CN103310172A - Echo frequency discrimination method for passive radio frequency identification temperature measurement system - Google Patents
Echo frequency discrimination method for passive radio frequency identification temperature measurement system Download PDFInfo
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Abstract
The invention relates to an echo frequency discrimination method for a passive radio frequency identification temperature measurement system. The method comprises the following steps of 1, dividing different frequency points for a frequency band of starting frequency, setting different frequency point numbers for the different frequency points, setting the starting frequency, and performing step-scan within a frequency range; 2, acquiring a group of power sampling signals and a group of frequency sampling signals; 3, performing time-domain judgment-based time-domain energy validation for five times for characteristics of a unique medium of a radio frequency identification tag; 4, converting a time-domain signal into a frequency-domain signal, and performing frequency-domain validation twice; and 5, obtaining a final result by combining the time-domain validation and the frequency-domain validation. According to the method, acquired echo frequency is subjected to strict multi-stage time-domain and frequency-domain judgment, a combined multi-stage frequency addition mode is adopted, and correct echo frequency is obtained by hybrid time-domain and frequency-domain discrimination and multi-stage condition judgment, so that air interference factors existing all the time in a radio frequency identification technology are better avoided, accurate and high-quality echo frequency can be effectively acquired, and the reading distance of a passive tag is greatly prolonged.
Description
Technical field
The invention belongs to radio-frequency (RF) identification is RFID(Radio Frequency IDentification) technology, claim electronic tag, radio frequency identification communication technical field again, the echo frequency discriminating method in especially a kind of passive RFID temp measuring system.
Background technology
The RFID radio-frequency (RF) identification is a kind of contactless automatic identification technology, need not to set up machinery between recognition system and the specific objective or optics contacts, and it is identified specific objective automatically and obtain related data by radiofrequency signal, and identification work need not manual intervention.Radiofrequency signal can penetrate snow, mist, ice, coating, dust and dirt, thereby the system that makes can work in various rugged surroundings.The RFID technology can be identified high-speed moving object and can identify a plurality of labels simultaneously, and is swift and convenient to operate.
The basic functional principle of RFID technology is also uncomplicated: after label enters magnetic field, receive the radiofrequency signal that plug-in reader sends, the energy that relies on induction current to obtain sends out product information (the Passive Tag that is stored in the chip, passive label or passive label), perhaps initiatively sent signal (the Active Tag of a certain frequency by label, active label or active tag), after plug-in reader reads information and decoding, deliver to CIS and carry out the relevant data processing.
The groundwork frequency of passive RFID product has low frequency 125KHZ, high frequency 13.56MHZ, ultrahigh frequency 433MHZ, ultrahigh frequency 915MHZ.
REID in low-frequency range based on transformer coupled model, energy transmission between elementary and secondary and signal transmission, at the space coupling model of high band based on the radar detection target, the radar emission electromagnetic wave signal is run into and is carried target information after the target and return radar receiver.
But have aerial disturbing factor in the RFID technology, aerial various disturbing factors tend to disturb the tag recognition that enters behind the magnetic field always, particularly remote weak signal identification are caused the identification difficulty, have had a strong impact on RFID The Application of Technology scope and effect.
Summary of the invention
The objective of the invention is to overcome the deficiencies in the prior art, the echo frequency discriminating method in a kind of passive RFID temp measuring system is provided.
The present invention solves its technical matters and takes following technical scheme to realize:
Echo frequency discriminating method in a kind of passive radio frequency identification temp measuring system, the step of this method is as follows:
The first step marks off different frequencies at the frequency range of initial frequency, the frequency point number different to different frequency point setting, carry out that initial frequency is set and frequency range in step-scan;
In second step, obtain one group of power samples signal and a class frequency sampled signal;
In the 3rd step, at the feature of the unique medium of RFID tag, carry out five time domain energy authorizations that time domain is judged; Concrete steps comprise:
⑴ one group of power samples signal power superposed average to obtaining is set up the signal power curve, whether judges the maximal value of average power greater than zero, if greater than zero continuation, if less than zero, abandon;
⑵ judge that whether powertrace satisfies 3 moulding, obtains power maximal value frequency point number;
⑶ judge whether powertrace has enough effectively counting;
⑷ judge whether echoed signal meets attenuation law;
Judge this measure signal intensity whether greater than last time measurement result n doubly, n is between 0-1;
The 4th step at first was converted into frequency-region signal with time-domain signal, carried out twice frequency domain authorization then; Concrete steps comprise:
⑴ carry out Fourier transform with time-domain signal; The above-mentioned time domain authorization signal of having authorized is carried out Fourier transform, signal is converted to frequency spectrum;
⑵ spectrum analysis; Find out maximum crest and time big crest, whether judge ratio between peak-peak and the second largest peak value greater than threshold value a, if greater than threshold value a, reception, otherwise give up;
⑶ calculate actual frequency according to peak-peak, judges whether record frequency is adjudicating within the frequency deviation;
In the 5th step, end product is obtained in comprehensive time domain authorization and frequency domain authorization.
And the concrete implementation step in described second step is:
⑴ repeatedly sample to the frequency range that is provided with different frequent points number, calculates the average power content of this frequency range;
⑵ compare the frequency range average power of repeatedly sampling, obtains average power maximal value in the record frequency range, and its frequency point number, obtains one group of power samples signal and a class frequency sampled signal.
And the concrete determination methods of step ⑵ was during described step the three went on foot:
1. the description of 3 moulding is when having only power points when power peak point and both sides thereof greater than all the other all power points, to think that the label power characteristic is correct;
2. when except the power points of power peak point and both sides thereof, when also having other power points that front three can be come, think that power characteristic does not meet tag feature.
And, step ⑷'s judged whether echoed signal meets attenuation law and refer to during described step the three went on foot, this attenuation law is the characteristic of passive label in the system, this characteristic must meet the parameter characteristic of system just can think correct passive label echo, this judgement is the important basis for estimation in the native system, the judgment value that claims this decay is the Q value, and the concrete account form of Q value is as follows:
1. the db number of voltage attenuation 1/e correspondence is e2=20*LOG(1/EXP (1) in the known system);
2. in the power echo curve value of obtaining greater than the afterbody noise and greater than 0 frequency position, read the magnitude of voltage (suppose to try to achieve be (b, power (b))) of this frequency, (suppose to try to achieve and be a with the peak-peak point of having tried to achieve, power (a))) as parameter, obtain the time of curve decay 1db.
Annotate: n is 1db corresponding voltage value (mV) in the system in the formula;
A calculates the time ζ of amplitude fading 1/e:
ζ=e2*d2;
B calculates the Q value:
Q=ζ * ω/2=ζ * (median frequency (Hz of unit)) * π
3. the Q value that finally calculates must drop within the Q value scope of passive label, can think that just this echo meets the systematic parameter characteristic, regards as correct echo, carries out next step judgement.
And the n value of step ⑸ was 0.8 during described step the three went on foot, and ratio illustrates not great fluctuation process of echo frequency energy hunting greater than 0.8, satisfies condition, and does not satisfy less than 0.8 result, gives up.
And, described five steps of step the, comprehensive time domain authorization and frequency domain authorization, the end product that obtains is:
Echo frequency=starting point frequency+peak power frequency point number * sweep frequency gap+spectrum analysis frequency.
Advantage of the present invention and good effect are:
1, the present invention adopts the multistage harsh judgement of time-domain and frequency-domain on stream to the echo frequency of obtaining, after receiving the echo of passive label, adopt multistage frequency to add and integrated mode, mix examination by time-domain and frequency-domain, multistage condition judgment obtains correct echo frequency, better evades the aerial disturbing factor that always exists in the RFID technology.
2, the present invention is directed to unique medium in the RFID label and carry out feature and judge, effective and high-qualityly obtain accurate echo frequency, improved the distance that reads of passive label greatly.
3, the inventive method has greatly improved the recognition capability of RFID label, has expanded the range of application of RFID REID, for the multi-field application of RFID REID provides may.
Description of drawings
Fig. 1 is that power peak is judged synoptic diagram in the inventive method;
Fig. 2 is that schematic diagram data is chosen in 3 moulding judgements in the inventive method;
Fig. 3 is that 3 moulding are declared and given up data and decide synoptic diagram in the inventive method;
Fig. 4 is that the Q value is judged synoptic diagram in the inventive method;
Fig. 5 is that the inventive method intermediate frequency spectrum peakedness ratio is judged synoptic diagram.
Embodiment
Below in conjunction with accompanying drawing the embodiment of the invention is further described; it is emphasized that; embodiment of the present invention is illustrative; rather than it is determinate; therefore the present invention is not limited to the embodiment described in the embodiment; every other embodiments that drawn by those skilled in the art's technical scheme according to the present invention belong to the scope of protection of the invention equally.
Echo frequency discriminating method in a kind of passive RFID temp measuring system, the step of this method is as follows:
The first step marks off different frequencies at the frequency range of initial frequency, and the frequency point number different to different frequency point setting advanced
The concrete job step of row:
⑴ initial frequency is set;
⑵ step-scan in the frequency range;
Second step, obtain one group of power samples signal and a class frequency sampled signal, concrete steps are:
⑴ repeatedly sample to the frequency range that is provided with different frequent points number, calculates the average power content of this frequency range;
⑵ compare the frequency range average power of repeatedly sampling, obtains average power maximal value in the record frequency range, and its frequency point number, obtains one group of power samples signal and a class frequency sampled signal;
The 3rd step, at the feature of the unique medium of RFID label, carry out five time domain energy authorizations that time domain is judged, concrete steps are as follows:
⑴ one group of power samples signal power superposed average to obtaining is set up the signal power curve, judges that whether the maximal value of average power is greater than zero; This step is after eliminating the direct current biasing of sampling, and the basis of signal power sampling is judged, if less than zero, abandon, if greater than zero continuation, as shown in Figure 1;
⑵ judge that whether powertrace satisfies 3 moulding, obtains power maximum of points maxpoint; Concrete decision method is:
1. the description of 3 moulding is when having only power points when power peak point and both sides thereof greater than all the other all power points, to think that the label power characteristic is correct, and as shown in Figure 2, formula table is shown;
Try to achieve n point as us and be power peak point, power (n);
As (power (n-1), power (n+1))〉power (x), { m, m ≠ n when m ≠ n+1, m ≠ n-1}, set up x ∈;
2. when except the power points of power peak point and both sides thereof, when also having other power points to come front three, think that power characteristic does not meet tag feature, as shown in Figure 3, abandon this signal, formula table is shown;
Try to achieve n point as us and be power peak point, power (n);
As (power (n-1), power (n+1))≤power (x), x ∈ { when m ≠ n+1, m ≠ n-1}, be false by m, m ≠ n;
⑶ judge whether powertrace has enough effectively counting;
The definition of effectively counting is: the powertrace greater than the echo noise peak value is counted, the powertrace of echoed signal is subjected to space outerpace and disturbs, have only when signal has enough energy, it shows counting on our the power energy trace, just enough counting can be arranged, can remove interference of noise, we think that just signal is available, and this is counted and can artificially set, as shown in Figure 4, if be set at 9 points for limiting, think that then curve can use; If be set at 10 points for limiting, think that then curve is unavailable;
⑷ judge whether echoed signal meets attenuation law;
This attenuation law is the characteristic of passive label in the system, this characteristic must meet the parameter characteristic of system just can think correct passive label echo, and this judgement is the important basis for estimation in the native system, and we claim that the judgment value of this decay is the Q value, as shown in Figure 4, the concrete account form of Q value is as follows:
1. the db number of voltage attenuation 1/e correspondence is e2=20*LOG(1/EXP (1) in the known system);
2. in the power echo curve value of obtaining greater than the afterbody noise and greater than 0 frequency position, read the magnitude of voltage (suppose to try to achieve be (b, power (b))) of this frequency, (suppose to try to achieve and be a with the peak-peak point of having tried to achieve, power (a))) as parameter, obtain the time of curve decay 1db.
Annotate: n is 1db corresponding voltage value (mV) in the system in the formula;
A calculates the time ζ of amplitude fading 1/e:
ζ=e2*d2;
B calculates the Q value:
Q=ζ * ω/2=ζ * (median frequency (Hz of unit)) * π
3. the Q value that finally calculates must drop within the Q value scope of passive label, can think that just this echo meets our systematic parameter characteristic, regards as correct echo, carries out next step judgement;
Judge this measure signal intensity whether greater than last time measurement result n doubly, n is between 0-1;
It is 0.8 that this step is specifically got the n value, and this step is that the basis of power is judged, the passive label of invariant position, and the echo frequency energy can not produce too great fluctuation process, if measurement result does not satisfy, thinks that this measurement result is unacceptable;
The 4th step, to this class frequency sampled signal superposed average, calculate the efficiently sampling signal spectrum, carry out signal frequency domain and judge;
Comprise time-domain signal in this step and be converted into frequency-region signal and twice frequency domain authorization, concrete steps are as follows:
⑴ carry out Fourier transform with time-domain signal; The above-mentioned time domain authorization signal of having authorized is carried out Fourier transform, signal is converted to frequency spectrum, level and smooth laggard line frequency spectrum is judged;
⑵ spectrum analysis; Because the echoing characteristics of passive label in the system, be in echo, to seek the resonance frequency by peak position, we will judge whether that other frequencies disturb, at this moment find out wherein maximum crest and time big crest, judge that ratio between peak-peak and the second largest peak value is whether in our tolerance interval, as shown in Figure 5, peak-peak and second largest peak value ratio must be value between 0.5-1 greater than threshold value a(a, generally are set at 0.8); If greater than threshold value a, receive, otherwise give up;
⑶ calculate actual frequency according to peak-peak, judges whether record frequency is adjudicating within the frequency deviation; After the judgement before the process, the echoed signal spectrum results of obtaining must drop near the certain limit of intermediate frequency, and concrete scope is chosen as between ± 3 frequencies intervals, we are referred to as to adjudicate frequency deviation, if then available, the spectrum analysis frequency is freq to frequency deviation, otherwise gives up in above-mentioned scope;
The 5th step, comprehensive time domain authorization and frequency domain authorization, obtain end product:
Echo frequency=starting point frequency+peak power frequency point number * sweep frequency gap+spectrum analysis frequency.
Claims (6)
1. the echo frequency discriminating method in the passive radio frequency identification temp measuring system, it is characterized in that: the step of this method is as follows:
The first step marks off different frequencies at the frequency range of initial frequency, the frequency point number different to different frequency point setting, carry out that initial frequency is set and frequency range in step-scan;
In second step, obtain one group of power samples signal and a class frequency sampled signal;
In the 3rd step, at the feature of the unique medium of RFID tag, carry out five time domain energy authorizations that time domain is judged; Concrete steps comprise:
⑴ one group of power samples signal power superposed average to obtaining is set up the signal power curve, whether judges the maximal value of average power greater than zero, if greater than zero continuation, if less than zero, abandon;
⑵ judge that whether powertrace satisfies 3 moulding, obtains power maximal value frequency point number;
⑶ judge whether powertrace has enough effectively counting;
⑷ judge whether echoed signal meets attenuation law;
Judge this measure signal intensity whether greater than last time measurement result n doubly, n is between 0-1;
The 4th step at first was converted into frequency-region signal with time-domain signal, carried out twice frequency domain authorization then; Concrete steps comprise:
⑴ carry out Fourier transform with time-domain signal; The above-mentioned time domain authorization signal of having authorized is carried out Fourier transform, signal is converted to frequency spectrum;
⑵ spectrum analysis; Find out maximum crest and time big crest, whether judge ratio between peak-peak and the second largest peak value greater than threshold value a, if greater than threshold value a, reception, otherwise give up;
⑶ calculate actual frequency according to peak-peak, judges whether record frequency is adjudicating within the frequency deviation;
In the 5th step, end product is obtained in comprehensive time domain authorization and frequency domain authorization.
2. the echo frequency discriminating method in the passive radio frequency identification temp measuring system according to claim 1 is characterized in that:
The concrete implementation step in described second step is:
⑴ repeatedly sample to the frequency range that is provided with different frequent points number, calculates the average power content of this frequency range;
⑵ compare the frequency range average power of repeatedly sampling, obtains average power maximal value in the record frequency range, and its frequency point number, obtains one group of power samples signal and a class frequency sampled signal.
3. the echo frequency discriminating method in the passive radio frequency identification temp measuring system according to claim 1 is characterized in that: described step the in three steps the concrete determination methods of step ⑵ be:
1. the description of 3 moulding is when having only power points when power peak point and both sides thereof greater than all the other all power points, to think that the label power characteristic is correct;
2. when except the power points of power peak point and both sides thereof, when also having other power points that front three can be come, think that power characteristic does not meet tag feature.
4. the echo frequency discriminating method in the passive radio frequency identification temp measuring system according to claim 1, it is characterized in that: step ⑷'s judged whether echoed signal meets attenuation law and refer to during described step the three went on foot, this attenuation law is the characteristic of passive label in the system, this characteristic must meet the parameter characteristic of system just can think correct passive label echo, this judgement is the important basis for estimation in the native system, the judgment value that claims this decay is the Q value, and the concrete account form of Q value is as follows:
1. the db number of voltage attenuation 1/e correspondence is e2=20*LOG(1/EXP (1) in the known system);
2. in the power echo curve value of obtaining greater than the afterbody noise and greater than 0 frequency position, read the magnitude of voltage (suppose to try to achieve be (b, power (b))) of this frequency, (suppose to try to achieve and be a with the peak-peak point of having tried to achieve, power (a))) as parameter, obtain the time of curve decay 1db.
Annotate: n is 1db corresponding voltage value (mV) in the system in the formula;
A calculates the time ζ of amplitude fading 1/e:
ζ=e2*d2;
B calculates the Q value:
Q=ζ * ω/2=ζ * (median frequency (Hz of unit)) * π
3. the Q value that finally calculates must drop within the Q value scope of passive label, can think that just this echo meets the systematic parameter characteristic, regards as correct echo, carries out next step judgement.
5. the echo frequency discriminating method in the passive radio frequency identification temp measuring system according to claim 1, it is characterized in that: the n value of step ⑸ was 0.8 during described step the three went on foot, ratio illustrates not great fluctuation process of echo frequency energy hunting greater than 0.8, satisfy condition, do not satisfy less than 0.8 result, give up.
6. the echo frequency discriminating method in the passive radio frequency identification temp measuring system according to claim 1 is characterized in that: described five steps of step the, and comprehensive time domain authorization and frequency domain authorization, the end product that obtains is:
Echo frequency=starting point frequency+peak power frequency point number * sweep frequency gap+spectrum analysis frequency.
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Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103490830A (en) * | 2013-10-22 | 2014-01-01 | 天津七一二通信广播有限公司 | Denoising radio frequency spectrum peak value acquisition method based on Internet of things electric power temperature measurement equipment |
| CN103528711A (en) * | 2013-10-22 | 2014-01-22 | 天津七一二通信广播有限公司 | Label bandwidth expansion measurement and analysis method based on Internet of Things electric power temperature measurement equipment |
| CN104316761A (en) * | 2014-10-24 | 2015-01-28 | 中国电子科技集团公司第五十五研究所 | Test circuit of acoustic surface wave resonator type wireless sensor sensing echo frequency |
| CN105115592A (en) * | 2015-09-02 | 2015-12-02 | 深圳奥博瑞脑健科技有限公司 | Cranial cavity vibration detection method and device |
| CN105277294A (en) * | 2015-11-16 | 2016-01-27 | 北京华朔物联网科技有限公司 | Anti-interference method for frequency division multiplexing label based on Internet of Things electric power temperature measurement equipment |
| CN111076841A (en) * | 2019-12-30 | 2020-04-28 | 中国船舶重工集团公司第七一一研究所 | Method and system for improving frequency sweeping efficiency of resonant acoustic surface wave temperature measurement system |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1271480A2 (en) * | 2001-06-28 | 2003-01-02 | STMicroelectronics, Inc. | Circuit and method for demodulating a servo position burst |
| JP2006170864A (en) * | 2004-12-16 | 2006-06-29 | Pegasus Net Kk | Room temperature management and fire alarm system with saw thermometer |
| CN100561162C (en) * | 2007-07-20 | 2009-11-18 | 广州市计量检测技术研究院 | A kind of virtual oscillating table detection signal processing method and equipment thereof |
| CN101853565A (en) * | 2010-05-18 | 2010-10-06 | 电子科技大学 | Ultra-low power consumption wireless temperature measurement node based on RFID |
-
2013
- 2013-05-13 CN CN2013101742536A patent/CN103310172A/en active Pending
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1271480A2 (en) * | 2001-06-28 | 2003-01-02 | STMicroelectronics, Inc. | Circuit and method for demodulating a servo position burst |
| JP2006170864A (en) * | 2004-12-16 | 2006-06-29 | Pegasus Net Kk | Room temperature management and fire alarm system with saw thermometer |
| CN100561162C (en) * | 2007-07-20 | 2009-11-18 | 广州市计量检测技术研究院 | A kind of virtual oscillating table detection signal processing method and equipment thereof |
| CN101853565A (en) * | 2010-05-18 | 2010-10-06 | 电子科技大学 | Ultra-low power consumption wireless temperature measurement node based on RFID |
Non-Patent Citations (2)
| Title |
|---|
| RYAN S. WESTAFER ETAL: "functionalization of high frequency saw RFID devices for ozone dosimetry", 《SENSORS,2009 IEEE》 * |
| 朱亚萍等: "标签检测抗干扰数字滤波方法研究", 《传感技术学报》 * |
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103490830A (en) * | 2013-10-22 | 2014-01-01 | 天津七一二通信广播有限公司 | Denoising radio frequency spectrum peak value acquisition method based on Internet of things electric power temperature measurement equipment |
| CN103528711A (en) * | 2013-10-22 | 2014-01-22 | 天津七一二通信广播有限公司 | Label bandwidth expansion measurement and analysis method based on Internet of Things electric power temperature measurement equipment |
| CN104316761A (en) * | 2014-10-24 | 2015-01-28 | 中国电子科技集团公司第五十五研究所 | Test circuit of acoustic surface wave resonator type wireless sensor sensing echo frequency |
| CN105115592A (en) * | 2015-09-02 | 2015-12-02 | 深圳奥博瑞脑健科技有限公司 | Cranial cavity vibration detection method and device |
| CN105277294A (en) * | 2015-11-16 | 2016-01-27 | 北京华朔物联网科技有限公司 | Anti-interference method for frequency division multiplexing label based on Internet of Things electric power temperature measurement equipment |
| CN105277294B (en) * | 2015-11-16 | 2018-05-15 | 北京华朔物联网科技有限公司 | The anti-interference method of frequency division multiplexing label based on Internet of Things electric power temperature measuring equipment |
| CN111076841A (en) * | 2019-12-30 | 2020-04-28 | 中国船舶重工集团公司第七一一研究所 | Method and system for improving frequency sweeping efficiency of resonant acoustic surface wave temperature measurement system |
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