CN202735288U - Radio frequency identification device (RFID) system for testing gas concentration - Google Patents
Radio frequency identification device (RFID) system for testing gas concentration Download PDFInfo
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- CN202735288U CN202735288U CN 201220258922 CN201220258922U CN202735288U CN 202735288 U CN202735288 U CN 202735288U CN 201220258922 CN201220258922 CN 201220258922 CN 201220258922 U CN201220258922 U CN 201220258922U CN 202735288 U CN202735288 U CN 202735288U
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Abstract
The utility model provides a radio frequency identification device (RFID) system for testing gas concentration. The RFID system for testing the gas concentration comprises a RFID reader, a first RFID label and a second RFID label, wherein the first RFID label and the second RFID label are provided with the same chip and antenna. After the first RFID label is placed at a certain gas concentration level for a period of time, the first RFID label works under a first resonant frequency. The second RFID label is a RFID label with a gas sensitive device, the gas sensitive device and an antenna of the second RFID label are in a parallel structure, at the moment, the second RFID label is placed in a certain gas concentration level for a period of time, and the second RFID label works under the second resonant frequency. The first RFID label and the second RFID label respectively receive orders sent by the RFID reader and feedback signals, and the RFID reader detects change of gas concentration by comparing difference between signal strength with different frequency of the first RFID label and the second RFID label. The RFID system for the testing gas concentration can detect change of gas concentration with low cost.
Description
Technical field
The utility model relates to RFID (Radio Frequency Identification, radio-frequency (RF) identification) technical field, relates in particular to a kind of rfid system of surveying gas concentration.
Background technology
In recent years, rfid system had become more prevalent.Rfid system is mainly used in the identification to people and thing.In general, this system comprises a RFID reader at least, and the radiofrequency signal from one or more RFID labels can be launched and accept to this RFID reader in the scope of a setting.This RFID label generally is encapsulated, can be attached on the object, it comprises the chip that an energy and antenna carry out information interchange, this chip is microchip, it is an integrated circuit in general, it can be used for storing and process information, the modulation /demodulation radiofrequency signal, and can move other specific function.The antenna of RFID label is to receive and the transmission radiofrequency signal, and usually is applicable to a kind of special frequency.
In some equipment, when the gas concentration that a kind of rfid system of surveying gas concentration has been used to monitor product environment of living in has surpassed the acceptable gas concentration.In general these equipment requirement induction installations will have a lasting energy source, are used for detecting the change of gas concentration, but this can increase the cost of equipment.In addition, some equipment requirement induction installations also will link to each other with a comparator circuit, thereby detect the degree size that departs from reference voltage, and this requirement has increased the cost of equipment greatly.In a word, improve rfid system and be necessary, it requires to be used for detecting gas concentration when not using lasting energy source or using a kind of cheaply adjunct circuit and changes.
The utility model content
The utility model embodiment provides a kind of rfid system of surveying gas concentration, detects at lower cost gas concentration and changes.
On the one hand, the utility model embodiment provides a kind of rfid system of surveying gas concentration, the rfid system of described survey gas concentration comprises: RFID reader, a RFID label and the 2nd RFID label, and a described RFID label has identical chip and antenna with described the 2nd RFID label; After a described RFID label was placed on certain lower a period of time of gas concentration level, the first resonant frequency and the signal intensity of the antenna of a described RFID label remained unchanged, and this moment, a described RFID label was operated under the first resonant frequency; Described the 2nd RFID label is the RFID label with gas sensitive devices, and two pins are arranged on the chip of described the 2nd RFID label; Two pins of described gas sensitive devices and this link to each other, and form parallel-connection structure with the antenna of described the 2nd RFID label, the variation of ambient atmos concentration can cause the variation of the resistance of gas sensitive devices own, after being placed on certain lower a period of time of gas concentration level this moment, the characteristic frequency of the antenna of described the 2nd RFID label and signal intensity have at least one and change, and this moment, described the 2nd RFID label was operated under the second resonant frequency; A described RFID label and described the 2nd RFID label receive respectively instruction and the feedback signal that described RFID reader sends, and described RFID reader is by relatively detecting the change of gas concentration from the difference between the signal intensity of a described RFID label and described the 2nd RFID label different frequency.
Optionally, in the utility model one embodiment, the antenna of a described RFID label and described the 2nd RFID label is monopole antenna: the antenna of described gas sensitive devices and described the 2nd RFID label forms parallel-connection structure.
Optionally, in the utility model one embodiment, the antenna of a described RFID label and described the 2nd RFID label is double-doublet antenna: an antenna of described gas sensitive devices and described the 2nd RFID label forms parallel-connection structure, perhaps forms simultaneously parallel-connection structure with two antennas.
Optionally, in the utility model one embodiment, described gas sensitive devices is the resistor-type gas sensitive devices, and described gas sensitive devices comprises: semiconductor-type gas sensitive devices, stannous oxide gas sensitive devices, semiconductor ceramics gas sensitive devices, catalytic combustion type gas sensitive devices.
On the other hand, the utility model embodiment provides a kind of rfid system of surveying gas concentration, the rfid system of described survey gas concentration comprises: RFID reader, a RFID label and the 2nd RFID label, and a described RFID label has identical chip and antenna with described the 2nd RFID label; After a described RFID label was placed on certain lower a period of time of gas concentration level, the first resonant frequency and the signal intensity of the antenna of a described RFID label remained unchanged, and this moment, a described RFID label was operated under the first resonant frequency; Described the 2nd RFID label is the RFID label with gas sensitive devices, and a pin is arranged on the chip of described the 2nd RFID label; One end of described gas sensitive devices links to each other with this pin, the other end is connected on the antenna of described RFID label, and form parallel-connection structure with antenna, the variation of ambient atmos concentration can cause the variation of the resistance of gas sensitive devices own, after being placed on certain lower a period of time of gas concentration level this moment, the characteristic frequency of the antenna of described the 2nd RFID label and signal intensity have at least one and change, and this moment, described the 2nd RFID label was operated under the second resonant frequency; A described RFID label and described the 2nd RFID label receive respectively instruction and the feedback signal that described RFID reader sends, and described RFID reader is by relatively detecting the change of gas concentration from the difference between the signal intensity of a described RFID label and described the 2nd RFID label different frequency.
Optionally, in the utility model one embodiment, the antenna of a described RFID label and described the 2nd RFID label is monopole antenna: the antenna of described gas sensitive devices and described the 2nd RFID label forms parallel-connection structure.
Optionally, in the utility model one embodiment, the antenna of a described RFID label and described the 2nd RFID label is double-doublet antenna: an antenna of described gas sensitive devices and described the 2nd RFID label forms parallel-connection structure, perhaps forms simultaneously parallel-connection structure with two antennas.
Optionally, in the utility model one embodiment, described gas sensitive devices is the resistor-type gas sensitive devices, and described resistor-type gas sensitive devices comprises: semiconductor-type gas sensitive devices, stannous oxide gas sensitive devices, semiconductor ceramics gas sensitive devices, catalytic combustion type gas sensitive devices.
Another aspect, the utility model embodiment provides a kind of rfid system of surveying gas concentration, the rfid system of described survey gas concentration comprises: RFID reader, a RFID label and the 2nd RFID label, and a described RFID label has identical chip and antenna with described the 2nd RFID label; After a described RFID label was placed on certain lower a period of time of gas concentration level, the first resonant frequency and the signal intensity of the antenna of a described RFID label remained unchanged, and this moment, a described RFID label was operated under the first resonant frequency; Described the 2nd RFID label is the RFID label with gas sensitive devices, described gas sensitive devices is connected on the antenna of described RFID label, and form parallel-connection structure with antenna, the variation of ambient atmos concentration can cause the variation of the resistance of gas sensitive devices own, after being placed on certain lower a period of time of gas concentration level this moment, the characteristic frequency of the antenna of described the 2nd RFID label and signal intensity have at least one and change, and this moment, described the 2nd RFID label was operated under the second resonant frequency; A described RFID label and described the 2nd RFID label receive respectively instruction and the feedback signal that described RFID reader sends, and described RFID reader is by relatively detecting the change of gas concentration from the difference between the signal intensity of a described RFID label and described the 2nd RFID label different frequency.
Optionally, in the utility model one embodiment, the antenna of a described RFID label and described the 2nd RFID label is monopole antenna: the antenna of described gas sensitive devices and described the 2nd RFID label forms parallel-connection structure.
Optionally, in the utility model one embodiment, the antenna of a described RFID label and described the 2nd RFID label is double-doublet antenna: an antenna of described gas sensitive devices and described the 2nd RFID label forms parallel-connection structure, perhaps forms simultaneously parallel-connection structure with two antennas.
Optionally, in the utility model one embodiment, described gas sensitive devices is the resistor-type gas sensitive devices, and described resistor-type gas sensitive devices comprises: semiconductor-type gas sensitive devices, stannous oxide gas sensitive devices, semiconductor ceramics gas sensitive devices, catalytic combustion type gas sensitive devices.
Technique scheme has following beneficial effect: because adopt the rfid system of described survey gas concentration to comprise: RFID reader, a RFID label and the 2nd RFID label, and a described RFID label has identical chip and antenna with described the 2nd RFID label; After a described RFID label was placed on certain lower a period of time of gas concentration level, a described RFID label was operated under the first resonant frequency; Described the 2nd RFID label is the RFID label with gas sensitive devices, the antenna of described gas sensitive devices and described the 2nd RFID label forms parallel-connection structure, after being placed on certain lower a period of time of gas concentration level, described the 2nd RFID label is operated under the second resonant frequency this moment; A described RFID label and described the 2nd RFID label receive respectively instruction and the feedback signal that described RFID reader sends, described RFID reader is by relatively detecting the technological means of the change of gas concentration from the difference between the signal intensity of a described RFID label and described the 2nd RFID label different frequency, so reached and detected at lower cost the technique effect that gas concentration changes, and the energy that utilizes RFID to obtain, solved the powerup issue that gas concentration detects.
Description of drawings
In order to be illustrated more clearly in the utility model embodiment or technical scheme of the prior art, the below will do to introduce simply to the accompanying drawing of required use in embodiment or the description of the Prior Art, apparently, accompanying drawing in the following describes only is embodiment more of the present utility model, for those of ordinary skills, under the prerequisite of not paying creative work, can also obtain according to these accompanying drawings other accompanying drawing.
Fig. 1 is a kind of rfid system structural representation of surveying gas concentration of the utility model embodiment;
Fig. 2 is the synoptic diagram that the utility model embodiment gas sensitive devices is connected with the 2nd RFID label chip;
Fig. 3 is the equivalent circuit diagram of the utility model embodiment the 2nd RFID label chip inside antenna;
Fig. 4 is the synoptic diagram that the utility model embodiment gas sensitive devices, the 2nd RFID label chip inside antenna equivalent electrical circuit are connected;
Fig. 5 synoptic diagram that to be the utility model embodiment gas sensitive devices directly be connected with the RFID label antenna;
Figure 61-Fig. 6 .2 is the structure key diagram of the utility model embodiment gas sensitive devices;
Fig. 7 is that the utility model embodiment is based on the method flow diagram of the survey gas concentration of signal intensity.
Embodiment
Below in conjunction with the accompanying drawing among the utility model embodiment, the technical scheme among the utility model embodiment is clearly and completely described, obviously, described embodiment only is the utility model part embodiment, rather than whole embodiment.Based on the embodiment in the utility model, those of ordinary skills are not making the every other embodiment that obtains under the creative work prerequisite, all belong to the scope of the utility model protection.
As shown in Figure 1, survey the rfid system structural representation of gas concentration for the utility model embodiment is a kind of, the rfid system of described survey gas concentration comprises: RFID reader 1, a RFID label 2 and the 2nd RFID label 3, and a described RFID label 2 has identical chip and antenna with described the 2nd RFID label 3; After a described RFID label 2 was placed on certain lower a period of time of gas concentration level, the first resonant frequency and the signal intensity of the antenna of a described RFID label 2 remained unchanged, and this moment, a described RFID label 2 was operated under the first resonant frequency; Described the 2nd RFID label 3 is the RFID label with gas sensitive devices, the antenna of described gas sensitive devices and described the 2nd RFID label 3 forms parallel-connection structure, the variation of ambient atmos concentration can cause the variation of the resistance of gas sensitive devices own, after being placed on certain lower a period of time of gas concentration level this moment, the characteristic frequency of the antenna of described the 2nd RFID label 3 and signal intensity have at least one and change, and this moment, described the 2nd RFID label 3 was operated under the second resonant frequency; A described RFID label 2 and described the 2nd RFID label 3 receive respectively instruction and the feedback signal that described RFID reader 1 sends, and described RFID reader 1 is by relatively detecting the change of gas concentration from the difference between the signal intensity of a described RFID label 2 and described the 2nd RFID label 3 different frequencies.The gas sensitive devices of the utility model embodiment links to each other with the chip of the 2nd RFID label and has at least three kinds of situations:
The two pins structure:
The utility model embodiment is a kind of rfid system that gas concentration changes that is used for detecting.This system has comprised two RFID labels: a RFID label and the 2nd RFID label.Two pins are arranged on the chip of the 2nd RFID label, and two pins of gas sensitive devices and this link to each other, and form parallel-connection structure with antenna, and the variation of ambient atmos concentration can cause the variation of the resistance of gas sensitive devices own.After being placed on certain lower a period of time of gas concentration level, the first resonant frequency and the signal intensity of the antenna of a RFID label remain unchanged this moment.The characteristic frequency of the antenna of the 2nd RFID label and signal intensity have at least one and change, and this moment, antenna was operated under the second resonant frequency.The RFID reader can send instruction to label, realizes communication, and the difference in the time of can working by comparison the one RFID label and the 2nd RFID label between the signal intensity of different frequency detects the change of gas concentration.
With regard to an example, this system has comprised a kind of RFID label, and described label comprises a RFID label and the 2nd RFID label, and a RFID label and the 2nd RFID label all only have an antenna.Two pins are arranged on the chip of the 2nd RFID label, and two pins of gas sensitive devices and this link to each other, and form parallel-connection structure with antenna, and the variation of ambient atmos concentration can cause the variation of the resistance of gas sensitive devices own.After being placed on certain lower a period of time of gas concentration level, the first resonant frequency and the signal intensity of the antenna of a RFID label remain unchanged this moment.The characteristic frequency of the antenna of the 2nd RFID label and signal intensity have at least one and change, and this moment, antenna was operated under the second resonant frequency.The RFID reader can send instruction to label, realizes communication, and the difference in the time of can working by comparison the one RFID label and the 2nd RFID label between the signal intensity of different frequency detects the change of gas concentration.
Or rather, gas sensitive devices should have lower resistance, and its instantiation comprises: semiconductor-type gas sensitive devices, stannous oxide gas sensitive devices, semiconductor ceramics gas sensitive devices, catalytic combustion type gas sensitive devices etc.
With regard to another example, this system has comprised two RFID labels: a RFID label and the 2nd RFID label; The one RFID label and the 2nd RFID label have two antennas.Two pins are arranged on the chip of the 2nd RFID label, and two pins of gas sensitive devices and this link to each other, and form simultaneously parallel-connection structure with two antennas.The variation of ambient atmos concentration can cause the variation of the resistance of gas sensitive devices own.The situation that this and the 2nd RFID label only contain an antenna is similar.After being placed on certain lower a period of time of gas concentration level, the first resonant frequency and the signal intensity of the antenna of a RFID label remain unchanged this moment.The characteristic frequency of the antenna of the 2nd RFID label and signal intensity have at least one and change, and this moment, antenna was operated under the second resonant frequency.The RFID reader can send instruction to label, realizes communication, and the difference in the time of can working by comparison the one RFID label and the 2nd RFID label between the signal intensity of different frequency detects the change of gas concentration.Or rather, gas sensitive devices should have lower resistance, and its instantiation comprises: semiconductor-type gas sensitive devices, stannous oxide gas sensitive devices, semiconductor ceramics gas sensitive devices, catalytic combustion type gas sensitive devices etc.
One pin configuration:
This system has comprised two RFID labels: a RFID label and the 2nd RFID label, a pin is arranged on the chip of the 2nd RFID label, and this pin outwards links to each other with an end of gas sensitive devices, and the other end of gas sensitive devices is directly linked on the antenna.Pin is similar in the situation of the tie point of chip internal and two pins, finally remains the purpose that will reach with the sky line parallel.The variation of ambient atmos concentration can cause the variation of the resistance of gas sensitive devices own.After being placed on certain lower a period of time of gas concentration level, the first resonant frequency and the signal intensity of the antenna of a RFID label remain unchanged this moment.The characteristic frequency of the antenna of the 2nd RFID label and signal intensity have at least one and change, and this moment, antenna was operated under the second resonant frequency.The RFID reader can send instruction to label, realizes communication, and the difference in the time of can working by comparison the one RFID label and the 2nd RFID label between the signal intensity of different frequency detects the change of gas concentration.
With regard to an example, this system has comprised two RFID labels: a RFID label and the 2nd RFID label; The one RFID label and the 2nd RFID label all only have an antenna.A pin is arranged on the chip of the 2nd RFID label, and gas sensitive devices links to each other with this pin, and the gas sensitive devices other end is directly linked on the antenna, forms parallel-connection structure with antenna.The variation of ambient atmos concentration can cause the variation of the resistance of gas sensitive devices own.After being placed on certain lower a period of time of gas concentration level, the first resonant frequency and the signal intensity of the antenna of a RFID label remain unchanged this moment.The characteristic frequency of the antenna of the 2nd RFID label and signal intensity have at least one and change, and this moment, antenna was operated under the second resonant frequency.The RFID reader can send instruction to label, realizes communication, and the difference in the time of can working by comparison the one RFID label and the 2nd RFID label between the signal intensity of different frequency detects the change of gas concentration.Or rather, gas sensitive devices should have lower resistance, and its instantiation comprises: semiconductor-type gas sensitive devices, stannous oxide gas sensitive devices, semiconductor ceramics gas sensitive devices, catalytic combustion type gas sensitive devices etc.
Without pin configuration:
This system has comprised two RFID labels: a RFID label and the 2nd RFID label, there is not pin on the chip of the 2nd RFID label, and gas sensitive devices is directly linked on the antenna.In this case, the antenna that links to each other with gas sensitive devices can not break away from gas sensitive devices and with normal frequency for communication.After being placed on certain lower a period of time of gas concentration level, the characteristic frequency of antenna and signal intensity have at least one and change.The RFID reader can send instruction to label apparatus, realizes communication, detects the change of gas concentration from the difference between the signal intensity of the different frequency of a RFID label and the 2nd RFID label by comparison.
With regard to an example, this system has comprised two RFID labels: a RFID label and the 2nd RFID label; The one RFID label and the 2nd RFID label all only have an antenna.Do not have pin on the chip of the 2nd RFID label, gas sensitive devices is directly linked on the antenna.The variation of ambient atmos concentration can cause the variation of the resistance of gas sensitive devices own.After being placed on certain lower a period of time of gas concentration level, the first resonant frequency and the signal intensity of the antenna of a RFID label remain unchanged this moment.The characteristic frequency of the antenna of the 2nd RFID label and signal intensity have at least one and change, and this moment, antenna was operated under the second resonant frequency.The RFID reader can send instruction to label, and the difference between the signal intensity of the different frequency during by relatively a RFID label and second label work can detect the change of gas concentration.Or rather, gas sensitive devices should have lower resistance, and its instantiation comprises: semiconductor-type gas sensitive devices, stannous oxide gas sensitive devices, semiconductor ceramics gas sensitive devices, catalytic combustion type gas sensitive devices etc.
In the same way, can be with on the chip of antenna also and can not be with pin, can be with one also can be with a plurality of pins.The radical of antenna can be one, two or even many.Also can connect one or more gas sensitive deviceses accordingly, the model of gas sensitive devices can be the same or different simultaneously.With regard to a kind of instantiation of device, after being placed on certain lower a period of time of gas concentration level, the characteristic frequency of the antenna that links to each other with gas sensitive devices and signal intensity have at least a meeting to change.The RFID reader can send instruction to label apparatus, detects the change of gas concentration from the difference between the signal intensity of the different frequency of antenna by comparison.
With regard to a kind of instantiation of gas sensitive devices, the method for simultaneous comparison numerical value comprises that the signal strength values with these comparison numerical value and majority compares.These signal strength values belong to different frequencies, and interrelate with the gas concentration value of majority, simultaneously based on the above-mentioned level that relatively can detect gas concentration of mentioning.
Yet with regard to another aspect, a rfid system comprises two RFID label apparatus and a RFID reader device.These two RFID label apparatus are used to send two kinds of signals, namely, the signal of the signal of the one RFID label and the 2nd RFID label, reader is received respectively the signal of a RFID label and the signal of the 2nd RFID label, through the fiducial value between the signal strength values of a RFID label of background process and the 2nd RFID label, and these fiducial values are converted into the varying level of gas concentration.
The synoptic diagram of the gas concentration sensor label 10 that is connected with the 2nd RFID label chip for the utility model embodiment gas sensitive devices as shown in Figure 2.Among Fig. 2, label apparatus 10 comprises 13, two pins 16,17 of 15, one surface-mounted integrated circuits of a base and a double-doublet antenna 11,12.Two pins 16,17 are arranged on the surface-mounted integrated circuit 13, and these two pins outwards link to each other with gas sensitive devices 14, and these two pins are in parallel with the equivalent electrical circuit of antenna at chip internal.This label can communicate with reader.
In an example, transmitting terminal 11,12 is made by one or more different low electrical resistant materials, these materials have higher electric conductivity, copper for example, silver, and aluminium, they and the above-mentioned gas sensitive devices of mentioning link to each other by two pins 16,17 and antenna 11,12, when antenna 11,12 be placed on certain lower a period of time of gas concentration level after, gas sensitive devices can cause the variation of one or more transmitting terminal generation resonant frequencies, thereby causes a different frequency.The frequency of the variation of this frequency and reception and transmission is all different.For example, after gas sensitive devices is positioned over certain lower a period of time of gas concentration level, will causes transmission frequency and accept that at least one changes in the frequency.
In another example, the antenna frequencies value of setting at the beginning will be higher than the antenna frequencies under the certain gas concentration environment, and then when reaching certain gas concentration, it will reduce.In another example, the antenna frequencies of setting at the beginning is lower than the antenna frequencies under the certain gas concentration level, and it will rise when reaching certain gas concentration level.Can be used for such gas sensitive devices of the present utility model has: semiconductor-type gas sensitive devices, stannous oxide gas sensitive devices, semiconductor ceramics gas sensitive devices, catalytic combustion type gas sensitive devices etc.
Type based on gas sensitive devices is different, and the gas concentration level that causes changing may be that a specific gas concentration value also may be a selectively scope of gas concentration value.The length of time must cause the variation of antenna resonance frequency, and antenna quality also can cause different variations.For example, on the antenna with the type of gas sensitive devices can affect the length that changes the antenna resonance frequency required time.
As shown in Figure 3, be the equivalent circuit diagram of a RFID label antenna.When the tag coil antenna enters in the alternating magnetic field that read write line produces, the interaction between label antenna and the reading and writing device antenna just is similar to transformer.Both coils are equivalent to primary coil and the secondary coil of transformer.The resonant tank that is formed by label antenna comprises coil inductance (L), the stray capacitance (C of label antenna as shown in the figure
p) and shunt capacitance (C
2), its resonance frequency is mistake! Do not find Reference source., C is C in the formula
pAnd C
2Equivalent capacity in parallel, R
1, R
2Equivalent resistance for circuit internal inductance coil and other devices.The carrier frequency that label and read write line two-way communication are used is exactly f.The tag antenna coil profile is very little when requiring, be that area is little, and need certain operating distance, the aerial coil mutual induction amount that RFID label and read write line are asked just obviously can not practical requirement, can be at the inner Ferrite Material with high permeability that inserts of tag antenna coil, with the increase mutual induction amount, thus the little problem of compensating coil xsect.
As shown in Figure 4, be the utility model embodiment gas sensitive devices, the synoptic diagram that is connected with the 2nd RFID label antenna equivalent electrical circuit.The resonant tank that is formed by label antenna comprises coil inductance (L), the stray capacitance (C of label antenna as shown in the figure
p) and shunt capacitance (C
2), its resonance frequency is mistake! Do not find Reference source., formula C is C
pAnd C
2Equivalent capacity in parallel, R
1, R
2Equivalent resistance for circuit internal inductance coil and other devices.M is the variable resistor of representative gas sensitive devices.After this label was placed on certain lower a period of time of gas concentration level, antenna was operated under the second resonant frequency, and its characteristic frequency and signal intensity have at least one and change.
As shown in Figure 5, be the sketch of the passive RFID tags device 40 of the utility model embodiment detectable gas concentration change.As shown in Figure 4, label apparatus 40 comprises 45, one integrated circuit 43 of a base and a double-doublet antenna 41,42.The gas sensitive devices 44 that links to each other with antenna 42 will affect the resistance of antenna 42.The material that gas sensitive devices 44 is suitable for can be controlled the frequency that any one had both been fixed a point according to any one current voltage in the antenna 41,42.With regard to an example, fixing up an aerial wire 41,42 can make it produce resonance in identical frequency.With regard to another example, fixing up an aerial wire 41,42 can make it produce resonance in different frequency.
In an example, transmitting terminal double- doublet antenna 41,42 is made by one or more different low electrical resistant materials, and these materials have higher electric conductivity, copper for example, silver, and aluminium, they link to each other with the above-mentioned gas sensitive devices of mentioning, when antenna 41,42 be placed on certain lower a period of time of gas concentration level after, gas sensitive devices can cause the variation of one or more transmitting terminal generation resonant frequencies, thereby causes a different frequency.The frequency of the variation of this frequency and reception and transmission is all different.For example, after gas sensitive devices is positioned over certain lower a period of time of gas concentration level, will causes transmission frequency and accept that at least one changes in the frequency.
In another example, the antenna frequencies value of setting at the beginning will be higher than the antenna frequencies under the certain gas concentration environment, and then when reaching certain gas concentration, it will reduce.In another example, the antenna frequencies of setting at the beginning is lower than the antenna frequencies under the certain gas concentration level, and it will rise when reaching certain gas concentration level.The such gas sensitive devices that can be used for this utility model has: semiconductor-type gas sensitive devices, stannous oxide gas sensitive devices, semiconductor ceramics gas sensitive devices, catalytic combustion type gas sensitive devices etc.
Type based on gas sensitive devices is different, and the gas concentration level that causes changing may be that a specific gas concentration value also may be a selectively scope of gas concentration value.The length of time must cause the variation of antenna resonance frequency, and antenna quality also can cause different variations.For example, on the antenna with the type of gas sensitive devices can affect the length that changes the antenna resonance frequency required time.
Shown in Fig. 6 .1, an example for the semiconductor-type gas sensitive devices, comprise two electrodes 611,612 and stannous oxide (SnO2) gas sensory 613, to be the conductance of utilizing stannous oxide (SnO2) change with the absorption of water vapor for it, the gas sensitive devices that this characteristic is made is used for detecting the variation of water vapor.Because these metal oxides all have gas sensitive effect, utilize ceramic process that these metal oxides are made the material with characteristic of semiconductor, therefore be referred to as semiconductor ceramics.Semiconductor ceramics is to make gas sensor according to the mechanism that adsorption effect changes the semiconductor resistance.
Shown in Fig. 6 .2, be the catalytic combustion type gas sensitive devices.It is a kind of gas sensitive devices of the heating power that produces owing to the catalytic Contact combustion.The coil 621 of making at platinum filament is coated the charge carrier materials 622 such as aluminium oxide and is made spheroidite and carry out sintering.Lay outside again the catalyzer 623 of the rare metals such as Pt, Pd, Rh.621 energisings of platinum filament coil are heated to 300-400 degree centigrade, this moment, detecting element was as contacting with the gas of can lighting the passion, gas will be in 623 burnings of rare metal Catalytic Layer, therefore the temperature of rare metal Catalytic Layer 623 and platinum filament coil 621 will rise, and the resistance value of platinum filament coil 621 will change.If the structure of gas sensor, material are definite, and the kind of tested gas is changeless, the resistance change of sensor is directly proportional with the concentration of tested gas so.As long as measure the resistance change of sensor, just can record the concentration of inflammable gas.
As shown in Figure 7, be the method flow diagram of the utility model embodiment based on the survey gas concentration of signal intensity, described method is applied to the rfid system of above-mentioned survey gas concentration, comprising:
701, a described RFID label is placed on certain lower a period of time of gas concentration level after, the first resonant frequency and the signal intensity of the antenna of a described RFID label remain unchanged, this moment a described RFID label be operated under the first resonant frequency:
702, described the 2nd RFID label is placed on certain lower a period of time of gas concentration level after, the characteristic frequency of the antenna of described the 2nd RFID label and signal intensity have at least one and change, and this moment, described the 2nd RFID label was operated under the second resonant frequency;
703, send instruction to a described RFID label and described the 2nd RFID label and receiving feedback signals by described RFID reader;
Difference when 704, utilizing the work of the more described RFID label of described RFID reader and described the 2nd RFID label between the signal intensity of different frequency detects the change of gas concentration.
The RFID reader can be measured the energy intensity of receiving signal, calculates the fiducial value of a reaction signal intensity, then fiducial value is changed into different gas concentration value.With regard to an example, reader can be set the signal that a time period is used for receiving label, if do not receive signal, reader will be recorded as 0 with signal intensity.
In this system, the RFID reader will from the signal strength values of a RFID label that does not link to each other with gas sensitive devices as a reference value, compare its signal strength values with the 2nd RFID label that links to each other with gas sensitive devices.By receive from linking to each other with gas sensitive devices and a RFID label that does not link to each other with gas sensitive devices and the signal of the 2nd RFID label, the RFID reader can be collected the fiducial value that represents unlike signal intensity.Then, the RFID reader can be converted into the residing gas concentration level of label to such fiducial value.With regard to a concrete example, dispose this RFID reader and be in order to be converted into gas concentration value by the difference from the RF signal intensity of the RFID label that connects or do not connect gas sensitive devices of using that the reference data that stores will receive.
Best situation is, the RFID label that do not connect gas sensitive devices as a reference, can be filtered out the variation that causes owing to the coupling between label and the reader.In addition, just as previously mentioned, gas sensitive devices is applied to the time length that the variation of the resistance value that can make it in the design and the 2nd RFID label be placed under the specific gas concentration and forms one to one relation.The same, by using the utility model, under the passive condition of RFID label, the RFID reader can detect label apparatus whether be placed under certain gas concentration and this gas concentration whether within the acceptable range.
Also can not perceive with gas sensitive devices the variation of gas concentration with the various RFID labels of two antennas, the variation that the variation of perception gas concentration is based on resonant frequency on the antenna also can recognize antenna reception to the variation of signal.
For example pass through the design to the antenna that links to each other with gas sensitive devices, can make the frequency of antenna at ISM (IndustrialScientific Medical, industry, science, medical science) the interior variation of frequency range, can connect this antenna that links to each other with gas sensitive devices and logical circuit on the label of standard.
For example label antenna can so be set in a concrete example, before in being exposed to the certain gas concentration environment, the resonant frequency of antenna is 902-928MHZ, but in a single day label is exposed in the certain gas concentration environment, because the impact of gas concentration, the resonant frequency of antenna is just reduced to 899.5-927.5MHZ, frequency frequency range (902-928MHZ) at U.S. RFID is split into 52 channels, reader can be skipped the channel that can not receive at random in these 52 channels, and the benefit of this jump of reader is exactly to prevent effectively that a plurality of readers from attempting the conflict of using same frequency to cause in same physical space.
For example in an example, RFID frequency range (902-928MHZ) is not to be divided into 52 channels but the antenna settings that on average has been divided into n channel tag is carried out work under this frequency range (902-928MHZ).Because label antenna links to each other with gas sensitive devices, so as long as gas concentration has surpassed the scope of predefined value, the frequency of operation of antenna tag antenna just drops among (899.5-927.5MHZ) this frequency range.Therefore compare just channel n to be got rid of from band limits with original frequency range and go, the frequency range (899.5-927.5MHZ) after therefore changing just no longer allows label to carry out exchanging of information with channel n.
In concrete example, if the environment at label place has surpassed the gas concentration scope of expection, reader can only send instruction to label by channel 1 to n-1, label also can be made a response, because the antenna in the label just can only be worked in this frequency range, when reader sends instruction with the frequency of n channel to label, so no longer reach the 928MHZ label and just no longer make a response because the variation of tag gas bulk concentration has caused the resonant frequency of label antenna to drop to 899.5-927.5MHZ, pass information back reader.
Favourable aspect is just to be reflected by the disappearance of this information interchange owing to variation that gas concentration has exceeded the operating frequency of antenna that predefined value causes.
In model, reader can send an instruction between channel n-1 and channel n to label and check that further drift has occured the operating frequency range of label antenna, because label can receive the instruction that sends by channel n-1, and can be to the reader feedback information by channel n-1, because label can not receive the instruction that sends by channel n, and can not can to the reader feedback information, so just determine that drift has occured the operating frequency range of label antenna by channel n.
Drift and present utility model that the variation of gas concentration causes the frequency of operation of label antenna to occur up and down are not limited in frequency range on average are divided into n channel.
The utility model embodiment can detect gas concentration at lower cost to be changed, and the energy that utilizes RFID to obtain, and has solved the powerup issue that gas concentration detects.
The enforcement of each characteristics of this system may relate to software, the combination that hardware also may relate to software and hardware just can reach, and for example the enforcement of many advantages of system is to realize with the mutual mode that exchanges of computer and other equipment machines with OO programming language with a kind of high-caliber processing by programming.Each such function program may be stored in the storage intermediary and for example be read to realize above-mentioned function by a computer and processor in the ROM (read-only memory).
Those skilled in the art can also recognize the various illustrative components, blocks (illustrative logical block) that the utility model embodiment lists, the unit, and step can pass through electronic hardware, computer software, or both combinations realize.Be the clear replaceability (interchangeability) of showing hardware and software, above-mentioned various illustrative components (illustrative components), unit and step have been described their function generally.Such function is to realize depending on the designing requirement of specific application and whole system by hardware or software.Those skilled in the art can be for every kind of specific application, and can make ins all sorts of ways realizes described function, but this realization should not be understood to exceed the scope of the utility model embodiment protection.
Various illustrative logical block described in the utility model embodiment, or the unit can pass through general processor, digital signal processor, special IC (ASIC), field programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or the design of above-mentioned any combination realizes or operates described function.General processor can be microprocessor, and alternatively, this general processor also can be any traditional processor, controller, microcontroller or state machine.Processor also can realize by the combination of calculation element, for example digital signal processor and microprocessor, multi-microprocessor, Digital Signal Processor Core of one or more microprocessors associatings, or any other similarly configuration realize.
Method described in the utility model embodiment or the step of algorithm can directly embed hardware, the software module of processor execution or the two combination.Software module can be stored in the storage medium of other arbitrary form in RAM storer, flash memory, ROM storer, eprom memory, eeprom memory, register, hard disk, moveable magnetic disc, CD-ROM or this area.Exemplarily, storage medium can be connected with processor so that processor can be from storage medium reading information, and can deposit write information to storage medium.Alternatively, storage medium can also be integrated in the processor.Processor and storage medium can be arranged among the ASIC, and ASIC can be arranged in the user terminal.Alternatively, processor and storage medium also can be arranged in the different parts in the user terminal.
In one or more exemplary designs, the described above-mentioned functions of the utility model embodiment can realize in hardware, software, firmware or this three's combination in any.If realize in software, these functions can be stored on the medium with computer-readable, or are transmitted on the medium of computer-readable with one or more instructions or code form.The computer-readable medium comprises the computer storage medium and is convenient to so that allow computer program transfer to other local telecommunication media from a place.Storage medium can be the useable medium that any general or special computer can access.For example, such computer readable media can include but not limited to RAM, ROM, EEPROM, CD-ROM or other optical disc storage, disk storage or other magnetic storage device, or other anyly can be used for carrying or storage can be read by general or special computer or general or special processor the program code of form with instruction or data structure and other medium.In addition, any connection can suitably be defined as the computer-readable medium, for example, if software is by a concentric cable, optical fiber computer, twisted-pair feeder, Digital Subscriber Line (DSL) or also being comprised in the defined computer-readable medium with wireless way for transmittings such as infrared, wireless and microwave from a web-site, server or other remote resource.Described video disc (disk) and disk (disc) comprise Zip disk, radium-shine dish, CD, DVD, floppy disk and Blu-ray Disc, and disk is usually with the magnetic duplication data, and video disc carries out the optical reproduction data with laser usually.Above-mentioned combination also can be included in the computer-readable medium.
Above-described embodiment; the purpose of this utility model, technical scheme and beneficial effect are further described; institute is understood that; the above only is embodiment of the present utility model; and be not used in and limit protection domain of the present utility model; all within spirit of the present utility model and principle, any modification of making, be equal to replacement, improvement etc., all should be included within the protection domain of the present utility model.
Claims (9)
1. rfid system of surveying gas concentration, it is characterized in that, the rfid system of described survey gas concentration comprises: RFID reader, a RFID label and the 2nd RFID label, and a described RFID label has identical chip and antenna with described the 2nd RFID label; After a described RFID label was placed on certain lower a period of time of gas concentration level, the first resonant frequency and the signal intensity of the antenna of a described RFID label remained unchanged, and this moment, a described RFID label was operated under the first resonant frequency; Described the 2nd RFID label is the RFID label with gas sensitive devices, and two pins are arranged on the chip of described the 2nd RFID label; Two pins of described gas sensitive devices and this link to each other, and form parallel-connection structure with the antenna of described the 2nd RFID label, the variation of ambient atmos concentration can cause the variation of the resistance of gas sensitive devices own, after being placed on certain lower a period of time of gas concentration level this moment, the characteristic frequency of the antenna of described the 2nd RFID label and signal intensity have at least one and change, and this moment, described the 2nd RFID label was operated under the second resonant frequency; A described RFID label and described the 2nd RFID label receive respectively instruction and the feedback signal that described RFID reader sends, and described RFID reader is by relatively detecting the change of gas concentration from the difference between the signal intensity of a described RFID label and described the 2nd RFID label different frequency.
2. survey as claimed in claim 1 the rfid system of gas concentration, it is characterized in that, the antenna of a described RFID label and described the 2nd RFID label is monopole antenna: the antenna of described gas sensitive devices and described the 2nd RFID label forms parallel-connection structure.
3. survey as claimed in claim 1 the rfid system of gas concentration, it is characterized in that, the antenna of a described RFID label and described the 2nd RFID label is double-doublet antenna: an antenna of described gas sensitive devices and described the 2nd RFID label forms parallel-connection structure, perhaps forms simultaneously parallel-connection structure with two antennas.
4. rfid system of surveying gas concentration, it is characterized in that, the rfid system of described survey gas concentration comprises: RFID reader, a RFID label and the 2nd RFID label, and a described RFID label has identical chip and antenna with described the 2nd RFID label; After a described RFID label was placed on certain lower a period of time of gas concentration level, the first resonant frequency and the signal intensity of the antenna of a described RFID label remained unchanged, and this moment, a described RFID label was operated under the first resonant frequency; Described the 2nd RFID label is the RFID label with gas sensitive devices, and a pin is arranged on the chip of described the 2nd RFID label; One end of described gas sensitive devices links to each other with this pin, the other end is connected on the antenna of described RFID label, and form parallel-connection structure with antenna, the variation of ambient atmos concentration can cause the variation of the resistance of gas sensitive devices own, after being placed on certain lower a period of time of gas concentration level this moment, the characteristic frequency of the antenna of described the 2nd RFID label and signal intensity have at least one and change, and this moment, described the 2nd RFID label was operated under the second resonant frequency; A described RFID label and described the 2nd RFID label receive respectively instruction and the feedback signal that described RFID reader sends, and described RFID reader is by relatively detecting the change of gas concentration from the difference between the signal intensity of a described RFID label and described the 2nd RFID label different frequency.
5. survey as claimed in claim 4 the rfid system of gas concentration, it is characterized in that, the antenna of a described RFID label and described the 2nd RFID label is monopole antenna: the antenna of described gas sensitive devices and described the 2nd RFID label forms parallel-connection structure.
6. survey as claimed in claim 4 the rfid system of gas concentration, it is characterized in that, the antenna of a described RFID label and described the 2nd RFID label is double-doublet antenna: an antenna of described gas sensitive devices and described the 2nd RFID label forms parallel-connection structure, perhaps forms simultaneously parallel-connection structure with two antennas.
7. rfid system of surveying gas concentration, it is characterized in that, the rfid system of described survey gas concentration comprises: RFID reader, a RFID label and the 2nd RFID label, and a described RFID label has identical chip and antenna with described the 2nd RFID label; After a described RFID label was placed on certain lower a period of time of gas concentration level, the first resonant frequency and the signal intensity of the antenna of a described RFID label remained unchanged, and this moment, a described RFID label was operated under the first resonant frequency; Described the 2nd RFID label is the RFID label with gas sensitive devices, described gas sensitive devices is connected on the antenna of described RFID label, and form parallel-connection structure with antenna, the variation of ambient atmos concentration can cause the variation of the resistance of gas sensitive devices own, after being placed on certain lower a period of time of gas concentration level this moment, the characteristic frequency of the antenna of described the 2nd RFID label and signal intensity have at least one and change, and this moment, described the 2nd RFID label was operated under the second resonant frequency; A described RFID label and described the 2nd RFID label receive respectively instruction and the feedback signal that described RFID reader sends, and described RFID reader is by relatively detecting the change of gas concentration from the difference between the signal intensity of a described RFID label and described the 2nd RFID label different frequency.
8. survey as claimed in claim 7 the rfid system of gas concentration, it is characterized in that, the antenna of a described RFID label and described the 2nd RFID label is monopole antenna: the antenna of described gas sensitive devices and described the 2nd RFID label forms parallel-connection structure.
9. survey as claimed in claim 7 the rfid system of gas concentration, it is characterized in that, the antenna of a described RFID label and described the 2nd RFID label is double-doublet antenna: an antenna of described gas sensitive devices and described the 2nd RFID label forms parallel-connection structure, perhaps forms simultaneously parallel-connection structure with two antennas.
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 201220258922 CN202735288U (en) | 2012-06-01 | 2012-06-01 | Radio frequency identification device (RFID) system for testing gas concentration |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 201220258922 CN202735288U (en) | 2012-06-01 | 2012-06-01 | Radio frequency identification device (RFID) system for testing gas concentration |
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| CN202735288U true CN202735288U (en) | 2013-02-13 |
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| CN 201220258922 Expired - Fee Related CN202735288U (en) | 2012-06-01 | 2012-06-01 | Radio frequency identification device (RFID) system for testing gas concentration |
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