CN108020153A - Metal microspur measurement sensor, measuring system and measuring method - Google Patents
Metal microspur measurement sensor, measuring system and measuring method Download PDFInfo
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- CN108020153A CN108020153A CN201711303124.7A CN201711303124A CN108020153A CN 108020153 A CN108020153 A CN 108020153A CN 201711303124 A CN201711303124 A CN 201711303124A CN 108020153 A CN108020153 A CN 108020153A
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- 238000005259 measurement Methods 0.000 title claims abstract description 25
- 239000002184 metal Substances 0.000 title claims abstract description 23
- 229910052751 metal Inorganic materials 0.000 title claims abstract description 23
- 238000000034 method Methods 0.000 title claims abstract description 20
- 239000011159 matrix material Substances 0.000 claims description 9
- 239000003990 capacitor Substances 0.000 claims description 5
- 238000001514 detection method Methods 0.000 claims description 4
- 239000000758 substrate Substances 0.000 claims description 3
- 230000003321 amplification Effects 0.000 abstract description 7
- 238000003199 nucleic acid amplification method Methods 0.000 abstract description 7
- 238000007493 shaping process Methods 0.000 abstract description 7
- 238000012360 testing method Methods 0.000 abstract description 3
- 239000011248 coating agent Substances 0.000 abstract description 2
- 238000000576 coating method Methods 0.000 abstract description 2
- 239000002131 composite material Substances 0.000 abstract description 2
- 238000005555 metalworking Methods 0.000 abstract description 2
- 230000005611 electricity Effects 0.000 description 5
- 230000000694 effects Effects 0.000 description 3
- 238000012545 processing Methods 0.000 description 3
- 238000005516 engineering process Methods 0.000 description 2
- 230000006870 function Effects 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 230000000630 rising effect Effects 0.000 description 2
- 238000004458 analytical method Methods 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000009514 concussion Effects 0.000 description 1
- 238000009795 derivation Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 239000003989 dielectric material Substances 0.000 description 1
- 238000003698 laser cutting Methods 0.000 description 1
- 239000007769 metal material Substances 0.000 description 1
- 150000002739 metals Chemical class 0.000 description 1
- 230000010355 oscillation Effects 0.000 description 1
- 230000011664 signaling Effects 0.000 description 1
- 238000013519 translation Methods 0.000 description 1
Classifications
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
- G01B7/00—Measuring arrangements characterised by the use of electric or magnetic techniques
- G01B7/02—Measuring arrangements characterised by the use of electric or magnetic techniques for measuring length, width or thickness
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- General Physics & Mathematics (AREA)
- Measurement Of Length, Angles, Or The Like Using Electric Or Magnetic Means (AREA)
Abstract
The present invention provides metal microspur measurement sensor and measuring method, which includes capacitance test side, signal amplification and shaping unit, measurement and calculating end, be tested between two poles of metal object, there are an interelectrode capacity.In transducer tip, we access this interelectrode capacity oscillating circuit, then produce the oscillator signal of a certain frequency, the signal is accessed amplification and shaping circuit again, by amplifying and the signal after shaping, access FPGA circuitry, progress frequency measurement, curve matching, calculating distance, finally again the distance value calculated, by SPI interface, export to other main control devices, such as metal-working plant, metal spare and accessory parts assembly equipment etc..The metal microspur measurement sensor realized using above thinking, of low cost, measurement and calculating time are shorter, and precision is highly suitable for the industries such as intermetallic composite coating, the assembling of metal spare and accessory parts from the influence of working environment.
Description
Technical field
The present invention relates to analysis and survey control technology field, more particularly to a kind of high-speed, high precision metal microspur measurement passes
Sensor.
Background technology
Traditional slight distance measuring method, is to use capacitance method, inductance method, tellurometer survey method, laser ranging method etc..Its
In, inductance method, tellurometer survey method precision in laser cutting is applied is inadequate, and laser ranging method again easily light a fire by stimulated light and processing
Flower influences, it is impossible to reliability application；Capacitance method is two faces metal to be measured（Or a point and another face）, regard two as
Electrode, between the two electrodes there are a capacitance, which is C=ε S/d.（Wherein ε dielectrics of medium between pole plate are normal
Number, S are polar plate area, distances of the d between pole plate.）Understand according to formula above, the distance between capacitance C1 pole plate spacing is more
Greatly, capacitance is smaller, i.e. the distance between capacitance C1 pole plates spacing, the size with capacitance, there are correspondence, in this way, can
Measurement distance, to change into measurement capacitance, but what is solved first is how to measure between two capacitance C1 pole plate spacing etc.
Imitate the capacitance of capacitance.
The content of the invention
Present patent application provides metal microspur measurement sensor, and the capacitance variations data collected are carried out curve fitting
Processing, obtains the functional relation of the equivalent capacitance value and distance between two metal coverings, including resonance circuit, switch amplification electricity
Road, operational amplifier circuit, the switch input amplifier are connected with resonance circuit, export termination switch amplifying circuit；Resonance electricity
The RLC resonance circuits that road is formed using inductance L1, resistance R2 and detected capacitance C1；NPN ditches are used in switch amplifying circuit
The collector of the triode Q1 in road, triode Q1 connect the connection common port of inductance L1 and resistance R2, base stage in RLC resonance circuits and connect
The change of pull-up resistor R1, measured capacitance C1 cause the change of current collection electrode potential, the switch of control triode Q1；Operational amplifier circuit is adopted
With reverse operational amplifier circuit, the collector terminal of triode Q1 is followed by the reverse input of the transport and placing device U1 of operational amplifier circuit by capacitance C3
End, is amplified detection signal.
Preferably, in resonance circuit, capacitance C1 anode ground connection, cathode meet inductance L1, another terminating resistor R2 of inductance L1,
The other end of resistance R2 draws power supply；The pole plate of capacitance C1 is metal polar plate.
Preferably, switch in amplifying circuit, the base stage of triode Q1 also meets the RC being made of resistance R5, capacitance C7 parallel connections and filters
Wave circuit, the emitter of triode Q1 meet pull down resistor R7, and the indirect capacitance C6 of emitter and collector, capacitance C8 are connected in parallel on electricity
Resistance R7 both ends also constitute RC filter circuits.
Preferably, in operational amplifier circuit, the positive input IN+ of transport and placing device meets capacitance C3, output terminal and reverse input end IN-
Connecting resistance R6, resistance R6 and reverse input end IN- public termination pull down resistor R8, resistance R6 and the public termination capacitors of transport and placing device U1
Another the termination pull down resistor R4 and capacitance C5 of another terminating resistor R3 of C4, capacitance C4, R3.
A kind of measuring system using the sensor, including above-mentioned sensor, further include FPGA and main control device,
FPGA input termination sensors, calculate the capacitance C1 changing values of sensor measurement, are exported after calculating to main control device.
A kind of measuring method, within FPGA each clock cycle, sensor measures M signal value point, M signal value point
For pi (xi, yi), wherein i=1,2 ..., m；In X clock periodicity, for calculating capacity substrate spacing L；Using least square
The curve that M signal of law is formed carries out curve fitting, and chooses curve of approximation y=φ (x) of curve y=f (x) of M signal,
Deviation δ i=φ (xi)-y, i=1,2 ..., m of the curve of approximation at point pi；S1. set polynomial fitting as：
S2. each point is the sum of to the distance of this curve, i.e., sum of square of deviations is as follows：
S3. in order to try to achieve qualified a values, ai partial derivatives are sought on peer-to-peer the right, thus we obtain：
S4. the equation left side is subjected to abbreviation, then should can obtains following equation：
S5. these equatioies are expressed as the form of matrix, it is possible to obtain following matrix：
S6. can obtain after this vandermonde being obtained matrix abbreviation:
S7. that is X*A=Y, then A=(X'*X) -1*X'*Y, has just obtained coefficient matrices A, meanwhile, we also must
Matched curve is arrived.
Beneficial effects of the present invention：The interelectrode capacity between two metals, oscillating circuit is accessed.Oscillator signal is by putting
After big and shaping, FPGA is accessed.FPGA can undergo certain FPGA system during the external pulse of fixed number is captured
Clock periodicity, the numerical value of the system clock cycle number correspond to the frequency of external pulse.By learning and measuring whole distance
In the range of system clock cycle number, come obtain the numerical value of the system clock cycle number in the distance range it is corresponding with distance close
System.The correspondence can be represented with the form of curve, to the curve Function Fitting, obtain the vibration of the distance measuring sensor
The correspondence of signal frequency value and distance.In actual work, only need to be according to the frequency values of oscillator signal, you can calculate target
Distance, then the distance value, by SPI interface, exports to main control device.The metal microspur measurement sensing that the thinking is realized
Device, it is of low cost, measurement and calculate the time it is shorter, precision from working environment influence.
Brief description of the drawings
Fig. 1 is circuit diagram of the present patent application present patent application on sensor circuit；
Fig. 2 is principle framework figure of the present patent application on this patent；
Fig. 3 is the curve of the actual measured value for the capacitor plate spacing that present patent application is measured on sensor；
Fig. 4 is to the matched curve after the actual measurement profile fitting of Fig. 3 by FPGA.
Embodiment
Shown in Fig. 1, present patent application provides a kind of sensor circuit, and capacitance concussion frequency is carried out using sensor circuit
Test, sensor detection circuit use RLC resonance circuits by resonance circuit, switch amplifying circuit, operational amplifier circuit, resonance circuit,
It is made of detected capacitance C1, inductance L1, resistance R2, capacitance C1 anode ground connection, cathode connect inductance L1, the other end of inductance L1
Connecting resistance R2, the other end of resistance R2 draw power supply；Capacitance C1 is adjustable, and the effects of capacitance C1 in this patent are tested
Element is surveyed, the electrode plate of capacitance C1 uses metal material, electrode plate distance, the change of pole plate relative area and the plate of capacitance C1
The change of part medium can all cause the faint change of resonance circuit.
Amplifying circuit is switched by triode Q1, resistance R1, R5, R7, capacitance C6, C7, C8, resistance R5, capacitance C7 parallel connection structures
Into RC filter circuits, RC filter circuits one end ground connection, the other end connects pull-up resistor R1 and triode Q1 base stages, triode Q1 are adopted
With NPN raceway grooves, common port, the emitter of the collector connecting resistance R2 and inductance L1 of triode Q1 connect pull down resistor R7, triode
The indirect capacitance C6 of Q1 emitters and collector, capacitance C8 are connected in parallel on resistance R7 both ends and also constitute RC filter circuits.
Inductance L1, capacitance C6, the public termination capacitor C3 of resistance R2 and triode Q1 collectors, capacitance C3's
Another termination operational amplifier circuit.
Operational amplifier circuit uses reverse operational amplifier circuit, including：Transport and placing device U1, capacitance C2, C4, C5, resistance R6, R8, R4, R3,
Transport and placing device U1 connects power supply, and the positive input IN+ of transport and placing device meets capacitance C3, output terminal and reverse input end IN- connecting resistance R6, electricity
The R6 and reverse input end IN- public termination capacitor C4 of public termination pull down resistor R8, resistance R6 and transport and placing device U1 are hindered, capacitance C4's
Another the termination pull down resistor R4 and capacitance C5 of another terminating resistor R3, R3.
Change of the sensor detection circuit to adjustable condenser C1 is detected in real time, i.e.,：Using above-mentioned hardware electricity
The sensor on road, the frequency of the frequency of its oscillator signal, i.e. capacitance measured signal, with two capacitance C1 pole plate distances
Change, the frequency of measured signal, occurs faint change, if two capacitance C1 pole plate spacing are in contact, measured signal
Frequency, change dramatically are simultaneously handled by amplification switch circuit and operational amplifier circuit, calculated after processing using FPGA.
Shown in Fig. 2, the present patent application also provide a kind of frequency measuring system, including above-mentioned sensor measuring circuit,
FPGA and main control device, further include：Capacitance test side, signal amplification and shaping unit, measurement and calculating end,
There are an interelectrode capacity between two poles of tested metal object, in transducer tip, we are this interelectrode capacity, access
Oscillating circuit, then produces the oscillator signal of a certain frequency, then the signal is accessed amplification and shaping circuit, by amplification and whole
Signal after shape, accesses FPGA circuitry, carries out frequency measurement, curve matching, calculates distance, finally again the distance calculated
Value, by SPI interface, exports to other main control devices, such as metal-working plant, metal spare and accessory parts assembly equipment etc..
Conventional frequency measuring method, that is, measure the interval between the rising edge of two neighboring measured signal, with measured signal
Exemplified by 2MHz, its cycle is 500ns, if we are measured with the time scale of 5ns, its worst error is less than two FPGA's
The system cycle, i.e., be 10/500=2% less than 10ns, error rate, so big error rate, can not ensure system accuracy.
The present patent application also provide a kind of frequency measurement to calculate method, and oscillator signal is accessed by amplifying with after shaping
FPGA, FPGA can undergo certain FPGA system clock periodicity, this is during the external pulse of fixed number is captured
The numerical value of system clock periodicity correspond to the frequency of external pulse, we are by learning and measuring the system in whole distance range
Clock periodicity, to obtain the numerical value of system clock cycle number and the correspondence of distance in the distance range, which closes
System can represent that the curve is the intrinsic curve of sensor, the shape of the curve with the form of curve, only with sensor in itself
Characteristic it is related, will not change because of the change of working environment, only need to be to the curve when temperature, humidity are when changing
Make translation to correct.
For further, which is by measuring two neighboring measured signal rising edge（That is 1 cycle）It
Between interval realize that, if measured signal has continuous N number of cycle, we, which can pass through, measures the upper of two signals of head and the tail
The interval on edge is risen, to calculate the frequency of single measured signal, then error rate=2%/N at this moment, that is, precision improve
N times.
The pulse signal of collection sensor measuring circuit in the FPGA clock cycle, if：M signal is collected in clock cycle
It is worth point, X clock periodicity is shared, for calculating capacity substrate spacing L, wherein the coordinate information of each signaling point is（X, y）,
The curve of capacitance and distance is carried out curve fitting using least square method multinomial, according to m given point, it is not required that this
Bar curve accurately passes through these points, but curve of approximation y=φ (x) of curve y=f (x), data-oriented point pi (xi, yi),
Wherein i=1,2 ..., m, seek curve of approximation y=φ (x), and make it that the deviation of curve of approximation and y=f (x) are minimum, curve of approximation
Deviation δ i=φ (xi)-y, i=1,2 ..., m at point pi.
Common curve-fitting method:
1. make the sum of absolute value of the bias minimum
2. make the minimum of absolute value of the bias maximum
3. make sum of square of deviations minimum
Matched curve is chosen by the principle of sum of square of deviations minimum, and takes the method that binomial equation is matched curve, is claimed
For least square method.
Derivation：
1. set polynomial fitting as：
2. each point the sum of to the distance of this curve, i.e., sum of square of deviations is as follows：
3. in order to try to achieve qualified a values, ai partial derivatives are sought on the right of peer-to-peer, thus we obtain：
4. the equation left side is carried out abbreviation, following equation then should can be obtained：
5. these equatioies are expressed as the form of matrix, it is possible to obtain following matrix：
6. it can obtain after this vandermonde is obtained matrix abbreviation:
7. that is X*A=Y, then A=(X'*X) -1*X'*Y, has just obtained coefficient matrices A, meanwhile, we also must
Matched curve is arrived.
The curve that we arrive study, with Function Fitting, obtains the oscillation signal frequency value and distance of the distance measuring sensor
Correspondence, in actual work, only need to be according to the frequency values of oscillator signal, you can calculate target range, then this away from
From value, by SPI interface, export to main control device.
The metal microspur measurement sensor realized using above thinking, of low cost, measurement and calculating time are shorter, precision
From the influence of working environment, it is highly suitable for the industries such as intermetallic composite coating, the assembling of metal spare and accessory parts.
The principles and effects of present patent application is only illustrated in above-described embodiment, not for limitation this patent Shen
Please.Any person skilled in the art can all carry out above-described embodiment under the spirit and scope without prejudice to present patent application
Modifications and changes.Therefore, such as those of ordinary skill in the art without departing from the revealed essence of present patent application
With all lamps effect modifications and changes completed under technological thought, the claim that should be asked by this patent is covered god.
Claims (6)
1. metal microspur measurement sensor, it is characterised in that：It is described to open including resonance circuit, switch amplifying circuit, operational amplifier circuit
Input amplifier is closed to be connected with resonance circuit, export termination switch amplifying circuit；Resonance circuit uses inductance L1, resistance R2
The RLC resonance circuits formed with detected capacitance C1；Switch the triode Q1 that NPN raceway grooves are used in amplifying circuit, triode
The collector of Q1 connects the connection common port of inductance L1 and resistance R2, base stage in RLC resonance circuits and connects pull-up resistor R1, measured capacitance
The change of C1 causes the change of current collection electrode potential, the switch of control triode Q1；Operational amplifier circuit uses reverse operational amplifier circuit, three poles
The collector terminal of pipe Q1 is followed by the reverse input end of the transport and placing device U1 of operational amplifier circuit by capacitance C3, and detection signal is put
Greatly.
2. metal microspur measurement sensor according to claim 1, it is characterised in that：In resonance circuit, capacitance C1 anode
Ground connection, cathode meet inductance L1, another terminating resistor R2 of inductance L1, and the other end of resistance R2 draws power supply；The pole plate of capacitance C1 is
Metal polar plate.
3. metal microspur measurement sensor according to claim 1, it is characterised in that：Switch in amplifying circuit, triode
The base stage of Q1 also connects the RC filter circuits being made of resistance R5, capacitance C7 parallel connections, and the emitter of triode Q1 meets pull down resistor R7,
The indirect capacitance C6 of emitter and collector, capacitance C8 are connected in parallel on resistance R7 both ends and also constitute RC filter circuits.
4. metal microspur measurement sensor according to claim 1, it is characterised in that：In operational amplifier circuit, transport and placing device is just
Capacitance C3, output terminal and reverse input end IN- connecting resistance R6, resistance R6 and reverse input end IN- common ports are connect to input terminal IN+
Connect another terminating resistor R3 of pull down resistor R8, resistance R6 and transport and placing device U1 public termination capacitor C4, capacitance C4, the other end of R3
Meet pull down resistor R4 and capacitance C5.
A kind of 5. measuring system using the sensor, it is characterised in that：Including above-mentioned sensor, FPGA and master are further included
Equipment is controlled, FPGA input termination sensors, calculate the capacitance C1 changing values of sensor measurement, exported after calculating to master control
Equipment.
A kind of 6. measuring method, it is characterised in that：Within FPGA each clock cycle, sensor measures M signal value point, M
A signal value point is pi (xi, yi), wherein i=1,2 ..., m；In X clock periodicity, for calculating capacity substrate spacing L；Adopt
The curve formed with M signal of least square law carries out curve fitting, and chooses the curve of approximation of curve y=f (x) of M signal
Y=φ (x), deviation δ i=φ (xi)-y, i=1,2 ..., m of the curve of approximation at point pi；S1. set polynomial fitting as：
S2. each point is the sum of to the distance of this curve, i.e., sum of square of deviations is as follows：
S3. in order to try to achieve qualified a values, ai partial derivatives are sought on peer-to-peer the right, thus we obtain：
.......
S4. the equation left side is subjected to abbreviation, then should can obtains following equation：
.......
S5. these equatioies are expressed as the form of matrix, it is possible to obtain following matrix：
S6. can obtain after this vandermonde being obtained matrix abbreviation:
S7. that is X*A=Y, then A=(X'*X) -1*X'*Y, has just obtained coefficient matrices A, meanwhile, we also must
Matched curve is arrived.
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Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112304206A (en) * | 2019-07-30 | 2021-02-02 | 广州汽车集团股份有限公司 | Object distance measuring device and method |
| CN112400143A (en) * | 2019-08-02 | 2021-02-23 | 深圳市越疆科技有限公司 | Sensing circuit, logic circuit board, joint control board, main controller board and robot |
| CN113155012A (en) * | 2021-01-25 | 2021-07-23 | 上海兰宝传感科技股份有限公司 | Capacitive proximity switch sensor |
| CN113720248A (en) * | 2021-09-01 | 2021-11-30 | 西京学院 | Linear displacement measuring device and method based on capacitance sensing |
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| CN101246203A (en) * | 2008-04-02 | 2008-08-20 | 吉林大学 | Amorphous alloy low-intensity magnetic field sensor |
| CN201146489Y (en) * | 2007-12-17 | 2008-11-05 | 伊玛精密电子（苏州）有限公司 | Intelligent type capacitive approach switch |
| CN101382411A (en) * | 2007-09-06 | 2009-03-11 | 联想(北京)有限公司 | Capacitance distance measuring method and device |
| CN208140017U (en) * | 2017-12-11 | 2018-11-23 | 无锡超强伟业科技有限公司 | Metal microspur measurement sensor and measuring system |
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2017
- 2017-12-11 CN CN201711303124.7A patent/CN108020153A/en active Pending
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| CN2062083U (en) * | 1989-12-26 | 1990-09-12 | 赵济仓 | Theft-proof electronic alarm by human body induction |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN112304206A (en) * | 2019-07-30 | 2021-02-02 | 广州汽车集团股份有限公司 | Object distance measuring device and method |
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| CN112400143B (en) * | 2019-08-02 | 2023-09-08 | 深圳市越疆科技股份有限公司 | Sensing circuit, logic circuit board, joint control board, master controller board and robot |
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| CN113720248A (en) * | 2021-09-01 | 2021-11-30 | 西京学院 | Linear displacement measuring device and method based on capacitance sensing |
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