基于电感传感器的钢珠直径分选器设计（Design of ball diameter classifier based on inductance sensor）

1、基于电感传感器的钢珠直径分选器设计（Design of ball diameter classifier based on inductance sensor）No.Volume 192Electronic design engineering2011JanuaryVol.19No.2ElectronicDesignEngineeringJan.Two thousand and elevenDesign of ball diameter classifier based on inductance sensorYu Chung Chen1, 2(1. 、 Hohai University, J

2、iangsu, Nanjing)210098;2. 、 Nanjing branch of Jiangsu Lianhe Technical Institute, Jiangsu, Nanjing210019)Abstract: with the application of inductance sensor in the steel ball diameter sorting circuit, the design idea of the application circuit of inductance sensor is put forward, that is circuit fun

3、ction analysis,The block diagram is designed and the circuit is simulated, and the micro displacement signal of the steel ball diameter is detected and converted into a voltage signal which is convenient for transmission, processing and displayData processing and display circuits are used to measure

4、 data and realize classification, selection and counting functions. The experimental results show that the measuring system is simple in structure, high in accuracy and good in safety,The cost is low and the debugging is convenient, which can meet the requirement of measurement in practical engineer

5、ing.Key words: inductance sensor; diameter; separator; phase sensitive detectorCLC number:TP212.9 document identifier:A article number: 16746236 (2011) 02-0062-04DesignOfSteelBallDiameterSeparatorBasedOnInductanceTypeTransducerCHENYu-zhong1, 2(1.HohaiUniversity, NanjingTwo hundred and ten thousand a

6、nd ninety-eightChina;TwoJiangsuUnionTechnicalInstitute, Nanjing210019, China)Abstract:TheArticleTookTheApplicationOfInductanceTypeTransducerInSteelBallDiameterSortingCircuitAsAnExampleToPresentTheDesignConceptionForApplicationCircuitOfInductanceTypeTransducer,WhichContainedFunctionalAnalysisOfCircui

7、t,FrameworkDesignAndMeasuringCircuitSimulation.WeDetectedTheMicro-displacementSignalsOfSteelBallDiametersAndTurnedThemIntoVoltageSignals,WhichWereEasyToTransmit,ProcessAndDisplay.WeThenUsedSignalProcessingAndDisplayedCircuitsToMeasureTheDataAndAchievedTheSortingAndCountingFunctions.ThroughTheExperim

8、ent, itShowsThatTheSystemIsSimple,HighPrecision,GoodSafetyPerformance,LowCost,DebuggingEasily,AndMeetsTheMeasurementRequirementsInTheActualProject.KeyWords:InductanceTypeTransducer;Diameter;Separator;PhaseSensitiveDetectorSensors are tools for collecting and acquiring informationElectrical features1

9、. Sensor, DC stabilized voltage power supply, sensor, DC motor and signal processing circuit module1.It is widely used in household, agriculture, industry, medicine and 1.1 basic structuresIn the fields of science, military, environmental protection, transportation and so on, the degree of automatio

10、n of the system and the excitation element of the inductive inductance sensor are composed of coils and ferrite cores, as shown in Fig.OneControl quality plays an important role. In modern industrial production, measurement is often required.Type (1) is a mathematical model of inductive sensors1, 8.

11、Do not allow the diameter of the ball work to be within the allowable range, with a standard diameter of L=N2 S(1)By comparison, it can be concluded that the speed and accuracy are not 2 Delta only by manual inspectionIn reality, automatic detection must be realized by means of advanced technology.

12、Effectively get, be testedThe signal is the key, and the best component to obtain the signal is the sensorThe inductance sensor (Inductance) is usedTypeTransducer) as signal pickupA small change in the geometric size of the measured part is converted to an inductance change of the coilThe measuremen

13、t has the advantages of reliable work, high sensitivity, long life, good linearity and resolutionHigh precision, stable performance, good repeatability and so on.Inductance sensorOneInductance sensors are widely used in measurement technology for acceleration, displacement and vibrationMeasurement o

14、f non electrical quantities such as amplitude, speed, nondestructive testing etc.2. In its control system, steel ball type (1)L is the inductance, N is the number of turns of the coil, with gas permeability, SDiameter sorting selector (referred to as sorter)1 micro displacement detection devices are

15、 used to achieve the air gap sectional area, and the delta is the air gap thickness.The detection and counting of steel ball size is a typical application of inductive sensors. The coil inductance is knownL and air gap thicknessDelta is inversely proportional to the air gap sectionControl system ado

16、pts BOSCH Rexroth sensing experiment device, the sensor experimental platform, productS is proportional to. Assuming that the air gap at the starting position isDelta 0, corresponding to the initial inductance forReceived: 2010-09-13 copy number: 201009041About the author: Chen Yuzhong (1981 -), mal

17、e, Jiangsu, Yancheng, master degree, lecturer. Research interests: sensor and detection technology, electronic technology.62chart1 excitation elementFig.OneIncentiveElementChen Yuzhong design of ball diameter classifier based on inductance sensorL0, andS fixed whenThere is a slight change in DeltaTh

18、e amount of self induced by delta timesVariationDL is (ignoring the high-order term) 2:OneDelta LDelta DeltaDelta Delta= =1 +!Delta DeltaL0Delta 0+, Delta, delta 00.Sensitivity: K Delta=Delta Delta LDelta=L 8 00=N22, delta 2Zero1.2 working principleThe inductance sensor is based on the theory of ele

19、ctromagnetic field and is used to be measuredThe variation of magnetic circuit magnetic resistance causes the inductance or mutual inductance coefficient of the sensor coil to changeThe inductance of the coil is varied to achieve non electrical measurement1-3.When alternating current passes through

20、the coil, the coil produces an alternating magnetic field through which the magnetic field passesThe core is directed to the side of the core, that is, the actuator of the sensor. When there is a metal object orWhen a magnetic object approaches a sensor, it causes a magnetic field to deform. Use com

21、puterThe simulation gives a magnetic field state diagram, as shown in Fig.2 shows. From the map2 it can be seen that electricity is conductiveThe effect of a magnetic field on a material (such as a steel plate) close to the exciting endThe impedance of the inductor coil varies.chart2 magnetic field

22、state diagramFig.TwoStateChartOfMagneticThe sensor coil forms the primary winding of the transformer, and the metal plate forms a short-circuit secondaryWinding, as shown in3 shows. Resulting from the secondary circuit due to inductive couplingInduced currentI2It also acts on the primary circuit, re

23、sulting in mutual inductance coefficientsM12. mostEventually, the impedance of the coil itself changes2. Through the ideal transformer circuitBy comparison, the following conclusions can be drawn:Primary loop:In the U1= (R1+j Omega L1)I Duo1+j M12I Duo.2 (2)Secondary loop:In the U2= (R2+j L2) I Duo1

24、+j M12I Duo.1 (3)Primary loop impedance:TwelveZ=In the U1=R1+j Omega L1+ (R2-j Omega L2)Omega 2M2(4)Twelvereal part:I1Re (Z) =R1+R2R22+Omega (RTwo hundred and twenty-twoOmega + ML2(2.)L22) 2 (5)imaginary part:Im (Z) = Omega L1+ Omega L2R22+(omega2M Omega L1222) 2 (6)chartFig. 3 equivalent circuit of

25、 transformerFig.ThreeCircuitOfTransformerEquivalentTo sum up, when a conductive material approaches the sensor, the impedance of the coilZAn increase in value equal to the coil resistanceR1AddR2, L2, M12andOmega barrierAnti. Experience shows that impedanceThe virtual value of Z indicates only the se

26、nsor coil and the metal plateMeasurement variation between very small distances. Inductive sensors use only impedanceZThe real valued variation is used to detect the measured object of the conductive material.2 industrial applications2.1 function analysisNominal diameter of steel ball (9Mm) control

27、to allow tolerance range+ 3M, qualified products within this range, shall be retained beyond this scopeThat is defective, should be eliminated, and automatically count the number of qualified products and defective products. Will pickSignal (error signal) versus standard signal (9)Mm value contrast,

28、 if in+ 3M fanWithin the enclosure, the qualified product is automatically counted (C1=Cn1+1), and if this range is exceeded, thenAutomatic counting of defective products (C2=Cn2+1), when qualified products and defective products are only equal to or equal to the quantity producedWhen the total numb

29、er of products, automatically withdraw from the detection system 2-3. Circuit design flow chart4 shows.chart4 circuit design processFig.FourDesignOfProcessCircuit2.2 system block diagram designAccording to the working principle of inductance sensor, the circuit is designed according to the electric

30、control circuitDetection circuit. The circuit is divided into two parts: mechanical control and electrical measurement. machineThe mechanical control part mainly completes the selection of inductive sensors, the promotion and positioning of steel balls,The control function of turning plate of cylind

31、er and material box; the main part of electrical measurement is to pick up signals,Signal processing and execution display function. In the detection process, digital oscilloscope can be usedDynamic observation and measurement of output signals 4-5. Measuring and controlling system of steel ball dia

32、meter sorterThe schematic diagram of the circuit is shown in Fig.5 shows.2.3 working principle2.3.1 mechanical control circuitWhen cylinder intakeAZero point eightHigh intake of MPa, anterior residual cylinderLeaving gas byB mouth removal, the piston from left to right, push the steel ball at the di

33、scharge portTo the bottom of the inductive sensor for its pickup signal2, 6. During testing, the piston willControlled by electromagnetic valve drive circuit, the outlet of pistonB instead of air intakeenterZero point eightMPa high pressure air intakeA instead of the vent, remove the gas from the pi

34、stonThe piston automatically recovers its initial state and waits for the next ball to come. For the sake of spermCount the sizes of each steel ball accuratelyNineMm is the standard diameter of the steel ballOneThe M difference is divided into units -3, -2, -1, 0, 1, 2, 3, and so onM, defective prod

35、ucts8, etc.Class, correspondenceThe 8 charging boxes, the turning boards at the upper end of each receiving box, are controllable activitiesPlate by8 electromagnets corresponding to the drive circuit control, and finally through countThe device feedback the statistical results of each dimension stee

36、l ball to the computer and display it.2.3.2 electrical measuring circuit1) signal pickup moduleIn this case, taking into accountOneThe detection accuracy of the order of magnitude M is relatively high63Electronic design engineering, 20112chart5 Schematic diagram of the circuitFig.FiveCircuitPrincipl

37、eDiagramThe choice of sensors is very important for the final resultSensors minimize interference. So adoptAD6987 high precision linearDifferential inductance sensor (LVDT:Linear)VariableDifferentialTransformer) is a signal pickup circuit, with the mechanical shift of the magnetic core as inputThe f

38、low voltage signal is output, which is directly proportional to the position of the magnetic core. Sensor primary lineThe coil is excited by an external reference sinusoidal signal source, and the two secondary coils are connected in reverse seriesThe movement of the core can change the coupling flu

39、x between the primary coils, resulting in two amplitudeDifferent AC voltage signals are applied to meet the signal requirements of the following circuits.2) signal processing moduleIt is composed of phase sensitive detection circuit, standard signal setting circuit and voltage comparison amplifying

40、circuitAnd electromagnetic drive circuit 8. The phase sensitive detection circuit is used as the core to complete the differential demodulationSignal phase and frequency selection function, such as6 shows.chart6 phase detector circuitFig.SixPhaseSensitiveDetectorPhase sensitive detector circuitCircu

41、it composition: 4 rectifier diodes with consistent performanceVD1VD4Series into oneA closed bridge, 4 nodesThe A, B, C and D are connected to the transformer respectivelyT1, T2TheInput signal on secondary coilUyiReference voltage with detectorUy0After respectivelyT1, T2Sandwiched between the two dia

42、gonal angles of the bridge and the resistance in the bridgeR1R4Current limiting resistor,Resistance values areR, play the role of protecting the bridge arm diode.U0 Uyi=u1+u2, andandUyiSame frequency to ensure accurate controlConduction state of 4 diodes.642-How it works: when the armature moves abo

43、ve the zero (midpoint), it is shiftedX (T)0, uyiandUyoSame frequency and phase.WhenUyiandUy0Its almost half a week, T1Secondary coil output voltageU1byUp, down, and negative, depending on the end of the same name, U2Also for the positive and negative; T2;Secondary coiloutput voltageU01For the left,

44、right, and negative, according to the same name end, u02Also for the left, right, and rightNegative. According to the principle of circuit analysis, 3 can tell that the secondary output of transformer at all levels is:U01=u02=2un02 (7)U1=u2=2unyi1 (N1, N2)Respectively indicateT1, T2Turns ratio) (8)L

45、oop current is:IL=U2RL (9)RTwoOutput voltage is:Ux1=iLRL=RLuyi(10)N1 (R+2RL)WhenUyiandUy0Are negative half week, analysis of the same way.When the armature moves below the zero (midpoint), it is the displacementX (T) 0, and assumes the increase tendency, may know is the titleUpward movement of iron;

46、No.The 2 stage: the positive half week decline section, ux10, and assumes the reduction tendency, may know is the titleDownward movement of iron;No.The 3 stage: negative half week decline stage, ux10, and showed an increasing trend, known as the titleChen Yuzhong design of ball diameter classifier b

47、ased on inductance sensorDownward movement of iron;No.The 4 stage: negative half week rising stage, ux10, and showing a decreasing trend, which is known as the titleUpward movement of iron.chartWaveform of 7 phase sensitive detection circuitFig.SevenWaveformOfPhaseSensitiveDetectorOther circuitsFor

48、ease of analysis, byR1, RP1, RP23 resistor compositionNineMm, 9Mm + 3M,Any standard level is set to a standard signal file, which can be chosen by different standardsThe utility model can meet various standard quantities and compare with a phase sensitive detection signal (an error signal)9.When the

49、 signal is the same (within the range of error), the electromagnetic drive is driven by a voltage amplifierController17, open the corresponding steel ball receiving box and count the numbers. When the signal is notIn the same range (over error range), the electromagnetic control is driven by a voltage comparatorController8, open the defective steel ball receiving box and count the number, as shown in the figure8 shows.chart8 other circuitsFig.EightTheOtherCircuit3 signal execution moduleThe selection result is realized by computer, data storage