CN115643634B - Wireless cooperative tracking monitoring method, device and system - Google Patents

Abstract

The invention discloses a wireless cooperative tracking monitoring method, a wireless cooperative tracking monitoring device and a wireless cooperative tracking monitoring system.A plurality of RFID hosts are used as wireless base stations to perform cooperative tracking monitoring on a plurality of RFID labels in a coverage area, and the RFID hosts are in wireless cooperative synchronization to ensure that the RFID labels obtain time synchronization; obtaining hash bit segment conversion parameters for mapping and converting the current RFID label codes through code domain distribution monitoring, and implanting corresponding hash conversion identifications into the synchronous data frames; and the RFID label carries out hash bit segment conversion on the label code of the RFID label according to the received hash conversion identification, and sends a label data frame in the appointed label response time slot. The device refers to an RFID host device as a wireless base station. The system comprises a system cooperation host, a plurality of RFID hosts and a plurality of tracked RFID tags. The invention improves the real-time performance and the continuity of the RFID label tracking through the cooperative synchronization and the code domain distribution monitoring, and has the advantages of low label power consumption, quick response and high tracking efficiency.

Description

Wireless cooperative tracking monitoring method, device and system

Technical Field

The invention relates to the technical field of wireless communication and edge intelligence of the Internet of things, mainly relates to signal time sequence, data efficiency and flow mechanism of an RFID wireless communication data transceiving protocol layer, and particularly relates to a wireless cooperative tracking monitoring method, device and system.

Background

The RFID host serves as a wireless base station, wireless tracking monitoring is carried out on RFID label group reading, and when the RFID label does not enter a wireless tracking coverage area or is not awakened and excited, the RFID label is in a dormant ultra-low power consumption state.

Compared with other short-distance wireless communication modes, the passive or active RFID group reading technology mainly solves the problem that the transient communication data efficiency in the group reading process is needed to be solved, so that transient channel resources must be more effectively utilized; and the method is not like other wireless communication modes, consumes more wireless channel resources to establish stable protocol handshake or communication connection so as to improve the subsequent data communication efficiency.

The related technical standards of RFID mainly relate to: RFID radio channels and modulation schemes, RFID air interface communication protocol specifications, and RFID industry application coding specifications (e.g., logistics, animals, goods, and assets). The existing related technical standard of the RFID mainly solves the problems of compatibility and interoperability between different manufacturers of equipment. However, for the group reading technology of the RFID tag, especially when the number of target objects facing the RFID tag is large, there are still large problems and optimization improvement spaces in the efficiency of group reading transient communication data, the group reading success rate, and the reliability.

Because group reading communication needs to be completed within a transient time, the RFID host (reader, reader/writer) cannot allocate a channel time slot for tag response data transmission to each RFID cluster (tag) in an asynchronous manner, resulting in high uncertainty of the tag response channel time slot in the group reading process. Therefore, one of the core problems of the RFID group reading technology is how to more effectively utilize the wireless channel resources while avoiding collision of RFID tag response data. In the existing RFID group reading technical standard, the method for avoiding collision of RFID tag response data mainly comprises the following steps:

1) Random response: the RFID host does not need to allocate channel time slots to the RFID labels, and the communication protocol is simple; however, when the number of RFID tags is large, the probability of collision of transient response data is high, and the efficiency of channel resource utilization is very low.

2) Synchronizing time slots: the RFID host needs to allocate a synchronous channel time slot to the RFID label, and the RFID label responds in the specified synchronous channel time slot; according to the method, under the condition that the number and the code domain characteristics of the RFID are known, the RFID host allocates the tag channel time slot through a command, and then the utilization efficiency of wireless channel resources can be effectively improved.

3) Grouping excitation: the channel is distributed according to the group code or the code domain interval, and the method has the advantages that the label response data collision between different code domains can be avoided; but still can not avoid the collision of the label response data in the same code field; and may result in wasting radio channel resources due to the absence of an electronic tag in a certain code domain.

4) Host arbitration: and when the tag response data collide, the RFID host machine performs collision correction: sending an arbitration command in a specific channel time slot, pausing to send response data after receiving the arbitration command by the RFID tag, and sending the response data again after random delay; this method cannot effectively reduce collision of already-occurring response data, and may cause re-collision due to random delay, resulting in inefficient use of channel time slots.

5) Channel detection: the RFID label firstly carries out channel CAD detection before sending the response data, when the channel time slot is idle, the label response data is sent, otherwise, the CAD detection is carried out after random time delay; the method can effectively avoid collision, but due to the randomness and time occupation of starting CAD detection, the possibility of collision with a larger probability still exists when the label data volume is larger, and the power consumption is increased due to the long time of the CAD detection of the electronic label.

The anti-collision technical method for the response data of the RFID tag has different advantages and defects, but still does not fundamentally solve the balance problem between avoiding response collision and improving the utilization efficiency of a channel, and comprises the following steps: 1) How to rapidly wake up or rapidly excite the low-power-consumption RFID label; 2) How to detect the code domain distribution of label codes in the excitation group reading process; 3) How to allocate the RFID label response channel to solve the imbalance of channel allocation; 4) How to make RFID tags more aggressive in utilizing free channel time slots in collision avoidance conditions.

When a low-power-consumption RFID label enters a wireless coverage field area of a plurality of RFID hosts as a tracking target object, the RFID hosts are used as wireless base stations to cooperatively track the RFID label, and the problem of how to arouse and wake the low-power-consumption RFID label and obtain cooperative time synchronization needs to be solved.

The method comprises the steps that an RFID host wireless base station is utilized to cooperatively track an article turnover device covering a field area, RFID tags placed in the turnover device can be tracked, and group reading comparison verification needs to be carried out on the RFID tags in key sensitive areas (such as an entrance and an exit and a settlement area).

Because the code domain distribution of the tracked RFID label codes has certain code domain characteristics and null probability distribution, how to utilize the code domain characteristics (including quantity, coding range, groups, sensitive bit sections and the like) and the null probability distribution of the known target group RFID label codes can optimize the transient channel resource utilization efficiency of subsequent RFID tracking response data and effectively avoid the time slot collision problem of multi-machine communication RFID label response data by adjusting and changing the wireless response channel distribution of the RFID labels and appointing corresponding response time slots.

Therefore, how to perform cooperative synchronous excitation on the low-power-consumption RFID tags, how to extract code domain distribution characteristic parameters of target group RFID tag codes through cooperative tracking monitoring and tracking calculation, and how to perform quick and effective code mapping transformation on the target RFID tags according to the currently known code domain distribution characteristics in the group reading process of the RFID host computer on the RFID tag slave computers so as to effectively allocate channel time slots for tag response, avoid tag response data collision and improve the utilization efficiency of the wireless channel time slots; therefore, the cooperative tracking efficiency, the response speed and the success rate of the RFID host to a large number of low-power-consumption RFID tags are improved, and the technical problem to be solved urgently is solved.

Disclosure of Invention

The technical problem to be solved by the invention is how to enable the RFID tags to obtain cooperative time synchronization through cooperative synchronization by a plurality of RFID hosts in a cooperative tracking state, and the balance problem of low-power consumption awakening and high-efficiency synchronization is solved; how to acquire sensitive characteristics of code domain distribution of the RFID tags of a target group through code domain distribution monitoring on the basis of cooperative tracking by the RFID host so as to acquire code mapping transformation parameters and solve the problem of balance of utilization of a tag response channel; how the RFID label calculates the corresponding channel time slot parameter through label coding mapping transformation so as to send a label data frame in the appointed label response time slot, thereby avoiding the time slot collision of label response data and improving the utilization efficiency of the RFID response channel time slot; therefore, the data efficiency of RFID cooperative tracking is improved.

In order to solve the above problems, the present invention provides a wireless cooperative tracking monitoring method, device and system.

In a first aspect, the present invention discloses a wireless cooperative tracking monitoring method, in which a plurality of RFID hosts are used as a wireless base station to perform cooperative tracking monitoring on a plurality of RFID tags in a coverage area, and the method specifically includes the following steps: the RFID host sends a synchronous data frame including a wireless synchronous identifier at least once in a synchronous tracking period through wireless cooperative synchronization, so that the RFID tag obtains time synchronization; the RFID host acquires hash bit segment conversion parameters for mapping and converting the current RFID label codes through code domain distribution monitoring; the RFID host implants the corresponding generated hash transformation identification into the synchronous data frame according to the hash bit segment transformation parameter; and the RFID label carries out hash bit segment conversion on the label code of the RFID label according to the received hash conversion identification, and sends a label data frame in the appointed label response time slot.

Optionally, the RFID tag obtains wireless cooperative synchronization, and obtains a channel timeslot for sending a tag data frame by mapping and transforming tag codes, and specifically includes the following steps: the RFID label receives the wireless synchronization identification which is sent by any one RFID host and is contained in the synchronization data frame at least once in a synchronization tracking period, so as to obtain the cooperative synchronization; the RFID label carries out hash bit segment conversion on the label code of the RFID label according to the hash conversion identification contained in the synchronous data frame to generate a hash label code, and calculates the corresponding channel time slot parameter; and the RFID label sends a label data frame in a designated label response time slot according to the channel time slot parameter.

Optionally, the cooperative synchronization means that a plurality of RFID hosts have the same cooperative synchronization period; the cooperative synchronization period refers to a synchronization period shared by a plurality of RFID hosts, and synchronization identifiers sent by the RFID hosts have an associated consistent synchronization phase relationship.

Optionally, the synchronization tracking period includes at least one synchronization response period, and when a plurality of synchronization response periods are included, a number of default response periods may be skipped; and the RFID label is in a low-power-consumption dormant state in the default response period, is awakened before the effective response period based on a synchronous timer, and detects and receives a synchronous excitation signal sent by the RFID host.

Optionally, a plurality of RFID hosts in a cooperative synchronization state in the coverage area send cooperative and consistent wireless synchronization identifiers: namely, sending wireless synchronous identification and synchronous data frames in synchronous offset time zones with different synchronous offsets; the RFID label carries out synchronization time correction according to the received wireless synchronization identification sent by any one RFID host, and can obtain the same and consistent synchronization response period and the contained label response channel time slot.

Optionally, the RFID tag enters the coverage field area and is covered by a wake-up excitation signal, and is first awakened for the first time by receiving a radio frequency wake-up excitation pulse, and then is awakened successively or synchronously by detecting a time slot extension.

Optionally, if the RFID tag receives a synchronous response verification identifier sent by the RFID host, when it is determined that the sent tag data frame is received by the RFID host, sending of the tag response information and the tag data frame thereof may be immediately stopped.

Optionally, when the RFID tag identifies that the transmitted tag data frame is not received by the RFID host, in a tag response timeslot subsequent to the same tag response period, performing timeslot detection with a low timeslot priority, and transmitting the tag data frame again under a condition that the timeslot is idle.

Optionally, the hash bit segment transform is a hash mapping transform based on sensitive bit segments for tag encoding; and the RFID label maps and converts the label code of the RFID label into a new Hash label code through the Hash bit segment conversion, replaces the original label code with the Hash label code, and calculates the channel time slot parameter for sending the label response data.

Optionally, the code domain bit segment monitoring is to perform persistent cooperative monitoring on the hash degree or frequency dispersion of different sensitive bit segments in the code domain distribution of the RFID tag tracking object in the specified target area, and calculate a refresh bit segment hash table.

Optionally, the RFID host evaluates and calculates frequency dispersion of different sensitive bit segments in the code domain distribution according to a time-space sliding weighting method; and comparing the frequency dispersion, selecting a sensitive bit segment with relatively lower frequency dispersion, namely corresponding to a hash degree higher than the frequency dispersion, and generating corresponding hash bit segment conversion parameters.

In a second aspect, the present invention further discloses a wireless cooperative tracking and monitoring device, where the device refers to an RFID host device as a wireless base station, and the device performs cooperative tracking and monitoring on a plurality of RFID tags in a coverage area, and the device is composed of the following modules: a collaborative synchronization module: the RFID tag is used for transmitting a synchronization data frame including a wireless synchronization identifier at least once in one synchronization tracking period through wireless cooperative synchronization, so that the RFID tag obtains time synchronization; code domain monitoring module: the hash bit segment conversion parameter is used for obtaining the hash bit segment conversion parameter for the current RFID label code mapping conversion through code domain distribution monitoring; a transformation identification module: the hash bit segment conversion parameter is used for implanting a corresponding generated hash conversion identifier into the synchronous data frame; and the RFID label carries out hash bit segment conversion on the label code of the RFID label according to the received hash conversion identification, and sends a label data frame in the appointed label response time slot.

In a third aspect, the invention further discloses a wireless cooperative tracking monitoring system, which is established by using the wireless cooperative tracking monitoring method and comprises a system cooperative host, a plurality of RFID hosts and a plurality of tracked RFID tags; the RFID host serves as a wireless base station, performs cooperative tracking monitoring on the RFID tags in a coverage area through wireless cooperative synchronization, and transmits tracking monitoring information to the system cooperative host; the system cooperates with the host computer to perform code domain distribution monitoring by tracking and calculating a bit segment hash table of the current RFID label code to obtain hash bit segment conversion parameters, and sends the hash bit segment conversion parameters to the associated RFID host computer; the RFID label carries out mapping transformation on label codes according to the received Hash bit segment transformation parameters sent by the RFID host to obtain a channel time slot for sending a label data frame; the system collaboration host comprises a system server or an edge management host and an RFID host with collaboration service capability.

According to the technical scheme provided by the invention, the RFID label receives the synchronous data frame which is sent by the host and is contained in the synchronous excitation signal in the specified synchronous channel after being awakened; therefore, the balance efficiency of low power consumption and triggering of wake-up excitation and time synchronization is improved; according to the channel code domain identification in the synchronous data frame, the RFID label can quickly obtain the time slot parameter of the adjusting channel based on the label coding calculation of the RFID label; and sending tag response information in the appointed tag response channel and the response time slot thereof according to the channel time slot parameter, solving the problem of response time slot data conflict, and improving the utilization efficiency of the RFID response channel time slot so as to improve the RFID group reading receiving efficiency.

Therefore, compared with the prior art, the invention adjusts the channel time slot parameter responded by the RFID label through the channel code field identification, improves the utilization efficiency of channel time slot resources, avoids group reading label response conflict, and has obvious technical effect and benefit for the active electronic label to group read and receive label data frames with low power consumption, quick awakening synchronization and high efficiency.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings needed to be used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and other drawings can be obtained by those skilled in the art without creative efforts.

Fig. 1 is a flowchart of a wireless cooperative tracking monitoring method, i.e., a flowchart of an RFID host, according to an embodiment of the present invention;

fig. 2 is a block diagram of a wireless cooperative tracking monitoring device, that is, a block diagram of an RFID host device according to an embodiment of the present invention;

FIG. 3 is a timing diagram illustrating comparison between signals of a synchronization channel and a tag response channel during a group reading process of cooperative tracking and monitoring of an RFID tag by an RFID host according to an embodiment of the present invention;

fig. 4 is a time slot composition and a response signal timing chart in a synchronous response period of a tag response channel in a group read response process of cooperative tracking and monitoring of an RFID tag by an RFID host according to an embodiment of the present invention.

Detailed description of the preferred embodiments

In order to make the objects, technical solutions and advantages of the present invention more clearly apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It is to be understood that the described embodiments are part of the present invention, and not all embodiments, and are intended to illustrate and not limit the present invention.

In a first embodiment, please refer to fig. 1, which is a flowchart of a wireless cooperative tracking monitoring method disclosed in this embodiment, in which a plurality of RFID hosts are used as a wireless base station to perform cooperative tracking monitoring on a plurality of RFID tags in a coverage area, the method specifically includes the following steps:

step S101, the RFID host sends a synchronous data frame including a wireless synchronous identifier at least once in a synchronous tracking period through wireless cooperative synchronization, so that the RFID tag obtains time synchronization;

step S102, the RFID host computer obtains hash bit segment conversion parameters for mapping and converting the current RFID label codes through code domain distribution monitoring;

step S103, the RFID host implants the corresponding generated hash transformation identifier into the synchronous data frame according to the hash bit segment transformation parameter;

and step S104, the RFID label carries out hash bit segment conversion on the label code of the RFID label according to the received hash conversion identification, and sends a label data frame in the appointed label response time slot.

The implementation of the above steps is further explained as follows:

the channel code domain identification is a wireless identification for allocating, adjusting and indicating code domain intervals of a plurality of different channels and the distribution of the quantity values of the code domain intervals; the magnitude distribution includes an absolute quantity, a distribution ratio, or an adjustment quantity (e.g., an increment, a proportional increment).

When the RFID tag is awakened in any awakening mode, the RFID tag continues to try to receive the synchronous identification in a specified synchronous detection time slot: 1) If the RFID label does not receive the synchronous identification in the appointed synchronous detection time slot, the low-power-consumption sleep-following state is immediately returned; 2) And if the RFID tag receives the synchronous identification in the synchronous detection time slot, the RFID tag is immediately awakened synchronously to obtain time synchronization, synchronous time correction is carried out according to a synchronous offset code following the synchronous identification, and a synchronous response period is started according to the synchronous time according to the channel code domain identification.

The synchronous detection time slot is a wireless detection time slot for trying to receive the synchronous identification; the synchronization detection time slot is at least larger than the sending interval time of one or more series synchronization marks.

The RFID tag receives the synchronous excitation signal, and transmits a code clock signal through a code clock time slot in a synchronous response period by section code clock conversion based on time synchronization.

The RFID tag converts the tag code X of the RFID tag into pulse sending time in a code clock pulse time slot Tp in a linear and/or random mode through the code time conversion according to the current channel code width Wi.

The code clock pulse time slot refers to a time slot allowing different tags to send the code clock pulse signal in the synchronous response period in the current tag response channel i; the pulse transmission time Tc is the relative time t of the RFID tag for transmitting the code clock pulse signal within the code clock pulse time slot Tp, which is obtained based on the code time conversion; t ∈ [0, tp).

The code clock time slot is contained in a synchronous reply period; the code clock pulse signal is a preposed response signal sent by the RFID label in the code clock pulse time slot and is used for the time code distribution detection of the RFID host.

The code time conversion (i.e., C/T conversion) is a conversion manner that maps code domain distribution to time domain distribution; the RFID label obtains code clock pulse time by code-time conversion according to the channel label code X' in a synchronous response period of the label response channel, and sends the code clock pulse signal; the code clock pulse time T ' = X ' × Δ T/Δ Xw, where X ' is channel label coding, Δ T is code time division step size, and the code time division step size refers to a time step size corresponding to a minimum code width Δ Xw (default is 1).

The label code X refers to the ID code of the RFID label or a code obtained by performing code mapping transformation on the ID code of the RFID label; the code mapping transformation can be reversible transformation (non-compression code domain space), such as linear transformation and exclusive-or operation; it may also be an irreversible transform (compressed code domain space), such as a HashMap transform. The mapping transformation function may be expressed as: x = Φ (ID, pi), where X is the label code X after mapping and Pi is the mapping parameter.

The label code X is a code which tries to make the code width of different code domain intervals approximately proportional to the expected label probability distribution; the probability distribution is proportional to the maximum number of labels that may occur in the code domain interval.

The channel label code X' is a label code which is subjected to retransformation processing on a certain channel; the channel label code X' is an offset code that maps the label code against the code domain reference of a given channel. When the label response channel is distributed by grouping excitation or synchronous multi-channel excitation, the label coding is replaced by the channel label coding X', so that the code domain interval in the same channel is greatly reduced.

If the channel start code X0 is taken as the code domain reference, the channel tag code X' can be expressed as: x' = X-X0, wherein X0 is the channel start coding. The channel start code refers to a start boundary value of the tag code assigned to a specific tag response channel.

The Code Time conversion (or C/T conversion) refers to the conversion of the tag Code from Code domain (Code domain) to Time domain (Time domain); the label code X is first converted into channel label code X' and then converted into code clock time in proportion.

When the channel tag code X 'transmits a code clock signal in multi-slots, the segment code in the channel tag code X' is time-code converted every slot. When the code clock pulse time slot Tp includes a plurality of time slots, the time code conversion includes a plurality of times of segmented time code conversion, and the code domain distribution of the label-coded segmented code is obtained by each time of segmented time code conversion.

When the channel tag code X 'transmits a code clock signal in multi-slots, the segment code in the channel tag code X' is code-time converted every slot. When the code clock pulse timeslot Tp comprises a plurality of timeslots, the code time conversion comprises a plurality of fractional code time conversions, and the timeslot distribution of the label-coded fractional code is obtained by each fractional code time conversion.

The code width index marks the code domain width of the code X; the code field is the value field of the index tag code X. The code width may refer to an absolute or relative code width, such as representing the relative code width by the complement of the code width ratio.

The time code conversion (i.e., T/C conversion) is a conversion for estimating the code domain distribution according to the time domain distribution; the time code distribution detection is that the host obtains the time domain distribution of a plurality of code clock pulse signals through wireless scanning detection, and obtains corresponding code domain distribution through time code conversion; the channel label code X ' = T ' × Δ Xw/Δ T, where T ' is a code pulse time, Δ T is a code time resolution step size, and the code time resolution step size refers to a time step size corresponding to a minimum code width Δ Xw (default 1).

The Time Code conversion (or T/C conversion) refers to the conversion of Time domain pulses from Time domain (Time domain) to Code domain (Code domain); the code clock pulse time t is firstly converted into the channel label code X 'or the code domain interval which is subordinate to the channel label code X' in proportion.

The RFID host monitors the distribution quantity of the time slot activity of the code clock pulse signals of different channels simultaneously through wireless scanning detection, and the time code distribution detection is carried out.

The active electronic tag is an active RFID tag; the active is able to transmit the tag reply signal using the tag's internal energy (e.g., battery, AC/DC).

The RFID host is a group of read hosts (which may be simply referred to as hosts according to context) and is a host device capable of synchronously exciting a plurality of RFID tags and simultaneously reading tag response information in a transient state. The RFID host serves as wireless communication equipment of a wireless communication base station or a wireless gateway.

The RFID host refers to a wireless communication device which can rapidly read the tag response data sent by the RFID tag group through wireless excitation, control and monitoring. The RFID host carries out corresponding real-time indexing and association processing according to the received and identified label coding information; and the association processing comprises data storage, uploading and linkage processing.

The RFID tag (which may be referred to simply as a tag depending on the context) is a wireless device that can be energized to transmit tag data frames on a designated channel and time slot. The channels generally refer to frequency channels; the tag data frame includes a tag ID or a type of tag encoding information that can be converted into a tag ID.

And the code domain distribution refers to the label probability distribution corresponding to different code domain intervals when the label code X is in a specified code domain limited range.

The hash bit segment, namely a hash sensitive bit segment, refers to a bit segment with higher hash degree contained in the label code; the hash degree refers to the dispersion degree of different bit segment code values of a certain bit segment; the degree of hashing may be represented by calculating a frequency dispersion of different bit segment code values, the lower the frequency dispersion the higher the degree of hashing.

For example, if f (i) represents the frequency corresponding to the bit segment code value i, the discrete variance is used to represent the frequency dispersion Sr = SQRT (∑ (f (i) -fa) 2)/fa, where fa is the average frequency of different bit segment code values, fa = Fn/N, where Fn is the total frequency, N is the number of the bit segment code values, N = 2k, k > =1, k is the binary number of the bit segment; the total frequency Fn of the different bit segments comprised by the tag code is the same.

When a certain RFID turnover device enters a wireless coverage field area, the RFID turnover device serves as a tracked RFID label target object, and a plurality of far-field RFID hosts serving as wireless base stations in the coverage field area cooperatively track the RFID turnover device.

And the far-field RFID host sends the label response information in the response channel time slot appointed by the synchronous response period by sending the Hash conversion mark and/or the channel code domain mark contained in the synchronous data frame according to the code domain distribution uploaded by the RFID turnover device.

The RFID turnaround device enters a coverage field area to be awakened, and starts to perform group reading excitation on the RFID tags of the articles covered by the near field.

And after the RFID tag is placed in the near field coverage area of the RFID turnover device, the RFID turnover device sends the group code verification identification contained in the synchronous data frame when obtaining the response of induction triggering, so that the group code verification identification associated with the RFID turnover device is set for the RFID tag.

And when the RFID turnover device is used as an RFID host to set a group code verification identifier for the RFID label, and the RFID label receives a synchronous data frame which is sent by the far-field RFID host and is used for group reading comparison verification, the label data frame containing the group code verification identifier is sent in a specified response channel time slot.

The group reading comparison check is to perform group reading on the RFID tags provided with the group code check identification and perform comparison check on the difference of the group members corresponding to the group code check identification.

The group code check identifier (called group code identifier for short) is group check information set by the group read RFID host. And when the RFID tag judges that the received group code check identifier is a new effective value, updating the configuration corresponding to the group code check identifier, and sending a tag data frame in a tag response time slot with high time slot priority.

The RFID turnover device is used as a group reading RFID host to generate the group code verification identification by being associated with the RFID turnover device and/or the binding object coding information. The user can be used as the binding object to identify the two-dimensional code on the RFID turnover device through the mobile phone, so that the user code information is bound and associated with the RFID turnover device.

Example two, the implementation of the steps described above with reference to the flowchart of fig. 1 is further illustrated as follows:

the RFID tag obtains the channel time slot for sending the tag data frame by obtaining wireless cooperative synchronization and mapping and transforming the tag code, and specifically comprises the following steps:

the RFID label receives the wireless synchronization identification which is sent by any one RFID host and is contained in the synchronization data frame at least once in a synchronization tracking period, so as to obtain the cooperative synchronization;

the RFID label carries out hash bit segment conversion on the label code of the RFID label according to the hash conversion identification contained in the synchronous data frame to generate a hash label code, and calculates the corresponding channel time slot parameter;

and the RFID label sends a label data frame in a designated label response time slot according to the channel time slot parameter.

The implementation of the above steps is further explained as follows:

the tag data frame is a data frame containing tag codes; the tag data frame is a data frame which is sent by the RFID tag in the tag response time slot and contains the tag coding information of the RFID tag. The tag code can be the tag ID (such as MAC address or application ID) itself or reversible coded information after mapping conversion; it should be noted that, code domain conversion calculation may be performed according to the irreversible hash tag encoding, and a tag response channel and a corresponding channel timeslot parameter are allocated.

The channel time slot parameter refers to a channel and a time slot parameter where the assigned tag response is distributed; for example, the channel codes and corresponding frequency point parameters, timeslot codes, timeslot priorities and corresponding timeslot delays are included.

If the code width (or code width ratio) corresponding to any tag response channel i is w (i), the initial code of the channel i is: x0 (i) = packet offset Xg + channel offset Xc (i); the group offset refers to the offset of the current excitation group relative to the total code domain range; the channel offset refers to the offset of the current response channel relative to a single group of limited code domain ranges; assuming that the current packet serial number is k and the nominal number of groups is n, xg = k/n × Wn, where Wn is the total code width of the label code, if there is no packet (i.e., k = n = 1).

The channel offset Xc (i) is obtained by summing the channel code widths smaller than i: xc (i) = ∑ w (i); when judging that X0 (i) < = X < X0 (i + 1), the RFID tag code X is allocated to the response channel i in the current synchronous response period.

The tag response time slot (response time slot for short) is a time slot for sending a tag data frame by the RFID tag; a synchronous reply period may comprise one multi-tag reply slot or multiple single-tag reply slots.

Example three, the implementation of the steps previously described with reference to the flow diagram of fig. 1 is further illustrated as follows:

the wireless cooperative synchronization, namely cooperative time synchronization, means that a plurality of RFID hosts have the same cooperative synchronization period; the cooperative synchronization period refers to a synchronization period shared by a plurality of RFID hosts, and synchronization identifiers sent by the RFID hosts have an associated consistent synchronization phase relationship. The RFID tag obtains corresponding synchronous offset time according to the synchronous offset code; the synchronization offset time refers to the phase time of the current synchronization mark in one synchronization period.

The synchronous tracking period at least comprises one synchronous response period, and can skip a plurality of default response periods when a plurality of synchronous response periods are included; and the RFID label is in a low-power-consumption dormant state in the default response period, is awakened before the effective response period based on a synchronous timer, and detects and receives a synchronous excitation signal sent by the RFID host. After an effective response period, the RFID tag sets a synchronous timer corresponding to a plurality of default response periods and enters a low-power-consumption dormant state.

A plurality of RFID hosts in a collaborative synchronization state in the coverage field area send collaborative consistent wireless synchronization identification: namely, sending wireless synchronous identification and synchronous data frames in synchronous offset time zones with different synchronous offsets; the RFID label carries out synchronization time correction according to the received wireless synchronization identification sent by any one RFID host, and can obtain the same and consistent synchronization response period and the contained label response channel time slot.

In a cooperative synchronization period, the wireless synchronization identifier sent by the RFID host comprises a series of synchronization offset identifiers, and when any synchronization offset identifier is received by the RFID tag, a subsequent consistent synchronization response period can be obtained through synchronization time correction.

The synchronous excitation signal is composed of a series of awakening excitation signals and synchronous data frame signals and is respectively used for awakening the RFID tag and obtaining time synchronization; and the RFID host respectively sends the awakening excitation signal and the synchronous data frame signal on the same or different frequency channels. The RFID tag obtains the time synchronization by receiving a wireless synchronization identification and performing synchronization time correction.

The synchronous channel is a channel for enabling a plurality of RFID labels to obtain time synchronization; and the RFID tag obtains time synchronization by receiving the wireless synchronization identification sent by the RFID host and performing synchronization time correction.

The tag response channel (tag channel for short) is a channel through which the RFID tag transmits its tag data frame. The tag response channel is a communication channel for the RFID tag to transmit tag response data, and the channel is a radio frequency channel based on frequency and/or time division.

The label response channel is a series of synchronous response periods keeping time synchronization according to the synchronous excitation signal, and the RFID label sends label response information according to the channel time slot parameter in the label synchronous response period.

The synchronous data frame comprises a wireless synchronous identification, and the RFID tag obtains the time synchronization according to the synchronous identification; and the RFID host sends the synchronous identification at least once in one synchronous period. The synchronization period refers to a period in which the RFID host transmits a synchronization data frame, and may include one or more synchronization response periods.

The synchronization mark is a wireless modulation pulse signal used for time synchronization; the synchronization mark comprises or follows a synchronization offset code, and the synchronization offset code is a code corresponding to synchronization offset time, namely synchronization offset; the synchronization mark is located before (with a certain gap or starting position) a synchronization data frame; when a synchronization packet comprises a plurality of synchronization data frames, at least one synchronization mark is included. The RFID host obtains a synchronization offset sequence number for avoiding local collision through one or a combination of the following modes: 1) Specified by the system host/server; 2) Performing wireless detection learning by synchronous identification sent by other peripheral RFID hosts; 3) And actively adjusting by the RFID host with low priority according to the synchronization priority.

The synchronization shift amount (i.e., synchronization shift time) is a synchronization phase time based on a synchronization time step magnification, and the synchronization phase time is a shift time with respect to the synchronization shift amount of 0.

If the cooperative synchronization period Tc is expressed as a multiple with respect to the synchronization time step, one cooperative synchronization period Tc is divided into n synchronization shift time zones, and one synchronization shift time zone includes m synchronization time steps, the maximum synchronization shift is allowed to be m-1. For example, tc =64, n =4 offset time zones, each offset time zone including m =16 synchronization offsets, each RFID host can transmit 4 synchronization data frames at the 4 offset time zones at the maximum in one cooperative synchronization period.

The synchronous response period is a period allocated to the multi-tag to send the tag response information, and includes a code clock time slot (C/T time slot for short) and a tag response time slot. The code clock time slot is the time slot for the RFID tag to send the code clock signal.

And after receiving the synchronous identification, the RFID label immediately corrects the synchronous time according to the synchronous offset time corresponding to the synchronous offset code, and sends a label data frame of the RFID label in a specified channel time slot in a synchronous response period based on time synchronization. And after receiving the synchronous identification, the RFID label immediately corrects the synchronous time according to the synchronous offset time corresponding to the synchronous offset code, and sends a label data frame of the RFID label in a specified channel time slot in a synchronous response period based on time synchronization.

When the RFID host learns the wireless synchronization identifier sent by the nearby cooperative RFID host through detection, and according to the synchronization offset codes of the two parties, when the synchronization offset time of the RFID host is inconsistent with the synchronization offset code, the synchronization offset correction is carried out on the synchronization offset time of the wireless synchronization identifier actually sent by the RFID host.

The RFID host takes the synchronization priority as a necessary condition whether to carry out the synchronization offset correction or not: and when the synchronization priority of the RFID master is lower than that of the adjacent cooperative RFID master, performing the synchronization offset correction. The priority for synchronization is given by one or a combination of the following ways: 1) specified by the system host, 2) according to the timing of the joining of the cooperative synchronization, and 3) pseudo-randomly specified.

The RFID tag enters the coverage field area and is covered by a wake-up excitation signal contained in the synchronous excitation signal, and is firstly awakened for the first time by receiving a low-frequency wake-up signal or a radio-frequency wake-up excitation pulse, and then is awakened successively or synchronously by detecting time slot expansion.

When a certain RFID label enters the coverage field area and is awakened for the first time, the detection time slot delta t of the transient detection is expanded, so that a synchronous excitation signal sent by the group control host is quickly and reliably received at any time, and secondary awakening (or successive awakening) is obtained.

The awakening excitation pulse is a wireless modulation pulse signal with ultrashort pulse width sent by the RFID host, and is used for carrying out primary preparatory awakening on the RFID label in a low-power-consumption sleep state before the RFID label obtains time synchronization; when the RFID label receives the wake-up excitation pulse in the transient detection time slot, the RFID label is immediately woken up.

The wake-up excitation pulse is a series of wireless modulation pulse signals with extremely short pulse width time (typically not more than microsecond) far less than one data frame sent by the RFID host.

The RFID label keeps a low-power-consumption sleep-following state in an un-awakening normal state, and is awakened by receiving the awakening excitation pulse signal through transient detection before the RFID label obtains the time synchronization; and if the RFID label fails to receive at least one wake-up excitation pulse in the micro time slot delta t of transient detection, immediately returning to the low-power-consumption sleep-following state.

After the RFID tag enters a coverage field area of an awakening excitation signal, preliminary initial awakening is obtained through transient detection, and the RFID tag is awakened gradually through detection time slot expansion so as to achieve a dynamic balance strategy for self-state power consumption and trigger response time; the coverage field may be a larger area of wireless coverage than the active burst read synchronous excitation.

The detection time slot expansion comprises increasing the duty ratio of the detection time slot (such as increasing the detection time slot and quickening the detection period) and/or improving the detection sensitivity (such as adjusting the high-frequency receiving front-end of an antenna); typically, the detection time slot expansion refers to increasing the detection time slot and/or speeding up the detection period.

The primary wake-up excitation signal for preparing the RFID tag can be a low-frequency wake-up signal or a modulation signal of a radio-frequency wake-up excitation pulse; receiving the low-frequency wake-up signal through a low-frequency passive antenna, and obtaining the receiving response of the low-frequency coupling signal; the low-frequency coupling signal enters a low-frequency preamplifier and is output to a comparator to obtain a trigger signal for waking up a main processor.

And after the RFID label is awakened and the wireless synchronous identification sent by the RFID host is received in the synchronous detection time slot, the channel code domain identification following the synchronous identification is continuously received. The channel code field identification is included in the synchronization data frame. The RFID label checks the group code identification following the synchronous identification, and 1) if the group code identification fails to pass the check, the RFID label immediately returns to the low-power-consumption sleep-following state; 2) And if the verification is passed, continuously reading the channel code domain identification, and starting a synchronous response cycle according to the channel code domain identification and the synchronous time.

The channel code domain identifier is a wireless identifier describing channel code domain parameters; the channel code domain parameters refer to parameters of code domain ranges or intervals of the label codes corresponding to different label response channels (of course, the channel may be other than the channel). Optionally, the channel code domain parameter is a parameter or an identifier of a code width corresponding to different channels; of course, code widths outside of the channel may also be included.

If the RFID label receives the synchronous response verification identification sent by the RFID host, when the sent label data frame is identified and judged to be received by the RFID host, the sending of the label response information and the label data frame can be immediately stopped.

And when the transmitted tag data frame is identified and judged not to be received by the RFID host, the time slot detection can still be carried out by the low time slot priority in the tag response time slot following the same tag response period, and the tag data frame is transmitted again under the condition that the time slot is idle.

And after the RFID host receives a certain tag data frame in a certain tag response time slot, the RFID host sends a verification data frame serving as asynchronous response to the RFID tag in the following tag response time slot. And the RFID host sends the verification data frame for parallel response and control instruction to the appointed tag data frame through the asynchronous response.

When the RFID host receives the tag data frame sent by the RFID tag in the tag response channel, the RFID host sends a verification data frame as an asynchronous response to one or more RFID tags according to one of the following modes:

in the first mode, the RFID host immediately occupies the following response time slot, the verification data frame is sent at the highest time slot priority, and other RFID tags do not send the tag data frame any more through time slot detection;

and in the second mode, the RFID host occupies a certain idle response time slot through time slot detection and sends the verification data frame to one or more RFID labels.

The asynchronous response refers to a tag data frame sent by the RFID host to one or more received RFID tags in a synchronous response period of a certain tag response channel and a verification data frame sent as response information in a subsequent asynchronous response time slot. The RFID host selects and adopts the following different time slot obtaining modes according to different asynchronous response requirements (such as verification, configuration and control) based on the current channel time slot occupation condition, and the method comprises the following steps: 1) Preempting acknowledgement slots based on high slot priority, 2) finding idle slots based on channel slot detection.

After the RFID host machine receives the tag data frames sent by the RFID tags in a synchronous response period in different tag response channels, implanting corresponding synchronous response verification marks into the synchronous data frames; the group reading verification mark comprises a plurality of verification bit marks so as to reflect whether the label data frames of different label response channels and label response time slots thereof are received.

The RFID tag identifies the corresponding verification bit identification in the synchronous response verification identification to judge whether the tag data frame sent before is received by the RFID host; the check bit identification can reflect check response information of a plurality of label response time slots in the current period; the verification response information of whether the tag data frames of different tag response time slots are received in the previous N periods can also be represented by different bits or bit segments through rolling iteration.

If the RFID label does not receive the synchronous or asynchronous response verification identification sent by the RFID host in a certain synchronous response period, the time slot detection can be carried out in the following label response time slot with low time slot priority, and the label data frame is sent again under the condition of judging that the time slot is idle. If the RFID label fails to successfully send the label data frame in a synchronous response period, waiting for receiving an updated synchronous data frame sent by the RFID host; and the synchronous data frame comprises the Hash transformation identifier and the synchronous response verification identifier.

According to the received synchronous response verification identification, when the RFID tag judges that the tag data frame sent by the RFID tag is received by the RFID host, the RFID tag can immediately stop sending the tag response information; and otherwise, waiting for receiving a new synchronous data frame sent by the RFID host, and sending label response information according to the updated channel time slot parameters in the new synchronous response period. Otherwise, waiting for receiving a new synchronous data frame sent by the RFID host, and sending label response information according to the updated channel time slot parameter in the new synchronous response period.

The RFID label identifies and judges the received synchronous or asynchronous response information sent by the RFID host: when the tag data frame is received by the RFID host, immediately stopping sending the tag data frame; otherwise, the RFID label selects one of the following modes to resend the label response data frame according to the judgment of the current synchronous phase and asynchronous time slot: 1) In the following label response time slot in the same synchronous response period, the label data frame is sent again with low time slot priority; 2) And waiting for the receiving RFID host to send a new synchronous data frame, and sending label response information according to the updated channel time slot parameters in a new synchronous response period.

Referring to fig. 3, a timing chart of a comparison between signals of a synchronization channel and a tag response channel in a group reading process of cooperative tracking and monitoring of an RFID tag by an RFID host according to an embodiment of the present invention includes a timing chart of signals of the synchronization channel 310, the synchronization channel 320, and the tag response channel 330, which is specifically described as follows:

the synchronization channels 310: the RFID host sends a wake-up excitation pulse signal 311 on the synchronization channel 310;

synchronization channel 320: the RFID host transmits a series of sync data frames 321 over the sync channel 320, wherein each sync data frame contains one or more sync identifiers 3211, 3212 \8230; the synchronization marks 3211, 3212 \8230, the time differences relative to the start time of the synchronization response period 3301 (assuming that the synchronization phase time is 0) are synchronization offsets (i.e., synchronization offset time) 3201, 3202 \8230, respectively;

tag reply channel 330: the RFID host transmits tag reply information during a series of synchronous reply cycles 3301 in the tag reply channel 330, including: a code clock signal 3311 is transmitted in the code clock slot 331 and a tag response data frame 3321 is transmitted in the tag response slot 332;

it should be noted that the synchronization channels 310 and 320 may be the same or different synchronization channels.

Example four, the implementation of the steps previously described with reference to the flow diagram of fig. 1 is further illustrated as follows:

and when the RFID tag identifies and judges that the sent tag data frame is not received by the RFID host, the time slot detection can still be carried out by low time slot priority in the tag response time slot following the same tag response period, and the tag data frame is sent again under the condition that the time slot is idle.

The time slot detection, i.e. channel time slot detection (i.e. TSD detection), is a tentative wireless detection performed by the RFID tag before sending data in the designated channel time slot, and is intended to determine whether the current channel time slot is idle.

The RFID tag is used for judging whether the current response time slot is idle or not before sending a response data frame by carrying out time slot detection (namely TSD detection) on the current tag response time slot so as to avoid channel collision; optionally, the RFID tag calculates a time slot delay step size and a corresponding time slot priority of the tag data frame by detecting and identifying all or end features (such as an identification end symbol or an end time) of the tag data frame sent by other RFID tags in the current response time slot.

Before the RFID label sends the response data frame according to the delay step length corresponding to the time slot priority, channel time slot detection condition exemption is carried out to be the highest time slot priority; and if and only if the return result of the time slot detection is that the channel time slot is idle, allowing to transmit, otherwise, forbidding to transmit the response data frame in the current response time slot. The lower the priority, the larger the delay step without exceeding the maximum allowed delay.

The time slot priority is the competition priority of the RFID label which allows to send the self response data frame in the same response time slot; the time slot priority corresponds to the time slot delay step of the preset sending time of the current response time slot. When the delay step is larger than the maximum allowable value, indicating that the label data frame is not allowed to be sent in the current response time slot; when the delay step corresponding to the time slot priority of the RFID label is larger than the maximum allowable value, forbidding sending a response data frame in the current response time slot; it may wait to find a tag acknowledgement slot that allows it to transmit a tag data frame in a subsequent acknowledgement slot or subsequent synchronous acknowledgement period.

Referring to fig. 4, a time slot composition and a response signal timing chart in a synchronous response period 400 of a tag response channel in a group read response process of cooperative tracking and monitoring of an RFID tag by an RFID host according to an embodiment of the present invention are shown, where the synchronous response period 400 includes a code clock time slot 410 and a tag/asynchronous response time slot 420, and the following description is specifically made:

code clock time slot 410: the RFID tags pass code time conversion, and code time pulses 4101, 4102 \8230withdifferent code time pulse sending time (relative time is t) are sent in the code time pulse time slot 410;

tag/asynchronous reply slot 420: the RFID tag comprises a plurality of tag response time slots 421, 422, 423, \ 8230; 42X, and a certain RFID tag transmits a tag data frame 4211 based on time slot priority; other RFID tags with relatively low time slot priority forbid sending tag data frames 4212, 4213, \ 8230, 421X through channel time slot detection so as to avoid time slot response data collision; where Td is the maximum allowed value of the slot delay step.

When the RFID host has a need for asynchronous reply, the tag reply timeslot 42X occupied with the highest timeslot priority (or found to be free based on channel timeslot detection) may be selected to transmit the host asynchronous reply data frame 42X0.

The time slot delay step refers to a step length corresponding to a preset time for sending a response data frame of the current response time slot; one time slot priority corresponds to one delay step, and one delay step is increased when one time slot priority is reduced. In the actual development process, the slot priorities may be defined as follows: time slot priority 0, delay step 0; time slot priority 1, delay step 1; 8230; time slot priority n, delay step n.

In a synchronous response period, if the RFID label fails to send the label data frame in a certain label response time slot, or does not receive the response verification information of the RFID host or fails to verify, the RFID label adjusts the time slot priority of the RFID label data frame in the subsequent response time slot according to a mode of circularly increasing the priority.

When a plurality of label response time slots exist in a synchronous response period, the priority is increased according to the circulation; if the time slot priority of the current response time slot is the highest level, the time slot priority of the next response time slot is adjusted to be the lowest level, but not the time slot priority of the highest level, and a priority is increased in the next response time slot.

When the RFID tag judges that the time slot priority of the tag data frame actually sent by the current response time slot is reduced by n levels through channel time slot detection, n +1 levels are allowed to be increased at most in the next response time slot of the same synchronous response period, namely n +1 delay steps are advanced.

The RFID tag calculates the time slot delay step length and the corresponding time slot priority of the current tag data frame by detecting and identifying all or ending characteristics (such as an identification special ending symbol or ending time) of tag data frames sent by other RFID tags in the current response time slot.

The RFID label sends a label data frame in a first label response time slot according to the time slot priority consistent with the code clock time slot; and before the label data frame is sent, channel time slot detection is carried out, if and only if the returned result of the time slot detection is that the channel time slot is idle, the channel time slot is allowed to be sent, otherwise, the time slot priority is adjusted in the next response time slot according to a mode of circularly increasing the priority.

After the RFID tag determines the time slot delay step length, the time slot priority of each single tag response time slot can be consistent with the code pulse time, but different code width time step lengths are determined according to the minimum code width; the code width time step refers to the minimum time step corresponding to the minimum code width.

When a certain RFID label sends synchronous response data in a plurality of synchronous response periods, but does not receive response information from an RFID host, the RFID label can send the response information in one or the combination of the following ways through channel time slot detection in a certain idle channel time slot: 1) Sending a help seeking data frame comprising a help seeking identifier; 2) The tag data frame is transmitted with increased radio frequency power.

When the data signal state between a certain RFID label and the RFID host fails to reach the expected index within a certain time, the RFID label can send a help data frame comprising a help identifier within a certain idle channel time slot through channel time slot detection.

For example, the following data signal states occur, and the RFID tag may transmit the help data frame: 1) After the RFID label is awakened for a period of time, the synchronous data frame sent by the RFID host machine cannot be successfully received; 2) The tag response data is sent for many times, and the response verification information sent by the RFID host cannot be successfully received; the "failure" includes failure to receive, too weak a signal, or a failed verification.

After a certain RFID label receives the response information of the RFID host, the RFID label can be used as a relay agent node to provide relay agent service for other RFID labels nearby in a help seeking state according to the relay agent condition; after receiving a help-seeking data frame sent by an adjacent RFID label, the relay agent node immediately sends an agent label data frame in a subsequent asynchronous response time slot when a certain response time slot is idle based on channel time slot detection; the help data frame is a tag data frame containing a help identifier.

The mode of the active RFID label becoming the relay agent node comprises one or the combination of the following modes:

in the first mode, the active RFID label sends a label data frame and receives response information, and the active RFID label becomes a relay agent node according to a relay agent indication mark sent by an RFID host, wherein the relay agent indication mark is contained in the host response data frame;

in the second mode, when the signal received strength (RSSI) of the synchronous excitation signal received by the active RFID tag from the RFID host reaches a predetermined condition value, the active RFID tag becomes a relay agent node.

The condition value may be a predetermined value or an indication value included in the synchronization packet; the condition value may be associated with a self-capability status (e.g., remaining power) of the RFID tag, such as when the remaining power is insufficient, reducing or no longer actively relaying the proxy.

When a certain RFID label is repeatedly excited in a short time, if a certain relay agent node receives a label data frame sent by the RFID label in the last period, the time slot priority of the agent response is provided in the period.

The hash bit segment transform is a hash mapping transform based on the sensitive bit segment for tag encoding; and the RFID label maps and converts the label code of the RFID label into a new Hash label code through the Hash bit segment conversion, replaces the original label code with the Hash label code, and calculates the channel time slot parameter for sending the label response data.

The hash bit segment transforms into a mapping transform that hashes a number of hash bit segments (hash-sensitive bit segments) contained in the label encoding and recombines (sorts, shifts, superposes).

The hash transformation identifier is a wireless identifier reflecting hash bit segment transformation parameters; the hash bit segment transformation parameters are mapping transformation parameters Pi for carrying out the hash bit segment transformation, and comprise parameters of selection and combination modes of the hash bit segment; the hash bit segment transform is a sensitive bit segment based hash map transform of the tag code; the hash bit segment conversion parameter is a hash bit segment code composed of a bit selection code or a bit segment selection code.

The hash bit segment conversion parameter is a hash bit segment code comprising one or a combination of the following modes: the method comprises the steps of 1, 2, \ 8230, selecting a bit segment bit number (optional), wherein the bit sequence refers to the bit sequence number (or bit pointer) of the start bit of the bit segment in the label code, and the default value of the bit segment bit number is omitted; the mode two is multi-selection code 1, multi-selection code 2, \ 8230, bit segment bit number (optional), and binary bit in the multi-selection code is 1.

In the actual development process, the multiple selection codes include bit selection codes or bit segment selection codes, such as: 1) Bit selection, 0 xaaaaa 5555h indicates selection of the even bits of the upper 2 bytes and the odd bits of the lower 2 bytes in the 4-byte tag code, 2) bit segmentation, e.g., 01010101b represents selection of the lower half of each byte in the 4-byte tag code; optionally, the hashed bit segment transform code further includes a bit segment sequence code, such as a starting bit sequence, a shift number of the selected bit segment; optionally, the hash bit segment transform code further comprises an opcode, such as a bitwise logical xor superposition of the selected bit segment with the non-selected bit segment.

The hash bit segment transformations are associated with the current synchronization identification information such that when the hash tag codes of two or more RFID tags collide for one synchronization response period, then at the next synchronization response period, there will be no further consecutive collisions. The synchronization identification information refers to indication information associated with the current synchronization period, such as a synchronization sequence number and an offset code.

And the cooperative host evaluates the probability weight of expected entering of a specified RFID host to cover the field according to the time and position frequency of the tracking object of the RFID tag in the hot list of the adjacent area, and calculates a refresh bit segment hash table based on the probability weight. The bit segment hash table comprises hash degree information of different sensitive bit segments in code domain distribution of the RFID tag tracking object.

The cooperative host is a peripheral RFID host and/or an upper host; the cooperating host may be a system server.

And the code domain bit segment monitoring is to continuously and cooperatively monitor the hash degree or frequency dispersion degree of different sensitive bit segments in the code domain distribution of the RFID label tracking object in the specified target area and calculate a refresh bit segment hash table.

The sensitive bit segment refers to a bit segment with higher hash degree (namely lower frequency dispersion);

the cooperative monitoring refers to probability weight obtained by performing code domain distribution statistics on a designated coverage area according to the time position frequency of the current RFID label code by the cooperative host.

The RFID host evaluates and calculates the frequency dispersion of different sensitive bit segments in the code domain distribution according to a space-time sliding weighting method; and comparing the frequency dispersion, selecting a sensitive bit segment with relatively lower frequency dispersion, namely corresponding to a hash degree with relatively higher hash degree, and generating the corresponding hash bit segment conversion parameter such as a hash bit segment code.

The space-time sliding weighting is a filtering calculation method for target variable acquisition for carrying out weighting limitation on a space-time range, and the method is suitable for filtering calculation of frequency and frequency dispersion of variable code values;

the RFID host calculates the hash degree or the frequency dispersion of the sensitive bit segment in one or a combination mode;

firstly, weighting according to the space-time sliding, tracking and calculating the frequency f (i) corresponding to different bit segment code values, and evaluating and calculating the corresponding hash degree or frequency dispersion according to the frequency f (i);

directly weighting according to the space-time sliding in a second mode, and evaluating and calculating the current hash degree or frequency dispersion degree; for example, according to the space-time sliding weighting, the frequency f (i, t) and the frequency dispersion Sr (t) corresponding to the current different bit segment code values are evaluated and calculated:

f(i,0) = ∑(W(t)*f(i,t))/∑W(t)，Sr(0) = ∑(W(t)*Sr(t))/∑W(t)，

where Σ is the sum of the specified space-time range (e.g. within the time window T1 and the distance range R1), f (i, 0), sr (0) and Sr (T) respectively represent the frequency and frequency dispersion of the current (i.e. T = 0) bit segment code value, and W (T) is the relative weight of the previous T.

The space-time sliding weighting is a filtering calculation method for evaluating and calculating the acquisition of target variables by weighting according to space-time distance relative to the current time and the target position; for example, by adopting an iterative method of space-time exponential decay, the frequency f (i, t) and the frequency dispersion Sr (t) corresponding to the current different bit segment code values are calculated:

f(i,0) = (W(r)*f(i,0)+W(t)*f(i,t))/(W(r)+W(t))，

Sr(0) = (W(r)*Sr(0)+W(t)*Sr(t))/(W(r)+W(t))，

wherein W (R) is a weight attenuation coefficient based on spatial exponential attenuation, reflecting the relative weight attenuation of the current (t = 0) target object at the position R, wherein W (R) = Exp (-R/R1), and R1 is a given exponential attenuation distance; w (T) is a weight attenuation coefficient based on time exponential attenuation and reflects the relative weight attenuation of the target object at the previous T time, wherein W (T) = Exp (-T/T1), and T1 is a given time attenuation period.

The embodiment of the present invention further discloses a wireless cooperative tracking and monitoring device, please refer to fig. 2, which refers to an RFID host device 200 as a wireless base station, and the device performs cooperative tracking and monitoring on a plurality of low power consumption active RFID tags in a coverage area as a target group through wireless cooperative synchronization, where the RFID host device 200 includes: a cooperative synchronization module 201, a code domain monitoring module 202 and a transformation identification module 203, wherein:

the cooperative synchronization module 201: the RFID tag is used for transmitting a synchronous data frame comprising a wireless synchronous identifier at least once in a synchronous tracking period through wireless cooperative synchronization, so that the RFID tag receives the synchronous identifier at least once in the synchronous tracking period to obtain time synchronization;

code domain monitoring module 202: the method comprises the steps that code domain distribution monitoring is carried out through cooperation of a plurality of system hosts, and Hash bit segment conversion parameters for mapping and converting current RFID label codes are obtained;

the transformation identification module 203: the hash bit segment conversion parameter is used for implanting a corresponding generated hash conversion identifier into the synchronous data frame;

and the RFID label carries out hash bit segment conversion on the label code of the RFID label according to the received hash conversion identification, and sends a label data frame in the appointed label response time slot.

In practical implementation, the device is a computer device, and the processor executes computer instructions to implement the embodiment of the wireless cooperative tracking and monitoring device disclosed in the foregoing.

Those skilled in the art will appreciate that all or part of the processes of the methods of the embodiments described above can be implemented by a computer program, which can be stored in a computer-readable storage medium, and when executed, can include the processes of the embodiments of the methods described above.

The embodiment of the invention also discloses a wireless cooperative tracking and monitoring system which is established by utilizing the wireless cooperative tracking and monitoring method in the first aspect and comprises a system cooperative host, a plurality of RFID hosts and a plurality of tracked RFID labels;

the RFID host serves as a wireless base station, performs cooperative tracking monitoring on the RFID tags in a coverage area through wireless cooperative synchronization, and transmits tracking monitoring information to the system cooperative host;

the system is cooperated with a host to perform code domain distribution monitoring by tracking and calculating a bit segment hash table of the current RFID label code to obtain a hash bit segment conversion parameter, and the hash bit segment conversion parameter is sent to an associated RFID host;

and the RFID label carries out mapping transformation on label codes according to the received Hash bit segment transformation parameters sent by the RFID host to obtain a channel time slot for sending the label data frame.

The system collaboration host comprises a system server or an edge management host and an RFID host with collaboration service capability.

For several terms referred to in the foregoing embodiments, further description is as follows:

the turnover device is a traceable target device which is bound by an RFID label and can carry articles; the turnover device is used as a near field RFID host to read the label response information of the RFID label of the article; the turnaround device is capable of wirelessly communicating with the wireless base station covering the field area as a far-field RFID host.

The transfer device is an intelligent tool device with RFID communication capability for carrying articles (goods, materials, commodities) into or out of a covered field area (such as an in-out area, a checkout area). The form of the turnover device can be a turnover disc (such as an article tray and a dinner plate), a turnover vehicle (such as a storage vehicle, a shopping vehicle and an article conveying vehicle), and a turnover box/cabinet/frame (such as a material box, a goods shelf and a shopping frame).

The article RFID tag is an active RFID tag and can be excited by an RFID host in a near field or far field mode; the RFID tag of the article selects to transmit the tag response information in a near-field low-power mode or a far-field high-power mode through the identification of the RFID host class. When the article RFID tag receives a near field excitation signal sent by a near field RFID host, sending tag response information in a near field low power mode; and when the article RFID label receives a far-field synchronous excitation signal transmitted by a far-field RFID host, the label response information is transmitted in a far-field high-power mode.

The induction trigger is derived from a high-frequency signal actively transmitted when the article RFID enters; the inductive trigger is derived from the detection of an object sensor sensing the movement of an object into and out of the epicyclic arrangement. The transfer device comprises an object sensor, and the object sensor is used for triggering the transfer device to read the RFID tags of the placed articles and the change conditions of the RFID tags; the object sensor can be one or a combination of weighing, infrared, camera shooting or electromagnetic sensors.

The channel rated code width refers to the maximum code width allowed to be distributed in a channel in a synchronous response period; the channel rating code width may be a default value or a dynamic setting value included in the synchronization data frame.

It should be understood that the above examples are only for clarity of illustration and are not intended to limit the embodiments. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. These should also be construed as the scope of the present invention, and they should not be construed as affecting the effectiveness of the practice of the present invention or the applicability of the patent. And are neither required nor exhaustive of all embodiments. The scope of the claims of the present application shall be determined by the contents of the claims, and the description of the embodiments and the like in the specification shall be used to explain the contents of the claims. And obvious variations or modifications therefrom are within the scope of the invention.

Claims (13)

1. A wireless cooperative tracking monitoring method is characterized in that a plurality of RFID hosts are used as wireless base stations to perform cooperative tracking monitoring on a plurality of RFID labels in a coverage area, and the method specifically comprises the following steps:

the RFID host sends a synchronous data frame including a wireless synchronous identifier at least once in a synchronous tracking period through wireless cooperative synchronization, so that the RFID tag obtains time synchronization, and the cooperative synchronization means that a plurality of RFID hosts have the same cooperative synchronization period;

the RFID host acquires the sensitive characteristics of the code domain distribution of the RFID tags of a target group through code domain distribution monitoring, acquires hash bit segment conversion parameters for mapping and converting the current RFID tag codes, and the hash bit segment is converted into hash mapping conversion for the tag codes based on the sensitive bit segment;

the RFID host implants the corresponding generated hash transformation identification into the synchronous data frame according to the hash bit segment transformation parameter;

and the RFID label carries out Hash bit segment conversion on the label code of the RFID label according to the received Hash conversion identification, calculates the corresponding channel time slot parameter and sends a label data frame in the appointed label response time slot according to the channel time slot parameter.

2. The method for monitoring wireless cooperative tracking according to claim 1, wherein the RFID tag obtains the channel slot for transmitting the tag data frame by obtaining the wireless cooperative synchronization and mapping the tag code, and comprises the following steps:

the RFID label receives the wireless synchronization identification which is sent by any one RFID host and is contained in the synchronization data frame at least once in a synchronization tracking period, so as to obtain the cooperative synchronization;

the RFID label carries out hash bit segment conversion on the label code of the RFID label according to the hash conversion identification contained in the synchronous data frame to generate a hash label code, and calculates the corresponding channel time slot parameter;

and the RFID label sends a label data frame in a designated label response time slot according to the channel time slot parameter.

3. The wireless cooperative tracking monitoring method according to claim 1, wherein the cooperative synchronization means that a plurality of RFID hosts have the same cooperative synchronization period;

the cooperative synchronization period refers to a synchronization period common to a plurality of RFID hosts, and synchronization identifiers sent by the RFID hosts have associated consistent synchronization phase relationship.

4. The method according to claim 1, wherein the synchronization tracking period comprises at least one synchronization response period, and skips a plurality of default response periods when a plurality of synchronization response periods are included;

and the RFID label is in a low-power-consumption dormant state in the default response period, is awakened before the effective response period based on a synchronous timer, and detects and receives a synchronous excitation signal sent by the RFID host.

5. The wireless cooperative tracking monitoring method according to claim 1, wherein a plurality of RFID hosts in cooperative synchronization status in the coverage area transmit cooperative and consistent wireless synchronization identifiers: namely, sending wireless synchronous identification and synchronous data frames in synchronous offset time zones with different synchronous offsets;

and the RFID label carries out synchronization time correction according to the received wireless synchronization identifier sent by any one RFID host, so as to obtain the same and consistent synchronization response period and the contained label response channel time slot.

6. The method as claimed in claim 1, wherein the RFID tag entering the coverage area is covered by the wake-up excitation signal, and is first awakened for the first time by receiving the rf wake-up excitation pulse, and then is awakened sequentially or synchronously by detecting the timeslot extension.

7. The method according to any one of claims 1 to 6, wherein if the RFID tag receives a synchronous response verification identifier sent by the RFID host, when it is determined that the sent tag data frame has been received by the RFID host, sending of the tag response information and the tag data frame thereof is immediately stopped.

8. The method as claimed in claim 7, wherein when the RFID tag identifies and determines that the transmitted tag data frame is not received by the RFID host, the time slot detection is performed with a low time slot priority in a tag response time slot following the same tag response period, and the tag data frame is transmitted again under a condition that the time slot is idle.

9. A wireless cooperative tracking monitoring method according to any of claims 1 to 6, wherein said hashed bit segment transform is a hashed mapping transform of tag codes based on sensitive bit segments; and the RFID label maps and converts the label code of the RFID label into a new Hash label code through the Hash bit segment conversion, replaces the original label code with the Hash label code, and calculates the channel time slot parameter for sending the label response data.

10. The wireless cooperative tracking and monitoring method according to any one of claims 1 to 6, wherein the code domain distribution monitoring is a continuous cooperative monitoring of the hash degree or frequency dispersion of different sensitive bit segments in the code domain distribution of the RFID tag tracking object in the designated target area, and a refresh bit segment hash table is calculated.

11. The method for monitoring the wireless cooperative tracking as recited in any one of claims 1 to 6, wherein the RFID host evaluates and calculates frequency dispersion of different sensitive bit segments in the code domain distribution according to a space-time sliding weighting method; and comparing the frequency dispersion, selecting the sensitive bit segment with low frequency dispersion, namely corresponding to the sensitive bit segment with high hash degree, and generating the corresponding hash bit segment conversion parameter.

12. A wireless cooperative tracking and monitoring device is characterized in that the device refers to an RFID host device as a wireless base station, and the device performs cooperative tracking and monitoring on a plurality of RFID tags in a coverage area, and the device is composed of the following modules:

a collaborative synchronization module: the RFID tag is used for sending a synchronous data frame including a wireless synchronous identifier at least once in a synchronous tracking period through wireless cooperative synchronization, so that the RFID tag obtains time synchronization, and the cooperative synchronization means that a plurality of RFID hosts have the same cooperative synchronization period;

code domain monitoring module: the system comprises a code domain distribution monitoring module, a data processing module and a data processing module, wherein the code domain distribution monitoring module is used for acquiring sensitive characteristics of code domain distribution of RFID tags of a target group through code domain distribution monitoring, and acquiring hash bit segment conversion parameters for mapping and converting current RFID tag codes;

a transformation identification module: the hash bit segment conversion parameter is used for implanting a corresponding generated hash conversion identifier into the synchronous data frame;

and the RFID label carries out Hash bit segment conversion on the label code of the RFID label according to the received Hash conversion identification, calculates the corresponding channel time slot parameter and sends a label data frame in the appointed label response time slot according to the channel time slot parameter.

13. A wireless cooperative tracking monitoring system, characterized in that the system is a system established by using the wireless cooperative tracking monitoring method according to any one of claims 1 to 11, and comprises a system cooperative host, a plurality of RFID hosts and a plurality of tracked RFID tags;

the RFID host serves as a wireless base station, performs cooperative tracking monitoring on the RFID tags in a coverage area through wireless cooperative synchronization, and transmits tracking monitoring information to the system cooperative host;

the system is cooperated with a host to perform code domain distribution monitoring by tracking and calculating a bit segment hash table of the current RFID label code to obtain a hash bit segment conversion parameter, and the hash bit segment conversion parameter is sent to an associated RFID host;

and the RFID label carries out mapping transformation on label codes according to the received Hash bit segment transformation parameters sent by the RFID host to obtain a channel time slot for sending the label data frame.

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