CN101739795B - Gas sensing module, wireless transmitting device and wireless sensing system using the same - Google Patents
Gas sensing module, wireless transmitting device and wireless sensing system using the same Download PDFInfo
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- CN101739795B CN101739795B CN200810173900A CN200810173900A CN101739795B CN 101739795 B CN101739795 B CN 101739795B CN 200810173900 A CN200810173900 A CN 200810173900A CN 200810173900 A CN200810173900 A CN 200810173900A CN 101739795 B CN101739795 B CN 101739795B
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- gas sensing
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- piezoelectric resonator
- gas
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- 238000012360 testing method Methods 0.000 claims description 6
- 238000001514 detection method Methods 0.000 abstract 1
- 238000010586 diagram Methods 0.000 description 16
- 239000003990 capacitor Substances 0.000 description 5
- 230000006870 function Effects 0.000 description 3
- UGFAIRIUMAVXCW-UHFFFAOYSA-N Carbon monoxide Chemical compound [O+]#[C-] UGFAIRIUMAVXCW-UHFFFAOYSA-N 0.000 description 2
- 229910002091 carbon monoxide Inorganic materials 0.000 description 2
- 239000000969 carrier Substances 0.000 description 2
- 238000012544 monitoring process Methods 0.000 description 2
- 150000001335 aliphatic alkanes Chemical class 0.000 description 1
- 230000000740 bleeding effect Effects 0.000 description 1
- 230000034994 death Effects 0.000 description 1
- 231100000517 death Toxicity 0.000 description 1
- 238000007599 discharging Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000005265 energy consumption Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 231100001261 hazardous Toxicity 0.000 description 1
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Abstract
The invention relates to a gas sensing module, a wireless transmitting device and a wireless sensing system using the same. The gas sensing module comprises a piezoelectric resonator, a gas sensing unit and a modulation element. The piezoelectric resonator is connected to the gas sensing unit and the active circuit, so that the active circuit outputs a carrier related to the concentration of the gas to be detected. The modulation element is connected to the piezoelectric resonator to set the frequency or amplitude of the carrier wave. The invention has low power consumption and low cost; is suitable for throwing occasions; and to multi-point detection.
Description
Technical field
The present invention relates to a kind of gas sensing module and use its wireless launcher and wireless sensor system; And particularly do not need the extra carrier wave that provides, but the gas sensing module of carrier wave is provided and uses its wireless launcher and wireless sensor system by oscillator relevant for a kind of.
Background technology
At sewer, culvert, prospect, operating environments such as pit and oil groove, exist just like harmful gas gas such as carbon monoxide (gas) and alkanes often, just can carry out operation after must bleeding.Because whether the harmful gas concentration in the environment differs, bleed fully, will cause injures and deaths to the workmen easily if can't confirm.So, in order to increase safety guarantee, must detect the harm gas concentration in the operating environment before constructing, to prevent unexpected the generation to the workmen in advance.
Yet conventional wireless sensor power consumption is big and cost is high, so inapplicable in the throwing occasion.Particularly when the operation environment need carry out multipoint sensing, the site work personnel more can not a plurality of expensive conventional wireless sensor sensing harm gas concentrations of a throwing.
Summary of the invention
In order to solve prior art problems, the purpose of this invention is to provide the gas sensing module and use its wireless launcher and wireless sensor system.
For reaching said purpose, the present invention proposes a kind of gas sensing module, and the gas sensing module comprises piezoelectric resonator, gas sensing unit and varying element.Piezoelectric resonator is connected to a gas sensing unit and an active circuits; Make the carrier wave that active circuits output one is relevant with gas concentration to be measured; Gas sensing unit is connected to piezoelectric resonator, and varying element is connected to piezoelectric resonator, to set the frequency or the amplitude of carrier wave.
According to the present invention, a kind of wireless launcher is proposed, wireless launcher comprises active circuits, gas sensing module and transmitter.The gas sensing module comprises piezoelectric resonator, gas sensing unit and varying element.Piezoelectric resonator is connected to a gas sensing unit and an active circuits, makes the carrier wave that active circuits output one is relevant with gas concentration to be measured, and varying element is connected to piezoelectric resonator, with the frequency or the amplitude of setting carrier wave.Transmitter is connected to active circuits, and in order to the emission carrier wave.
According to the present invention, a kind of wireless sensor system is proposed, the wireless sensor system comprises wireless launcher and radio receiver; Wireless launcher comprises active circuits, gas sensing module and transmitter, and the gas sensing module comprises piezoelectric resonator, gas sensing unit and varying element, and piezoelectric resonator is connected to a gas sensing unit and an active circuits; Make the carrier wave that active circuits output one is relevant with gas concentration to be measured; Gas sensing unit is connected to piezoelectric resonator, and varying element is connected to piezoelectric resonator, to set the frequency or the amplitude of carrier wave; Transmitter is connected to active circuits; And in order to the emission carrier wave, radio receiver comprises receiver, signal processing unit and display unit, and receiver is in order to reception carrier.Signal processing unit is connected to receiver, and according to carrier wave output shows signal, display unit is connected to signal processing unit, and shows shows signal.
The present invention relates to a kind of gas sensing module and use its wireless launcher and wireless sensor system, it has following advantage at least:
One, power consumption is little;
Two, cost is low;
Three, be applicable to the throwing occasion; And
Four, be applicable to that multiple spot detects.
Description of drawings
Fig. 1 illustrates the synoptic diagram into the wireless sensor system.
Fig. 2 illustrates the synoptic diagram into wireless launcher.
Fig. 3 illustrates the synoptic diagram into oscillator.
Fig. 4 is the synoptic diagram of radio receiver.
Fig. 5 illustrates the synoptic diagram of connecting with piezoelectric resonator into gas sensing unit.
Fig. 6 illustrates the equivalent circuit diagram of connecting with piezoelectric resonator into gas sensing unit.
Fig. 7 illustrates and is the gas sensing unit synoptic diagram parallelly connected with piezoelectric resonator.
Fig. 8 illustrates and is the gas sensing unit equivalent circuit diagram parallelly connected with piezoelectric resonator.
The curve map of the resistance at resonance when Fig. 9 illustrates and connects with piezoelectric resonator into gas sensing unit.
Figure 10 illustrates the curve map into the antiresonance resistance of gas sensing unit when parallelly connected with piezoelectric resonator.
The voltage curve of the carrier wave when Figure 11 illustrates and connects with piezoelectric resonator into gas sensing unit.
Figure 12 illustrates the voltage curve into the carrier wave of gas sensing unit when parallelly connected with piezoelectric resonator.
Figure 13 illustrates the oscillogram into carrier wave before the sensing.
Figure 14 illustrates the oscillogram into carrier wave behind the sensing.
The resonant frequency curve map of the carrier wave when Figure 15 illustrates and connects with piezoelectric resonator into varying element.
Figure 16 illustrates and is the antiresonant frequency curve map of varying element when parallelly connected with piezoelectric resonator.
Figure 17 illustrates the thin portion circuit into wireless launcher.
Figure 18 illustrates and is the consumes electric power comparison sheet.
[main element symbol description]
10: the wireless sensor system
20: wireless launcher
30: radio receiver
210: oscillator
212: the gas sensing module
214: active circuits
220: transmitter
230: memory element
240: output control circuit
242: comparer
310: receiver
320: signal processing unit
330: display unit
340: charging circuit
350: test circuit
360: power supply unit
2122: varying element
2124: piezoelectric resonator
2126: gas sensing unit
21242: perforation
Tr1～Tr3: transistor
R1～R10, Rs, Rp: resistance
C1～C9: electric capacity
D1, D2: diode
L1: inductance
Embodiment
For letting the foregoing of the present invention can be more obviously understandable, hereinafter is special lifts a preferred embodiment, and cooperates appended graphicly, elaborates as follows:
Please be simultaneously with reference to Fig. 1, Fig. 2, Fig. 3 and Fig. 4, Fig. 1 illustrates the synoptic diagram into the wireless sensor system, and Fig. 2 illustrates the synoptic diagram into wireless launcher, and Fig. 3 illustrates the synoptic diagram into oscillator, and Fig. 4 is the synoptic diagram of radio receiver.Wireless sensor system 10 comprises wireless launcher 20 and radio receiver 30.Wireless launcher 20 comprises oscillator 210 and transmitter 220 at least.Oscillator 210 comprises gas sensing module 212 and active circuits 214, and gas sensing module 212 is connected to active circuits 214, and active circuits 214 is connected to transmitter 220.Gas sensing module 212 sensings one gas concentration to be measured makes active circuits 214 export carrier wave a to transmitter 220 with gas concentration change to be measured accordingly, again by transmitter 220 emission carrier wave to radio receivers 30.Because oscillator 210 itself promptly has sensing gas concentration to be measured and the function of carrier wave is provided, and does not therefore need to provide extraly expensive oscillating integrated circuit.
In addition, in order to save the power consumption of wireless launcher 20, wireless launcher 20 further more comprises output control circuit 240.Output control circuit 240 is connected in transmitter 220, optionally launches carrier wave in order to control transmitter 220.Output control circuit 240 for example is comparator circuit or timing circuit.If output control circuit 240 is a comparator circuit, then output control circuit 240 can judge in advance whether carrier wave arrives a default value, whether launches carrier wave with decision transmitter 220.In addition, if output control circuit 240 is a timing circuit, then output control circuit 240 is just controlled transmitter 220 emission carrier wave to radio receivers 30 at set intervals.Thus, can significantly reduce the power consumption of wireless launcher 20, and improve the service time of wireless launcher 20.
Varying element 2122 is connected to piezoelectric resonator 2124, to set the frequency or the amplitude of carrier wave.Varying element 2122 for example is frequency-modulation element or amplitude modulation element.When gas sensing unit 2126 was resistance sensor, the amplitude of expression carrier wave changed with gas concentration to be measured.We can adopt frequency-modulation element as varying element 2122 to set the frequency of carrier wave, make radio receiver 30 according to carrier wave that this frequency identification received.
On the contrary, when gas sensing unit 2126 was capacitance type sensor, the frequency of expression carrier wave changed with gas concentration to be measured.We can adopt the amplitude modulation element as the amplitude of varying element 2122 with the setting carrier wave, make radio receiver 30 discern the carrier wave that is received according to this amplitude.Wherein, frequency-modulation element and amplitude modulation element are for example realized by resistance, electric capacity, inductance, variable resistor, variable capacitance, variable inductance and combination thereof.
Above-mentioned oscillator 210 provides functions such as sensing gas concentration to be measured, carrier wave and identification signal simultaneously, simplifies the required element of gas sensing circuit significantly.Thus, not only power consumption is little and cost is low, can also further be designed to deserted wireless launcher 20 or disposable.Dangerous operation environment such as wireless launcher 20 deserted or disposable quite is fit to be applied to sewer, culvert, prospects, pit and oil groove.In addition, because wireless launcher 20 is with low cost, therefore, the site work personnel can endanger gas concentration by a plurality of wireless launcher 20 sensings of a throwing, to reach the purpose of comprehensive monitoring operating environment.
Please be simultaneously with reference to Fig. 5 to Fig. 8; Fig. 5 illustrates the synoptic diagram of connecting with piezoelectric resonator into gas sensing unit; Fig. 6 illustrates the equivalent circuit diagram of connecting with piezoelectric resonator into gas sensing unit; Fig. 7 illustrates and is that the gas sensing unit synoptic diagram parallelly connected with piezoelectric resonator, Fig. 8 illustrate and is the gas sensing unit equivalent circuit diagram parallelly connected with piezoelectric resonator.As previously mentioned, gas sensing unit 2126 can with piezoelectric resonator 2124 serial or parallel connections.With Fig. 5 is example, and gas sensing unit 2126 is a gas sensing film, and forms on piezoelectric resonator 2124 surfaces, makes gas sensing unit 2126 connect with piezoelectric resonator 2124 (as shown in Figure 6).And in Fig. 7, piezoelectric resonator 2124 comprises perforation 21242, and gas sensing unit 2126 is arranged in the perforation 21242, makes gas sensing unit 2126 and piezoelectric resonator 2124 parallelly connected (as shown in Figure 8).
Please be simultaneously with reference to Fig. 9 and Figure 10, the curve map of the resistance at resonance when Fig. 9 illustrates and connects with piezoelectric resonator into gas sensing unit, Figure 10 illustrate the curve map into the antiresonance resistance of gas sensing unit when parallelly connected with piezoelectric resonator.Main variation is the resistance at resonance of equivalence behind gas sensing unit 2126 and piezoelectric resonator 2124 serial or parallel connections.Can find out by Fig. 9; When gas sensing unit 2126 is connected with piezoelectric resonator 2124; Piezoelectric resonator 2124 resistance at resonance increase with the resistance of gas sensing unit 2126, and other characteristic of piezoelectric resonator 2124 such as resonant frequency, antiresonant frequency, antiresonance resistance etc. have no significant change.And can find out by Figure 10; Piezoelectric resonator 2124 antiresonance resistance increase with the resistance of gas sensing unit 2126 when gas sensing unit 2126 and piezoelectric resonator 2124 are parallelly connected, and other characteristic of piezoelectric resonator 2124 such as resonant frequency, antiresonant frequency, resistance at resonance etc. have no significant change.A result also can foresee thus, and the outgoing carrier voltage of oscillator 210 is changed and the generation change by the resistance at resonance of piezoelectric resonator 2124 or antiresonance resistance.
Please be simultaneously with reference to Figure 11 and Figure 12, the voltage curve of the carrier wave when Figure 11 illustrates and connects with piezoelectric resonator into gas sensing unit, Figure 12 illustrate the voltage curve into the carrier wave of gas sensing unit when parallelly connected with piezoelectric resonator.When gas sensing unit 2126 was connected with piezoelectric resonator 2124, the carrier voltage Vp-p variation of oscillator 210 outputs illustrated like Figure 11.And gas sensing unit 2126 and piezoelectric resonator 2124 be when parallelly connected, and the carrier voltage Vp-p of oscillator 210 outputs changes and illustrates like Figure 12.Magnitude of voltage for fear of carrier voltage Vp-p is too low, and when connecting with piezoelectric resonator 2124 as if gas sensing unit 2126, it be good that the equivalent resistance of gas sensing unit 2126 needs less than 300 Ω.Likewise, too low for fear of the magnitude of voltage of carrier voltage Vp-p, if when gas sensing unit 2126 and piezoelectric resonator 2124 are parallelly connected, the equivalent resistance need of gas sensing unit 2126 are greater than 10K Ω.
Moreover, by the presentation of results of Figure 11 and Figure 12, when the resistance value of gas sensing module 212 changes because of sense gasses concentration has a resistance, can cause the magnitude of voltage of oscillator 210 outgoing carriers to be close to linear variation.So, the voltage of as long as we detect oscillator 210 outgoing carriers and resistance change that needn't the detected gas sensing module can reach the sensing purpose.Thus, wireless launcher 20 can not produce too big power consumption because of the resistance value of detected gas sensing module 212, help to reduce overall electric power consumption.
Please be simultaneously with reference to Figure 13 and Figure 14, Figure 13 illustrates the oscillogram into carrier wave before the sensing, and Figure 14 illustrates the oscillogram into carrier wave behind the sensing.With gas sensing unit 2126 is that resistance sensor is an example, when gas sensing unit 2126 is connected with piezoelectric resonator 2124, if the amplitude of the little then carrier wave of sensing resistor of gas sensing unit 2126 is big; Otherwise the amplitude of the big then carrier wave of the sensing resistor of gas sensing unit 2126 is little.And when gas sensing unit 2126 and piezoelectric resonator 2124 are parallelly connected, if the amplitude of the little then carrier wave of sensing resistor of gas sensing unit 2126 is little; Otherwise the amplitude of the big then carrier wave of the sensing resistor of gas sensing unit 2126 is big.
For making the present invention more clear understandable, Figure 13 and Figure 14 are parallelly connected with gas sensing unit 2126 and piezoelectric resonator 2124 to be the example explanation.When gas sensing unit 2126 not before the sensing gas to be measured, its sensing resistor makes that greatly the carrier amplitude of oscillator 210 outputs is big.And behind gas sensing unit 2126 sensings gas to be measured, its sensing resistor diminishes and makes the carrier amplitude of oscillator 210 outputs diminish.So we can learn gas concentration height to be measured through the variation of carrier amplitude.
In addition, can find out, no matter before and after gas sensing module 212 sensings, the fixed-frequency of carrier wave is constant, and this frequency can be set by the varying element 2122 that Fig. 3 illustrates by Figure 13 and Figure 14.Radio receiver 30 is according to the further carrier wave that whether receives for institute's desire of identification of this frequency.
When 20 utilizations of most wireless launchers, must encode to each wireless launcher 20, for radio receiver 30 identifications.The way of conventional wireless sensing must provide scrambler and code translator extraly, uses for decoding and coding.In the present invention, wireless launcher 20 preferably utilizes cheap varying element 2122 to set the frequency of carrier wave, makes radio receiver 30 according to frequency estimation wireless launcher 20, and with the identification sign indicating number of this frequency as wireless launcher 20.
Please be simultaneously with reference to Figure 15 and Figure 16, the resonant frequency curve map of the carrier wave when Figure 15 illustrates and connects with piezoelectric resonator into varying element, Figure 16 illustrate and are the antiresonant frequency curve map of varying element when parallelly connected with piezoelectric resonator.For making the present invention more clear understandable, Figure 15 and Figure 16 are the example explanation with varying element with the capacitor of frequency modulation.Can find out by Figure 15; When connecting with piezoelectric resonator 2124 as the capacitor of varying element 2122; Along with capacitance increases, the resonant frequency of piezoelectric resonator 2124 (side's point broken line) all is intimate linear reduction with resistance at resonance (round dot broken line), to antiresonance point characteristic and no change.And can find out by Figure 16; When as the capacitor of varying element 2122 and piezoelectric resonator 2124 when parallelly connected; Along with capacitance increases, the antiresonant frequency of piezoelectric resonator (side's point broken line) also presents intimate linear reduction trend with antiresonance resistance (round dot broken line), to resonance point characteristic and no change.So people can be through changing the frequency that capacitance comes the modulation carrier wave, as the identification sign indicating number of wireless launcher 20.
Thus, promote the competitiveness of product in market with avoiding significantly because of coding too much energy consumption and the cost of producing.Though above-mentioned explanation to be adjusting frequency as the identification sign indicating number of a plurality of different radio emitters 20 of identification, and judge the concentration height of gas to be measured with the amplitude size.So the present invention is not limited thereto, and we also can be with the adjustment amplitude as the identification sign indicating number of a plurality of different radio emitters 20 of identification, and just judge the concentration height of gas to be measured with frequency.
Please with reference to Figure 17, it illustrates the thin portion circuit into wireless launcher.Active circuits 214 comprises transistor Tr 1, resistance R 1 to R7, capacitor C 1 to C5, diode D1 and D2.Output control circuit 240 comprises comparer 242, resistance R 8 and transistor Tr 3.Transmitter 220 comprises transistor Tr 2, resistance R 9 and R10, capacitor C 6 to C9 and inductance L 1.The voltage of Node B changes with gas concentration to be measured, and voltage vcc is by resistance R 5 and the R6 dividing potential drop default value with decision comparer 242.When the voltage of Node B during less than default value, comparer 242 driving transistors Tr3 are to be emitted to radio receiver 30 with carrier wave via transmitter 220.
Please with reference to Figure 18, it illustrates and is the consumes electric power comparison sheet.Product type FIGARO-TSG2422 is the device of traditional sensing hazardous gas, for example: carbon monoxide.We are compared to Figure 18 with itself and consumed power size of the present invention and illustrate.Wherein symbol Rs is the equivalent resistance of the gas sensing unit of connecting with piezoelectric resonator, and symbol Rp is the equivalent resistance of the gas sensing unit parallelly connected with piezoelectric resonator.Can be clear that by Figure 18 no matter gas sensing unit and piezoelectric resonator serial or parallel connection, its power consumption is all much smaller than FIGARO-TSG2422.So above-mentioned wireless launcher 20 has the effect that reaches low power consumption in fact.
The gas sensing module that the above embodiment of the present invention is related and use its wireless launcher and radio receiver not only power consumption is little and cost is low is so quite be fit to be applied in the throwing occasion.In addition, because power consumption is little and cost is low, so the site work personnel can a plurality of gas sensing module senses of a throwing endanger gas concentration, to reach the purpose of comprehensive monitoring operating environment.
In sum, though the present invention discloses as above with a preferred embodiment, so it is not in order to limit the present invention.Have common knowledge in the technical field under the present invention, do not breaking away from the spirit and scope of the present invention, when doing various changes and retouching.Therefore, protection scope of the present invention is when looking being as the criterion that claim defines.
Claims (25)
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| CN200810173900A CN101739795B (en) | 2008-11-21 | 2008-11-21 | Gas sensing module, wireless transmitting device and wireless sensing system using the same |
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| CN200810173900A CN101739795B (en) | 2008-11-21 | 2008-11-21 | Gas sensing module, wireless transmitting device and wireless sensing system using the same |
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| CN101739795A CN101739795A (en) | 2010-06-16 |
| CN101739795B true CN101739795B (en) | 2012-09-26 |
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| US9270254B2 (en) * | 2011-09-30 | 2016-02-23 | Qualcomm Mems Technologies, Inc. | Cross-sectional dilation mode resonators and resonator-based ladder filters |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1727875A (en) * | 2005-07-19 | 2006-02-01 | 大连理工大学 | A kind of detection method of hydrogen concentration |
| CN2831113Y (en) * | 2005-05-25 | 2006-10-25 | 友力微系统制造股份有限公司 | Multifunctional wireless detection device |
| CN1896720A (en) * | 2005-10-20 | 2007-01-17 | 汪胜前 | Gas and liquid concentration testing sensor and testing system |
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Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN2831113Y (en) * | 2005-05-25 | 2006-10-25 | 友力微系统制造股份有限公司 | Multifunctional wireless detection device |
| CN1727875A (en) * | 2005-07-19 | 2006-02-01 | 大连理工大学 | A kind of detection method of hydrogen concentration |
| CN1896720A (en) * | 2005-10-20 | 2007-01-17 | 汪胜前 | Gas and liquid concentration testing sensor and testing system |
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