An adaptive range control method and system for joint reading of RFID and barcode

Abstract

The present invention discloses an adaptive range control method and system for combined RFID and barcode reading. The method comprises the following steps: using an RFID reader to capture the backscattered signal of a tag in real time, extracting the carrier frequency offset, and calculating the real-time movement speed and direction of the tag based on the Doppler effect; predicting the first distance between the tag and the RFID reader and the second distance between the tag and the barcode scanner at the next moment based on the real-time movement speed and direction, combined with the fixed spatial coordinates of the RFID reader and the barcode scanner; obtaining the RFID effective reading radius and the barcode effective reading distance; and setting an adjustment strategy to adjust the reading mode based on the relationship between the first distance, the second distance, the RFID effective reading radius, and the barcode effective reading distance. The present invention can improve the dynamic adaptability, collaborative efficiency, and robustness in complex environments of combined tag reading.

Description

Technical Field

[0001] The present invention belongs to the technical field of information management, and in particular relates to an adaptive range control method and system for combined reading of RFID and barcodes. Background Art

[0002] RFID (Radio Frequency Identification) and barcode technology are currently the two mainstream technologies in the field of automatic identification, each with significant advantages. RFID technology supports contactless, long-distance, and batch reading, making it suitable for scenarios such as high-speed logistics and warehouse management. However, it is susceptible to environmental interference such as metal and liquids, and there are signal collision issues in high-density tag scenarios. Barcode technology offers low cost and high accuracy, especially at close range, in static, or low-light environments. However, it has a short reading range, requires optical alignment, and is difficult to adapt to high-speed moving objects.

[0003] Chinese patent application publication number CN118229200A discloses a warehouse management method, device and equipment based on RFID and barcode, including scanning RFID tags in an identification area to obtain RFID information of items in the identification area; the RFID tags are installed on the items; the warehouse database is queried based on the RFID information to obtain item information; the database includes all item information in the warehouse; the camera parameters and the light intensity of the light source system are adaptively adjusted to obtain a barcode image in the identification area; the barcode image is decoded to obtain barcode information; the item information and the barcode information are matched, and the matching results are synchronized to the warehouse database.

[0004] While the patented solution improves warehouse management accuracy through dual data matching between RFID and barcodes, it still suffers from significant deficiencies in dynamic adaptability, collaborative efficiency, and robustness in complex environments. The solution acquires RFID and barcode information only through fixed-area scanning, without considering the real-time motion of items. For example, high-speed movement of items on a conveyor belt can cause blurry barcode images; the distance between the item and the scanning device cannot be predicted, leading to delayed mode switching. Furthermore, the solution faces issues such as excessive energy consumption due to continuous operation of dual-mode hardware, which limits battery life on mobile devices. Summary of the Invention

[0005] The present invention provides an adaptive range control method and system for joint reading of RFID and barcode, aiming to solve the problems of the existing technology such as excessive energy consumption, insufficient dynamic adaptability, collaborative efficiency and robustness in complex environments.

[0006] To solve the above technical problems, the present invention proposes an adaptive range control method for combined RFID and barcode reading, comprising the following steps:

[0007] The RFID reader captures the tag's backscattered signal in real time, extracts the carrier frequency offset, and calculates the tag's real-time movement speed and direction based on the Doppler effect.

[0008] According to the real-time movement speed and the real-time movement direction, combined with the fixed spatial coordinates of the RFID reader and the barcode scanner, a first distance between the tag and the RFID reader and a second distance between the tag and the barcode scanner at the next moment are predicted;

[0009] Obtain RFID effective reading radius and barcode effective reading distance;

[0010] According to the relationship between the first distance, the second distance, the RFID effective reading radius, and the barcode effective reading distance, an adjustment strategy is set to adjust the reading mode.

[0011] Preferably, the specific method for extracting the carrier frequency offset is:

[0012] down-converting the received backscattered signal to baseband or intermediate frequency;

[0013] Perform phase demodulation on the down-converted signal to extract the instantaneous phase information of the signal ;

[0014] Calculate at consecutive time intervals Phase change within ;

[0015] Carrier frequency offset Approximately the average value of the phase change rate: .

[0016] Preferably, the calculation formula of the real-time motion speed is:

[0017]

[0018] Where, is the real-time movement speed of the tag, is the carrier frequency offset, is the speed of light, is the carrier frequency of the RFID reader, is the angle between the tag's movement direction and the RFID antenna's main lobe;

[0019] Among them, the angle The calculation method is as follows: use the phase difference direction finding method of the RFID antenna array to obtain the real-time azimuth of the tag; combine the geometric relationship between the tag movement direction and the azimuth to calculate The cosine of .

[0020] Preferably, the method for obtaining the RFID effective reading radius is:

[0021]

[0022] Where, is the effective reading radius of RFID, is the preset maximum RFID reading radius, is the preset attenuation coefficient, It is the environmental electromagnetic noise intensity obtained in real time by the spectrum analyzer.

[0023] Preferably, the method for obtaining the effective barcode reading distance is:

[0024]

[0025] Where, is the effective reading distance of the barcode, The preset minimum barcode reading distance. is the scale factor, is the ambient light intensity, is the minimum effective light intensity threshold.

[0026] Preferably, the adjustment strategy includes:

[0027] If the first distance is less than or equal to the effective RFID reading radius, and the second distance is greater than the effective barcode reading distance, RFID single-mode reading is activated;

[0028] If the first distance is greater than the RFID effective reading radius, and the second distance is less than or equal to the barcode effective reading distance, activate the barcode single-mode reading;

[0029] If the first distance is less than or equal to the RFID effective reading radius, and the second distance is less than or equal to the barcode effective reading distance, the RFID and barcode combined reading is activated.

[0030] Preferably, the first distance and the second distance are calculated as follows:

[0031] Predict the position of the label at the next moment:

[0032]

[0033] Where, For the current moment Elapsed time interval The label position after For the current moment The label position, is the real-time movement speed of the tag, is the unit vector of the tag’s real-time motion direction;

[0034] According to the position of the label at the next moment Fixed spatial coordinates with RFID reader , calculate the first Euclidean distance as the first distance;

[0035] According to the position of the label at the next moment Fixed spatial coordinates with barcode scanners , calculate the second Euclidean distance as the second distance.

[0036] Preferably, the calculation of the first distance and the second distance further includes dynamic confidence correction of the first Euclidean distance and the second Euclidean distance:

[0037] Calculate the confidence of motion direction prediction by using the signal-to-noise ratio of RFID signals , ;

[0038] The corrected first distance and second distance are:

[0039]

[0040]

[0041] Where, are the corrected first Euclidean distance and second Euclidean distance, respectively, as the first distance and second distance, are the first Euclidean distance and the second Euclidean distance respectively, is the measured distance corresponding to the current first distance, is the actual measured distance corresponding to the current second distance.

[0042] Preferably, the method further adjusts the reading mode according to the tag movement speed setting adjustment strategy, and the specific adjustment method is:

[0043] If the tag movement speed exceeds the threshold, the RFID batch reading mode is forcibly enabled.

[0044] Accordingly, the present invention further proposes an adaptive range control system for combined RFID and barcode reading, the system being used to implement the above-mentioned adaptive range control method, comprising:

[0045] RFID reader / writer, used to transmit continuous waves and receive tag backscatter signals, and read RFID tags;

[0046] A barcode scanner for scanning the barcode on the label to perform barcode reading;

[0047] The signal processing module is used to down-convert and phase-demodulate the backscattered signal, extract the carrier frequency offset, and calculate the real-time speed and direction of the tag based on the Doppler effect;

[0048] A coordinate prediction module is used to predict the position of the tag at the next moment by combining the speed and direction and the current position of the tag;

[0049] a distance calculation module, configured to calculate a first distance and a second distance based on the predicted position of the tag and the fixed spatial coordinates of the RFID reader and the barcode scanner;

[0050] The reading range acquisition module is used to obtain the RFID effective reading radius and the barcode effective reading distance;

[0051] The control decision module is used to set an adjustment strategy and dynamically control the reading mode according to the first distance, the second distance, the relationship between the reading radius and the reading distance, and the tag speed threshold.

[0052] Compared with the prior art, the present invention has the following technical effects:

[0053] 1. The adaptive range control method proposed in this paper calculates the tag's speed and direction in real time through the carrier frequency shift of the RFID backscatter signal, and combines it with spatial coordinates to predict future distances, thereby resolving the problem of mode switching delays in high-speed scenarios. It also adjusts the RFID's effective reading radius and barcode scanning distance based on real-time noise intensity, improving robustness in complex environments. It also addresses the issue of excessive energy consumption caused by continuously running dual-mode hardware, which limits battery life, particularly in mobile devices.

[0054] 2. The adaptive range control method proposed in this invention can automatically select RFID reading, barcode reading, or combined reading mode based on the predicted first and second distances, combined with their respective effective reading ranges. This effectively avoids blindly triggering scanning when the barcode is not in the visual range, or reading and writing failures caused by RFID reading signal blind spots, greatly improving reading efficiency and reading success rate.

[0055] 3. The adaptive range control method proposed in this invention can switch the recognition mode in real time according to the actual scenario, combining the advantages of both methods and avoiding their respective limitations. It is particularly suitable for complex recognition tasks in logistics, warehousing, retail and other scenarios.

[0056] 4. The adaptive range control method proposed in this invention dynamically adjusts the effective reading range model through external parameters such as environmental noise intensity and light intensity. It can effectively adapt to reading interference in different environments, such as high electromagnetic noise or low light scenes, ensuring that the system is always in the optimal reading state and enhancing system robustness. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] Figure 1 It is a schematic flow chart of the method of the present invention. DETAILED DESCRIPTION

[0058] In order to make the objectives, technical solutions and advantages of the present invention more clear, the technical solutions of the present invention will be clearly and completely described below in combination with specific embodiments of the present application and with reference to the accompanying drawings.

[0059] Example 1

[0060] This embodiment is an adaptive range control method for combined RFID and barcode reading. Figure 1 As shown, the following steps are included from step 1 to step 4:

[0061] Step 1: Use the RFID reader to capture the tag's backscattered signal in real time, extract the carrier frequency offset, and calculate the tag's real-time movement speed and direction based on the Doppler effect.

[0062] The Doppler shift is manifested in the time domain as a linear change in the phase of the received signal over time. Therefore, the Doppler shift can be estimated by measuring the rate of change of the phase of the received signal over time. In one embodiment of the present invention, the specific method for extracting the carrier frequency offset is:

[0063] down-converting the received backscattered signal to baseband or intermediate frequency;

[0064] Perform phase demodulation on the down-converted signal to extract the instantaneous phase information of the signal ;

[0065] Calculate at consecutive time intervals Phase change within ;

[0066] Carrier frequency offset Approximately the average value of the phase change rate: .

[0067] Obtaining the carrier frequency offset using the above method can provide a more real-time frequency offset estimation.

[0068] In addition, the backscattered signal of the passive tag will be affected by the Doppler effect, and its spectrum will be offset relative to the original carrier frequency. By performing spectrum analysis on the received backscattered signal, it can be observed that the spectrum peak of the signal is no longer located at the original carrier frequency, but has been offset. Therefore, some other embodiments of the present invention also include obtaining the carrier frequency offset based on the spectrum analysis method. .

[0069] Specifically, the process includes the following steps: an RFID reader receives backscattered signals from passive tags; samples the received analog signal and performs analog-to-digital conversion (ADC) to obtain a digital signal; windowing (e.g., using a Hamming window or Blackman window) is performed on the acquired digital signal to reduce spectral leakage and improve frequency resolution; and a Fast Fourier Transform (FFT) is performed on the windowed signal to obtain the signal spectrum. The spectrum is searched for the peak with the highest energy. The difference between the frequency corresponding to this peak and the original carrier frequency is the Doppler shift, or carrier frequency offset.

[0070] After the carrier frequency offset is obtained, the real-time motion speed can be calculated according to the carrier frequency offset. The calculation formula is:

[0071]

[0072] Where, is the real-time movement speed of the tag, is the carrier frequency offset, is the speed of light, is the carrier frequency of the RFID reader, is the angle between the tag's movement direction and the RFID antenna's main lobe;

[0073] Among them, the angle The calculation method is as follows: use the phase difference direction finding method of the RFID antenna array to obtain the real-time azimuth of the tag; combine the geometric relationship between the tag movement direction and the azimuth to calculate The cosine value of , to get the final angle The numerical value of .

[0074] In one embodiment of the present invention, the angle based on the phase difference direction finding method The calculation uses a 4-element uniform linear array with an antenna spacing of half the RFID reader's carrier wavelength and is equipped with an FPGA to achieve real-time phase difference measurement. The tag backscattered signal is received by the 4 elements of the antenna array, forming 4 channel signals. Cross-correlation operation is performed on adjacent antenna signals to extract 3 sets of phase differences; the horizontal azimuth angle is calculated by averaging the phase differences. and The predicted position at two moments is calculated to obtain the unit vector of the tag movement direction , since the azimuth angle can be converted into a unit direction vector pointing from the main lobe direction of the reader antenna to the tag , so the angle The cosine value can be calculated by the dot product between the two vectors, and the angle can be obtained. .

[0075] In some other embodiments of the present invention, the unit vector of the tag movement direction can also be obtained by historical position fitting: .

[0076] Step 2: Based on the real-time movement speed and real-time movement direction, combined with the fixed spatial coordinates of the RFID reader and the barcode scanner, predict the first distance between the tag and the RFID reader and the second distance between the tag and the barcode scanner at the next moment.

[0077] So far, the following known quantities have been obtained:

[0078] Fixed spatial coordinates of the device, including the location of the RFID reader (i.e. the fixed spatial coordinates of the RFID reader ) and the location of the barcode scanner (i.e. the fixed spatial coordinates of the barcode scanner );in, , ;

[0079] The current state of the tag, including the tag's current spatial coordinates 、Tag current movement speed and the unit vector of the current movement direction of the label ;in, , ;

[0080] The time interval from the current moment to the next moment .

[0081] In one embodiment of the present invention, the first distance and the second distance are calculated as follows:

[0082] The tag movement is continuous, and the position of the tag at the next moment can be predicted:

[0083]

[0084] Where, For the current moment Elapsed time interval The label position after For the current moment The label position, is the real-time movement speed of the tag, is the unit vector of the tag’s real-time motion direction;

[0085] Right now:

[0086]

[0087] Indicates the predicted label at the next moment The spatial coordinate value of .

[0088] According to the position of the label at the next moment Fixed spatial coordinates with RFID reader , calculate the first Euclidean distance as the first distance;

[0089] According to the position of the label at the next moment Fixed spatial coordinates with barcode scanners , calculate the second Euclidean distance as the second distance.

[0090] In some other embodiments of the present invention, the calculation of the first distance and the second distance further includes dynamic confidence correction of the first Euclidean distance and the second Euclidean distance:

[0091] Calculate the confidence of motion direction prediction by using the signal-to-noise ratio of RFID signals , ;

[0092] The corrected first distance and second distance are:

[0093]

[0094]

[0095] Where, are the corrected first Euclidean distance and second Euclidean distance, respectively, as the first distance and second distance, are the first Euclidean distance and the second Euclidean distance respectively, is the measured distance corresponding to the current first distance, is the actual measured distance corresponding to the current second distance.

[0096] In some other embodiments of the present invention, the corrected first and second distances further include obstacle detection compensation, and the compensated values ​​are used as the final first and second distances. Specifically, if a Time of Flight (TOF) sensor is used to detect an obstruction between the tag and the device, if there is an obstacle, the RFID distance compensation is expressed as ,in is the attenuation coefficient of the obstacle material; the barcode distance compensation is expressed as (Indicates that the optical occlusion is impenetrable). and as the final first distance and second distance.

[0097] In some other embodiments of the present invention, the obstacle detection compensation is directly applied to the first Euclidean distance and the second Euclidean distance. That is, the RFID distance compensation is expressed as ,in is the attenuation coefficient of the obstacle material; the barcode distance compensation is expressed as (Indicates that the optical occlusion is impenetrable). and as the final first distance and second distance.

[0098] Step 3: Obtain the RFID effective reading radius and barcode effective reading distance.

[0099] The method for obtaining the RFID effective reading radius is:

[0100]

[0101] Where, is the effective reading radius of RFID, is the preset maximum RFID reading radius, is the preset attenuation coefficient, It is the environmental electromagnetic noise intensity obtained in real time by the spectrum analyzer.

[0102] In one embodiment of the present invention, the preset maximum RFID reading radius and attenuation coefficient are determined experimentally. A UHF RFID module with adjustable power is configured, along with a spectrum analyzer for real-time scanning of carrier frequency band noise and a fixed passive tag (used to calibrate the RFID maximum reading radius). The reader power is then gradually increased in a shielded room to measure the maximum distance the tag can read, i.e., the RFID maximum reading radius. Controllable noise is injected, and the noise power and effective radius are measured to determine the attenuation coefficient. .

[0103] The method for obtaining the effective reading distance of the barcode is:

[0104]

[0105] Where, is the effective reading distance of the barcode, The preset minimum barcode reading distance. is the scale factor, is the ambient light intensity, is the minimum effective light intensity threshold.

[0106] Similar to the method for obtaining the maximum RFID reading radius, the preset minimum barcode reading distance and scale factor in this embodiment were also determined through experiments. First, a barcode scanner with an integrated ambient light sensor, a light sensor, and a barcode print sample with a standard reflectivity of 20% were configured. In a darkroom, the light intensity was gradually increased to measure the minimum illumination required to recognize the barcode. Continue to increase the light intensity to obtain the optimal reading distance and current illumination, and then calculate the proportional factor. .

[0107] The effective reading range model is dynamically adjusted through external parameters such as environmental noise intensity and light intensity. It can effectively adapt to reading interference in different environments, such as high electromagnetic noise or low light scenes, ensuring that the system is always in the best reading state and enhancing system robustness.

[0108] Step 4: According to the relationship between the first distance, the second distance, the RFID effective reading radius, and the barcode effective reading distance, an adjustment strategy is set to adjust the reading mode.

[0109] The adjustment strategies include:

[0110] If the first distance is less than or equal to the effective RFID reading radius, and the second distance is greater than the effective barcode reading distance, RFID single-mode reading is activated;

[0111] If the first distance is greater than the RFID effective reading radius, and the second distance is less than or equal to the barcode effective reading distance, activate the barcode single-mode reading;

[0112] If the first distance is less than or equal to the RFID effective reading radius, and the second distance is less than or equal to the barcode effective reading distance, the RFID and barcode combined reading is activated.

[0113] In addition to the above adjustments based on the first distance and the second distance, the reading mode can also be adjusted according to the tag movement speed setting adjustment strategy. The specific adjustment method is: if the tag movement speed exceeds the threshold, the RFID batch reading mode is forcibly enabled.

[0114] Furthermore, some other embodiments of the present invention provide a priority dynamic selection dominant mode for the case where the first distance is ≤ the RFID effective reading radius and the second distance is ≤ the barcode effective reading distance;

[0115] Calculate priority weights:

[0116]

[0117]

[0118] Where, represents the weight of RFID, represents the weight of the barcode, Score the current RFID signal quality based on the signal-to-noise ratio, Score the current signal quality of the barcode based on contrast, This is the first distance involved in the calculation of this step, The second distance calculated in this step is the first distance calculated in this step, which can be the original first Euclidean distance mentioned above. , the corrected first distance And the first distance after compensation The second distance calculated in this step can be the original second Euclidean distance mentioned above. , the corrected first distance And the first distance after compensation If , then start RFID mode first; or After multiplying by a preset coefficient, Compare.

[0119] Example 2

[0120] This embodiment is an adaptive range control system for combined RFID and barcode reading. The system is used to implement the adaptive range control method described in Example 1, including:

[0121] RFID reader / writer, used to transmit continuous waves and receive tag backscatter signals, and read RFID tags;

[0122] A barcode scanner for scanning the barcode on the label to perform barcode reading;

[0123] The signal processing module is used to down-convert and phase-demodulate the backscattered signal, extract the carrier frequency offset, and calculate the real-time speed and direction of the tag based on the Doppler effect;

[0124] A coordinate prediction module is used to predict the position of the tag at the next moment by combining the speed and direction and the current position of the tag;

[0125] a distance calculation module, configured to calculate a first distance and a second distance based on the predicted position of the tag and the fixed spatial coordinates of the RFID reader and the barcode scanner;

[0126] The reading range acquisition module is used to obtain the RFID effective reading radius and the barcode effective reading distance;

[0127] The control decision module is used to set an adjustment strategy and dynamically control the reading mode according to the first distance, the second distance, the relationship between the reading radius and the reading distance, and the tag speed threshold.

[0128] The above description is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this field, several variations and improvements can be made without departing from the creative concept of the present invention, which all fall within the scope of protection of the present invention.

Claims

1. An adaptive range control method for combined RFID and barcode reading, characterized in that: The following steps are involved: The RFID reader captures the tag's backscattered signal in real time, extracts the carrier frequency offset, and calculates the tag's real-time movement speed and direction based on the Doppler effect. According to the real-time movement speed and the real-time movement direction, combined with the fixed spatial coordinates of the RFID reader and the barcode scanner, a first distance between the tag and the RFID reader and a second distance between the tag and the barcode scanner at the next moment are predicted; Obtain RFID effective reading radius and barcode effective reading distance; Calculate the confidence of motion direction prediction by using the signal-to-noise ratio of RFID signals , ; Use the confidence level to correct the first distance and the second distance, and the correction method is as follows: Where, are the corrected first Euclidean distance and second Euclidean distance, respectively, as the first distance and second distance, are the first Euclidean distance and the second Euclidean distance respectively, is the measured distance corresponding to the current first distance, is the measured distance corresponding to the current second distance; Based on the corrected first distance and second distance, and in combination with the relationship between the RFID effective reading radius and the barcode effective reading distance, an adjustment strategy is set to adjust the reading mode.

2. The method according to claim 1, characterized in that The specific method for extracting the carrier frequency offset is: down-converting the received backscattered signal to baseband or intermediate frequency; Perform phase demodulation on the down-converted signal to extract the instantaneous phase information of the signal ; Calculate at consecutive time intervals Phase change within ; Carrier frequency offset Approximately the average value of the phase change rate: .

3. The method according to claim 2, characterized in that The calculation formula of the real-time motion speed is: Where, is the real-time movement speed of the tag, is the carrier frequency offset, is the speed of light, is the carrier frequency of the RFID reader, is the angle between the tag's movement direction and the RFID antenna's main lobe; Among them, the angle The calculation method is as follows: use the phase difference direction finding method of the RFID antenna array to obtain the real-time azimuth of the tag; combine the geometric relationship between the tag movement direction and the azimuth to calculate The cosine of .

4. The method according to claim 1, wherein The method for obtaining the RFID effective reading radius is: Where, is the effective reading radius of RFID, is the preset maximum RFID reading radius, is the preset attenuation coefficient, It is the environmental electromagnetic noise intensity obtained in real time by the spectrum analyzer.

5. The method according to claim 1, wherein The method for obtaining the effective reading distance of the barcode is: Where, is the effective reading distance of the barcode, The preset minimum barcode reading distance. is the scale factor, is the ambient light intensity, is the minimum effective light intensity threshold.

6. The method according to claim 1, characterized in that The adjustment strategies include: If the first distance is less than or equal to the effective RFID reading radius, and the second distance is greater than the effective barcode reading distance, RFID single-mode reading is activated; If the first distance is greater than the RFID effective reading radius, and the second distance is less than or equal to the barcode effective reading distance, activate the barcode single-mode reading; If the first distance is less than or equal to the RFID effective reading radius, and the second distance is less than or equal to the barcode effective reading distance, the RFID and barcode combined reading is activated.

7. The method according to claim 1, characterized in that The calculation method of the first distance and the second distance is: Predict the position of the label at the next moment: Where, For the current moment Elapsed time interval The label position after For the current moment The label position, is the real-time movement speed of the tag, is the unit vector of the tag’s real-time motion direction; According to the position of the label at the next moment Fixed spatial coordinates with RFID reader , calculate the first Euclidean distance as the first distance; According to the position of the label at the next moment Fixed spatial coordinates with barcode scanners , calculate the second Euclidean distance as the second distance.

8. The method according to claim 1, characterized in that The method also adjusts the reading mode according to the tag movement speed setting adjustment strategy, and the specific adjustment method is: If the tag movement speed exceeds the threshold, the RFID batch reading mode is forcibly enabled.

9. An adaptive range control system for combined RFID and barcode reading, characterized in that: The system is used to implement the adaptive range control method according to any one of claims 1 to 8, comprising: RFID reader / writer, used to transmit continuous waves and receive tag backscatter signals, and read RFID tags; A barcode scanner for scanning the barcode on the label to perform barcode reading; The signal processing module is used to down-convert and phase-demodulate the backscattered signal, extract the carrier frequency offset, and calculate the real-time speed and direction of the tag based on the Doppler effect; A coordinate prediction module is used to predict the position of the tag at the next moment by combining the speed and direction and the current position of the tag; a distance calculation module, configured to calculate a first distance and a second distance based on the predicted position of the tag and the fixed spatial coordinates of the RFID reader and the barcode scanner; The reading range acquisition module is used to obtain the RFID effective reading radius and the barcode effective reading distance; The control decision module is used to set an adjustment strategy and dynamically control the reading mode according to the first distance, the second distance, the relationship between the reading radius and the reading distance, and the tag speed threshold.

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