Adaptive range control method and system for RFID (Radio Frequency Identification) and bar code combined reading

Abstract

The invention discloses a self-adaptive range control method and system for RFID (Radio Frequency Identification) and bar code combined reading, and the method comprises the following steps: capturing a backscattering signal of a tag in real time through an RFID reader-writer, extracting the carrier frequency offset, and calculating the real-time movement speed and the real-time movement direction of the tag based on the Doppler effect; predicting a first distance between the tag and the RFID reader-writer and a second distance between the tag and the bar code scanner at the next moment according to the real-time movement speed and the real-time movement direction in combination with fixed space coordinates of the RFID reader-writer and the bar code scanner; obtaining an RFID effective reading radius and a bar code effective reading distance; and according to the relationship among the first distance, the second distance, the RFID effective reading radius and the bar code effective reading distance, setting an adjustment strategy to adjust the reading mode. According to the method, the dynamic adaptability, the cooperation efficiency and the complex environment robustness of label joint reading can be improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of information management, and particularly 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 technologies are two major mainstream technologies in the current field of automatic identification, each having significant advantages: RFID technology supports non-contact, long-distance, and batch reading, and is suitable for scenarios such as high-speed logistics and warehouse management. However, it is easily affected by environments such as metals and liquids, and there are signal collision problems in high-density tag scenarios. Barcode technology, on the other hand, has low cost and high accuracy, and performs excellently especially in close-range, static, or low-reflection environments. However, the reading distance is short, optical alignment is required, and it is difficult to adapt to high-speed moving objects.

[0003] Chinese Patent Application with Publication No. CN118229200A discloses a warehouse management method, device, and equipment based on RFID and barcodes, including scanning RFID tags within a recognition area to obtain RFID information of items within the recognition area; the RFID tags are installed on the items; querying the database of the warehouse according to the RFID information to obtain item information; the database includes all item information of the warehouse; adaptively adjusting the parameters of the camera and the light intensity of the light source system to obtain a barcode image within the recognition area; decoding the barcode image to obtain barcode information; matching the item information and the barcode information, and synchronizing the matching result to the database of the warehouse.

[0004] Although the above solution improves the accuracy of warehouse management through dual data matching of RFID and barcodes, there are still significant deficiencies in terms of dynamic adaptability, collaborative efficiency, and robustness in complex environments. The solution only obtains RFID and barcode information through fixed-area scanning without considering the real-time motion state of the items. For example, items on a high-speed moving conveyor belt may cause the barcode image to be blurred; the distance change between the item and the scanning device cannot be predicted, and the mode switching lags. There are also problems such as excessive energy consumption due to continuous operation of dual-mode hardware, resulting in limited battery life in mobile devices. Summary of the Invention

[0005] The present invention provides an adaptive range control method and system for combined reading of RFID and barcodes, aiming to solve the problems of excessive energy consumption, insufficient dynamic adaptability, collaborative efficiency, and robustness in complex environments in the prior art.

[0006] To solve the above technical problems, the adaptive range control method for combined reading of RFID and barcodes proposed by the present invention includes the following steps: The backscatter signal of the tag is captured in real time by an RFID reader, the carrier frequency offset is extracted, and the real-time movement speed and real-time movement direction of the tag are calculated based on the Doppler effect; According to the real-time movement speed and real-time movement direction, combined with the fixed spatial coordinates of the RFID reader and the barcode scanner, 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 are predicted; Obtain the effective reading radius of the RFID and the effective reading distance of the barcode; According to the relationship between the first distance, the second distance, the effective reading radius of the RFID and the effective reading distance of the barcode, set an adjustment strategy to adjust the reading mode.

[0007] Preferably, the specific method for extracting the carrier frequency offset is as follows: Down-convert the received backscatter signal to baseband or intermediate frequency; Perform phase demodulation on the down-converted signal to extract the instantaneous phase information of the signal ; Calculate the phase change amount within a continuous time interval ; ; The carrier frequency offset is approximately the average value of the phase change rate: .

[0008] Preferably, the calculation formula for the real-time movement speed is:

[0009] In the formula, 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 included angle between the tag movement direction and the main lobe of the RFID antenna; Among them, the calculation method for the included angle is: use the phase difference direction finding method of the RFID antenna array to obtain the real-time azimuth angle of the tag; combine the geometric relationship between the tag movement direction and the azimuth angle to calculate the cosine value of.

[0010] Preferably, the method for obtaining the effective reading radius of the RFID is:

[0011] In the formula, is the effective reading radius of the RFID, is the preset maximum reading radius of RFID, is the preset attenuation coefficient, is the environmental electromagnetic noise intensity obtained in real time by a spectrum analyzer.

[0012] Preferably, the method for obtaining the effective reading distance of the barcode is:

[0013] In the formula, is the effective reading distance of the barcode, is the preset minimum reading distance of the barcode, is the scale factor, is the environmental light intensity, is the minimum effective light intensity threshold.

[0014] Preferably, the adjustment strategy includes: If the first distance ≤ the effective reading radius of RFID and the second distance > the effective reading distance of the barcode, activate the single-mode reading of RFID; If the first distance > the effective reading radius of RFID and the second distance ≤ the effective reading distance of the barcode, activate the single-mode reading of the barcode; If the first distance ≤ the effective reading radius of RFID and the second distance ≤ the effective reading distance of the barcode, activate the combined reading of RFID and the barcode.

[0015] Preferably, the calculation method of the first distance and the second distance is: Predict the position of the tag at the next moment:

[0016] In the formula, is the current moment After the time interval The position of the tag, is the current moment The position of the tag, is the real-time movement speed of the tag, is the unit vector of the real-time movement direction of the tag; According to the position of the tag at the next moment And the fixed space coordinates of the RFID reader , calculate the first Euclidean distance as the first distance; According to the position of the tag at the next moment And the fixed space coordinates of the barcode scanner , calculate the second Euclidean distance as the second distance.

[0017] Preferably, the calculation of the first distance and the second distance further includes dynamic confidence correction for the first Euclidean distance and the second Euclidean distance: Calculate the confidence of the motion direction prediction through the signal-to-noise ratio of the RFID signal , ; The corrected first distance and second distance are:

[0018]

[0019] In the formula, are the corrected first Euclidean distance and the second Euclidean distance respectively, and are used as the first distance and the second distance respectively, 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.

[0020] Preferably, the method also sets an adjustment strategy according to the label movement speed to adjust the reading mode, and the specific adjustment method is: If the label movement speed exceeds the threshold, force the RFID batch reading mode to be enabled.

[0021] Correspondingly, the present invention also proposes an adaptive range control system for RFID and barcode combined reading. The system is used to implement the above-mentioned adaptive range control method, and includes: An RFID reader / writer, which is used to transmit a continuous wave and receive the tag backscattered signal, and read the RFID tag; A barcode scanner, which is used to scan the barcode on the tag to perform barcode reading; A signal processing module, which is used to down-convert and phase-demodulate the backscattered signal, extract the carrier frequency offset, and calculate the real-time movement speed and direction of the tag based on the Doppler effect; A coordinate prediction module, which 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, which is used to calculate the first distance and the second distance according to the predicted position of the tag and the fixed spatial coordinates of the RFID reader / writer and the barcode scanner; A reading range acquisition module, which is used to acquire the effective reading radius of the RFID and the effective reading distance of the barcode; A control decision module, which is used to set an adjustment strategy and dynamically control the reading mode according to the relationship between the first distance, the second distance, the reading radius and the reading distance, and the tag speed threshold.

[0022] Compared with the prior art, the present invention has the following technical effects: 1. The adaptive range control method proposed by the present invention calculates the real-time movement speed and direction of the tag through the carrier frequency shift of the RFID backscatter signal, predicts the future distance in combination with the spatial coordinates, and solves the problem of mode switching delay in high-speed scenarios; and adjusts the effective reading radius of RFID and the barcode scanning distance according to the real-time noise intensity, improving the robustness in complex environments; solving the problem of excessive energy consumption caused by continuously operating dual-mode hardware, especially limited battery life in mobile devices.

[0023] 2. The adaptive range control method proposed by the present invention can automatically select the RFID reading, barcode reading or combined reading mode according to the predicted first distance and second distance, in combination with their respective effective reading ranges; effectively avoiding blind triggering of barcode scanning when the barcode is not within the visible range, or reading and writing failures caused by the RFID reading signal blind area, greatly improving the reading efficiency and reading success rate.

[0024] 3. The adaptive range control method proposed by the present invention can switch the reading method in real time according to the actual scenario, integrate the advantages of both, avoid their respective limitations, and is particularly suitable for complex identification tasks in scenarios such as logistics, warehousing, and retail.

[0025] 4. The adaptive range control method proposed by the present invention dynamically adjusts the effective reading range model through external parameters such as environmental noise intensity and light intensity; can effectively adapt to reading interference in different environments, such as high electromagnetic noise or low light scenarios, ensuring that the system is always in the best reading state and enhancing the system robustness. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 is a schematic flow chart of the method of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0027] To make the objectives, technical solutions and advantages of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below in conjunction with specific embodiments of the present application and with reference to the accompanying drawings.

[0028] Embodiment 1 This embodiment is an adaptive range control method for combined RFID and barcode reading, as Figure 1 shown, including the following steps 1 to 4: Step 1, the RFID reader captures the backscatter signal of the tag in real time, extracts the carrier frequency offset, and calculates the real-time movement speed and real-time movement direction of the tag based on the Doppler effect.

[0029] The Doppler frequency shift appears as a linear change in the phase of the received signal over time in the time domain. Therefore, the Doppler frequency 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 as follows: Down-convert 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 the phase change amount within consecutive time intervals ; ; The carrier frequency offset is approximately the average value of the phase change rate: .

[0030] Obtaining the carrier frequency offset through the above method can provide a more real-time frequency offset estimation.

[0031] In addition, the backscattered signal of the passive tag is affected by the Doppler effect, and its spectrum will shift relative to the original carrier frequency. By performing spectrum analysis on the received backscattered signal, it can be observed that the spectral peak of the signal no longer lies at the original carrier frequency but has shifted. Therefore, in some other embodiments of the present invention, it also includes obtaining the carrier frequency offset based on the spectrum analysis method .

[0032] Specifically, it includes the following steps: The RFID reader receives the backscattered signal from the passive tag; sample and perform analog-to-digital conversion (ADC) on the received analog signal to obtain a digital signal; perform windowing processing (such as Hamming window, Blackman window, etc.) on the collected digital signal to reduce spectral leakage and improve frequency resolution; perform fast Fourier transform (FFT) on the windowed signal to obtain the spectrum of the signal. Search for the peak with the maximum energy in the spectrum, and the difference between the frequency corresponding to this peak and the original carrier frequency is the Doppler frequency shift, that is, the carrier frequency offset.

[0033] After obtaining the carrier frequency offset, the real-time motion speed can be calculated based on the carrier frequency offset, and the calculation formula is:

[0034] In the formula, is the real-time motion speed of the tag, is the carrier frequency offset, is the speed of light, is the carrier frequency of the RFID reader, is the included angle between the tag movement direction and the main lobe of the RFID antenna; wherein, the included angle is calculated as follows: the phase difference direction finding method of the RFID antenna array is adopted to obtain the real-time azimuth angle of the tag; combined with the geometric relationship between the tag movement direction and the azimuth angle, calculate the cosine value of to obtain the final included angle value.

[0035] In an embodiment of the present invention, for the included angle based on the phase difference direction finding method the calculation adopts a 4-element uniform linear array, the antenna spacing is half of the carrier wavelength of the RFID reader-writer, and an FPGA is equipped to realize real-time phase difference measurement. The tag backscattered signal is received by 4 units of the antenna array to form 4-channel signals, and the cross-correlation operation is performed on the adjacent antenna signals to extract 3 groups of phase differences; the horizontal azimuth angle is calculated by averaging the phase differences. By calculating the predicted positions of the tag at two consecutive times and the unit vector of the tag movement direction is obtained. Since the azimuth angle can be converted into the unit direction vector pointing from the main lobe direction of the reader-writer antenna to the tag, therefore the included angle can calculate the cosine value through the dot product between the two vectors, and finally the included angle is obtained.

[0036] In some other embodiments of the present invention, the unit vector of the tag movement direction can also be obtained by fitting the historical positions.

[0037] Step 2, according to the real-time movement speed and real-time movement direction, combined with the fixed space coordinates of the RFID reader-writer and the barcode scanner, predict the first distance between the tag and the RFID reader-writer and the second distance between the tag and the barcode scanner at the next moment.

[0038] So far, the following known quantities have been obtained: The fixed space coordinates of the device, including the position of the RFID reader-writer (i.e., the fixed space coordinates of the RFID reader-writer ) and the position of the barcode scanner (i.e., the fixed space coordinates of the barcode scanner ); wherein, , ; The current state of the tag, including the current space coordinates of the tag , the current movement speed of the tag and the unit vector of the current movement direction of the tag ; wherein, , ; The time interval from the current moment to the next moment .

[0039] In one embodiment of the present invention, the calculation methods of the first distance and the second distance are as follows: The movement of the tag is continuous, and the position of the tag at the next moment can be predicted:

[0040] In the formula, is the position of the tag after the time interval at the current moment , is the position of the tag at the current moment , is the real-time movement speed of the tag, is the unit vector of the real-time movement direction of the tag; That is:

[0041] represents the predicted spatial coordinate value of the tag at the next moment , that is, the predicted position is .

[0042] According to the position of the tag at the next moment and the fixed spatial coordinates of the RFID reader / writer , calculate the first Euclidean distance as the first distance; According to the position of the tag at the next moment and the fixed spatial coordinates of the barcode scanner , calculate the second Euclidean distance as the second distance.

[0043] In some other embodiments of the present invention, the calculation of the first distance and the second distance further includes dynamic confidence correction for the first Euclidean distance and the second Euclidean distance: Calculate the confidence of the movement direction prediction through the signal-to-noise ratio of the RFID signal , ; The corrected first distance and second distance are:

[0044]

[0045] In the formula, are the corrected first Euclidean distance and second Euclidean distance respectively, and are used as the first distance and the second distance respectively, They 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.

[0046] In some other embodiments of the present invention, for the corrected first distance and second distance, obstacle detection compensation is further included, and the compensated values are used as the final first distance and second distance. Specifically, for example, an object blocking between the tag and the device is detected by a Time of Flight (TOF) sensor. If there is an obstacle, the RFID distance compensation is expressed as where is the attenuation coefficient of the obstacle material; the barcode distance compensation is expressed as (indicating that the optical occlusion is impenetrable). The compensated and are used as the final first distance and second distance.

[0047] In some other embodiments of the present invention, the obstacle detection compensation directly acts on the first Euclidean distance and the second Euclidean distance. That is, the RFID distance compensation is expressed as where is the attenuation coefficient of the obstacle material; the barcode distance compensation is expressed as (indicating that the optical occlusion is impenetrable). The compensated and are used as the final first distance and second distance.

[0048] Step 3: Obtain the effective reading radius of the RFID and the effective reading distance of the barcode.

[0049] The method for obtaining the effective reading radius of the RFID is as follows:

[0050] In the formula, is the effective reading radius of the RFID, is the preset maximum reading radius of the RFID, is the preset attenuation coefficient, is the environmental electromagnetic noise intensity obtained in real time by a spectrum analyzer.

[0051] In one embodiment of the present invention, the preset maximum RFID reading radius and attenuation coefficient are determined through experiments. First, configure a UHF RFID module with adjustable power; a spectrum analyzer for real-time scanning of the carrier frequency band noise; and passive tags at fixed positions (for calibrating the maximum RFID reading radius). Then, gradually increase the reader power in a shielded room to measure the farthest distance at which the tag can be read, which is the maximum RFID reading radius. Inject controllable noise, measure the noise power and effective radius, and the attenuation coefficient can be solved 。

[0052] The method for obtaining the effective reading distance of the barcode is as follows:

[0053] In the formula, is the effective reading distance of the barcode, is the preset minimum reading distance of the barcode, is the scaling factor, is the ambient light intensity, is the minimum effective light intensity threshold.

[0054] Similar to the method for obtaining the maximum RFID reading radius, the preset minimum reading distance and scaling factor of the barcode in this embodiment are also determined through experiments. First, configure a barcode scanner integrated with an ambient light sensor, a light sensor, and a barcode printing sample with a standard reflectivity of 20%. Gradually increase the light in a dark room to measure the minimum illuminance at which the barcode can be recognized 。Continue to increase the light, obtain the optimal reading distance and the current illuminance, and the scaling factor can be solved 。

[0055] Dynamically adjust the effective reading range model through external parameters such as ambient noise intensity and light intensity; it can effectively adapt to reading interference in different environments, such as high electromagnetic noise or low light scenarios, ensure that the system is always in the best reading state, and enhance the system robustness.

[0056] Step four, according to the relationship between the first distance, the second distance, the RFID effective reading radius, and the barcode effective reading radius, set an adjustment strategy to adjust the reading mode.

[0057] The adjustment strategy includes: If the first distance ≤ RFID effective reading radius and the second distance > barcode effective reading radius, activate the RFID single-mode reading; If the first distance > RFID effective reading radius and the second distance ≤ barcode effective reading radius, activate the barcode single-mode reading; If the first distance ≤ the effective reading radius of the RFID, and the second distance ≤ the effective reading distance of the barcode, activate the combined reading of the RFID and the barcode.

[0058] In addition to the above adjustments based on the first distance and the second distance, the reading mode can also be adjusted by setting an adjustment strategy according to the label movement speed. The specific adjustment method is as follows: If the label movement speed exceeds the threshold, force the activation of the RFID batch reading mode.

[0059] Furthermore, in some other embodiments of the present invention, for the case where the first distance ≤ the effective reading radius of the RFID and the second distance ≤ the effective reading distance of the barcode, a priority dynamic selection of the dominant mode is also provided; Calculate the priority weight:

[0060]

[0061] In the formula, represents the weight of the RFID, represents the weight of the barcode, is the current signal quality score of the RFID based on the signal-to-noise ratio, is the current signal quality score of the barcode based on the contrast, is the first distance involved in the calculation of this step, is the second distance involved in the calculation of this step. The first distance involved in the calculation of this step can be one of the above-mentioned original first Euclidean distance , the corrected first distance and the compensated first distance . The second distance involved in the calculation of this step can be one of the above-mentioned original second Euclidean distance , the corrected first distance and the compensated first distance . If , then give priority to starting the RFID mode; or multiply by a preset coefficient and then compare it with .

[0062] Embodiment 2 This embodiment is an adaptive range control system for the combined reading of the RFID and the barcode. The system is used to implement the adaptive range control method as described in Embodiment 1, and includes: An RFID reader / writer, which is used to transmit a continuous wave and receive the tag backscattered signal, and to read the RFID tag; A barcode scanner, which is used to scan the barcode on the tag to perform barcode reading; A signal processing module, which is used to down-convert and phase-demodulate the backscattered signal, extract the carrier frequency offset, and calculate the real-time movement speed and direction of the tag based on the Doppler effect; A coordinate prediction module, which 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, which is used to calculate a first distance and a second distance according to the predicted position of the tag and the fixed spatial coordinates of the RFID reader and the barcode scanner; A reading range acquisition module, which is used to acquire the effective reading radius of the RFID and the effective reading distance of the barcode; A control decision module, which is used to set an adjustment strategy and dynamically control the reading mode according to the relationship between the first distance, the second distance, the reading radius and the reading distance, and the tag speed threshold.

[0063] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the inventive concept of the present invention, several modifications and improvements can still be made, and these all belong to the protection scope of the present invention.

Claims

1. An adaptive range control method for combined RFID and barcode reading, characterized in that It includes the following steps: Capture the backscattered signal of the tag in real time through an RFID reader, extract the carrier frequency offset, and calculate the real-time movement speed and real-time movement direction of the tag based on the Doppler effect; According to the real-time movement speed and real-time movement direction, and combining 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; Obtain the effective reading radius of the RFID and the effective reading distance of the barcode; According to the relationship between the first distance, the second distance, the effective reading radius of the RFID and the effective reading distance of the barcode, set an adjustment strategy 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-convert 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 the phase change amount within consecutive time intervals ; Carrier frequency offset Approximately the average value of the phase change rate: .

3. The method according to claim 2, wherein The calculation formula for the real-time movement speed is: In the formula, 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 / writer, is the angle between the tag movement direction and the main lobe of the RFID antenna; Among them, the included angle is calculated as follows: The phase difference direction finding method of the RFID antenna array is used to obtain the real-time azimuth angle of the tag; combining the geometric relationship between the tag movement direction and the azimuth angle, calculate the cosine value of.

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

5. The method according to claim 1, characterized in that, The method for obtaining the effective reading distance of the barcode is: Wherein, is the effective barcode reading distance, is the preset minimum barcode reading distance, is the scale factor, is the environmental light intensity, is the minimum effective light intensity threshold.

6. The method according to claim 1, characterized in that The adjustment strategy includes: If the first distance ≤ the effective reading radius of the RFID and the second distance > the effective reading distance of the barcode, activate the single-mode reading of the RFID; If the first distance > the effective reading radius of the RFID and the second distance ≤ the effective reading distance of the barcode, activate the single-mode reading of the barcode; If the first distance ≤ the effective reading radius of the RFID and the second distance ≤ the effective reading distance of the barcode, activate the combined reading of the RFID and the barcode.

7. The method according to claim 1, wherein The calculation method for the first distance and the second distance is: Predict the position of the tag at the next moment: In the formula, is the label position after a time interval from the current moment , is the label position at the current moment , is the real-time movement speed of the label is the unit vector of the real-time movement direction of the label; According to the position of the next moment label and the fixed space coordinates of the RFID reader , calculate the first Euclidean distance as the first distance; According to the position of the next moment label and the fixed spatial coordinates of the barcode scanner , calculate the second Euclidean distance as the second distance.

8. The method according to claim 7, wherein The calculation of the first distance and the second distance also includes the dynamic confidence correction of the first Euclidean distance and the second Euclidean distance: Calculating the confidence of motion direction prediction through the signal-to-noise ratio of RFID signals , ; The corrected first distance and second distance are: Wherein, are the corrected first Euclidean distance and the second Euclidean distance respectively, serving as the first distance and the second distance respectively, 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.

9. The method according to claim 1, characterized in that The method also sets an adjustment strategy according to the tag movement speed to adjust the reading mode, and the specific adjustment method is: If the tag movement speed exceeds the threshold, force the activation of the RFID batch reading mode.

10. 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 1-9, and includes: An RFID reader, which is used to transmit a continuous wave, receive the backscattered signal of the tag, and read the RFID tag; A barcode scanner, which is used to scan the barcode on the tag to perform barcode reading; A signal processing module, which is used to down-convert and phase-demodulate the backscattered signal, extract the carrier frequency offset, and calculate the real-time movement speed and direction of the tag based on the Doppler effect; A coordinate prediction module, which is used to combine the speed and direction and the current position of the tag to predict the position of the tag at the next moment; A distance calculation module, which is used to calculate the first distance and the second distance according to the predicted position of the tag and the fixed spatial coordinates of the RFID reader and the barcode scanner; A reading range acquisition module, which is used to obtain the effective reading radius of the RFID and the effective reading distance of the barcode; A control decision module, which is used to set an adjustment strategy and dynamically control the reading mode according to the relationship between the first distance, the second distance, the reading radius and the reading distance, and the tag speed threshold.

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