Anti-loss access card data transmission method based on NFC technology

Abstract

The present invention relates to the technical field of near field communication data transmission, and in particular to a method for data transmission of an anti-loss access card based on NFC technology. The method comprises: obtaining near field communication signals of different access cards at the current moment and historical access data within a preset neighborhood time period; determining the propagation distance according to the strength of the near field communication signal; determining the local access trend index according to the number and propagation distance of all identified access cards; determining the overall access trend index according to the change of historical access data; determining the adjustment access cycle at the current moment according to the initial access cycle, the local access trend index at the current moment, and the overall access trend index; and realizing data transmission between the access card and the identification device according to the adjustment access cycle. The present invention can realize adaptive transmission cycle adjustment, avoid communication congestion and reduced system response speed, improve the timeliness of data transmission, reduce meaningless power consumption, and enhance the reliability of data transmission.

Description

Technical Field

[0001] The present invention relates to the technical field of near field communication data transmission, and in particular to a method for data transmission of an anti-loss access card based on NFC technology. Background Art

[0002] Active near field communication (NFC), as a short-range wireless communication technology, has been widely used in access control systems. NFC access control systems simplify the communication process between anti-loss access control cards and identification devices into wireless data exchange, thus achieving convenient access management, secure identity authentication and efficient access control.

[0003] In the related technology, a fixed data transmission cycle is used to transmit access card data. In this way, the traditional NFC access control system will face challenges when dealing with high-density traffic. When the traffic volume increases, it will usually cause data transmission congestion, affecting the timeliness of the data transmission of the entire access control system. If the transmission frequency is simply increased and the transmission cycle is reduced, more meaningless power consumption will be generated during idle time, making the access control system data transmission less reliable. Summary of the invention

[0004] In order to solve the technical problem that the fixed data transmission cycle in the related art will lead to data transmission congestion and more meaningless power consumption, resulting in insufficient reliability of data transmission in the access control system, the present invention provides an anti-lost access card data transmission method based on NFC technology, and the technical solution adopted is as follows:

[0005] The present invention proposes a method for transmitting data of an anti-loss access card based on NFC technology, the method comprising:

[0006] Based on the initial access cycle, obtain the near field communication signals of different access control cards at the current moment and the historical access data within a preset neighborhood time period;

[0007] Determine the propagation distance between the access card and the identification device at the current moment according to the strength of all the near field communication signals at the current moment;

[0008] Determine the local access trend indicator at the current moment based on the number and propagation distance of all recognized access control cards at the current moment;

[0009] Determine the overall access trend indicator according to the changes in historical access data at other times within the preset neighborhood time period;

[0010] Determine an adjusted access period at the current moment according to the initial access period, the local access trend indicator at the current moment, and the overall access trend indicator;

[0011] The data transmission between the access card and the identification device is realized according to the access cycle adjustment.

[0012] Furthermore, the method for obtaining the local access trend indicator at the current moment includes:

[0013] The ratio of the number of all identified access control cards to the range of the propagation distances corresponding to the identified access control cards is determined as the propagation density;

[0014] According to the propagation distances and the propagation densities of all the identified access control cards, a local access trend indicator for data transmission by the access control card to be identified at the current moment is determined.

[0015] Furthermore, the local access trend index for data transmission of the access card to be identified at the current moment is determined based on the propagation distances and the propagation density of all identified access cards, including:

[0016] The average of the propagation distances of all identified access control cards is taken as the distance mean;

[0017] The distance mean and the propagation density are numerically fused to determine a local access trend index for data transmission of the access card to be identified at the current moment, wherein the value of the local access trend index is a normalized value.

[0018] Furthermore, the method for obtaining the overall access trend indicator includes:

[0019] Take one day as an analysis cycle, and determine the time point in each analysis cycle that is the same as the current time as the analysis time;

[0020] Determine the access trend index at the time of analysis based on the changes in historical access data within the local time range at the time of analysis;

[0021] The mean of the access trend index at all analysis moments is normalized as the overall access trend index.

[0022] Furthermore, the historical access data is access frequency, and determining the access trend index at the analysis time according to the change of the historical access data within the local time range at the analysis time includes:

[0023] The difference between the access frequency within the preset first time range centered at the time sequence analysis moment and the access frequency of the next preset first time range closest to the time sequence analysis moment is used as the first fluctuation indicator;

[0024] The difference between the access frequency within the preset second time range centered at the time sequence analysis moment and the access frequency of the next preset second time range closest to the time sequence analysis moment is used as the second fluctuation indicator, wherein the preset first time range is different from the preset second time range;

[0025] The first fluctuation index and the second fluctuation index are numerically fused to obtain a moment access trend index at each analysis moment.

[0026] Furthermore, the method for obtaining the adjusted access period at the current moment includes:

[0027] Determine the degree of change of the access trend at the current moment according to the local access trend indicator at the current moment and the overall access trend indicator;

[0028] The initial access period and the access trend change degree at the current moment are numerically fused to obtain the adjusted access period at the current moment.

[0029] Furthermore, the method for obtaining the access trend change degree at the current moment includes:

[0030] Taking the difference between the local access trend index and the overall access trend index as the first trend change coefficient at the current moment;

[0031] The ratio of the local access trend index to the overall access trend index is used as the second trend change coefficient at the current moment;

[0032] The access trend change degree at the current moment is determined according to the first trend change coefficient and the second trend change coefficient.

[0033] Further, determining the access trend change degree at the current moment according to the first trend change coefficient and the second trend change coefficient includes:

[0034] The sum of the second trend change coefficient and the first trend change coefficient is negatively correlated and mapped to a numerical range of (0, 2] as the access trend change degree at the current moment.

[0035] Furthermore, the data transmission between the access card and the identification device is realized according to the access cycle adjustment, including:

[0036] The access adjustment cycle is used as the data access cycle at the current moment, and after each time period corresponding to the access adjustment cycle, the identification device is controlled to send a near field communication signal of the access card identified within the access adjustment cycle to the data processing center.

[0037] Furthermore, the method for obtaining the propagation distance between the access card and the identification device includes:

[0038] Based on the conversion formula between signal strength and distance, combined with the strength of the near field communication signal between the access card and the identification device, the propagation distance between each access card and the identification device is determined.

[0039] The present invention has the following beneficial effects:

[0040] The embodiment of the present invention obtains the near field communication signal of the access control card at the current moment, analyzes the access trend at the current moment, and obtains the local access trend index. The local access trend index can accurately characterize the access situation of the access control card at the current moment; further, the overall access trend index is determined in combination with the change of historical access data, and the overall access trend index characterizes the indicator information of the access trend change in the preset neighborhood time period. Therefore, the embodiment of the present invention adjusts the initial access cycle in combination with the local access trend index and the overall access trend index to obtain the adjusted access cycle at the current moment. The adjusted access cycle is an adaptive access cycle determined by combining the change of the current moment and the change of the historical moment, so that the corresponding adjusted access cycle can be determined at each moment, which is convenient for realizing the data transmission related to the access control card according to the adjusted access cycle. When the data flow corresponding to the access control card to be identified is different, the corresponding adjusted access cycle is determined, so that the adaptive transmission cycle adjustment is realized according to the near field communication signal and the historical access data, so as to avoid communication congestion and reduced system response speed, improve the timeliness of data transmission, and reduce meaningless power consumption and enhance the reliability of data transmission. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] In order to more clearly illustrate the technical solutions and advantages in the embodiments of the present invention or the prior art, the drawings required for use in the embodiments or the prior art descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0042] Figure 1 A flow chart of a method for transmitting data of an anti-loss access card based on NFC technology provided by an embodiment of the present invention;

[0043] Figure 2 A schematic diagram of a door access control scenario provided by an embodiment of the present invention;

[0044] Figure 3 A schematic flow chart of a method for obtaining a local access trend indicator provided by an embodiment of the present invention;

[0045] Figure 4 A schematic flow chart of a method for obtaining an overall access trend indicator provided by an embodiment of the present invention;

[0046] Figure 5 A structural diagram of an anti-loss access card data transmission system based on NFC technology provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0047] In order to further explain the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the following is a detailed description of the specific implementation method, structure, features and effects of a method for transmitting data of an anti-lost access card based on NFC technology proposed by the present invention in combination with the accompanying drawings and preferred embodiments. In the following description, different "one embodiment" or "another embodiment" does not necessarily refer to the same embodiment. In addition, specific features, structures or characteristics in one or more embodiments may be combined in any suitable form.

[0048] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

[0049] The following describes in detail a specific scheme of a method for transmitting data of an anti-loss access card based on NFC technology provided by the present invention in conjunction with the accompanying drawings.

[0050] Among them, Near Field Communication (NFC), also known as short-range wireless communication, is a short-range high-frequency wireless communication technology that allows contactless point-to-point data transmission and data exchange between electronic devices. Near field communication technology is promoted for standardization under the framework of ISO18092, ECMA340 and ETSI TS 102 190, and is also compatible with the widely used ISO 14443, Type-A, ISO 15693, B and Felica standard contactless smart card infrastructure. Active near field communication is used to increase signal power and thus increase propagation distance by setting a power supply in the electronic device. The anti-loss access control card used in the embodiment of the present invention uses active near field communication technology to achieve signal transmission.

[0051] See also Figure 1 , which shows a flow chart of a method for data transmission of an anti-loss access card based on NFC technology provided by an embodiment of the present invention, the method comprising:

[0052] S101: Based on an initial access cycle, near field communication signals of different access control cards at the current moment and historical access data within a preset neighborhood time period are obtained.

[0053] A specific implementation scenario of the present invention is: office building access control scenario, combined with Figure 2 , Figure 2A schematic diagram of a door access control scenario provided by an embodiment of the present invention, in which a user holds an anti-loss door access card close to an identification device, and the identification device detects and obtains the near-field communication signal corresponding to the door access card based on wireless communication transmission of the NFC protocol, and sends it to the data processing center based on wired or wireless transmission. It should be noted that the data processing center obtains relevant identification information from the identification device through periodic access, which facilitates data processing and analysis.

[0054] In this scenario, the access card is identified through the identification device, and the obtained near-field communication signal is temporarily stored. When the initial access cycle is reached, it is transmitted to the data processing center. The transmission method can be that the identification device actively transmits, or the data processing center sends a transmission instruction to the identification device to control the identification device to transmit. Under normal circumstances, since the data processing center has security requirements and higher authority, it is generally in the form of a transmission instruction sent by the data processing center to the identification device. Of course, in other embodiments, the process can also be implemented in a variety of different ways, which is not limited to this.

[0055] It is understandable that the access control of office buildings has the characteristics of higher traffic during specific time periods (during rush hour) and lower traffic on weekdays. In other words, the frequency of using anti-loss access control cards is inconsistent in different time periods. At this time, the data processing center still transmits data to the access control card identification device according to the preset initial access cycle, which will cause meaningless power consumption during the low traffic period and insufficient timeliness for data analysis during the peak traffic period.

[0056] Therefore, the present invention can be combined with this feature to realize adaptive access cycle adjustment at the current moment according to the near-field communication signals of the access control cards and the identification devices in the current scene and the historical access data within a preset neighborhood time period, thereby reducing meaningless power consumption when the number of access control cards to be identified at the current moment is small, and improving transmission timeliness when the number of access control cards to be identified at the current moment is large.

[0057] Among them, the near-field communication signal is a communication signal generated in the identification device by electromagnetic induction coupling between the access card and the identification device to prevent loss. The communication signal has certain identification information and signal strength, and the identification information is used to identify the user.

[0058] Among them, the preset neighborhood time period is the time period corresponding to the historical access data. Optionally, the embodiment of the present invention can specifically set the preset neighborhood time period to 30 days, that is, store the historical access data within 30 days, and combine the historical access data within 30 days and the near-field communication signal at the current moment to perform data analysis.

[0059] The anti-loss access control card in the embodiment of the present invention usually has an anti-loss system, that is, the access control card usually has an active NFC module, that is, the near-field communication signal emitted by the NFC module has a higher frequency and a longer transmission distance, and the identification device can identify the access control card based on a preset range.

[0060] It can be understood that in the embodiment of the present invention, the anti-loss access control card within the preset range around the identification device can be identified. When the distance is far, the access control card cannot be identified due to the reduced strength of the near-field communication signal. That is, the identified access control card is the access control card within the preset range around the identification device. Furthermore, the preset range can be specifically, for example, a 2-meter range. It should be noted that the preset range may be different depending on the actual equipment conditions.

[0061] In an embodiment of the present invention, the data processing center periodically accesses the identification device, for example, once every 15 seconds, and the 15 seconds is the initial access cycle. It can be understood that when there are a large number of access cards to be identified in the surrounding area, it means that the data transmission traffic at the corresponding moment becomes larger. If the data processing center still performs data transmission according to 15 seconds, it will lead to low timeliness of data processing. In idle time periods, such as working hours, the corresponding access frequency is reduced. If the access is still performed according to 15 seconds, meaningless power consumption will be generated. Therefore, it is necessary to realize adaptive access cycle adjustment at the current moment according to the access situation and historical information at the current moment. Please refer to the subsequent embodiments for details.

[0062] S102: Determine the propagation distance between the access card and the identification device at the current moment according to the strength of all near field communication signals at the current moment.

[0063] It can be understood that the identification device in the embodiment of the present invention can identify the access control card in the surrounding scene, that is, through NFC technology, the closer the access control card is to the identification device, the higher the strength of the corresponding near-field communication signal is, and the farther the access control card is from the identification device, the lower the strength of the corresponding near-field communication signal is.

[0064] Furthermore, in some embodiments of the present invention, the method for obtaining the propagation distance includes: determining the propagation distance between each access card and the identification device based on a conversion formula between signal strength and distance and combining the strength of the near-field communication signal between the access card and the identification device.

[0065] It is understandable that the conversion formula between signal strength and distance is a prior art, which is specifically:

[0066]

[0067] In the formula, Indicates the signal strength of the near field communication signal received by the identification device. Indicates the signal strength of the signal received by the identification device when the near field communication signal is transmitted 1m away. It is a characteristic value of the identification device itself and can be set to 20 according to experience in the embodiment of the present invention; represents the signal propagation factor, which is set to 1.5 according to experience in the embodiment of the present invention; express The propagation distance is the distance between the near field communication signal received by the identification device and the identification device.

[0068] Therefore, by transforming the above formula, a calculation formula for the propagation distance is obtained, and the specific transformation process is not repeated here. Through this formula, the propagation distance between each access card and the identification device can be obtained.

[0069] S103: Determine the local access trend index at the current moment according to the number and propagation distance of all recognized access control cards at the current moment.

[0070] Among them, the identified access card is the near-field communication signal of the access card identified by the identification device within the preset range of the local neighborhood, and the number of corresponding access cards is determined by the near-field communication signals of different identified access cards. It can be understood that the number of access cards is easier to identify. To obtain more information about the access card, such as the authority level of the user holding the access card, the access card needs to be close to the identification device to obtain a more accurate near-field communication signal without attenuation. In addition to identification, the identification device also regularly transmits the corresponding identification situation to the data processing center for data processing, or directly performs information identification and authority analysis of the access card through the data processing center, and there is no restriction on this process.

[0071] Among them, the local access trend index is the index information of the degree of change of the access trend of data access at the current moment. The embodiment of the present invention can combine the number of identified access control cards and the transmission distance to realize the analysis process of the local access trend index.

[0072] S104: Determine an overall access trend indicator according to changes in historical access data at other times within a preset neighborhood time period.

[0073] The overall access trend index is the access trend change obtained by comprehensively analyzing the changes in historical access data at different times. In the embodiment of the present invention, since the preset neighborhood time period can be set to 30 days, the overall access trend index is obtained based on the changes in historical access data at different times within 30 days.

[0074] It should be noted that, due to the regularity of the flow of personnel in various scenarios such as office building access control scenarios or community access control scenarios, that is to say, the similarity of the flow of personnel at the same time on different days is high. The historical access data at the same time point on different dates can be analyzed at the current moment, or the analysis process can be adjusted according to the actual situation to obtain the overall access trend indicator, and there is no restriction on this.

[0075] S105: Determine the adjusted access period at the current moment according to the initial access period, the local access trend index at the current moment, and the overall access trend index.

[0076] In an embodiment of the present invention, since the local access trend index at the current moment represents the changes in the accesses to be performed at the current moment, and the overall access trend index represents the changes in the accesses summarized from the historical access data within a preset neighborhood time period, the present invention can combine the two characteristics to realize the analysis of the degree of change of the access trend at the current moment.

[0077] It should be noted that since the local access trend index and the overall access trend index are obtained by different calculation methods, in order to facilitate analysis, the maximum and minimum values ​​of the indexes can be normalized in their respective calculation processes to unify the dimensions.

[0078] Furthermore, in some other embodiments of the present invention, the degree of change of the access trend at the current moment is determined based on the local access trend index and the overall access trend index at the current moment; the initial access cycle and the degree of change of the access trend at the current moment are numerically fused to obtain the adjusted access cycle at the current moment.

[0079] The access trend change degree is the difference between the access trends at the current moment and at other moments in the preset neighborhood time period. In the embodiment of the present invention, a specific analysis can be performed in combination with the local access trend index and the overall access trend index.

[0080] Furthermore, in some embodiments of the present invention, the difference between the local access trend index and the overall access trend index is used as the first trend change coefficient at the current moment; the ratio of the local access trend index to the overall access trend index is used as the second trend change coefficient at the current moment; and the degree of change of the access trend at the current moment is determined based on the first trend change coefficient and the second trend change coefficient.

[0081] Among them, the difference, that is, the absolute value of the difference, in the embodiment of the present invention, the absolute value of the difference between the local access trend index and the overall access trend index can be calculated as the first trend change coefficient, and the ratio of the local access trend index to the overall access trend index can be calculated as the second trend change coefficient. Then both the first trend change coefficient and the second trend change coefficient can characterize the consistency between the local access trend index and the overall access trend index at the current moment.

[0082] It should be noted that in order to ensure that the calculation results are meaningful, when performing fractional operations, the embodiments of the present invention can add a parameter adjustment factor greater than 0 to the denominator to prevent the denominator from being 0 when the parameter at the denominator position is identified as 0. The value of the parameter adjustment factor is set by the implementer according to the actual situation, and this application does not impose any special restrictions. For example, this application calculates the ratio of the local access trend index and the overall access trend index as the second trend change coefficient. After the overall access trend index appears to be 0, 0.01 can be used as a parameter adjustment factor and added to the overall access trend index 0, so that the denominator becomes 0.01, ensuring the effectiveness of the overall calculation process.

[0083] In an embodiment of the present invention, a larger value of the first trend change coefficient indicates a greater difference between the local access trend index and the overall access trend index, that is, a lower consistency. In this case, the access cycle needs to be reduced to improve the sensitivity of data access analysis.

[0084] The larger the value of the second trend change coefficient is, the higher the trend of the flow of people is at the current moment in the actual scene analysis. At this time, the access cycle should be reduced to cope with the increased access demand.

[0085] Therefore, in the embodiment of the present invention, the sum of the second trend change coefficient and the first trend change coefficient is negatively correlated and linearly mapped to a numerical range of (0, 2] as the access trend change degree at the current moment.

[0086] Since the degree of change of the access trend at the current moment represents the adjustment of the initial access cycle at the current moment, the present invention can calculate the sum of the second trend change coefficient and the first trend change coefficient, and perform negative correlation processing to map it to the numerical interval of (0,2].

[0087] Among them, the negative correlation relationship means that the dependent variable will decrease as the independent variable increases, and the dependent variable will increase as the independent variable decreases, which is determined by actual application. Therefore, the present invention can calculate the sum of the second trend change coefficient and the first trend change coefficient, and use exp (-x) to implement the negative correlation processing of the sum, where x represents the sum, exp represents an exponential function with a natural constant as the base, or the negative number of the corresponding sum can be directly calculated. Among them, the numerical interval mapped to (0,2] can be specifically a linear mapping method, which is a well-known technology in the art and will not be repeated here.

[0088] In the embodiment of the present invention, the larger the numerical value of the access trend change degree, the more access demands there are at the current moment, and the greater the difference from the access demands at previous moments, that is, the more abnormal the access demands at the current moment are, and the access cycle needs to be reduced to improve the overall data transmission sensitivity and, at the same time, enhance the timeliness of data transmission.

[0089] In an embodiment of the present invention, the initial access cycle and the degree of change of the access trend at the current moment are numerically fused to obtain the adjusted access cycle at the current moment. Thus, the product of the initial access cycle and the degree of change of the access trend at the current moment can be calculated to adjust the initial access cycle and obtain the adjusted access cycle.

[0090] S106: Implement data transmission between the access card and the identification device according to the adjusted access cycle.

[0091] In the embodiment of the present invention, the access adjustment cycle is used as the data access cycle at the current moment, and after each time period corresponding to the access adjustment cycle, the control identification device sends the near field communication signal of the access card identified within the access adjustment cycle to the data processing center. The access adjustment cycle obtained in the embodiment of the present invention can effectively combine the changes in the access trend of the access card at the current moment, thereby realizing adaptive access regulation.

[0092] For example, when the access cycle is adjusted to 1 second, the identification device sends the near field communication signal of the access card identified within 1 second to the data processing center every 1 second.

[0093] The embodiment of the present invention obtains the near-field communication signal of the access control card at the current moment, analyzes the access trend at the current moment, and obtains a local access trend indicator. The local access trend indicator can accurately characterize the access situation of the access control card at the current moment; further, the overall access trend indicator is determined in combination with the changes in historical access data. The overall access trend indicator characterizes the indicator information of the access trend changes in the preset neighborhood time period. Therefore, the embodiment of the present invention adjusts the initial access cycle in combination with the local access trend indicator and the overall access trend indicator to obtain the adjusted access cycle at the current moment. The adjusted access cycle is an adaptive access cycle determined by combining the changes at the current moment and the changes at the historical moments, so that the corresponding adjusted access cycle can be determined at each moment, which is convenient for realizing the data transmission related to the access control card according to the adjusted access cycle. When the flow of people is different, the corresponding adjusted access cycle is determined, so that the adaptive transmission cycle adjustment is realized according to the near-field communication signal and the historical access data, so as to avoid communication congestion and reduced system response speed, improve the timeliness of data transmission, and reduce meaningless power consumption and enhance the reliability of data transmission.

[0094] Furthermore, combined with Figure 3 , Figure 3 A flowchart of a method for obtaining a local access trend indicator provided by an embodiment of the present invention. In step S103 of the present embodiment, the method for obtaining the local access trend indicator at the current moment may be specifically, for example, as follows:

[0095] S1031: Determine the propagation density as the ratio of the number of all recognized access control cards to the range of the propagation distances corresponding to the recognized access control cards.

[0096] Among them, the range of the propagation distance is the range of the propagation distance of all access control cards identified within a preset range, that is, the difference between the maximum and minimum propagation distances. It should be noted that when only one access control card has been identified, the range is the distance between the access control card and the identification device.

[0097] In an embodiment of the present invention, the smaller the range of the propagation distance, the larger the corresponding density, and the more access control cards that have been identified, the larger the corresponding density. Therefore, the propagation density is determined by the ratio of the number of all identified access control cards to the range of the propagation distance corresponding to the identified access control cards. The larger the propagation density, the more access control cards to be identified at the current moment, and the shorter the identification time.

[0098] It is understood that the transmission density is the density of the access card when transmitting data, and the number of access cards within a unit distance is the density. In the embodiment of the present invention, the transmission density is used for characterization. For example, the number of all identified access cards is 10, and the range of the transmission distance corresponding to the identified access cards is 10 cm, then the corresponding transmission density is 1 per cm. It is understood that the greater the transmission density, the faster the recognition device needs to recognize the access card to avoid recognition delays.

[0099] S1032: Determine the local access trend index for data transmission of the access card to be identified at the current moment according to the transmission distance and transmission density of all identified access control cards.

[0100] Among them, both the propagation distance and the propagation density can indicate the urgency of the identification device to identify the access card, that is, the more urgent the local access trend is. Therefore, the embodiment of the present invention can combine the propagation distance and the propagation density to realize the process of obtaining the local access trend indicator. The propagation distance and the propagation density are both positively correlated with the local access trend indicator.

[0101] Furthermore, in some embodiments of the present invention, the average of the propagation distances of all identified access control cards is taken as the distance mean; the distance mean and the propagation density are numerically fused to determine the local access trend index for data transmission of the access control card to be identified at the current moment, wherein the value of the local access trend index is a normalized value.

[0102] In the embodiment of the present invention, the distance mean is obtained by calculating the mean of the propagation distances of all identified access control cards, and the distance mean represents the average distance to be performed for access control card identification at the current moment.

[0103] In the embodiment of the present invention, numerical fusion is the fusion of two numerical values ​​in a positive correlation. It should be noted that all indicator data involved in numerical fusion in the embodiment of the present invention are pre-processed to eliminate the dimension effect. The specific means of eliminating the dimension effect are technical means well known to those skilled in the art and are not limited here.

[0104] In one embodiment of the present invention, the normalization processing can be specifically, for example, maximum and minimum value normalization processing, and the normalization in subsequent steps can all adopt maximum and minimum value normalization processing. In other embodiments of the present invention, other normalization methods can be selected according to the specific range of numerical values, which will not be described in detail.

[0105] Among them, the positive correlation relationship means that the dependent variable will increase as the independent variable increases, and the dependent variable will decrease as the independent variable decreases. The specific relationship can be a multiplication relationship, an addition relationship, and the power of an exponential function, which is determined by actual application. Therefore, the present invention can calculate the product of the distance mean and the propagation density, and normalize it as a local access trend indicator for data transmission of the access card to be identified at the current moment.

[0106] The present invention effectively analyzes the trend of access card recognition at the current moment through the number of access cards recognized at the current moment and the characteristics of the propagation distance, and obtains accurate and reliable local access trend indicators.

[0107] Furthermore, combined with Figure 4 , Figure 4 A flowchart of a method for obtaining an overall access trend indicator provided by an embodiment of the present invention. In step S104 of the embodiment of the present invention, the method for obtaining an overall access trend indicator may be specifically, for example, as follows:

[0108] S1041: Taking one day as an analysis cycle, determine the time point in each analysis cycle that is the same as the current time point as the analysis time point.

[0109] It should be noted that in an office scenario, the daily commuting times are relatively fixed, so the analysis is performed based on the same time period on different days. For example, if the current time is 9:00, the time corresponding to 9:00 on different days is used as the analysis time.

[0110] In the embodiment of the present invention, a week or a month may be used as an analysis period to determine the analysis time, that is, the analysis time has a corresponding trend similarity with the current time, so as to facilitate specific analysis of the current time in combination with the analysis time.

[0111] S1042: Determine a moment access trend indicator at the analysis time according to changes in historical access data within a local time range at the analysis time.

[0112] In an embodiment of the present invention, the historical access data may specifically be, for example, access frequency, that is, each time the identification device records an access situation of the access card, the access frequency is increased by one, thereby obtaining the statistical access frequency situation and using it as the historical access data.

[0113] Furthermore, in some embodiments of the present invention, the difference between the access frequency within a preset first time range centered on the time series analysis moment and the access frequency of the next preset first time range closest to the time series analysis moment is used as the first fluctuation indicator; the difference between the access frequency within a preset second time range centered on the time series analysis moment and the access frequency of the next preset second time range closest to the time series analysis moment is used as the second fluctuation indicator, wherein the preset first time range is different from the preset second time range; the first fluctuation indicator and the second fluctuation indicator are numerically fused to obtain the moment access trend indicator for each analysis moment.

[0114] Among them, the preset first time range and the preset second time range are two corresponding different time ranges. Optionally, the preset first time range is one hour, and the preset second time range is 10 minutes. Of course, the present invention can also adjust the preset first time range and the preset second time range, and there is no limitation on this.

[0115] The present invention combines the first fluctuation index and the second fluctuation index obtained in different time ranges to conduct a specific analysis of the access situation. When the analysis time is 9:30, 9:00-10:00 is used as the preset first time range corresponding to the analysis time, and 10:00-11:00 is used as the next preset first time range. Similarly, 9:25-9:35 is used as the preset second time range corresponding to the analysis time, and 9:35-9:45 is used as the next preset second time range. Thus, the first fluctuation index and the second fluctuation index are calculated.

[0116] In the embodiment of the present invention, the first fluctuation index and the second fluctuation index are numerically fused, for example, by calculating the product of the first fluctuation index and the second fluctuation index as the moment access trend index at each analysis moment. That is, the moment access trend index represents the access change at the corresponding analysis moment.

[0117] S1043: Normalize the mean values ​​of the access trend indicators at all analysis moments to obtain the overall access trend indicator.

[0118] In an embodiment of the present invention, a moment access trend indicator is obtained at each analysis moment, and the moment access trend indicators of all analysis moments can be combined to determine the overall access trend indicator. In some embodiments of the present invention, the mean of all moment access trend indicators can be calculated. Of course, in other embodiments of the present invention, the median value, mode, etc. can also be taken as the overall access trend indicator, and there is no limitation on this.

[0119] The present invention determines the overall access trend index by combining the changes in historical access data at the same time point under different analysis cycles, and can perform an overall analysis based on the access rules in actual scenarios, so that the overall access trend index can more accurately and effectively characterize the overall access changes, facilitate specific analysis of the situation associated with the current moment within a preset neighborhood time period, and improve the reliability of access trend change analysis.

[0120] The present invention also provides an anti-loss access card data transmission system based on NFC technology, see Figure 5 , Figure 5 This is a structural diagram of a system for transmitting data to an anti-lost access card based on NFC technology provided by an embodiment of the present invention. The system 600 includes a memory 601, a processor 602, and a computer program 603 stored in the memory 601 and executable on the processor 602. When the processor 602 executes the computer program 603, the steps of the aforementioned method for transmitting data to an anti-lost access card based on NFC technology are implemented.

[0121] This embodiment also provides a computer-readable storage medium, in which a computer program code is stored. When the computer program code is executed on a computer, the computer executes the above-mentioned related method steps to implement an anti-loss access card data transmission method based on NFC technology provided in the above embodiment.

[0122] This embodiment also provides a computer program product. When the computer program product runs on a computer, the computer executes the above-mentioned related steps to implement an anti-loss access card data transmission method based on NFC technology provided in the above embodiment.

[0123] Among them, the system, computer-readable storage medium or computer program product provided in this embodiment is used to execute the corresponding method provided above. Therefore, the beneficial effects that can be achieved can refer to the beneficial effects in the corresponding method provided above, and will not be repeated here.

[0124] It should be noted that the sequence of the above embodiments of the present invention is only for description and does not represent the advantages and disadvantages of the embodiments. The processes depicted in the accompanying drawings do not necessarily require the specific order or continuous order shown to achieve the desired results. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0125] The various embodiments in this specification are described in a progressive manner, and the same or similar parts between the various embodiments can be referenced to each other, and each embodiment focuses on the differences from other embodiments.

Claims

1. A method for transmitting data of an anti-lost access card based on NFC technology, characterized in that: The method comprises: Based on the initial access cycle, obtain the near field communication signals of different access control cards at the current moment and the historical access data within a preset neighborhood time period; Determine the propagation distance between the access card and the identification device at the current moment according to the strength of all the near field communication signals at the current moment; Determine the local access trend indicator at the current moment based on the number and propagation distance of all recognized access control cards at the current moment; Determine the overall access trend indicator according to the changes in historical access data at other times within the preset neighborhood time period; Determine an adjusted access period at the current moment according to the initial access period, the local access trend indicator at the current moment, and the overall access trend indicator; According to the access cycle adjustment, data transmission between the access card and the identification device is realized; The method for determining the local access trend indicator at the current moment includes: The ratio of the number of all identified access control cards to the range of the propagation distances corresponding to the identified access control cards is determined as the propagation density; Determine the local access trend indicator for data transmission of the access card to be identified at the current moment according to the transmission distance and the transmission density of all identified access cards; The method for determining the overall access trend indicator includes: Taking one day in the preset neighborhood time period as an analysis period, determining the time point in each analysis period that is the same as the current time point as the analysis time; Determine the access trend index at the time of analysis based on the changes in historical access data within the local time range at the time of analysis; Normalize the mean of the access trend index at all analysis moments as the overall access trend index; The historical access data is the access frequency, and the moment access trend indicator at the analysis moment is determined according to the change of the historical access data within the local time range at the analysis moment, including: The difference between the access frequency within a preset first time range centered on the analysis moment and the access frequency within the next preset first time range closest to the analysis moment in time sequence is used as the first fluctuation indicator; The difference between the access frequency within a preset second time range centered on the analysis moment and the access frequency within the next preset second time range closest to the analysis moment in time sequence is used as a second fluctuation indicator, wherein the preset first time range is different from the preset second time range; The first fluctuation index and the second fluctuation index are numerically fused to obtain a moment access trend index at each analysis moment.

2. The method for transmitting data of an anti-lost access card based on NFC technology as claimed in claim 1, characterized in that: Determining the local access trend indicator for data transmission of the access card to be identified at the current moment according to the propagation distance and the propagation density of all identified access cards includes: The average of the propagation distances of all identified access control cards is taken as the distance mean; The distance mean and the propagation density are numerically fused to determine a local access trend index for data transmission of the access card to be identified at the current moment, wherein the value of the local access trend index is a normalized value.

3. The method for transmitting data of an anti-lost access card based on NFC technology as claimed in claim 1, characterized in that: The method for determining the adjusted access period at the current moment includes: Determine the degree of change of the access trend at the current moment according to the local access trend indicator at the current moment and the overall access trend indicator; The initial access period and the access trend change degree at the current moment are numerically fused to obtain the adjusted access period at the current moment.

4. The method for transmitting data of an anti-loss access card based on NFC technology as claimed in claim 3, characterized in that: The method for determining the degree of change of the access trend at the current moment includes: Taking the difference between the local access trend index and the overall access trend index as the first trend change coefficient at the current moment; The ratio of the local access trend index to the overall access trend index is used as the second trend change coefficient at the current moment; The access trend change degree at the current moment is determined according to the first trend change coefficient and the second trend change coefficient.

5. The method for transmitting data of an anti-loss access card based on NFC technology as claimed in claim 4, characterized in that: Determining the access trend change degree at the current moment according to the first trend change coefficient and the second trend change coefficient includes: The sum of the second trend change coefficient and the first trend change coefficient is negatively correlated and then mapped to the numerical range of (0,2] as the degree of change of the access trend at the current moment, wherein the negative correlation processing of the sum is achieved using exp(-x), wherein x represents the sum, and exp represents an exponential function with a natural constant as the base.

6. The method for transmitting data of an anti-loss access card based on NFC technology as claimed in claim 1, characterized in that: The method of implementing data transmission between the access card and the identification device according to the access cycle adjustment includes: The access adjustment cycle is used as the data access cycle at the current moment, and after each time period corresponding to the access adjustment cycle, the identification device is controlled to send a near field communication signal of the access card identified within the access adjustment cycle to the data processing center.

7. The method for transmitting data of an anti-loss access card based on NFC technology as claimed in claim 1, characterized in that: The method for determining the propagation distance between the access card and the identification device includes: Based on the conversion formula between signal strength and distance, combined with the strength of the near field communication signal between the access card and the identification device, the propagation distance between each access card and the identification device is determined.

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