Control method and device of RFID reader-writer, computer equipment and storage medium

Abstract

The invention provides a control method of an RFID (Radio Frequency Identification) reader-writer. The method comprises the steps that fitting expressions corresponding to all first preset powers are obtained respectively; determining a solution set of the fitting expression corresponding to each first preset power when the second derivative is zero, and determining a minimum value in the solution set as a first time corresponding to each first preset power; sorting the first preset powers from small to large, and determining second time corresponding to other first preset powers except the maximum first preset power as the difference between the latter first preset power and the first time corresponding to the latter first preset power; determining the second time corresponding to the maximum first preset power as the first time corresponding to the maximum first preset power; and in the current inventory cycle, sequentially controlling the reader-writer to work for corresponding second duration under each first preset power according to a sequence from small to large so as to obtain an inventory result of the target scene. According to the method, the time slot collision problem can be effectively avoided, and the tag reading efficiency and accuracy in a complex environment are improved.

Description

Technical Field

[0001] The present application relates to the field of radio frequency identification technology, and in particular to a control method, device, computer equipment and readable storage medium of an RFID reader / writer. Background Art

[0002] In RFID (Radio Frequency Identification, RFID) systems, the time slot collision problem is an important technical challenge. It involves signal conflicts that occur when multiple RFID tags respond to reader requests at the same time. Specifically, when multiple tags try to send data to the reader in the same time slot, their signals interfere with each other, causing the reader to be unable to correctly parse the information of any tag. This is called a time slot collision. In order to alleviate the problem of time slot collisions, researchers and engineers have proposed a variety of solutions. For example, anti-collision algorithms can be used to optimize the response mechanism of tags so that tags can send data to the reader one by one in a certain order or rule, thereby avoiding collisions in the same time slot. However, with the increase in the number of tags and the complexity of the environment, the difficulty of designing and implementing such algorithms has also increased. Summary of the invention

[0003] The purpose of the present application is to solve at least one of the above technical defects, and in particular to provide a control scheme for an RFID reader that can effectively reduce the negative impact of the time slot collision problem.

[0004] In a first aspect, the present application provides a control method for an RFID reader / writer, comprising:

[0005] Respectively obtain fitting expressions when the RFID reader performs inventory in the target scene according to a plurality of different first preset powers; the fitting expression is a polynomial of a preset order, and the fitting expression takes the continuous working time of the RFID reader as an independent variable and the number of tags read by the RFID reader as a dependent variable;

[0006] Determine a solution set of the fitting expression corresponding to each first preset power when the second-order derivative is zero, and determine the minimum value in the solution set as the first time corresponding to each first preset power;

[0007] Sort the first preset powers from small to large, determine the second times corresponding to the other first preset powers except the largest first preset power as the difference between the latter first preset power and the first time corresponding to itself, and determine the second time corresponding to the largest first preset power as the first time corresponding to it;

[0008] In the current inventory cycle, the RFID reader is controlled to work at each first preset power for a corresponding second time period in order from small to large, so as to obtain an inventory result of the target scene.

[0009] In one embodiment, respectively obtaining fitting expressions when the RFID reader performs inventory in a target scene according to a plurality of different first preset powers includes:

[0010] For any first preset power, control the RFID reader to inventory the set total time in the target scene according to the first preset power, and record the number of tags corresponding to multiple set time points during the inventory process;

[0011] According to each set time point and its corresponding tag quantity, a data set corresponding to the first preset power is obtained;

[0012] With the continuous working time as the independent variable and the number of tags as the dependent variable, a polynomial fitting of a preset order is performed according to the data set to obtain a fitting expression corresponding to the first preset power.

[0013] In one embodiment, in the current inventory cycle, after sequentially controlling the RFID reader to work at each first preset power for a corresponding second time period in order from small to large to obtain an inventory result of the target scene, the method further includes:

[0014] For any first preset power, the first time corresponding to the first preset power and the number of tags corresponding to the first preset power in the current inventory cycle are taken as a data point and added to the data set of the first preset power;

[0015] Taking the continuous working time as the independent variable and the number of tags as the dependent variable, a polynomial fitting of a preset order is performed according to the updated data set to obtain a fitting expression corresponding to the first preset power;

[0016] Return to the step of determining a solution set of the fitting expression corresponding to each first preset power when the second-order derivative is zero, and determining the minimum value in the solution set as the first time corresponding to each first preset power, so as to enter the next inventory cycle.

[0017] In one embodiment, the control method further includes:

[0018] In response to a query instruction for a target tag identifier, query whether the target tag identifier exists in the tag identifier set corresponding to each second preset power; the tag identifier set is a set formed by all tag identifiers read when the RFID reader / writer performs inventory at the target scene with the corresponding second preset power and the growth rate of the number of tags is less than a set threshold;

[0019] If the target tag identifier does not exist in any tag identifier set, locating the target tag identifier according to the maximum value of each second preset power;

[0020] Otherwise, the tag identifier set having the target tag identifier is determined as the target set;

[0021] In order from small to large, the target tag identifiers are located according to the second preset power corresponding to each target set.

[0022] In one of the embodiments, before responding to the query instruction for the target tag identifier and respectively querying whether there is a target tag identifier in the tag identifier sets corresponding to the second preset powers, the method further includes:

[0023] For any second preset power, the RFID reader is controlled to continuously take inventory in the target scene according to the second preset power, and the growth rate of the number of tags is counted in real time until the growth rate of the number of tags is less than the set threshold;

[0024] According to the tag identifier read by the second preset power, a tag identifier set corresponding to the second preset power is obtained.

[0025] In one embodiment, the control method further includes:

[0026] When the update condition is met, for any second preset power, the RFID reader is controlled to continuously take inventory in the target scene according to the second preset power, and the growth rate of the number of tags is counted in real time until the growth rate of the number of tags is less than the set threshold;

[0027] According to the tag identifier read by the second preset power, the tag identifier set corresponding to the second preset power is updated.

[0028] In one embodiment, the update condition includes: a change in the label distribution in the target scene or a change in the target scene.

[0029] In a second aspect, the present application provides a control device for an RFID reader / writer, comprising:

[0030] A data acquisition module is used to respectively acquire fitting expressions when the RFID reader performs inventory in a target scene according to a plurality of different first preset powers; the fitting expression is a polynomial of a preset order, and the fitting expression takes the continuous working time of the RFID reader as an independent variable and the number of tags read by the RFID reader as a dependent variable;

[0031] A first time determination module, used to determine a solution set of the fitting expression corresponding to each first preset power when the second-order derivative is zero, and determine the minimum value in the solution set as the first time corresponding to each first preset power;

[0032] A second time determination module, used to sort the first preset powers from small to large, determine the second times corresponding to the other first preset powers except the largest first preset power as the difference between the latter first preset power and the first time corresponding to itself, and determine the second time corresponding to the largest first preset power as the first time corresponding to it;

[0033] The inventory module is used to control the RFID reader to work at each first preset power for a corresponding second time period in order from small to large in the current inventory cycle to obtain an inventory result of the target scene.

[0034] In a third aspect, the present application provides a computer device, including one or more processors and a memory, wherein the memory stores computer-readable instructions, and when the computer-readable instructions are executed by the one or more processors, the control method of the RFID reader in any of the above embodiments is executed.

[0035] In a fourth aspect, the present application provides a computer-readable storage medium, in which computer-readable instructions are stored. When the computer-readable instructions are executed by one or more processors, the one or more processors execute the control method of the RFID reader in any of the above embodiments.

[0036] It can be seen from the above technical solutions that the embodiments of the present application have the following advantages:

[0037] The control method of the RFID reader in the present application can effectively avoid the time slot collision problem caused by the simultaneous response of multiple tags through detailed analysis of the tag response under different powers and determination of time parameters, thereby improving the accuracy and completeness of the reader reading tag information; it can take into account the characteristic differences of tag responses under different powers, reasonably arrange the working power and time of the reader, so that tags at different distances from the reader can respond in a relatively orderly time period, thereby improving the system's recognition efficiency of tags at different locations; it can also help to ensure the stable and efficient operation of the RFID system in complex environments and with an increase in the number of tags, and reduce the risk of increased system costs due to problems such as time slot collisions. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0039] Figure 1A flowchart of a method for controlling an RFID reader / writer provided by one embodiment of the present application;

[0040] Figure 2 A schematic diagram of a flow chart of obtaining a fitting expression corresponding to each first preset power in an embodiment of the present application;

[0041] Figure 3 A flowchart of a method for controlling an RFID reader / writer provided by another embodiment of the present application;

[0042] Figure 4 This is a flow chart of a method for controlling an RFID reader when locating a target tag in one embodiment of the present application;

[0043] Figure 5 An internal structure diagram of a computer device provided for one embodiment of the present application. DETAILED DESCRIPTION

[0044] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0045] This application provides a control method for an RFID reader / writer. Figure 1 , including steps S102 to S108.

[0046] S102, respectively obtain fitting expressions when the RFID reader is taking inventory in a target scene according to a plurality of different first preset powers; the fitting expression is a polynomial of a preset order, and the fitting expression takes the continuous working time of the RFID reader as an independent variable and the number of tags read by the RFID reader as a dependent variable.

[0047] It can be understood that the RFID reader can communicate with the RFID tag through a wireless radio frequency signal. It can send an inquiry signal to the tag to obtain the information stored in the tag. The target scenario refers to the specific working environment in which the RFID system is located in actual applications, such as a warehouse environment for managing goods, a supermarket environment for commodity management, etc. The fitting expression is to find a mathematical expression that can approximately reflect the relationship between these data points by analyzing a series of data points. In this embodiment, the fitting expression is specifically a polynomial with the continuous working time of the RFID reader as the independent variable and the number of tags read as the dependent variable, and the order of the polynomial is a preset order. The selection of the preset order can be adjusted according to the performance of the processor and the requirements of the fitting accuracy.

[0048] This embodiment mainly solves the time slot collision problem by controlling the power and working time of the RFID. By performing inventory operations and recording relevant data under different first preset powers, a polynomial expression is fitted. This step plays an important role in paving the way for the subsequent solution of the time slot collision problem. Because the communication conditions between the reader and the tag are different under different powers, the number of tags read varies over time. By analyzing the fitting expressions under these different powers, the performance of the system in the target scenario can be more comprehensively understood, thereby laying the foundation for the subsequent reasonable arrangement of the working power and time of the reader to reduce time slot collisions.

[0049] S104, determining a solution set of the fitting expression corresponding to each first preset power when the second-order derivative is zero, and determining the minimum value in the solution set as the first time corresponding to each first preset power.

[0050] It can be understood that the first-order derivative of the fitting expression represents the rate of change of the number of tags with the continuous working time of the RFID reader at the corresponding first preset power. It can reflect the speed of the increase or decrease of the number of tags per unit time. For example, if the first-order derivative is positive, it means that as the first duration increases; if the first-order derivative is negative, it means that the number of tags is decreasing. The second-order derivative represents the rate of change of the first-order derivative (rate of change). It reflects the change of the rate of change of the number of tags. The second-order derivative of 0 is the turning point of the change rate of the number of tags, at which point the trend of the growth rate of the number of tags has changed. Since the response of the radio frequency signal takes a certain amount of time, when working at any first preset power, the number of tags read by the reader will increase with the increase of time, and the growth rate also changes from fast to slow. Therefore, in this embodiment, the second-order derivative is 0, which marks the time point when the growth rate of the number of tags changes from accelerating to slowing down, that is, the highest point of the growth rate.

[0051] S106, sorting the first preset powers from small to large, determining the second times corresponding to the other first preset powers except the largest first preset power as the difference between the latter first preset power and the first time corresponding to itself, and determining the second time corresponding to the largest first preset power as the first time corresponding to it.

[0052] It can be understood that the control idea of ​​this embodiment in the actual control stage of RFID is to control the power of the RFID reader to gradually increase from the minimum first preset power, and focus on controlling the working time at each first preset power. Each first preset power has a corresponding second time, and the second time is used to control the length of time the RFID reader works at the corresponding power. Except for the largest first preset power, the second time corresponding to other first preset powers is the difference between the first time corresponding to the first preset power slightly larger than itself and the first time corresponding to itself. The method of using a function expression can be:

[0053]

[0054] Among them, L i represents the second time corresponding to the i-th first preset power, and N is the total number of first preset powers. Of course, if the result obtained is less than or equal to zero, the corresponding second time can be determined to be 0. That is, in the actual inventory stage, the second preset power with a second time of 0 can be skipped, and the next second preset power can be directly selected for inventory.

[0055] The selection of the second time in this embodiment takes into account that the response characteristics of tags under different powers are different. Under low power, the signal coverage of the reader is relatively small, and the tags that can respond are often tags that are closer to the reader, and these tags will gradually be activated before their corresponding first time. When the reader is controlled to work at low power according to the second time determined in step S106, these closer tags can respond in an orderly time period without conflicting with other tags that are farther away and respond at other powers, avoiding the chaotic situation of a large number of tags with different distances responding at the same time in the same time slot, thereby reducing the possibility of time slot collision.

[0056] As the power increases, the signal coverage of the reader / writer gradually expands, and more tags that are slightly farther away may respond. By controlling the reader / writer to work according to the corresponding second time at each power, tags at different distances and different powers can respond in their respective appropriate time periods. For example, when switching from low power to slightly higher power, due to the reasonable division of the second time, those tags at slightly higher power that might have interfered with the response of tags at low power due to blurred power edges can respond in an orderly manner within the time period determined by the new second time corresponding to the slightly higher power, without interfering with tags that are responding or about to respond at low power in the same time slot.

[0057] S108, in the current inventory cycle, controlling the RFID reader to work at each first preset power for a corresponding second time period in order from small to large, so as to obtain an inventory result of the target scene.

[0058] It can be understood that after determining that each first preset power corresponds to the second time, the inventory task for the target scene can be started according to the needs of the user. The inventory task in this embodiment can be started periodically. In each inventory cycle, starting from the minimum first preset power, the RFID reader is controlled to work at the power corresponding to the second duration. After the second duration under the power ends, it is then switched to the next slightly larger first preset power, and the reader is controlled to work at the power for its corresponding second duration, and so on, until the working duration control under all first preset powers is completed. In the whole process, the tag identification, tag information, etc. read by the reader at each stage should be accurately recorded. An RFID tag is set on each object to be inventoried in the target scene, and each RFID tag has a unique identification. Deduplication is performed according to the tag identification read in each stage, and the number of RFID tags in the target scene can be obtained according to the number of deduplicated tag identifications, and the number of objects to be inventoried in the target scene can be determined, thereby obtaining the inventory result of the target scene.

[0059] The control method of the RFID reader in this embodiment can effectively avoid the time slot collision problem caused by the simultaneous response of multiple tags through detailed analysis of the tag response under different powers and determination of time parameters, thereby improving the accuracy and completeness of the reader reading tag information; it can take into account the characteristic differences of tag responses under different powers, reasonably arrange the working power and time of the reader, so that tags at different distances from the reader can respond in a relatively orderly time period, thereby improving the system's recognition efficiency of tags at different locations; it can also help to ensure the stable and efficient operation of the RFID system in complex environments and with an increase in the number of tags, and reduce the risk of increased system costs due to problems such as time slot collisions.

[0060] In one embodiment, the fitting expressions when the RFID reader performs inventory in the target scene according to a plurality of different first preset powers are obtained respectively. Figure 2 , including steps S202 to S206.

[0061] S202: for any first preset power, control the RFID reader to inventory the set total time in the target scene according to the first preset power, and record the number of tags corresponding to multiple set time points during the inventory process.

[0062] It can be understood that this step is to control the RFID reader to perform continuous reading and writing operations on the tags in the target scene under a specific first preset power, and the total duration of the reading and writing operations is the set total duration. The setting of this duration needs to comprehensively consider factors such as the size of the target scene (such as the area of ​​the warehouse, the number of shelves in the supermarket, etc.), the approximate range of the number of tags, and the need to obtain sufficiently accurate data, so as to ensure that effective information related to the tag response can be obtained more comprehensively during this period. In the process of continuous reading and writing by the RFID reader, several specific time nodes are pre-determined at certain time intervals. At these time points, the number of RFID tags currently read should be recorded, so as to subsequently analyze the change pattern of the number of tags over time.

[0063] The core of this step is that at different first preset powers, the radio frequency signal strength emitted by the reader is different, which will affect the range and number of tags that can be activated and respond. By controlling the total duration of the inventory setting, it can be ensured that there is enough time to observe the complete process of tag response at each power, from the beginning when only a few tags closer to the reader may respond, to the entire dynamic change process over time when more tags that are slightly farther away may gradually respond. The purpose of setting the time point record is to discretize this continuous change process, so that the specific situation of the number of tags at different times can be analyzed more clearly, and then the possible patterns can be found.

[0064] S204: Obtain a data set corresponding to the first preset power according to each set time point and its corresponding tag quantity.

[0065] It can be understood that each first preset power has its own corresponding data set, and the data set contains two-dimensional coordinate points, the horizontal coordinate of each coordinate point is the continuous working time corresponding to the set time point, and the vertical coordinate is the total number of RFID tags read at the set time point. Through the method in step S204, the change of the number of tags over time under the specific first preset power can be presented in the form of discrete data points. This data set reflects the specific values ​​of the number of tags at different times in the entire time period from the start to the end of the inventory operation under this power, thereby providing direct data support for the subsequent search for the intrinsic relationship between the number of tags and time.

[0066] S206, taking the continuous working time as the independent variable and the number of tags as the dependent variable, performing a polynomial fitting of a preset order according to the data set to obtain a fitting expression corresponding to the first preset power.

[0067] It can be understood that, mathematically, polynomial fitting is a method of approximately describing the relationship between a set of data points by finding a polynomial function. The polynomial fitting of the preset order is to pre-set the highest power (i.e., order) of the polynomial before performing the fitting operation. Generally speaking, the higher the order, the closer the fitted curve can be to the actual data points, but at the same time, the problem of overfitting may also occur, that is, the fitting curve fits the current data points too well, and the prediction ability of other data points not involved in the fitting is poor. Therefore, it is necessary to reasonably select the preset order according to the actual situation. When the preset order is known, the coefficients of the polynomial are determined according to the given data points (here, the data set obtained in step S204), so that the polynomial function can fit these data points as well as possible, that is, the value of the polynomial function at each data point is as close as possible to the value of the actual data point.

[0068] In one embodiment, see Figure 3 , in the current inventory cycle, sequentially controlling the RFID reader to work at each first preset power for a corresponding second time period in order from small to large to obtain an inventory result of the target scene, further comprising:

[0069] S302, for any first preset power, control the RFID reader to inventory the set total time in the target scene according to the first preset power, and record the number of tags corresponding to multiple set time points during the inventory process; obtain a data set corresponding to the first preset power according to each set time point and its corresponding number of tags; take the continuous working time as the independent variable and the number of tags as the dependent variable, and perform a polynomial fitting of a preset order according to the data set to obtain a fitting expression corresponding to the first preset power.

[0070] S304, determining a solution set of the fitting expression corresponding to each first preset power when the second-order derivative is zero, and determining the minimum value in the solution set as the first time corresponding to each first preset power.

[0071] S306, sort the first preset powers from small to large, determine the second times corresponding to the other first preset powers except the largest first preset power as the difference between the latter first preset power and the first time corresponding to itself, and determine the second time corresponding to the largest first preset power as the first time corresponding to it.

[0072] The description of steps S302 to S306 can be found above.

[0073] S308, in the current inventory cycle, sequentially controlling the RFID reader to work at each first preset power for a corresponding second time period in order from small to large, so as to obtain an inventory result of the target scene.

[0074] It can be understood that the inventory in this embodiment can be periodic, and the second duration corresponding to each first preset power in each period will be dynamically updated. The reference basis for the update is the real-time data collected in the previous reference period.

[0075] S310: For any first preset power, take the first time corresponding to the first preset power and the number of tags corresponding to the first preset power in the current inventory cycle as a data point, and add them to a data set of the first preset power.

[0076] It can be understood that in the first inventory cycle, the second time corresponding to each first preset power is obtained based on the fitting expression fitted in the test phase. The fitting effect of the fitting expression will improve with the increase of data points. In the periodic inventory scenario, the actual working conditions of each round can also serve as the basis for improving the data set. Therefore, this step adds the first time corresponding to each first preset power in this round and the number of tags read by the reader at the second time obtained based on the first time as a data point to the data set of the first preset power to further enrich the content of the data set so that it can more comprehensively and accurately reflect the response characteristics of the tag under different conditions.

[0077] S312, performing polynomial fitting of a preset order with the continuous working time as the independent variable and the number of tags as the dependent variable according to the updated data set to obtain a fitting expression corresponding to the first preset power.

[0078] It is understandable that as the system runs and the data set is updated, refitting is required to obtain a more accurate mathematical expression that describes the relationship between the number of tags and time. By refitting the polynomial, the coefficients of the polynomial can be adjusted according to the new data distribution characteristics, so that the generated fitting expression can better adapt to the new situation and more accurately predict the possible changes in the number of tags at different time points, thereby providing more reliable mathematical model support for further optimization of the operation of the RFID system (such as determining a more appropriate first time, etc.).

[0079] S314, returning to the step of determining a solution set of the fitting expression corresponding to each first preset power when the second-order derivative is zero, and determining the minimum value in the solution set as the first time corresponding to each first preset power, so as to enter the next inventory cycle.

[0080] It can be understood that after the fitting expression is updated, the next inventory cycle can be entered. In the next inventory cycle, the control parameters corresponding to each first preset power need to be re-determined according to the updated fitting expression, so it is necessary to return to step S304 to continue execution. With the periodic inventory of the target scene, the second time corresponding to each first preset power will be closer and closer to the optimal value, further improving the inventory accuracy.

[0081] In one embodiment, see Figure 4 The control method further includes steps S402 to S4

[0082] S402 : In response to a query instruction for a target tag identifier, query whether a target tag identifier exists in the tag identifier sets corresponding to the second preset powers.

[0083] It can be understood that the query instruction is a command used to instruct the RFID reader to find a specific target tag. It clarifies the need to locate a specific target among the many tags in the RFID system. In the RFID system, each tag has a unique identifier that is used to distinguish different tag individuals. The target tag identifier is the unique identifier of the target tag, which can specifically be the EPC (Electronic Product Code) code of the RFID tag. Through this identifier, the reader can accurately identify a specific tag and obtain information related to it. The second preset power is a series of different power values ​​that are pre-set. Similar to the first preset power mentioned above, they are all set to adapt to different working scenarios and needs. They can be set in the same way as the first preset power, or they can be redefined as needed.

[0084] Each second preset power has a one-to-one corresponding tag identification set. The tag identification set is a set of all tag identifications read by the RFID reader when the target scene is inventoried at the corresponding second preset power and the growth rate of the number of tags is less than the set threshold. Specifically, it can be to control the RFID tags to continuously inventory and count the growth rate of the number of tags in real time until the growth rate of the number of tags is less than the set threshold. Then, based on the tag identification read by the second preset power, the tag identification set corresponding to the second preset power is obtained.

[0085] In the RFID system, the power of the reader is different, and its signal coverage, the number of tags that can be read, and the response characteristics of the tags will be different. When the inventory operation is performed with different second preset powers, the growth of the number of tags will also be different over time. By setting a threshold value for the growth rate of the number of tags, it can be ensured that under the corresponding second preset power, the response of most of the tags within the coverage range has been obtained, and the number of newly added tags is already very small, forming a corresponding tag identification set. In this way, each tag identification set reflects the limit of the tags that can be read under the corresponding second preset power. When a query instruction is received, a query can be made from each tag identification set. If the target tag identification does not exist in all tag identification sets, step S404 is entered, and the target tag is attempted to be located using the maximum second preset power. If the target tag identification exists in any tag identification set, it means that the information of the target tag identification can be read using the second preset power corresponding to the tag identification set, which provides a reference basis for subsequent power selection, and then steps S406 and S408 are entered.

[0086] S404: If the target tag identifier does not exist in any tag identifier set, locate the target tag identifier according to the maximum value of each second preset power.

[0087] It can be understood that the positioning in this step can be a rough positioning based on the strength of the signal fed back by the target tag to determine the distance between the reader and the tag. This positioning method has a wider range of applications and is not limited to the case where the position of the target tag is fixed. It can also be that the position of the target tag is unchanged, and its own position information is stored in it. The reader obtains the position information of the target tag by reading and writing the target tag.

[0088] In this step, since the target was not found in the tag identification set formed under different second preset powers, it means that the target tag identification may be in an area outside the normal power reading range, or its response characteristics are relatively special and it was not normally read in the previous inventory process. At this time, the basis for locating the target tag identification according to the maximum value of each second preset power is that a larger power usually has a wider signal coverage range, which can cover areas farther away from the reader and tags that may not have been read before. By using the maximum power for positioning operations, it is possible to find the target tag identification that was previously missed.

[0089] S406: Otherwise, determine the tag identifier set with the target tag identifier as the target set.

[0090] S408 , positioning the target tag identifiers in order from small to large according to the second preset power corresponding to each target set.

[0091] It can be understood that when it is found that there is a target tag identifier in a certain tag identifier set, this set is determined as a target set to facilitate the selection of the power for reading the target tag. When the target tag identifier appears in one of the sets, it means that the target tag has been successfully read using the second preset power corresponding to the set, and the second preset power corresponding to the set has a higher success rate for reading again. After all the target sets are determined, the second preset power corresponding to each target set will be selected in order from small to large to try to read the target tag. By performing positioning operations in order from small to large power, the area where the target tag identifier may exist can be explored step by step. Starting with a lower power can better save energy. As the power gradually increases, the signal coverage range of the reader / writer expands, and the most suitable reading power is gradually selected. Such reliance can effectively avoid the interference caused by tags at different power edges in the scene, and improve the accuracy of tag search and positioning in complex environments.

[0092] In one embodiment, the control method further includes: when the update condition is met, for any second preset power, controlling the RFID reader to continuously take inventory in the target scene according to the second preset power, and real-time statistics on the growth rate of the number of tags until the growth rate of the number of tags is less than a set threshold. According to the tag identifier read by the second preset power, the tag identifier set corresponding to the second preset power is updated.

[0093] It can be understood that in actual situations, the target scene and the label distribution within the scene will not remain unchanged, and the label identification set is obtained for the label distribution of a specific target scene. When the update condition is triggered, it is necessary to regenerate the label identification set corresponding to each second preset power in the new environment. Specific update conditions include: changes in the label distribution within the target scene or changes in the target scene. The updated label identification sets adapt to the dynamic changes of the entire system, and provide more accurate and timely basic data for subsequent operations such as querying target label identification and locating target labels.

[0094] The present application provides a control device for an RFID reader, comprising a data acquisition module, a first time determination module, a second time determination module and an inventory module. The data acquisition module is used to respectively obtain fitting expressions when the RFID reader performs inventory in a target scene according to a plurality of different first preset powers. The fitting expression is a polynomial of a preset order, and the fitting expression takes the continuous working time of the RFID reader as an independent variable and the number of tags read by the RFID reader as a dependent variable. The first time determination module is used to determine the solution set of the fitting expression corresponding to each first preset power when the second-order derivative is zero, and determine the minimum value in the solution set as the first time corresponding to each first preset power. The second time determination module is used to sort the first preset powers from small to large, determine the second time corresponding to other first preset powers except the largest first preset power as the difference between the next first preset power and the first time corresponding to itself, and determine the second time corresponding to the largest first preset power as the first time corresponding to it. The inventory module is used to control the RFID reader to work at each first preset power in the current inventory cycle in order from small to large, so as to obtain the inventory result of the target scene.

[0095] In one of the embodiments, in one of the embodiments, the data acquisition module is also used to control the RFID reader to inventory the set total time in the target scene according to the first preset power for any first preset power, and record the number of tags corresponding to multiple set time points during the inventory process; according to each set time point and its corresponding number of tags, a data set corresponding to the first preset power is obtained; with the continuous working time as the independent variable and the number of tags as the dependent variable, a polynomial fitting of a preset order is performed according to the data set to obtain a fitting expression corresponding to the first preset power.

[0096] In one of the embodiments, the inventory module is further used to, for any first preset power, take the first time corresponding to the first preset power and the number of tags corresponding to the first preset power in the current inventory cycle as a data point, and add them to the data set of the first preset power; use the continuous working time as the independent variable and the number of tags as the dependent variable, perform polynomial fitting of a preset order according to the updated data set to obtain a fitting expression corresponding to the first preset power; return to the step of determining a solution set of the fitting expression corresponding to each first preset power when the second-order derivative is zero, and determine the minimum value in the solution set as the first time corresponding to each first preset power, so as to enter the next inventory cycle.

[0097] In one of the embodiments, the control device also includes a query module and a positioning module. The query module is used to respond to the query instruction for the target tag identifier and query whether the target tag identifier exists in the tag identifier set corresponding to each second preset power; the tag identifier set is a set formed by all tag identifiers read by the RFID reader when the target scene is inventoried at the corresponding second preset power and the growth rate of the number of tags is less than the set threshold. The positioning module is used to locate the target tag identifier according to the maximum value of each second preset power if the target tag identifier does not exist in each tag identifier set; otherwise, the tag identifier set with the target tag identifier is determined as the target set; and the target tag identifier is located in order from small to large according to the second preset power corresponding to each target set.

[0098] In one of the embodiments, the data acquisition module is also used to control the RFID reader / writer to continuously take inventory in the target scene according to the second preset power for any second preset power, and to count the growth rate of the number of tags in real time until the growth rate of the number of tags is less than a set threshold; based on the tag identification read by the second preset power, a tag identification set corresponding to the second preset power is obtained.

[0099] In one embodiment, the control device further includes an update module. The update module is used to control the RFID reader to continuously take inventory in the target scene according to any second preset power when the update condition is met, and to count the growth rate of the number of tags in real time until the growth rate of the number of tags is less than a set threshold; and to update the tag identification set corresponding to the second preset power according to the tag identification read by the second preset power.

[0100] In one embodiment, the update condition includes: a change in the label distribution in the target scene or a change in the target scene.

[0101] For the specific definition of the control device of the RFID reader / writer, please refer to the definition of the control method of the RFID reader / writer mentioned above, which will not be repeated here. The various modules in the control device of the above-mentioned RFID reader / writer can be implemented in whole or in part by software, hardware and their combination. The above-mentioned modules can be embedded in or independent of the processor in the computer device in the form of hardware, or can be stored in the memory of the computer device in the form of software, so that the processor can call and execute the operations corresponding to the above modules. It should be noted that the division of modules in the embodiments of the present application is schematic and is only a logical function division. There may be other division methods in actual implementation.

[0102] The present application provides a computer device, including one or more processors and a memory, wherein the memory stores computer-readable instructions, and when the computer-readable instructions are executed by the one or more processors, the control method of the RFID reader in any of the above embodiments is executed.

[0103] Indicatively, Figure 5 As shown, Figure 5 A schematic diagram of the internal structure of a computer device provided in an embodiment of the present application. Figure 5 The computer device 500 includes a processing component 502, which further includes one or more processors, and a memory resource represented by a memory 501, for storing instructions executable by the processing component 502, such as an application. The application stored in the memory 501 may include one or more modules, each corresponding to a set of instructions. In addition, the processing component 502 is configured to execute instructions to execute the control method of the RFID reader / writer of any of the above embodiments.

[0104] The computer device 500 may further include a power supply component 503 configured to perform power management of the computer device 500 , a wired or wireless network interface 504 configured to connect the computer device 500 to a network, and an input / output (I / O) interface 505 .

[0105] The present application provides a computer-readable storage medium, in which computer-readable instructions are stored. When the computer-readable instructions are executed by one or more processors, the one or more processors execute the control method of the RFID reader in any of the above embodiments.

[0106] Finally, it should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0107] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The various embodiments can be combined as needed, and the same or similar parts can refer to each other.

[0108] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A control method for an RFID reader / writer, characterized in that: include: Respectively obtain fitting expressions when the RFID reader is taking inventory in a target scene according to a plurality of different first preset powers; the fitting expression is a polynomial of a preset order, and the fitting expression takes the continuous working time of the RFID reader as an independent variable and the number of tags read by the RFID reader as a dependent variable; Determine a solution set of the fitting expression corresponding to each of the first preset powers when the second-order derivative is zero, and determine the minimum value in the solution set as the first time corresponding to each of the first preset powers; Sort the first preset powers from small to large, determine the second times corresponding to the other first preset powers except the largest first preset power as the difference between the latter first preset power and the first time corresponding to itself, and determine the second time corresponding to the largest first preset power as the first time corresponding to it; In the current inventory cycle, the RFID reader is controlled to work at each of the first preset powers for the corresponding second time periods in order from small to large, so as to obtain an inventory result of the target scene.

2. The control method according to claim 1, characterized in that: The respectively obtaining fitting expressions when the RFID reader / writer performs inventory in the target scene according to a plurality of different first preset powers includes: For any of the first preset powers, control the RFID reader to count the total duration set in the target scene according to the first preset power, and record the number of tags corresponding to multiple set time points during the counting process; According to each of the set time points and the corresponding number of tags, a data set corresponding to the first preset power is obtained; The continuous working time is taken as an independent variable and the number of tags is taken as a dependent variable, and a polynomial fitting of the preset order is performed according to the data set to obtain the fitting expression corresponding to the first preset power.

3. The control method according to claim 2, characterized in that: After the RFID reader is controlled to work at each of the first preset powers for the corresponding second time periods in the current inventory cycle in ascending order to obtain an inventory result of the target scene, the method further includes: For any first preset power, the first time corresponding to the first preset power and the number of tags corresponding to the first preset power in the current inventory cycle are taken as a data point and added to the data set of the first preset power; Taking the continuous working time as an independent variable and the number of tags as a dependent variable, performing polynomial fitting of the preset order according to the updated data set to obtain the fitting expression corresponding to the first preset power; Return to the step of determining the solution set of the fitting expression corresponding to each first preset power when the second-order derivative is zero, and determining the minimum value in the solution set as the first time corresponding to each first preset power, so as to enter the next inventory cycle.

4. The control method according to claim 1, characterized in that: Also includes: In response to a query instruction for a target tag identifier, query whether the target tag identifier exists in the tag identifier set corresponding to each second preset power; the tag identifier set is a set formed by all tag identifiers read by the RFID reader / writer when the target scene is inventoried at the corresponding second preset power and the growth rate of the number of tags is less than a set threshold; If the target tag identifier does not exist in any of the tag identifier sets, locating the target tag identifier according to the maximum value of the second preset powers; Otherwise, determining the tag identifier set containing the target tag identifier as the target set; In order from small to large, the target tag identifiers are positioned according to the second preset power corresponding to each of the target sets.

5. The control method according to claim 4, characterized in that: Before the step of responding to the query instruction for the target tag identifier and respectively querying whether the target tag identifier exists in the tag identifier sets corresponding to the second preset powers, the step further includes: For any of the second preset powers, control the RFID reader to continuously take inventory in the target scene according to the second preset power, and count the growth rate of the number of tags in real time until the growth rate of the number of tags is less than the set threshold; According to the tag identifier read by the second preset power, the tag identifier set corresponding to the second preset power is obtained.

6. The control method according to claim 4, characterized in that: Also includes: When the update condition is met, for any second preset power, the RFID reader is controlled to continuously take inventory in the target scene according to the second preset power, and the growth rate of the number of tags is counted in real time until the growth rate of the number of tags is less than the set threshold; According to the tag identifier read by the second preset power, the tag identifier set corresponding to the second preset power is updated.

7. The control method according to claim 6, characterized in that: The update condition includes: a change in the label distribution in the target scene or a change in the target scene.

8. A control device for an RFID reader / writer, characterized in that: include: A data acquisition module, used to respectively acquire fitting expressions when the RFID reader / writer performs inventory in a target scene according to a plurality of different first preset powers; The fitting expression is a polynomial of a preset order, and the fitting expression takes the continuous working time of the RFID reader as an independent variable and the number of tags read by the RFID reader as a dependent variable; A first time determination module, used to determine a solution set of the fitting expression corresponding to each of the first preset powers when the second-order derivative is zero, and determine the minimum value in the solution set as the first time corresponding to each of the first preset powers; A second time determination module, configured to sort the first preset powers from small to large, determine the second times corresponding to the other first preset powers except the largest first preset power as the difference between the latter first preset power and the first time corresponding to itself, and determine the second time corresponding to the largest first preset power as the first time corresponding to it; The inventory module is used to control the RFID reader to work at each of the first preset powers for the corresponding second time periods in order from small to large in the current inventory cycle to obtain the inventory result of the target scene.

9. A computer device, characterized in that: The system comprises one or more processors and a memory, wherein the memory stores computer-readable instructions, and when the computer-readable instructions are executed by the one or more processors, the control method of the RFID reader-writer according to any one of claims 1 to 7 is executed.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores computer-readable instructions, and when the computer-readable instructions are executed by one or more processors, the one or more processors execute the control method of the RFID reader-writer according to any one of claims 1 to 7.

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