic field fromvehicles, a stop and **** can be judged during penetration of the vehiclesin a motor pool, and movement, and car presence information and ****information can be outputted. And the advantage of the vehicle detectingdevice of this invention can be enjoyed, a stop and **** can be correctlyjudged during penetration of vehicles, and movement by highly precise andreliable vehicle detection, and exact car presence information and ****information can be outputted. Therefore, the vehicle detection system ofthis embodiment is effectively [ as management of parking vehicles /because of management of parking duration, the empty area display in ascale parking lot, vehicle guiding, etc. ] available.DESCRIPTION OF DRAWINGS[Brief Description of the Drawings][Drawing 1]It is an explanatory view showing the arrangement and thedirection of magnetic field detection over the vehicles of the magnetismdetecting element of the magnetic sensor in the embodiment of the vehicledetecting method by this invention.[Drawing 2]They are the explanatory view and graph charts showing thesituation of the external magnetic field intensity change by movement ofthe vehicles detected with the magnetic sensor which comprised onemagnetism detecting element.[Drawing 3]They are the explanatory view and graph charts showing themagnetic field distribution of the cross direction of a bar magnet.[Drawing 4]It is a circuit diagram showing the circuitry of the magnetismdetecting element of the magnetic sensor used for the embodiment of thevehicle detecting device by this invention.[Drawing 5]They are graph charts showing the impedance change by the
  • AC bias magnetic field and external magnetic field of a magneticimpedance component in drawing 4.[Drawing 6]It is a wave form chart showing the bias current Ib in drawing4, the after-detection output of a detector circuit, and a comparatoroutput.[Drawing 7]They are graph charts showing the pulse width and the countnumber of a difference of the pulse which is two kinds from which thepulse width of the comparator output to an external magnetic field differs.[Drawing 8]It is a block diagram showing the composition of theembodiment of a vehicle detecting device.[Drawing 9]It is a block diagram showing the functional composition of theembodiment of the vehicle detection system by this invention.[Drawing 10]It is a flow chart figure showing the vehicle detectionprocedure in the vehicle detection system.[Explanations of letters or numerals]1 A magnetic impedance component2 The coil for bias3 Colpitts oscillator4 Detector circuit5 Comparator10 Vehicles11A-11N Magnetism detecting element12 Magnetic sensor14 Ground surface18 Microcomputer judgment part19 Control section20 Timer counter21 Selector22 Clock generator23 Clock divider24 Low pass filter25 Bias circuit26 RAM27 The measurement means of external magnetic field intensity change28 Initial value memory measure29 Vehicle detection judging means
  • 30 Penetration, a stop, and a **** judging means31 Car presence and a **** information output meansDRAWINGS[Drawing 1][Drawing 2]
  • [Drawing 7][Drawing 3]
  • [Drawing 5][Drawing 4]
  • [Drawing 6]
  • [Drawing 8]
  • [Drawing 9]
  • [Drawing 10]