CN1056751A - The method of man body approaching sensing and circuit - Google Patents
The method of man body approaching sensing and circuit Download PDFInfo
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- CN1056751A CN1056751A CN 90105664 CN90105664A CN1056751A CN 1056751 A CN1056751 A CN 1056751A CN 90105664 CN90105664 CN 90105664 CN 90105664 A CN90105664 A CN 90105664A CN 1056751 A CN1056751 A CN 1056751A
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- 238000000034 method Methods 0.000 title claims abstract description 30
- 238000001514 detection method Methods 0.000 claims abstract description 7
- 238000012512 characterization method Methods 0.000 claims description 9
- 230000000694 effects Effects 0.000 claims description 6
- 230000010355 oscillation Effects 0.000 claims description 4
- 230000015572 biosynthetic process Effects 0.000 claims description 2
- 230000005764 inhibitory process Effects 0.000 claims description 2
- 230000001960 triggered effect Effects 0.000 claims description 2
- 230000002463 transducing effect Effects 0.000 claims 4
- 239000000654 additive Substances 0.000 claims 2
- 230000000996 additive effect Effects 0.000 claims 2
- JEIPFZHSYJVQDO-UHFFFAOYSA-N ferric oxide Chemical compound O=[Fe]O[Fe]=O JEIPFZHSYJVQDO-UHFFFAOYSA-N 0.000 claims 2
- 230000003313 weakening effect Effects 0.000 claims 1
- 238000005516 engineering process Methods 0.000 description 11
- 238000010586 diagram Methods 0.000 description 6
- 230000004044 response Effects 0.000 description 4
- 230000035945 sensitivity Effects 0.000 description 4
- 230000003321 amplification Effects 0.000 description 2
- 230000006698 induction Effects 0.000 description 2
- 238000003199 nucleic acid amplification method Methods 0.000 description 2
- 230000033228 biological regulation Effects 0.000 description 1
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- 239000003990 capacitor Substances 0.000 description 1
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- 230000035772 mutation Effects 0.000 description 1
- 230000036581 peripheral resistance Effects 0.000 description 1
- 230000002265 prevention Effects 0.000 description 1
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Abstract
A kind of method of man body approaching sensing and circuit, this method and circuit utilize oscillator, counter directly the variation of the approaching caused distributed capacitance of human body to be converted to the variation of frequency codes, send into the digital operation device again and obtain high stability, high jamproof detection signal through certain related operation processing.Also utilize undesired signal to form the protection pulse in this method and the circuit, to eliminate strong interference affects.Method of the present invention and circuit can apply to aspects such as human body sensing burglar alarm, automaton.
Description
The present invention relates to a kind of method and circuit of man body approaching sensing of wide-azimuth.
Existing man body approaching sensing detection technique comprises reflection of electromagnetic wave or absorbs multiple technologies schemes such as induction technology, body capacitance sensing technology, human-body infrared sensing technology, visible light detection technique, ultrasonic detection technology, image processing techniques.In the technique scheme, image processing techniques has been used the intelligent digital treatment technology, thereby possesses high anti-interfering performance and high sensing sensitivity.But owing to adopted camera and complicated Computer Processing technology, with high costs when practical application, device is complicated, is unfavorable for popularizing utilization.Remaining human body mostly relates to the amplification of weak signal near sensing technology, promptly the human body close signal to be converted to the less analog electrical signal of amplitude, and, even need further deliver to the detection that trigger just can be finished the human-induced signal with this electric signal amplification ratio.Each link all is easy to disturbed by extraneous signal in this process, thereby the human body sensor of this kind form is applied to actual time, and its degree of stability comprises the limitation of interference free performance, and it is unfavorable to bring to use.And the infrared electronic technology that can find application preferably in these technology does not relate to the frequency discrimination technology that weak signal is amplified even if adopt, and it is little also will to be subjected to the sensing visual angle, the disadvantages affect that is subject to shield.
The object of the present invention is to provide a kind of high anti-interference, low-cost, wide sensing orientation, unshielded effect, be easy to the method and the circuit of the man body approaching sensing of popularization and application.
The object of the present invention is achieved like this: utilize capacitance sensing electrode and electric capacity modulation frequency oscillator directly will change into the stronger frequency variation signal of signal energy near the variation of the caused distributed capacitance of human body, Wai Jie undesired signal is weakened widely to the interference of sensor spoke degree like this.The circuit remainder almost all adopts jamproof digital circuit in addition, circuit not only scabbles the influence of the positive and negative fluctuation of count value that disturbing pulse causes counter to the computing that signal carried out, and the slow variation that circuit can be conformed automatically, and circuit also adopts disturbing pulse self inhibition method to weaken disturbing effect greatly.Therefore circuit has strong interference free performance and the stability of the variation that conforms automatically.In addition because capacitance sensing electrode distributed capacitance over the ground is that it doesn't matter direction, so this method for sensing also is a wide-azimuth, simultaneously also can not conductively-closed, because in case shielded, capacitance sensing electrode pair earth capacitance is just undergone mutation.Entire circuit reaches total digitalization substantially, if circuit is made monolithic processor, then cost is extremely cheap, again because of its performance is good, must be easy to popularize utilization.Therefore entire circuit being made monolithic processor should be optimum implementation of the present invention.
Method for sensing of the present invention and circuit elaborate conjunction with figs..
Accompanying drawing 1 is a theory diagram of the present invention.
Accompanying drawing 2 is a kind of enforcement circuit diagram of the present invention.
Accompanying drawing 3 is the program flow diagram of CPU among the embodiment.
In the block scheme of Fig. 1, each square frame is represented following functional circuit respectively:
1. capacitance sensing electrode;
2. the electric capacity oscillator of adjusting frequency;
3. count signal gate;
4. multi-stage cascade counter;
5. arithmetical unit;
6. storage circuit;
7. programming controller;
8. output trigger;
9. undesired signal protection circuit;
10. clock circuit;
11. clock signal gating gate;
12. power supply.
Among Fig. 1, dotted line is represented control line, and single straight line is represented the normal signal line, two-wire representative data line.
Capacitance sensing electrode 1 among the figure can be the conducting plate of required arbitrary shape or curved surface, conduction straight line or curve, conduction gauze.Human body causes that sensing electrode 1 ground capacitance changes during near induction electrode, thereby has directly changed the oscillation frequency of back level electric capacity modulation frequency oscillator 2.Under the control of programming controller 7, counter 4 repeats to detect pulse number Fi in this each time interval at interval by regular time, and it is the i time that the i indication circuit is connected the ordinal number that detects the back.
B
1＝0
Bj=(Bi+FiC)/(1+C), j=i+1, C are constant, and constant C has determined the influence degree to Bi as time measured value Fi of institute, and the more little then influence of C is more little.C has determined circuit response time of capacitance variations to external world, changes to another value and remains unchanged from a value as extraneous electric capacity, and then circuit stops response automatically after response a period of time.In the practical application, should determine the C value 0.0001 to 1 according to the required response time.
Because the enforcement circuit of man body approaching sensing method of the present invention can be barricaded as with multiple device on above-described basic circuit structure, only enumerate an enforcement circuit here, and will make circuit by it and further specify.
Fig. 2 is for implementing circuit diagram.The main element parameter is all indicated in the drawings.Among the figure, C
0To C
13Be fixed capacity, Cx is a capacitance sensing electrode total capacitance over the ground; R
1To R
14And Rb, Rc, 10Kx16 row resistance is the resistance of entire circuit; JT is the crystal of 3 to 4 megahertzes.Oscillator, trigger, clock circuit all are typical circuits, and its careful parameter can obtain from interrelated data.
In the circuit, Z80CPU is responsible for the control and the data operation of entire circuit; Row's resistance of 10Kx16 is served as the current potential pull-up resistor of its address leads; R
11, C
11And R
8The reset circuit of forming CPU.Two 1Kx4 static RAM (SRAM)s
2114Data memory as circuit; The EPROM of a slice 2Kx8
2716Memory under program as CPU.Counter is by two 12 grades of binary counter CD
4040Cascade forms; Three eight bit data impact damper 74LS
244CPU can all be read counter values by three reading methods.
Five outputs of three/eight address decoder 74LS138 are gating RAM, EPROM, three data buffers respectively; The 6th output is as the reset signal line of counter, and the 7th counting as counter allows signal wire, the 8th the detection output line as CPU.
Phase inverter in the circuit is provided by two hex inverter 74LS04, and wherein door 1 and 2 is formed clock oscillator, and all the other are all as phase inverter or impact damper.Sheffer stroke gate is gone into by the confession of a slice 74LS00 load in four two wires, door 1,2 counting gates wherein as counter, and door 3 is as the clock signal gate.
The electric capacity oscillator of adjusting frequency is made of triode 9013 and peripheral resistance thereof, electric capacity, power plant, belongs to the modified bikini oscillator.Its oscillation frequency
f＝1/（2×3.14159×√L·C0）
The amplitude output signal peak-to-peak value can reach 2V.Should adjust Rb and Rc in case of necessity, make it export enough trigger gate circuit.
The interference prevention circuit is made of detecting circuit and monostable trigger.Detecting circuit is by diode D
1And capacitor C
8Constitute, detect amplitude unusual in the vibration output by it and change, and trigger by LM
5 55Monostable trigger is triggered on the just edge of forming, and Sheffer stroke gate 2 and 3 is pinned in about about the 0.1 second low level protection pulse of trigger output pulse width.
Output circuit is by LM
555The monostable trigger of forming constitutes, its output pulse width is slightly smaller than three/eight code translator octal Y8 output recurrence interval, exports so that make each pulse of CPU computing output can be received (being that so-called output trigger is subjected to influencing jointly of each operation result) by this monostable trigger and be organized into approximate DC level.And because a disturbing pulse can only trigger out an output pulse that pulsewidth is very narrow, this pulse width is because of being slightly smaller than the computing output cycle of CPU, its width is below Millisecond, so discrete disturbing pulse almost can not influence the output of circuit, because they change the transient state of output at the most, can be eliminated by considering the ripple method.
Fig. 3 is the program flow diagram of CPU, and each time operation is as follows among the figure:
(1) initialization: this moment, circuit rigidly connected logically, and CPU carries out initialize routine, makes entire circuit enter readiness.
(2) from the counter peek, send into the CPU register, because counter has three eight outputs, so need get three times.
(3) with counter O reset and restart the counting.
(4) value Fi and the poor absolute value of characterization value Ai that just has been taken into from counter asked in (5) (6).
(7) this absolute value is differentiated greater than constant K in (8) (9) whether, be then make CPU in following time lapse constantly with address wire A
11, A
12, A
13, A
15Be set to 1, then three/eight code translator octal Y8 output low level pulses.
(10) the new characterization value of counting.
(11) carry out delay procedure.Rotate back into (2) after finishing, constantly circulation.
The practical programs of CPU can be compiled out according to this process flow diagram easily.
Claims (10)
1, a kind of method of man body approaching sensing, it is characterized in that to be directly changed into the variation of oscillator oscillation frequency near the variation of the caused distributed capacitance of human body, and according to the regular time interval, constantly repeatedly detect pulse number in each time interval with counter, again institute's measured value is carried out the digital correlation computing and relatively obtain transducing signal.
2, method according to claim 1, it is characterized in that carrying out by the following method the digital correlation computing, can obtain reliable transducing signal by this method, promptly after the i time (i is the natural number greater than 1) records number of pulses Fi, the measured value Fi of institute is carried out additive operation with the characterization value Bi of front institute measured value, if Bi-Fi＞K
1, it is approaching then to be judged as the people, if Fi-Bi＞K
2, then the people's goes to pot K near distance increase or sensor
1, K
2Be the positive constant of setting.
3, method according to claim 1 and 2 is characterized in that characterization value tries to achieve as follows, and this method makes circuit obtain to weaken the effect of the influence of undesired signal, and characterization value Bi satisfies relation:
B
1＝F
1
Bj＝（Bi+Fi·C）/（1+C）
C is a constant, j=i+1, and i is a natural number, represents circuit to connect the number of times sequence number that pulse number is detected in the back.
4, method according to claim 1 and 2 is characterized in that the final output of sensing is subjected to each computing to export result's common control.
5, method according to claim 1 and 2 is characterized in that adopting disturbing pulse self inhibition method to eliminate disturbing effect, promptly triggers monostable trigger formation protection pulse with disturbing pulse and removes to flood disturbing pulse.
6, a kind of circuit of man body approaching sensing, it comprises capacitance sensing electrode, electric capacity modulation frequency oscillator, clock, counter, digital operation device, storage circuit, controller, output trigger, power circuit.It is characterized in that the capacitance sensing electrode links to each other with electric capacity modulation frequency oscillator, variation near the caused distributed capacitance of human body is directly changed into the variation of oscillation frequency, programming controller control counter duplicate detection goes out the pulse number that electric capacity modulation frequency oscillator is exported in Fixed Time Interval, the umber of pulse that will at every turn record is sent into digital operational circuit again, obtains transducing signal by computing output control output trigger.
7, circuit according to claim 6, it is characterized in that circuit adopts following control, to obtain reliable transducing signal: after the i time (i is the natural number greater than 1) records umber of pulse Fi, the characterization value Bi that is stored in the storage circuit that this value is surveyed with the front carries out additive operation in arithmetical unit, if Bi-Fi＞K
1, it is approaching then to be judged as the people, if Fi-Bi＞K
2, then the people's goes to pot K near distance increase or sensor
1, K
2Be the positive constant of setting.
8, according to claim 6 or 7 described circuit, it is characterized in that characterization value Bi tries to achieve as follows, this method makes circuit obtain the effect of the influence of weakening undesired signal, and characterization value Bi satisfies relation:
B
1＝F
1
Bj＝（Bi+Fi·C）/（1+C）
C is a constant; J=i+1, i are natural number, and on behalf of circuit, i connect the number of times sequence number that frequency is detected in the back.
9,, it is characterized in that output trigger is subjected to the common control of each operation result according to claim 6 or 7 described circuit.
10, according to claim 6 or 7 described circuit, it is characterized in that having in the circuit single-shot trigger trigger by interference triggered, its input end links to each other with oscillator output by wave detector, its output terminal is connected to clock signal gate and count signal gate, makes the disturbing pulse quilt about the outer disturbing effect of eliminating of signal gate thereby control two gates.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 90105664 CN1056751A (en) | 1990-05-18 | 1990-05-18 | The method of man body approaching sensing and circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 90105664 CN1056751A (en) | 1990-05-18 | 1990-05-18 | The method of man body approaching sensing and circuit |
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| Publication Number | Publication Date |
|---|---|
| CN1056751A true CN1056751A (en) | 1991-12-04 |
Family
ID=4879472
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 90105664 Pending CN1056751A (en) | 1990-05-18 | 1990-05-18 | The method of man body approaching sensing and circuit |
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| Country | Link |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1325939C (en) * | 2001-08-24 | 2007-07-11 | 富士通天株式会社 | In-vehicle body detection method |
| CN101490566B (en) * | 2006-07-20 | 2011-10-12 | 爱迪半导体株式会社 | Method and apparatus for detecting capacitance using a plurality of time division frequencies |
-
1990
- 1990-05-18 CN CN 90105664 patent/CN1056751A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1325939C (en) * | 2001-08-24 | 2007-07-11 | 富士通天株式会社 | In-vehicle body detection method |
| CN101490566B (en) * | 2006-07-20 | 2011-10-12 | 爱迪半导体株式会社 | Method and apparatus for detecting capacitance using a plurality of time division frequencies |
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