A warehouse management method and system based on RFID

Abstract

This invention relates to an RFID-based warehouse management method. Specifically, based on the Q-value obtained from the signal received by each antenna in the reading device, the time slots within a frame are divided into multiple time slot intervals according to multiple tag signal strength intervals. The tag determines the time slot for transmitting data based on the Q-value and the multiple tag signal strength intervals. If at least two tags respond within a time slot, the time slot for transmitting data from the colliding tag is adjusted to an additional time slot in the next time slot interval of the same frame, and so on, until the entire frame ends. The Q-value is adjusted based on the collision situation of the additional time slots following the non-first time slot interval of the previous frame and the signal received by each antenna. The new Q-value and the new multiple tag signal strength intervals are then sent to the tags. The tags determine the time slot for transmitting data in the next frame based on the new Q-value and the new multiple tag signal strength intervals. This invention can improve warehouse management efficiency.

Description

Technical Field

[0001] This invention relates to the field of warehousing, specifically to an RFID-based warehouse management method and system. Background Technology

[0002] RFID technology, as an important tool in modern warehouse management, is widely used in logistics, supply chain management, and other fields due to its ability to achieve contactless, automated identification and tracking of goods. However, with the expansion of warehouse scale and the increase in the number of goods, collision problems in RFID systems are becoming increasingly prominent. In large warehouse environments, multiple RFID tags responding to reader signals simultaneously leads to signal overlap and data confusion, resulting in identification collisions. This not only affects the tag data reading speed but may also lead to data loss or misreading, severely restricting the application of RFID systems in complex warehouse environments. Optimizing RFID anti-collision algorithms has become a key step in improving warehouse management efficiency and reducing identification error rates. Summary of the Invention

[0003] To address the above problems, this invention provides an RFID-based warehouse management method, which includes the following steps:

[0004] The Q value is obtained based on the signal received by each antenna in the reading device. The Q value and multiple tag signal strength intervals are sent to the tag. The time slots in the frame are divided into multiple time slot intervals according to the multiple tag signal strength intervals. The tag determines the time slot for sending data according to the Q value and multiple tag signal strength intervals. At least one time slot is added after each time slot interval that is not the first time slot interval.

[0005] If at least two tags respond within a time slot, the time slot in which the colliding tags transmit data is adjusted to the next time slot interval of the same frame, and so on, until the end of the entire frame;

[0006] The Q value is adjusted based on the collision situation of the additional time slots added after the non-first time slot interval of the previous frame and the signal received by each antenna. The new Q value and multiple new tag signal strength intervals are sent to the tags. The tags determine the time slot for transmitting data in the next frame based on the new Q value and multiple new tag signal strength intervals.

[0007] Preferably, obtaining the Q value based on the signal received by each antenna in the reading device specifically involves:

[0008] The skewness and kurtosis of the signal are calculated based on the signal received by each antenna, and the degree to which the skewness and kurtosis are close to the standard values ​​of the standard Gaussian distribution are calculated.

[0009] Obtain the average proximity of all antennas, calculate the difference between the average and the threshold, weight the difference to obtain the adjustment factor, and use the sum of the adjustment factor and the preset Q value as the Q value.

[0010] Preferably, the tag determines the data transmission time slot based on the Q value and multiple tag signal strength ranges, specifically:

[0011] Establish a correspondence between tag voltage and signal strength, and divide the tags into different signal strength ranges based on the correspondence and multiple tag signal strength ranges;

[0012] The number of time slots is determined based on the Q value, and the number of time slots corresponding to each signal strength interval is determined based on the number of signal strength intervals.

[0013] The tag's ID is hashed to obtain a hash value. The hash value is then moduloed by the number of time slots within the signal strength interval where the tag is located. Finally, the result of the modulo operation is added to the starting time slot number of the signal strength interval where the tag is located to obtain the time slot number for the tag to transmit data.

[0014] Preferably, adjusting the Q value based on the collision situation of time slots added after the non-first time slot interval of the previous frame and the signal received by each antenna specifically involves:

[0015] The Q value is obtained by reading the signal received by each antenna in the reading device;

[0016] Calculate the average value of the collision time slot ratio of the time slots added after the non-first time slot interval in the previous frame, and adjust the Q value based on the average value.

[0017] Preferably, adjusting the Q value based on the average value specifically involves:

[0018] Determine the interval in which the average value falls, and adjust the Q value according to the coefficient corresponding to the interval.

[0019] Furthermore, the present invention also provides an RFID-based warehouse management system, the system comprising the following modules:

[0020] The time slot division module is used to obtain the Q value based on the signal received by each antenna in the reading device, send the Q value and multiple tag signal strength intervals to the tag, divide the time slots in the frame into multiple time slot intervals according to the multiple tag signal strength intervals, and the tag determines the time slot for sending data according to the Q value and multiple tag signal strength intervals, and adds at least one time slot after each time slot interval that is not the first time slot interval.

[0021] The tag response module is used to adjust the time slot in which the colliding tag sends data to the next time slot interval of the same frame if there are at least two tag responses in a time slot, and so on, until the end of the entire frame.

[0022] The frame adjustment module is used to adjust the Q value based on the collision situation of the time slots added after the non-first time slot interval of the previous frame and the signal received by each antenna, and send the new Q value and multiple new tag signal strength intervals to the tags. The tags determine the time slot for transmitting data in the next frame based on the new Q value and multiple new tag signal strength intervals.

[0023] Preferably, obtaining the Q value based on the signal received by each antenna in the reading device specifically involves:

[0024] The skewness and kurtosis of the signal are calculated based on the signal received by each antenna, and the degree to which the skewness and kurtosis are close to the standard values ​​of the standard Gaussian distribution are calculated.

[0025] Obtain the average proximity of all antennas, calculate the difference between the average and the threshold, weight the difference to obtain the adjustment factor, and use the sum of the adjustment factor and the preset Q value as the Q value.

[0026] Preferably, the tag determines the data transmission time slot based on the Q value and multiple tag signal strength ranges, specifically:

[0027] Establish a correspondence between tag voltage and signal strength, and divide the tags into different signal strength ranges based on the correspondence and multiple tag signal strength ranges;

[0028] The number of time slots is determined based on the Q value, and the number of time slots corresponding to each signal strength interval is determined based on the number of signal strength intervals.

[0029] The tag's ID is hashed to obtain a hash value. The hash value is then moduloed by the number of time slots within the signal strength interval where the tag is located. Finally, the result of the modulo operation is added to the starting time slot number of the signal strength interval where the tag is located to obtain the time slot number for the tag to transmit data.

[0030] Preferably, adjusting the Q value based on the collision situation of time slots added after the non-first time slot interval of the previous frame and the signal received by each antenna specifically involves:

[0031] The Q value is obtained by reading the signal received by each antenna in the reading device;

[0032] Calculate the average value of the collision time slot ratio of the time slots added after the non-first time slot interval in the previous frame, and adjust the Q value based on the average value.

[0033] Preferably, adjusting the Q value based on the average value specifically involves:

[0034] Determine the interval in which the average value falls, and adjust the Q value according to the coefficient corresponding to the interval.

[0035] Furthermore, the present invention also provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the method described above.

[0036] To address the issue of collisions that easily occur when using RFID in high-density warehouse management, this invention obtains the Q value based on the signal received by the antenna and divides each tag into a time slot interval. If a tag collides within a time slot interval, the colliding tag is adjusted to an additional time slot in the next time slot interval, resolving conflicting tags within a single frame as much as possible. Furthermore, this invention adjusts the Q value based on the collision situation of additional time slots added after the first time slot interval of the previous frame and the signal received by the antenna, achieving dynamic management of frame time slots and improving communication efficiency. Attached Figure Description

[0037] Figure 1 This is a flowchart of Example 1;

[0038] Figure 2 This is a schematic diagram of RFID collision.

[0039] Figure 3 This is a structural diagram of Example 2. Detailed Implementation

[0040] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them.

[0041] It should be noted that, in the embodiments of this application, "at least one" refers to one or more, and "more than one" refers to two or more. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the specification of this application is for the purpose of describing particular embodiments only and is not intended to be limiting of this application.

[0042] It should be noted that in the embodiments of this application, terms such as "first" and "second" are used only for descriptive purposes and should not be construed as indicating or implying relative importance or order. Features specified as "first" or "second" may explicitly or implicitly include one or more of the stated features. In the description of the embodiments of this application, words such as "exemplary" or "for example" are used to indicate examples, illustrations, or explanations. Any embodiment or design scheme described as "exemplary" or "for example" in the embodiments of this application should not be construed as being better or more advantageous than other embodiments or design schemes. Specifically, the use of words such as "exemplary" or "for example" is intended to present the relevant concepts in a specific manner. If this application uses users' personal information or usage records during use, it will issue a prompt to the user and collect users' personal information or usage records with the user's permission. If this application conflicts with laws and regulations during production or use, it will be produced and used within the scope permitted by laws and regulations.

[0043] Based on the embodiments described in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0044] Example 1, as Figure 1 As shown, the present invention provides an RFID-based warehouse management method, the method comprising the following steps:

[0045] Step 1: Obtain the Q value based on the signal received by each antenna in the reading device, and send the Q value and multiple tag signal strength intervals to the tag. The tag divides the time slots in the frame into multiple time slot intervals according to the multiple tag signal strength intervals. The tag determines the time slot for transmitting data according to the Q value and multiple tag signal strength intervals, and adds at least one time slot after each time slot interval that is not the first time slot interval.

[0046] Before each frame begins, the RFID reader acquires the tag's signal strength RSSI. Signal strength is related to the tag's voltage; the closer the reader is to the tag, the stronger the radio frequency signal received by the antenna, resulting in a higher voltage after rectification and thus a stronger signal. The tag referred to here is a passive tag. When there are many tags, to prevent RFID collisions, this invention divides the acquired tag signal strength into multiple signal strength intervals and pre-establishes the relationship between tag voltage and signal strength. This can be established through statistical analysis, allowing the tag to determine its own signal strength interval based on its voltage.

[0047] In RFID collision avoidance through blind source separation, the principle of non-Gaussianity is used. This principle assumes that the source signals are independent and do not conform to a Gaussian distribution. Each antenna of the reading device receives a superposition of signals from multiple tags. Although the signal from each tag is not Gaussian, the more tags there are, the more the superimposed signal conforms to a Gaussian distribution. The number of tags can be roughly inferred by the matching of the antenna received signal with the Gaussian distribution. This invention obtains the Q-value based on the signal received by each antenna in the reading device; the specific method will be described below.

[0048] After obtaining the Q value and multiple tag signal strength ranges, the data is sent to the tags. The tags determine their own signal strength range based on the correspondence between their voltage and signal strength. Furthermore, the number of time slots can be determined after obtaining the Q value. Similarly, the time slots are divided into multiple time slot intervals, with the number of time slot intervals matching the number of signal strength intervals, and they correspond one-to-one. The tags determine the time slot for transmitting data based on the Q value and the multiple tag signal strength ranges.

[0049] Collisions can occur in any time slot interval, such as Figure 2 As shown, to resolve collisions within a frame, at least one time slot is added after all time slot intervals other than the first time slot interval. Here, "non-first time slot interval" refers to an interval that is not the first time slot interval, and "all time slot intervals other than the first time slot interval" refers to all other time slot intervals in a frame besides the first time slot interval. The added time slots allow tags that collided in the previous time slot interval to reuse these time slots to transmit data. In one embodiment, the number of added time slots is proportional to the time slot interval number; for example, one time slot is added after the second time slot interval, two time slots after the third time slot interval, and so on. After the addition, the other time slot intervals, except for the first time slot interval, consist of two parts: one part is the time slot determined by Q, and the other part is the added time slot. The time slot for each tag to transmit data is determined based on the first part when calculating the time slot for each tag to transmit data. In this invention, the tag first determines the time slot for transmitting data based on the Q value and multiple tag signal strength intervals, and then adds time slots after each time slot interval. The added time slots are numbered using other methods, such as an alphanumeric method.

[0050] Step 2: If at least two tags respond within a time slot, adjust the time slot in which the colliding tags transmit data to the next time slot interval of the same frame, and so on, until the entire frame ends.

[0051] If only one tag sends data to the RFID reader within a time slot, no collision occurs, and the reader can read the data. After decoding the tag's response, the data is stored in the reader. If multiple tags send data within a time slot, a collision occurs. In this case, the time slot in which the colliding tags send data is moved to a newly added time slot in the next time slot interval of the same frame. For example, if two tags collide in the second time slot interval, their data transmission time slot is moved to a newly added time slot in the third time slot interval. Similarly, if there are colliding tags in the third time slot interval, they are moved to a newly added time slot in the fourth time slot interval. The adjustment method includes, but is not limited to, random selection. This process continues until the end of the frame. If there are still colliding tags before the end of the frame, they will be placed in the next frame for transmission.

[0052] In one embodiment, in addition to sending the Q value and multiple signal strength intervals to the tag in advance, the reading device also sends the additional time slot information for each time slot interval to the tag in advance.

[0053] Step 3: Based on the collision situation of the time slots added after the non-first time slot interval of the previous frame and the signal received by each antenna, adjust the Q value and send the new Q value and multiple new tag signal strength intervals to the tag. The tag determines the time slot for transmitting data in the next frame based on the new Q value and multiple new tag signal strength intervals.

[0054] The Q value will be adjusted in the next frame based on collision conditions. Specifically, the Q value will be adjusted based on the collision conditions of the additional time slots added after the non-first time slot interval of the previous frame and the signal received by each antenna.

[0055] The Q value is obtained based on the signal received by each antenna in the reading device; the Q value is calculated in the same way as in step one.

[0056] Calculate the average collision time slot ratio of the time slots added after the non-first time slot interval in the previous frame, determine the interval in which the average value is located, and adjust the Q value according to the coefficient corresponding to the interval.

[0057] For example, if the collision time slot ratio is 0.2 for the time slots added after the second time slot interval and 0.5 for the time slots added after the third time slot interval, the average value is 0.35. If 0.35 is between [0.3, 0.4], and the coefficient for [0.3, 0.4] is -0.2, then the Q value is reduced by 0.2. Then, the number of time slots is calculated using Q. Since the number of time slots is an integer, it can be rounded up or down. The collision time slot ratio is the ratio of the number of time slots that collided to the number of newly added time slots. For example, if 5 time slots were added after the second time slot interval, and one time slot collided, then the collision time slot ratio is 0.2.

[0058] In one embodiment, obtaining the Q value based on the signal received by each antenna in the reading device specifically involves:

[0059] The skewness and kurtosis of the signal are calculated based on the signal received by each antenna, and the degree to which the skewness and kurtosis are close to the standard values ​​of the standard Gaussian distribution are calculated.

[0060] First, the skewness and kurtosis of the signal received by each antenna are calculated. Skewness reflects the degree of signal skewness, and kurtosis reflects the signal's amplitude. By calculating the closeness of the skewness to the standard Gaussian distribution's standard skewness and the kurtosis to the standard Gaussian distribution's standard kurtosis, the Gaussian distribution characteristics of the signal can be determined. The closer it is to a Gaussian distribution, the more tags are assigned, and vice versa. In one embodiment, a larger closeness value indicates a closer approximation to a Gaussian distribution, and a smaller closeness value indicates a less approximation. In another embodiment, the closeness can be calculated in various ways, including but not limited to using the reciprocal of the Euclidean distance as the closeness value. The specific calculation method for the closeness is not specifically limited here. Preferably, the closeness value is normalized to between 0 and 1 using an exponential function. In a preferred embodiment, the signal received by each antenna is pre-normalized.

[0061] Obtain the average proximity of all antennas, calculate the difference between the average and the threshold, weight the difference to obtain the adjustment factor, and use the sum of the adjustment factor and the preset Q value as the Q value.

[0062] After obtaining the proximity of each antenna, the average proximity of all antennas is calculated. Then, the difference between the average and a threshold is determined. The difference is weighted and then summed with a preset Q value to obtain a new Q value. In one embodiment, a negative difference indicates that the preset Q value is subtracted from the adjustment factor, and a positive difference indicates that the preset Q value is added to the adjustment factor.

[0063] In one embodiment, the tag determines the data transmission time slot based on the Q value and multiple tag signal strength ranges, specifically:

[0064] Establish a correspondence between tag voltage and signal strength, and divide the tags into different signal strength ranges based on the correspondence and multiple tag signal strength ranges;

[0065] For passive tags, the closer the reading device is to the tag, the higher the tag voltage, and the stronger the signal strength detected by the reading device. By using the correspondence between the tag voltage and the signal strength detected by the reading device obtained from statistical information, when the tag receives multiple tag signal strength ranges, it can determine the signal strength range to which it belongs based on the correspondence and its own voltage.

[0066] The number of time slots is determined based on the Q value, and the number of time slots corresponding to each signal strength interval is determined based on the number of signal strength intervals.

[0067] After determining the Q value, the number of time slots in the frame can be obtained. The time slots are divided into multiple time slot intervals. The number of time slot intervals is the same as the number of tag signal strength intervals. For example, if there are 3 signal strength intervals, the time slots are also divided into three intervals. Preferably, the time slot numbers in the time slot intervals are consecutive.

[0068] The tag's ID is hashed to obtain a hash value. The hash value is then moduloed by the number of time slots within the signal strength interval where the tag is located. Finally, the result of the modulo operation is added to the starting time slot number of the signal strength interval where the tag is located to obtain the time slot number for the tag to transmit data.

[0069] Through the above two steps, the tag can determine its own time slot interval. A hash operation is performed on the tag's ID to obtain a hash value, which is then modulo (the number of time slots in the time slot interval) to get a numerical value. This numerical value is added to the starting time slot number of the time slot interval to obtain the tag's time slot number. For example, if a tag belongs to a medium-intensity signal interval, its ID hashed to 3. Further assuming that the first time slot number of the medium-intensity signal interval (i.e., the second time slot interval) is 9, and the second time slot interval has 6 time slots, then the selected time slot is 9 + 3 mod 6 = 12. In one embodiment, the starting time slot number of the time slot interval is obtained by adding the numbers of the time slot portions determined by the Q value in the preceding time slot intervals. For example, if the first part of the first time slot interval has 4 time slots determined by the Q value, and the first part of the second time slot interval has 6 time slots determined by the Q value, then the starting time slot number of the third time slot interval is 11. In a more detailed embodiment, the additional time slots in each time slot interval are numbered using other methods, such as a combination of letters and numbers. The time slot numbers in each time slot interval, determined by the Q value, are numbered numerically. For example, the first part of the second time slot interval, which consists of 6 time slots determined by the Q value, is numbered 5-10. The second part of the second time slot interval, which consists of additional time slots, is numbered using the B1, B2, and other similar methods.

[0070] Example 2: The present invention also provides an RFID-based warehouse management system, such as... Figure 3 As shown, the system includes the following modules:

[0071] The time slot division module is used to obtain the Q value based on the signal received by each antenna in the reading device, send the Q value and multiple tag signal strength intervals to the tag, divide the time slots in the frame into multiple time slot intervals according to the multiple tag signal strength intervals, and the tag determines the time slot for sending data according to the Q value and multiple tag signal strength intervals, and adds at least one time slot after each time slot interval that is not the first time slot interval.

[0072] If at least two tags respond within a time slot, the tag response module will adjust the time slot in which the colliding tags send data to the next time slot interval of the same frame, and so on, until the end of the entire frame.

[0073] The frame adjustment module is used to adjust the Q value based on the collision situation of the time slots added after the non-first time slot interval of the previous frame and the signal received by each antenna, and send the new Q value and multiple new tag signal strength intervals to the tags. The tags determine the time slot for transmitting data in the next frame based on the new Q value and multiple new tag signal strength intervals.

[0074] Preferably, obtaining the Q value based on the signal received by each antenna in the reading device specifically involves:

[0075] The skewness and kurtosis of the signal are calculated based on the signal received by each antenna, and the degree to which the skewness and kurtosis are close to the standard values ​​of the standard Gaussian distribution are calculated.

[0076] Obtain the average proximity of all antennas, calculate the difference between the average and the threshold, weight the difference to obtain the adjustment factor, and use the sum of the adjustment factor and the preset Q value as the Q value.

[0077] Preferably, the tag determines the data transmission time slot based on the Q value and multiple tag signal strength ranges, specifically:

[0078] Establish a correspondence between tag voltage and signal strength, and divide the tags into different signal strength ranges based on the correspondence and multiple tag signal strength ranges;

[0079] The number of time slots is determined based on the Q value, and the number of time slots corresponding to each signal strength interval is determined based on the number of signal strength intervals.

[0080] The tag's ID is hashed to obtain a hash value. The hash value is then moduloed by the number of time slots within the signal strength interval where the tag is located. Finally, the result of the modulo operation is added to the starting time slot number of the signal strength interval where the tag is located to obtain the time slot number for the tag to transmit data.

[0081] Preferably, adjusting the Q value based on the collision situation of time slots added after the non-first time slot interval of the previous frame and the signal received by each antenna specifically involves:

[0082] The Q value is obtained by reading the signal received by each antenna in the reading device;

[0083] Calculate the average value of the collision time slot ratio of the time slots added after the non-first time slot interval in the previous frame, and adjust the Q value based on the average value.

[0084] Preferably, adjusting the Q value based on the average value specifically involves:

[0085] Determine the interval in which the average value falls, and adjust the Q value according to the coefficient corresponding to the interval.

[0086] In embodiment three, the present invention also provides a computer-readable storage medium on which a computer program is stored, wherein the computer program, when executed by a processor, implements the method described in embodiment one.

[0087] It should be noted that a portion of the electronic device described above can also be implemented using a computer. In this case, the program for implementing the control function can be recorded on a computer-readable recording medium, and the program recorded on the recording medium can be read into the computer system and executed.

[0088] It should be noted that the term "computer system" as used here refers to a computer system built into an electronic device, employing hardware including an operating system and peripheral devices. Furthermore, "computer-readable recording media" refers to removable media such as floppy disks, magneto-optical disks, ROMs, and CD-ROMs, as well as storage devices such as hard drives built into a computer system.

[0089] Furthermore, a "computer-readable recording medium" can include: a medium that dynamically stores a program for a short period of time, such as a communication line used when transmitting a program via a network such as the Internet or a communication line such as a telephone line; or a medium that stores a program for a fixed period of time, such as volatile memory within a computer system that serves as a server or client in this case. In addition, the aforementioned program can be a program used to implement the above-mentioned functions, or it can be a program that can implement the above-mentioned functions by combining with programs already recorded in the computer system.

Claims

1. A warehouse management method based on RFID, characterized in that, The method includes the following steps: The Q value is obtained based on the signal received by each antenna in the reading device. The Q value and multiple tag signal strength intervals are sent to the tag. The time slots in the frame are divided into multiple time slot intervals according to the multiple tag signal strength intervals. The tag determines the time slot for sending data according to the Q value and multiple tag signal strength intervals. At least one time slot is added after each time slot interval that is not the first time slot interval. If at least two tags respond within a time slot, the time slot in which the colliding tags transmit data is adjusted to the next time slot interval of the same frame, and so on, until the end of the entire frame; The Q value is adjusted based on the collision situation of the time slots added after the non-first time slot interval of the previous frame and the signal received by each antenna. The new Q value and multiple new tag signal strength intervals are sent to the tags. The tags determine the time slot for transmitting data in the next frame based on the new Q value and multiple new tag signal strength intervals. The adjustment of the Q value based on the collision situation of the time slots added after the non-first time slot interval of the previous frame and the signal received by each antenna is specifically as follows: The Q value is obtained by reading the signal received by each antenna in the reading device; Calculate the average value of the collision time slot ratio of the time slots added after the non-first time slot interval in the previous frame, and adjust the Q value based on the average value.

2. The method as described in claim 1, characterized in that, The process of obtaining the Q value based on the signal received by each antenna in the reading device is specifically as follows: The skewness and kurtosis of the signal are calculated based on the signal received by each antenna, and the degree to which the skewness and kurtosis are close to the standard values ​​of the standard Gaussian distribution are calculated. Obtain the average proximity of all antennas, calculate the difference between the average and the threshold, weight the difference to obtain the adjustment factor, and use the sum of the adjustment factor and the preset Q value as the Q value.

3. The method as described in claim 1, characterized in that, The tag determines the data transmission time slot based on the Q value and multiple tag signal strength ranges, specifically: Establish a correspondence between tag voltage and signal strength, and divide the tags into different signal strength ranges based on the correspondence and multiple tag signal strength ranges; The number of time slots is determined based on the Q value, and the number of time slots corresponding to each signal strength interval is determined based on the number of signal strength intervals. The tag's ID is hashed to obtain a hash value. The hash value is then moduloed by the number of time slots within the signal strength interval where the tag is located. Finally, the result of the modulo operation is added to the starting time slot number of the signal strength interval where the tag is located to obtain the time slot number for the tag to transmit data.

4. The method as described in claim 1, characterized in that, The adjustment of the Q value based on the average value specifically involves: Determine the interval in which the average value falls, and adjust the Q value according to the coefficient corresponding to the interval.

5. An RFID-based warehouse management system, characterized in that, The system includes the following modules: The time slot division module is used to obtain the Q value based on the signal received by each antenna in the reading device, send the Q value and multiple tag signal strength intervals to the tag, divide the time slots in the frame into multiple time slot intervals according to the multiple tag signal strength intervals, and the tag determines the time slot for sending data according to the Q value and multiple tag signal strength intervals, and adds at least one time slot after each time slot interval that is not the first time slot interval. The tag response module is used to adjust the time slot in which the colliding tag sends data to the next time slot interval of the same frame if there are at least two tag responses in a time slot, and so on, until the end of the entire frame. The frame adjustment module is used to adjust the Q value based on the collision situation of the time slots added after the non-first time slot interval of the previous frame and the signal received by each antenna, and send the new Q value and multiple new tag signal strength intervals to the tags. The tags determine the time slot for transmitting data in the next frame based on the new Q value and multiple new tag signal strength intervals. The adjustment of the Q value based on the collision situation of the time slots added after the non-first time slot interval of the previous frame and the signal received by each antenna is specifically as follows: The Q value is obtained by reading the signal received by each antenna in the reading device; Calculate the average value of the collision time slot ratio of the time slots added after the non-first time slot interval in the previous frame, and adjust the Q value based on the average value.

6. The system as described in claim 5, characterized in that, The process of obtaining the Q value based on the signal received by each antenna in the reading device is specifically as follows: The skewness and kurtosis of the signal are calculated based on the signal received by each antenna, and the degree to which the skewness and kurtosis are close to the standard values ​​of the standard Gaussian distribution are calculated. Obtain the average proximity of all antennas, calculate the difference between the average and the threshold, weight the difference to obtain the adjustment factor, and use the sum of the adjustment factor and the preset Q value as the Q value.

7. The system as described in claim 5, characterized in that, The tag determines the data transmission time slot based on the Q value and multiple tag signal strength ranges, specifically: Establish a correspondence between tag voltage and signal strength, and divide the tags into different signal strength ranges based on the correspondence and multiple tag signal strength ranges; The number of time slots is determined based on the Q value, and the number of time slots corresponding to each signal strength interval is determined based on the number of signal strength intervals. The tag's ID is hashed to obtain a hash value. The hash value is then moduloed by the number of time slots within the signal strength interval where the tag is located. Finally, the result of the modulo operation is added to the starting time slot number of the signal strength interval where the tag is located to obtain the time slot number for the tag to transmit data.

8. A computer-readable storage medium storing a computer program thereon, characterized in that, The computer program, when executed by a processor, implements the method as described in any one of claims 1-4.

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