A data acquisition method and system for RFID sensor tags

Abstract

The application relates to the technical field of data collection, in particular to a data collection method and system of an RFID sensor tag, which comprises the following steps: determining data priority transmission necessity according to signal fluctuation intensity characteristics of current data of each RFID sensor tag, obtaining data importance from signal fluctuation intensity increasing trends of the RFID sensor tags, the signal fluctuation intensity increasing trends representing increasing trends of signal fluctuation intensity characteristics of each historical data in a neighborhood range of the current data, determining channel occupation rates of the RFID sensor tags, and obtaining the channel occupation rates from the data priority transmission necessity and the data importance; the more critical the RFID sensor tag data is, the higher the channel occupation rate is, so that critical RFID sensor tag data can be preferentially uploaded, the communication delay problem of the critical sensor data is solved, and the data collection efficiency of the RFID sensor tag is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of data acquisition, in particular to a data acquisition method and system of RFID sensor tags. BACKGROUND

[0002] With the rapid development of Internet of Things technology, the deep integration of sensor and communication technology has become an important development direction of intelligent sensing system. As a non-contact automatic identification technology, Radio Frequency Identification (RFID) has the advantages of long-distance identification, no need for line of sight, and can be embedded in various carriers. By integrating sensor technology and RFID technology, RFID sensor tags can collect physical quantity information such as temperature, humidity, pressure, displacement, etc. while carrying an identity tag. In recent years, in order to efficiently and reliably acquire data from a large number of RFID sensor tags deployed in the environment, a tag self-reporting mode is usually used to actively send stored sensor data under certain conditions (such as sensor readings exceeding a threshold, timer expiration, external trigger), thereby realizing data acquisition of RFID sensor tags.

[0003] In the prior art, multiple RFID sensor tags are used to monitor various data in intelligent sensing scenarios, and an event or timing trigger mechanism is used to make RFID sensor tags actively upload data. When multiple RFID sensor tags respond to the query command of the reader or frequently upload data, in order to prevent collision conflicts, the ALOHA algorithm is usually used to alleviate collision conflicts. However, in intelligent scenarios, various types of information may interfere with each other. By randomly waiting to stagger the response, RFID sensor tag data is randomly uploaded, which cannot ensure that the uploaded data is helpful for analyzing the cause of the accident. At the same time, the key sensor data directly affected by the accident increases the number of retries and communication delay, which seriously affects the overall data acquisition efficiency and response speed of the system. The existing solution is to allocate equal channel occupancy rate to each RFID sensor tag data. However, this method still cannot solve the problem of communication delay of key sensor data, which seriously affects the data acquisition efficiency of RFID sensor tags. SUMMARY

[0004] In order to solve the technical problem that allocating equal channel occupancy rate to each RFID sensor tag data affects the data acquisition efficiency of RFID sensor tags, the purpose of the present application is to provide a data acquisition method and system of RFID sensor tags, and the technical solution adopted is as follows:

[0005] In the first aspect of the present application, a data acquisition method of RFID sensor tags is provided, comprising:

[0006] determining the data priority transmission necessity of each RFID sensor tag according to the signal fluctuation intensity feature of the current data of each RFID sensor tag;

[0007] obtaining the data importance of each RFID sensor tag from the signal fluctuation intensity increasing trend of each RFID sensor tag, the signal fluctuation intensity increasing trend representing an increasing trend of the signal fluctuation intensity feature of each historical data in the neighborhood range of the current data;

[0008] determining the channel occupancy rate of each RFID sensor tag, the channel occupancy rate being obtained from the data priority transmission necessity and the data importance.

[0009] In an exemplary embodiment, the signal fluctuation intensity feature acquisition process comprises:

[0010] obtaining the signal amplitude difference mean value of the current data and the signal amplitude variance of the current data;

[0011] obtaining the signal fluctuation intensity feature of the current data according to the signal amplitude difference mean value and the signal amplitude variance of the current data; the signal fluctuation intensity feature is positively correlated with the signal amplitude difference mean value and the signal amplitude variance.

[0012] In an exemplary embodiment, the data priority transmission necessity of each RFID sensor tag is obtained from the maximum-minimum normalization of the signal fluctuation intensity feature of the current data of each RFID sensor tag.

[0013] In an exemplary embodiment, before the determination of the data priority transmission necessity of each RFID sensor tag according to the signal fluctuation intensity feature of the current data of each RFID sensor tag, the data acquisition method of the RFID sensor tag further comprises:

[0014] determining the channel utilization rate of the current communication link and the overall level of the signal fluctuation intensity feature; the overall level of the signal fluctuation intensity feature being the average value of the signal fluctuation intensity feature of the current data of each RFID sensor tag;

[0015] judging whether the communication state of the current communication link has a high collision risk according to the channel utilization rate of the current communication link and the overall level of the signal fluctuation intensity feature;

[0016] if the current communication link has a high collision risk, performing the determination of the data priority transmission necessity of each RFID sensor tag according to the signal fluctuation intensity feature of the current data of each RFID sensor tag.

[0017] In an exemplary embodiment, the judgment process of whether the communication state of the current communication link has a high collision risk comprises:

[0018] obtaining a communication state index of the current communication link according to the channel utilization rate and the overall level of the signal fluctuation intensity characteristic of the current communication link;

[0019] comparing the communication state index with a preset threshold value, and determining that there is a high collision risk in the communication state of the current communication link if the communication state index is greater than or equal to the preset threshold value.

[0020] In an exemplary embodiment, the obtaining process of the signal fluctuation intensity increasing trend comprises:

[0021] determining a signal fluctuation intensity characteristic difference value between the latter historical data and the former historical data of the two adjacent historical data in the neighborhood range, calculating an average value of the signal fluctuation intensity characteristic difference value in the neighborhood range, and obtaining the signal fluctuation intensity increasing trend.

[0022] In an exemplary embodiment, the data importance of each RFID sensor tag is obtained by maximum-minimum normalization of the signal fluctuation intensity increasing trend of each RFID sensor tag.

[0023] In an exemplary embodiment, the obtaining process of the channel occupation rate comprises:

[0024] calculating the product of the data priority transmission necessity and the data importance of each RFID sensor tag, and obtaining a channel occupation rate characteristic of each RFID sensor tag;

[0025] taking the ratio of the channel occupation rate characteristic of each RFID sensor tag to the sum of channel occupation rate characteristics of all RFID sensor tags as the channel occupation rate of each RFID sensor tag; and the sum of channel occupation rate characteristics is the sum value of the channel occupation rate characteristics of all RFID sensor tags.

[0026] In an exemplary embodiment, after the channel occupation rate of each RFID sensor tag is determined, the data acquisition method of the RFID sensor tag further comprises:

[0027] allocating channels to each RFID sensor tag according to the channel occupation rate of each RFID sensor tag, so as to complete data uploading of each RFID sensor tag.

[0028] In a second aspect of the present application, a data acquisition system of an RFID sensor tag is provided, comprising a memory and a processor; the memory is connected with the processor; the memory is used for storing program instructions; and the processor is used for implementing the above-mentioned data acquisition method of the RFID sensor tag when the program instructions are executed.

[0029] The present application has the following beneficial effects: the present application allocates the channel occupancy rate of each RFID sensor tag according to the data priority transmission necessity and data importance of the current data of each RFID sensor tag, the more critical the RFID sensor tag data, the higher the channel occupancy rate, so that the critical RFID sensor tag data can be uploaded preferentially, the communication delay problem of critical sensor data is solved, and the data acquisition efficiency of the RFID sensor tag is improved. BRIEF DESCRIPTION OF DRAWINGS

[0030] Figure 1 is a composition schematic diagram of a data communication system of an RFID sensor tag provided by an embodiment of the present application;

[0031] Figure 2 is a flowchart of a data acquisition method of an RFID sensor tag provided by an embodiment of the present application;

[0032] Figure 3 is a flowchart of acquisition of signal fluctuation intensity characteristics provided by an embodiment of the present application;

[0033] Figure 4 is a process schematic diagram of multiple RFID sensor tags uploading data to an acquisition component through a communication link provided by an embodiment of the present application;

[0034] Figure 5 is a flowchart of steps further included in a data acquisition method of an RFID sensor tag provided by an embodiment of the present application;

[0035] Figure 6 is a flowchart of acquisition of channel occupancy rate provided by an embodiment of the present application. DETAILED DESCRIPTION

[0036] In order to further illustrate the technical means and effects taken by the present application to achieve the predetermined purposes, the specific embodiments, structures, features and effects of the present application are described in detail below in combination with the drawings and preferred embodiments. In the following description, different "one embodiment" or "another embodiment" do not necessarily refer to the same embodiment. In addition, the specific features, structures or characteristics in one or more embodiments can be combined in any suitable form.

[0037] 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 the present application belongs. The data information collected by the present application is obtained with full authorization.

[0038] The data communication system of the RFID sensor tag is briefly introduced as follows, such as Figure 1As shown, the system flow is: tag deployment and activation preparation: the RFID sensor tag is attached or embedded on the target object / environment, and the tag is preset with a unique ID (EPC code (Electronic Product Code)) and a sensor type; the reader sends a collection command: activates the tag through a radio frequency signal, sends a query or read command, and specifies the data area (such as sensor value storage address) that needs to be read; the tag senses and samples data: the sensor module in the tag collects environmental information in real time, stores the sample value in the storage area of the tag, and uploads the response according to the corresponding period or event trigger; data upload and reader reception: the tag uploads the EPC code and sensor data through backscatter modulation, and the reader receives and decodes to extract the valid monitoring value; data upload to the background system: upload all tag data to the server through the communication link; monitor the communication link state and record the real-time channel utilization of the communication link.

[0039] In the data monitoring of the intelligent scene by multiple RFID sensor tags, due to the power supply capability and communication bandwidth limitations of the RFID sensor tags, real-time data cannot be continuously uploaded, so in actual application, a fixed period upload combined with an event trigger mechanism is often used for data collection and upload. In general, each RFID sensor tag uploads sensor data at the same time interval, and when a sudden event occurs, the RFID sensor tag detects abnormal changes (such as exceeding a set threshold) in the sensor value, and immediately activates the communication module to trigger data upload.

[0040] It should be understood that the sensor data of different RFID sensor tags may not be of the same type, such as temperature, current, etc., and therefore, the sensor data of each RFID sensor tag needs to be standardized (such as using Z-Score standardization) to eliminate the dimension and facilitate subsequent data processing between the data of different RFID sensor tags. The sensor data of each RFID sensor tag involved later is standardized sensor data.

[0041] The embodiment provides a data collection method for an RFID sensor tag, as shown in Figure 2 The method comprises the following steps:

[0042] Step S1: determining the data priority transmission necessity of each RFID sensor tag according to the signal fluctuation intensity characteristics of the current data of each RFID sensor tag;

[0043] Step S2: obtaining the data importance of each RFID sensor tag from the signal fluctuation intensity increasing trend of each RFID sensor tag;

[0044] Step S3: determining the channel occupancy rate of each RFID sensor tag, which is obtained from the data priority transmission necessity and the data importance.

[0045] The various steps will be described in detail below in conjunction with the accompanying drawings.

[0046] Step S1: determining the data transmission necessity of each RFID sensor tag according to the signal fluctuation intensity feature of the current data of each RFID sensor tag.

[0047] First, the communication state of the current multiple RFID sensor tags uploading data needs to be analyzed. When a sudden event occurs, the sensors directly affected by the event will monitor the sensor data in a different fluctuation mode than before. By analyzing the signal fluctuation intensity of the RFID sensor tag upload frame, the importance of the upload data of each sensor tag to the analysis of the abnormal event can be determined. The tag upload frame is the data currently uploaded by the tag to the server, i.e., the current data of the RFID sensor tag. In the server, the current data of each RFID sensor tag, i.e., the latest successfully uploaded data frame, is obtained. According to the current data of each RFID sensor tag, the signal fluctuation intensity feature of the current data of each RFID sensor tag is obtained. The signal fluctuation intensity feature represents the signal fluctuation degree of the current data. The stronger the signal fluctuation degree exhibited by the current data, the more obvious the signal fluctuation intensity feature. In an exemplary embodiment, as shown in FIG. 2, a specific acquisition process of the signal fluctuation intensity feature is given as follows: Figure 3

[0048] Step S1-1: obtaining the signal amplitude difference mean value of the current data and the signal amplitude variance of the current data.

[0049] For any RFID sensor tag, defined as a target RFID sensor tag, for ease of illustration, the target RFID sensor tag is taken as an example.

[0050] It should be understood that the target RFID sensor tag uploads a piece of sensor data each time, and a piece of sensor data represents a frame of long sensor data. Therefore, the current data of the target RFID sensor tag is a piece of sensor data in time sequence, including multiple sensor signals in time sequence.

[0051] The signal amplitudes of the sensor signals in the current data of the target RFID sensor tag are obtained, and the absolute values of the signal amplitude differences between each two adjacent sensor signals are calculated as the signal amplitude differences between each two adjacent sensor signals. Then, the average value of the signal amplitude differences is calculated as the signal amplitude difference mean value of the current data of the target RFID sensor tag. The signal amplitude difference mean value represents the signal fluctuation intensity of the current data of the target RFID sensor tag. The larger the signal amplitude difference mean value, the greater the signal fluctuation intensity.

[0052] ​The variance of the signal amplitudes of the individual sensor signals in the current data of the target RFID sensor tag is calculated as the signal amplitude variance of the current data of the target RFID sensor tag. The signal amplitude variance characterizes the signal fluctuation strength of the current data of the target RFID sensor tag, and the greater the signal amplitude variance, the greater the signal fluctuation strength.

[0053] Step S1-2: According to the signal amplitude difference mean and the signal amplitude variance of the current data, the signal fluctuation strength feature of the current data is obtained.

[0054] The signal amplitude difference mean and the signal amplitude variance of the current data of the target RFID sensor tag are fused to obtain the signal fluctuation strength feature of the current data of the target RFID sensor tag. The signal fluctuation strength feature is positively correlated with both the signal amplitude difference mean and the signal amplitude variance. In an exemplary embodiment, the product of the signal amplitude difference mean and the signal amplitude variance of the current data of the target RFID sensor tag is calculated as the signal fluctuation strength feature of the current data of the target RFID sensor tag. Thus, the signal fluctuation strength feature of the current data of each RFID sensor tag is obtained.

[0055] As another implementation, only the signal amplitude difference mean or the signal amplitude variance can be used as the signal fluctuation strength feature.

[0056] It should be understood that there may be some correlation between various types of sensor data in a smart scene, and when a sudden event occurs, it may cause multiple sensor data to be abnormal at the same time. Multiple RFID sensor tags are triggered and upload a large amount of data at the same time, causing collision and continuous delay retransmission, resulting in reduced data acquisition efficiency. Therefore, in order to effectively alleviate the communication collision conflict problem of sensor data, it is necessary to determine whether there is a high collision risk in the current communication state, so as to trigger the corresponding collision mitigation mechanism. As shown in FIG. 1, it is the process of multiple RFID sensor tags uploading data to the acquisition component through the communication link. When an accident occurs, collision and conflict occur in this process. Figure 4

[0057] When the communication state of the communication link is poor, dynamic allocation of transmission occupancy (i.e., channel occupancy) is needed to ensure that important information is successfully and quickly uploaded. When the signal fluctuation strength features of all RFID sensor tags currently uploaded are strong, it indicates that the event interference is serious at this time, and the probability of collision and conflict is greater. At the same time, the probability of successful data upload by the tag is reduced, and the channel utilization rate is reduced, so the communication needs to be intervened in time. According to the signal fluctuation strength features of the data uploaded by all RFID sensor tags and the channel utilization rate of the current communication link, the communication state of the current communication link is obtained. And according to the communication state of the current communication link, it is determined whether there is a high collision risk. In an exemplary embodiment, as shown in FIG. 2, the signal fluctuation strength features of the data uploaded by all RFID sensor tags are compared with the channel utilization rate of the current communication link, and the communication state of the current communication link is obtained.​Figure 5 As shown, before determining the data priority transmission necessity of each RFID sensor tag according to the signal fluctuation intensity feature of the current data of each RFID sensor tag, the data acquisition method of the RFID sensor tag provided by the embodiment further includes the following steps:

[0058] Step S100: Determine the channel utilization of the current communication link and the overall level of the signal fluctuation intensity feature.

[0059] The channel utilization of the current communication link is obtained, and the channel utilization is the proportion of the actual bandwidth used by the communication link to the total bandwidth of the communication link, and the numerical range is 0-1. The commonly used acquisition method of the channel utilization is based on throughput measurement. The actual data amount (throughput) transmitted on the communication link within a period of time (i.e. the current time) is measured, and then divided by the maximum data amount that the communication link can theoretically transmit at that time. Among them, the actual throughput can be detected by network monitoring tools, such as: using professional network performance monitoring tools (such as distributed monitoring system, PRTG router flow plotter, solar wind network performance monitor, Nagios, cactus network traffic monitoring graphical analysis tool, MRTG, traffic analysis instrument, network packet analysis tool statistical function, etc.). These tools usually collect the byte count of the interface through SNMP, NetFlow / sFlow / IPFIX, or direct packet capture. It should be understood that the monitoring method of the channel utilization of the communication link is the existing method, which will not be described in detail.

[0060] The average value of the signal fluctuation intensity feature of the current data of each RFID sensor tag is calculated as the overall level of the signal fluctuation intensity feature.

[0061] Step S200: According to the channel utilization of the current communication link and the overall level of the signal fluctuation intensity feature, it is judged whether the communication state of the current communication link has a high collision risk.

[0062] In one exemplary embodiment, the communication state indicator of the current communication link is obtained according to the channel utilization rate of the current communication link and the overall level of the signal fluctuation intensity feature. The higher the channel utilization rate of the current communication link, the higher the probability of collision conflict in the signal transmission process, and accordingly, the higher the communication state indicator of the current communication link. The higher the overall level of the signal fluctuation intensity feature, the stronger the signal fluctuation intensity feature uploaded by all RFID sensor tags at present, which indicates that the event interference is serious at this time, the probability of collision conflict is greater due to frequent response uploading, and accordingly, the higher the communication state indicator of the current communication link. Therefore, the communication state indicator of the current communication link is positively correlated with the channel utilization rate of the current communication link and the overall level of the signal fluctuation intensity feature. As a specific example, one specific quantification method of the communication state indicator of the current communication link is given as follows: first, normalize the overall level of the signal fluctuation intensity feature, and the normalization method can be: wherein exp is the exponential function with the natural constant e as the base, and x is the object to be normalized. Then, the product of the channel utilization rate of the current communication link and the overall level of the normalized signal fluctuation intensity feature is calculated, and the result is the communication state indicator of the current communication link.

[0063] The embodiment presets a threshold value, which is used to compare with the obtained communication state indicator to determine whether the communication state indicator is high, so as to determine whether the communication state of the current communication link has a high collision risk. The numerical range of the preset threshold value is 0-1, and the specific value is set by judgment. If the high collision risk judgment is strict, the preset threshold value can be set smaller, such as 0.6. If the communication state indicator is greater than or equal to the preset threshold value, it is determined that the communication state of the current communication link has a high collision risk, and the channel occupancy rate of each RFID sensor tag needs to be dynamically allocated; if the communication state indicator is less than the preset threshold value, it is determined that the communication state of the current communication link does not have a high collision risk.

[0064] Step S300: If the current communication link has a high collision risk, the data priority transmission necessity of each RFID sensor tag is determined according to the signal fluctuation intensity feature of the current data of each RFID sensor tag.

[0065] If the current communication link has a high collision risk, the step S1 in the above embodiment is executed, that is, the implementation process of the data acquisition method of the RFID sensor tag provided by the embodiment is executed.

[0066] The signal fluctuation intensity feature of the current data of the target RFID sensor tag is determined according to the data priority transmission necessity of the target RFID sensor tag. The stronger the signal fluctuation intensity feature is, the more likely the target RFID sensor tag is affected by the emergency event, so that stronger data fluctuation occurs, and therefore, the higher the data priority transmission necessity of the target RFID sensor tag is, and the more obvious the signal fluctuation intensity feature of the current data of the target RFID sensor tag is, and therefore, the data priority transmission necessity of the target RFID sensor tag is positively correlated with the signal fluctuation intensity feature of the current data of the target RFID sensor tag.

[0067] When an abnormal event triggers the multi-RFID sensor tag to upload data, the existing way to alleviate RFID communication collision conflict is usually to reduce the collision probability by adjusting the data frame length uploaded by the tag or introducing a random delay retransmission mechanism, without considering important RFID sensor tag data, lacking recognition and distinction of the urgency of the uploaded data content. For multi-RFID sensor tags, some tags may carry critical environmental monitoring, device status or safety alarm data, and if they cannot be uploaded in time, it may lead to system response lag or risk perception failure. Therefore, relying only on the general collision mitigation mechanism cannot meet the differentiated scheduling of high-priority data transmission requirements, and there is obvious limitation in high-density or burst scenarios, and an adaptive scheduling strategy based on data urgency needs to be introduced.

[0068] When an emergency event occurs, it may cause abnormal fluctuations in the monitoring data of some RFID sensor tags, and even affect the overall tag perception behavior. In order to more accurately identify the key tags that truly reflect the emergency event, the difference between the signal fluctuation intensity features of the current data of a single RFID sensor tag and other RFID sensor tags can be compared to evaluate whether there is a need for channel priority allocation for a single RFID sensor tag.

[0069] If the signal fluctuation intensity features of the current data of all RFID sensor tags are close, it means that the emergency event affects the global state, and random uploading of tag data is sufficient. On the contrary, if the signal fluctuation intensity features of the data uploaded by all RFID sensor tags are quite different, it means that the emergency event affects part of the RFID sensor data, and the data of the RFID sensor tags directly affected should be uploaded in priority. According to the difference between the signal fluctuation intensity features of the current data of all RFID sensor tags, a global contrast of the signal intensity of the data uploaded by all RFID sensor tags is obtained. The maximum value and the minimum value in the signal fluctuation intensity feature of the current data of each RFID sensor tag are obtained, and the difference between the maximum value and the minimum value is calculated, which is the global contrast.

[0070] When the signal fluctuation intensity feature of the target RFID sensor tag is large and has a high global contrast, it indicates that the data collected by the target RFID sensor tag can reflect the core features of the burst event and has a higher upload priority. According to the contrast of the signal fluctuation intensity feature of the target RFID sensor tag affected by the burst event among all RFID sensor tags and the global contrast, the data priority transmission necessity of the target RFID sensor tag is obtained. The contrast of the signal fluctuation intensity feature of the target RFID sensor tag affected by the burst event among all RFID sensor tags is calculated in the following manner: the difference between the signal fluctuation intensity feature of the target RFID sensor tag and the minimum value is calculated, and the difference is the contrast of the signal fluctuation intensity feature of the target RFID sensor tag affected by the burst event among all RFID sensor tags. The minimum value here is the minimum value in the signal fluctuation intensity feature of the current data of each RFID sensor tag.

[0071] The ratio of the contrast of the signal fluctuation intensity feature of the target RFID sensor tag affected by the burst event among all RFID sensor tags and the global contrast is calculated as the data priority transmission necessity of the target RFID sensor tag. Through analysis, the calculation process essentially normalizes the maximum and minimum values of the signal fluctuation intensity feature of the current data of the target RFID sensor tag. Specifically, the maximum and minimum values in the signal fluctuation intensity feature of the current data of each RFID sensor tag are obtained, and then the signal fluctuation intensity feature of the current data of the target RFID sensor tag is normalized by using the maximum and minimum value normalization method, and the normalized result is taken as the data priority transmission necessity of the target RFID sensor tag.

[0072] More preferably, the communication state indicator of the current communication link can also participate in the calculation process of the data priority transmission necessity of the target RFID sensor tag, so that the data priority transmission necessity is also affected by the communication state indicator of the current communication link. Then, the product of the communication state indicator of the current communication link and the signal fluctuation intensity feature of the target RFID sensor tag after maximum and minimum value normalization is calculated, and the product is the data priority transmission necessity of the target RFID sensor tag.

[0073] Step S2: Obtain the data importance of each RFID sensor tag from the signal fluctuation intensity increasing trend of each RFID sensor tag.

[0074] If the emergency first affects the target RFID sensor tag, the data information uploaded by the target RFID sensor tag will gradually increase in the recent communication data. By analyzing the changes in the signal fluctuation intensity characteristics of the recently uploaded data of the target RFID sensor tag, the increasing trend of the signal fluctuation intensity of the target RFID sensor tag can be analyzed.

[0075] Determine the neighborhood of the target RFID sensor tag's current data. The neighborhood of the current data is the most recent uploaded historical data before the current data. The number of historical data included in the neighborhood is set based on the actual situation, for example, 5, which refers to the five data frames uploaded closest to the current data.

[0076] The increasing trend of the signal fluctuation intensity of the target RFID sensor tag represents the increasing trend of the signal fluctuation intensity characteristics of each historical data within the neighborhood of the current data of the target RFID sensor tag. The process of obtaining the increasing trend of the signal fluctuation intensity of the target RFID sensor tag is as follows: each historical data within the neighborhood of the current data of the target RFID sensor tag is arranged in time sequence, and the difference in the signal fluctuation intensity characteristics between the latter and the previous historical data of two adjacent historical data within the neighborhood of the current data of the target RFID sensor tag is calculated to obtain a number of signal fluctuation intensity characteristic differences, and then the average of these signal fluctuation intensity characteristic differences is calculated. The result obtained is the increasing trend of the signal fluctuation intensity, and the calculation formula is as follows:

[0077] ;

[0078] in, Indicates the The signal fluctuation intensity of each RFID sensor tag increases; Indicates the The number of historical data within the neighborhood of each RFID sensor tag; Indicates the The current data of the RFID sensor tag is within the neighborhood of the Signal fluctuation intensity characteristics of historical data; Indicates the The current data of the RFID sensor tag is within the neighborhood of the The signal fluctuation intensity characteristics of historical data.

[0079] In principle, since the signal fluctuation intensity feature of the later one of the two adjacent historical data is not definite in size with the signal fluctuation intensity feature of the former one, the difference between the two signal fluctuation intensity features can be positive, 0 or negative, and then the signal fluctuation intensity increasing trend of the target RFID sensor tag can be positive, 0 or negative. If it is positive, it indicates that the signal fluctuation intensity of the target RFID sensor tag is in an increasing trend, and the greater the value is, the more obvious the increasing trend of the signal fluctuation intensity is. If it is 0, it indicates that the signal fluctuation intensity of the target RFID sensor tag is in a stable state. If it is negative, it indicates that the signal fluctuation intensity of the target RFID sensor tag is in a decreasing trend. Therefore, no matter the signal fluctuation intensity increasing trend of the target RFID sensor tag is positive, 0 or negative, it satisfies that the greater the value of the signal fluctuation intensity increasing trend of the target RFID sensor tag is, the more obvious the increasing trend of the signal fluctuation intensity of the target RFID sensor tag is.

[0080] The more obvious the signal fluctuation intensity increasing trend of the target RFID sensor tag is, that is, the stronger the increasing trend of the signal fluctuation intensity feature of the target RFID sensor tag is, the more the target RFID sensor tag is affected by the emergency event, the higher the data importance of the target RFID sensor tag is, and the higher the transmission priority is. Therefore, the data importance of the target RFID sensor tag is obtained from the signal fluctuation intensity increasing trend of the target RFID sensor tag, and the data importance is positively correlated with the signal fluctuation intensity increasing trend. In an exemplary embodiment, the maximum value and the minimum value in the signal fluctuation intensity increasing trend of each RFID sensor tag are obtained, and then the maximum value and the minimum value normalization is used to normalize the signal fluctuation intensity increasing trend of the target RFID sensor tag, and the normalized result is the data importance of the target RFID sensor tag. Thus, the data importance of each RFID sensor tag is obtained.

[0081] Step S3: determining the channel occupancy rate of each RFID sensor tag, which is obtained from the data priority transmission necessity and the data importance.

[0082] The data priority transmission necessity and the data importance of each RFID sensor tag are obtained through steps S1 and S2, and the channel occupancy rate of each RFID sensor tag is obtained by fusing the data information of the two aspects. In an exemplary embodiment, as shown in FIG. 6, a specific acquisition process of the channel occupancy rate is as follows: Figure 6

[0083] Step S3-1: calculating the product of the data priority transmission necessity and the data importance of each RFID sensor tag to obtain the channel occupancy rate feature of each RFID sensor tag.

[0084] ​For the target RFID sensor tag, the product of the data priority transmission necessity and the data importance of the target RFID sensor tag is calculated, which is the channel occupancy rate feature of the target RFID sensor tag. The channel occupancy rate feature can be characterized as the data upload urgency of the target RFID sensor tag. The higher the data priority transmission necessity and the data importance, the higher the data upload urgency, and the more necessary it is to upload the sensor data of the target RFID sensor tag in priority.

[0085] Step S3-2: The ratio of the channel occupancy rate feature of each RFID sensor tag to the sum of the channel occupancy rate features is taken as the channel occupancy rate of each RFID sensor tag.

[0086] The higher the channel occupancy rate feature of the RFID sensor tag, that is, the higher the data upload urgency of the RFID sensor tag, generally means that the sensor data monitored by the RFID sensor tag is more likely to reflect a sudden event or a critical state change, and has a higher value for real-time sensing and response decision of the system. Therefore, for the RFID sensor tag with a higher channel occupancy rate feature, that is, the RFID sensor tag with a higher data upload urgency, the system should improve its opportunity to occupy the upload channel to ensure that critical data can be transmitted in priority, so that the system effectively improves the transmission success rate of critical data and reduces the response delay of high-priority data without changing the overall communication structure, thereby realizing rapid upload and collection of data of multiple RFID sensor tags in a sudden event.

[0087] The higher the channel occupancy rate feature of the RFID sensor tag, the more necessary it is to ensure that the sensor data of the RFID sensor tag is transmitted in priority and to improve the allocation weight of its upload channel. Therefore, the ratio of the channel occupancy rate feature of each RFID sensor tag to the sum of the channel occupancy rate features is taken as the channel occupancy rate of each RFID sensor tag. The sum of the channel occupancy rate features is the sum of the channel occupancy rate features of each RFID sensor tag. In this way, the RFID sensor tag with a higher data upload urgency can be ensured to have a higher channel occupancy rate, so that its sensor data can be transmitted in priority and reliably, effectively improving the data transmission success rate and reducing the data response delay.

[0088] After the channel occupancy rate of each RFID sensor tag is determined, the channel of each RFID sensor tag is allocated according to the channel occupancy rate of each RFID sensor tag, wherein the channel actual bandwidth of each RFID sensor tag is obtained by multiplying the channel occupancy rate of each RFID sensor tag and the total bandwidth of the communication link. In the next communication period, the channel actual bandwidth of each RFID sensor tag is taken as input to schedule each RFID sensor tag, and the corresponding channel actual bandwidth is allocated to each RFID sensor tag to complete the data upload of each RFID sensor tag. The channel resources are preferentially allocated to high channel occupancy rate (i.e. high priority) tags to realize differentiated upload control, preferentially guarantee the data upload demand of high priority RFID sensor tags, and at the same time avoid the data of low channel occupancy rate RFID sensor tags from occupying valuable communication resources, thereby improving the bandwidth utilization and data effective transmission rate of the overall network.

[0089] The embodiment also provides a data acquisition system of an RFID sensor tag, comprising a memory and a processor; the memory is connected with the processor and is used for storing program instructions; the processor is used for realizing the steps in the above-mentioned data acquisition method of an RFID sensor tag when the program instructions are executed.

[0090] In one exemplary embodiment, the present application provides a computer readable storage medium storing a computer program, which realizes the steps in the above-mentioned data acquisition method of an RFID sensor tag when executed by a processor.

[0091] It should be noted that the above-mentioned sequence of the embodiments of the present application is only for description, and does not represent the advantages and disadvantages of the embodiments. The processes depicted in the drawings do not necessarily require the specific order or continuous order shown to achieve the desired results. In some embodiments, multi-task processing and parallel processing are also possible or can be advantageous.

[0092] Each embodiment in the specification is described in a progressive manner, and the same and similar parts between each embodiment can be referred to each other. Each embodiment mainly describes the differences from other embodiments.

Claims

1. A data collection method for an RFID sensor tag, characterized by, The method comprises the following steps: determining the data priority transmission necessity of each RFID sensor tag according to the signal fluctuation intensity feature of the current data of each RFID sensor tag; obtaining the data importance of each RFID sensor tag from the signal fluctuation intensity increasing trend of each RFID sensor tag, wherein the signal fluctuation intensity increasing trend represents the increasing trend of the signal fluctuation intensity feature of each historical data in the neighborhood range of the current data; determining the channel occupation rate of each RFID sensor tag, wherein the channel occupation rate is obtained from the data priority transmission necessity and the data importance; the obtaining process of the signal fluctuation intensity feature comprises the following steps: obtaining the signal amplitude difference mean value of the current data and the signal amplitude variance of the current data; obtaining the signal fluctuation intensity feature of the current data according to the signal amplitude difference mean value and the signal amplitude variance of the current data, wherein the signal fluctuation intensity feature is positively correlated with the signal amplitude difference mean value and the signal amplitude variance.

2. The method of claim 1, wherein the RFID sensor tag is a passive RFID sensor tag. The data priority transmission necessity of each RFID sensor tag is obtained by maximum-minimum normalization of the signal fluctuation intensity feature of the current data of each RFID sensor tag.

3. The method of claim 1, wherein the RFID sensor tag is a passive RFID sensor tag. Before the step of determining the data priority transmission necessity of each RFID sensor tag according to the signal fluctuation intensity feature of the current data of each RFID sensor tag, the data acquisition method of the RFID sensor tag further comprises the following steps: determining the channel utilization rate of the current communication link and the overall level of the signal fluctuation intensity feature, wherein the overall level of the signal fluctuation intensity feature is the average value of the signal fluctuation intensity feature of the current data of each RFID sensor tag; judging whether the communication state of the current communication link has a high collision risk according to the channel utilization rate of the current communication link and the overall level of the signal fluctuation intensity feature; if the current communication link has a high collision risk, performing the step of determining the data priority transmission necessity of each RFID sensor tag according to the signal fluctuation intensity feature of the current data of each RFID sensor tag.

4. The method of claim 3, wherein the RFID sensor tag is a passive RFID sensor tag. The judgment process of whether the communication state of the current communication link has a high collision risk comprises the following steps: obtaining the communication state index of the current communication link according to the channel utilization rate of the current communication link and the overall level of the signal fluctuation intensity feature; comparing the communication state index with a preset threshold value, and if the communication state index is greater than or equal to the preset threshold value, determining that the communication state of the current communication link has a high collision risk.

5. The method of claim 1, wherein the RFID sensor tag is a passive RFID sensor tag. The obtaining process of the signal fluctuation intensity increasing trend comprises the following steps: ​ determining the signal fluctuation intensity feature difference value between the latter historical data and the former historical data in the neighborhood range, calculating the average value of the signal fluctuation intensity feature difference value in the neighborhood range, and obtaining the signal fluctuation intensity increasing trend.

6. The method of claim 5, wherein the RFID sensor tag is a passive RFID sensor tag. The data importance of each RFID sensor tag is obtained by maximum-minimum normalization of the signal fluctuation intensity increasing trend of each RFID sensor tag.

7. The method of claim 1, wherein the RFID sensor tag is a passive RFID sensor tag. The obtaining process of the channel occupation rate comprises the following steps: ​ calculating the product of the data priority transmission necessity and the data importance of each RFID sensor tag to obtain a channel occupation rate feature of each RFID sensor tag; taking the ratio of the channel occupation rate feature of each RFID sensor tag to a channel occupation rate feature sum as the channel occupation rate of each RFID sensor tag, wherein the channel occupation rate feature sum is the sum of the channel occupation rate features of all RFID sensor tags.

8. The method of claim 1, wherein the RFID sensor tag is a passive RFID sensor tag. After the channel occupation rate of each RFID sensor tag is determined, the data acquisition method of the RFID sensor tag further comprises: allocating channels to each RFID sensor tag according to the channel occupation rate of each RFID sensor tag to complete data uploading of each RFID sensor tag.

9. A data acquisition system for RFID sensor tags comprising: a memory and a processor; the memory is connected with the processor; the memory is configured to store program instructions; the processor is configured to implement the data acquisition method of the RFID sensor tag in any one of claims 1-8 when the program instructions are executed.

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