Intelligent inventory and allocation management system for library collection books

Abstract

The application relates to the technical field of radio frequency identification application, and discloses an intelligent inventory and deployment management system for library collection books, which collects the received signal strength and the carrier phase of an electronic tag through a radio frequency sensing module; a topology inference module constructs a book logical topology based on a phase frequency gradient, identifies structural dead zones by using a micro-translation disturbance strategy, and generates a mask vector; a feature analysis module adaptively switches a phase calibration mode according to neighborhood density, and calculates net radio frequency penetration rate in combination with the mask vector; a deployment execution module generates anonymous scheduling instructions of an electromagnetic breathing air gap adjustment or a dielectric isolation unit accordingly; and a feedback verification module performs closed-loop confirmation on the instructions through passive observation and active disturbance. The application effectively solves the problems of multipath interference and mutual coupling effect in a metal bookshelf environment, and improves the inventory accuracy and operation and maintenance deployment efficiency of high-density books.

Description

Technical Field

[0001] This invention relates to the field of radio frequency identification (RFID) application technology, specifically to an intelligent inventory and allocation management system for library collections. Background Technology

[0002] Ultra-high frequency (UHF) radio frequency identification (RFID) technology, due to its non-line-of-sight reading characteristics, has been widely used in library asset inventory and automated management. However, in actual deployment environments, especially in scenarios involving metal bookshelves, particularly in high-frequency, open-access environments like municipal public libraries (as opposed to the relatively controlled and user-single campus library environment), electromagnetic wave propagation is often affected by multipath effects. The strong reflective properties of metal shelves can easily create coherent destructive regions of signal superposition at specific spatial locations, making it difficult to effectively activate book tags located in these areas. Simultaneously, the high-density stacking of books causes strong mutual impedance and parasitic capacitance coupling between adjacent tag antennas, resulting in antenna center frequency drift and impedance mismatch, further weakening backscattered power.

[0003] Existing technologies largely rely on single received signal strength indicators or simple phase polling for presence detection. This approach struggles to distinguish between signal blind spots caused by environmental structures and signal interruptions caused by actual missing books at the physical level, easily leading to misjudgments of inventory status. Furthermore, conventional management methods lack proactive intervention mechanisms based on channel characteristics for optimizing the signal environment in densely populated storage areas, often failing to accurately perceive and dynamically adjust book spacing to mitigate mutual coupling effects. When executing allocation tasks, existing logistics logic typically requires operators to strictly follow pre-defined processes binding physical entities to system instructions. This serialized operation mode, when faced with the chaotic and unstructured allocation of massive amounts of books unique to public libraries, not only reduces operational efficiency but also increases the probability of errors from manual operation.

[0004] Therefore, this invention proposes an intelligent inventory and allocation management system for library collections to address the shortcomings of existing technologies. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides an intelligent inventory and allocation management system for library collections. It solves the problems of structural dead zones caused by multipath reflection and tag coupling effects in existing RFID systems in high-density stacked metal bookshelves, leading to book omissions, misjudgments, and low efficiency of manual allocation operations.

[0006] To achieve the above objectives, the present invention provides the following technical solution: an intelligent inventory and allocation management system for library collections, comprising: The radio frequency sensing module is configured to acquire the original radio frequency signal of the electronic tag through a multi-beam read / write unit, wherein the original radio frequency signal includes a received signal strength indication and a carrier phase; The topology inference module is configured to construct the logical topology of the book based on the phase frequency gradient and use a micro-translation perturbation strategy to identify structural dead zones in order to generate structural dead zone mask vectors. The feature analysis module is configured to use a neighborhood density-switching phase calibration mode and calculates the net radio frequency penetration rate in conjunction with the structural dead zone mask vector. The scheduling execution module is configured to generate electromagnetic breathing air gap adjustment commands or anonymous scheduling commands for the media isolation unit based on the net radio frequency penetration rate. The feedback verification module is configured to perform closed-loop confirmation of the electromagnetic breathing air gap adjustment command or the anonymous scheduling command by combining passive observation and active perturbation.

[0007] Preferably, the radio frequency sensing module further includes a reference unit and a medium isolation unit; The reference unit is an anti-metal printed circuit board electronic tag deployed at the physical geometric center of the bookshelf shelf, used to provide a physical reference system for absolute phase; The medium isolation unit consists of multiple medium isolation blocks, and an omnidirectional radio frequency identification (RFID) inlay layer is embedded inside the medium isolation block. The omnidirectional RFID inlay layer is configured such that the backscattering power is not lower than a preset radar cross section threshold under any physical placement posture.

[0008] Preferably, the specific method by which the topology inference module constructs the logical topology of the book is as follows: The multi-beam read / write unit is controlled to perform frequency switching within the ultra-high frequency operating band to obtain the phase response set of the same electronic tag under different carrier frequencies. The phase response set is unwound, and the slope of the phase frequency response curve is fitted using a linear fitting algorithm. The radial distance estimate of the electronic tag relative to the antenna phase center is calculated based on the slope, and the identified electronic tag set is sorted and discretized based on the radial distance estimate to generate a topological sequence vector representing the relative adjacency order of the books.

[0009] Preferably, the topology inference module identifies structural dead zones using a micro-translation perturbation strategy in the following specific way: Monitor the signal quality of logical locations in the logical topology of the book. When the received signal strength is detected to be lower than the received signal strength threshold or the phase variance exceeds the phase variance threshold, mark the logical location as a suspected structural dead zone. Generate a micro-translation excitation command to instruct the shelf books to be translated by a preset displacement in the horizontal direction; acquire the scan data after the translation operation is completed, and calculate the change in the received signal strength of the removed and inserted tags before and after the translation. If the received signal strength of the removed tag improves and the received signal strength of the inserted tag deteriorates, then the logical position is determined to be a structural dead zone, and the corresponding index in the structural dead zone mask vector is set to a valid state.

[0010] Preferably, the feature analysis module uses the neighborhood density switching phase calibration mode in the following specific manner: The neighborhood density is obtained by counting the number of adjacent tags within the preset signal strength difference range of the target electronic tag; When the neighborhood density is less than a preset neighborhood density threshold, it is determined to be a sparse island state, and the phase of the reference reference unit in the radio frequency sensing module is used as an absolute reference for calibration. When the neighborhood density is greater than or equal to the preset neighborhood density threshold, it is determined to be a high-density mutually coupled state, and the median of the phase statistical characteristics of all electronic tags in the neighborhood is calculated as a local floating reference for calibration.

[0011] Preferably, the feature analysis module is further configured to calculate a popularity index, specifically in the following manner: Obtain the differential phase sequence of the calibration phase within a preset time window; Construct the probability distribution of the differential phase sequence, and calculate the differential phase entropy based on the information entropy logic. Use the differential phase entropy as a popularity index to quantify the frequency of book touches.

[0012] Preferably, the feature analysis module calculates the net radio frequency penetration rate in the following specific way: Get the total number of valid book tags actually read in the area; calculate the theoretical maximum number of books that can be held based on the physical width of the bookshelf and the average thickness of a single book. The equivalent number of books occupying space that are identified as structural dead zones is counted using the structural dead zone mask vector. The net radio frequency penetration rate is obtained by calculating the ratio of the total number of valid book tags to the theoretical maximum book capacity after deducting the number of equivalent book occupants.

[0013] Preferably, the electromagnetic breathing air gap adjustment command generated by the allocation execution module is specifically used for: When the net radio frequency penetration rate is higher than the congestion warning threshold, the books with the lowest popularity index are selected as the removal targets. Calculate the average physical spacing required for the remaining books within the effective physical width of the shelf after the removal operation, to ensure that the average physical spacing can reduce parasitic capacitive coupling between adjacent books.

[0014] Preferably, the scheduling execution module generates anonymous scheduling instructions for the media isolation unit and executes the post-hoc binding logic: The anonymous scheduling instruction only includes physical segment information and media type requirements, and does not specify a unique identifier for the media isolation unit; The post-hoc binding logic is configured as follows: when a new media isolation unit tag is detected, it is determined whether the logical position inferred from the phase slope of the media isolation unit tag falls within the deviation tolerance of the target insertion center position specified by the anonymous scheduling instruction, and whether the media type matches; if they match, the media isolation unit tag is associated with the physical segment information.

[0015] Preferably, the feedback verification module, through a combination of passive observation and active perturbation, specifically includes: Passive observation is performed during the polling cycle after the electromagnetic breathing air gap adjustment command or the anonymous scheduling command is issued. If a new electronic tag that meets the position consistency constraint is detected, it is determined that the electromagnetic breathing air gap adjustment command or the anonymous scheduling command is completed. If the determination is not completed within the passive observation window, active interference is triggered in the preset idle window to increase the transmit power of the multi-beam read / write unit and extend the carrier dwell time, so as to increase the probability of capturing the channel transmission coefficient at the constructive interference peak. If no feedback signal is detected after active perturbation, a manual review work order is generated.

[0016] Compared with the prior art, the present invention has the following advantages: 1. This invention employs a topology inference based on phase-frequency gradients combined with a micro-translation perturbation strategy. By analyzing the signal strength and phase change characteristics of the tag before and after a small physical displacement, it can effectively distinguish between random occlusion in the environment and inherent dead zones caused by the metal bookshelf structure. Based on this, the system generates a structural dead zone mask vector, automatically eliminating the spatial weights of these invalid regions in subsequent inventory analysis. This solves the problem of missed reads or false empty space alarms caused by multipath effects and standing wave interference in traditional RFID systems operating in metal shelf environments, improving the accuracy of inventory status perception in complex electromagnetic environments.

[0017] 2. This invention adaptively switches the phase calibration mode by monitoring the neighborhood density of electronic tags. In a sparse state, it eliminates system drift using a fixed reference anchor point, and in a dense state, it suppresses nonlinear distortion caused by mutual coupling effects by using the median of the phase statistics of neighboring tags. Simultaneously, the system introduces net RF penetration calculation logic to deduct physical dead zones from the theoretical capacity, ensuring that congestion assessment is based on actually available physical space. This mechanism effectively avoids communication dead zones caused by antenna detuning due to the close fit of books, guaranteeing the signal readout rate of high-density storage areas.

[0018] 3. This invention establishes an electromagnetic breathing air gap adjustment mechanism based on thermal index and an anonymous scheduling strategy for media isolation units. Through physical-level spacing adjustment, the system actively reduces parasitic capacitive coupling between books that have been stationary for a long time, improving the radiation efficiency of the tags. At the same time, anonymous scheduling, combined with posterior binding logic, decouples the pre-forced binding between the physical medium and the allocation command, allowing managers to operate directly without scanning and pairing. The system then automatically verifies the location and completes registration via radio frequency signals, significantly reducing the complexity and time consumption of manual maintenance. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the system architecture of the present invention; Figure 2 This is a schematic diagram of the method flow of the present invention; Figure 3 This is a timing diagram of the RSSI signal response under the micro-translation perturbation strategy of the present invention; Figure 4 This is a schematic diagram showing the optimization of phase-frequency linearity of the electromagnetic breathing air gap according to the present invention.

[0020] Among them, 100 is the radio frequency sensing module; 200 is the topology inference module; 300 is the feature analysis module; 400 is the allocation and execution module; and 500 is the feedback verification module. Detailed Implementation

[0021] The specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings and examples.

[0022] See attached document Figure 1 This system, based on ultra-high frequency radio frequency identification (UHF) technology, integrates topology sequence analysis and a dual-mode phase calibration mechanism to achieve quantitative perception and dynamic closed-loop allocation of the collection's media status. The intelligent inventory and allocation management system includes: The RF sensing module 100 is configured as a physical layer data acquisition unit, including a multi-beam reader, a fixed reference anchor point, and a media isolation unit. The multi-beam reader acquires the received signal strength indication and carrier phase data of the tags within the acquisition area by switching antenna beams. The fixed reference anchor point is deployed at the physical center of the bookshelf shelf, providing an absolute phase reference. The media isolation unit embeds omnidirectional RF tags to change the mutual impedance coupling state between books.

[0023] The topology inference module 200 is connected to the radio frequency sensing module 100 and is configured to identify structural signal dead zones in the environment. The topology inference module 200 constructs the logical adjacency sequence of the current shelf books based on the phase frequency slope and performs micro-translation perturbation determination on low signal-to-noise ratio regions. By comparing the signal recovery characteristics and drop characteristics before and after the translation operation, a structural dead zone mask is generated to identify permanent dead zones caused by physical occlusion.

[0024] The feature analysis module 300 is connected to the topology inference module 200 and is configured to quantify the stacking density and activity of books. The feature analysis module 300 switches between constellation median mode and fixed anchor point mode based on the neighborhood label density, outputting the calibrated phase and differential phase entropy after environmental de-embedding. Simultaneously, the feature analysis module 300, combined with a structural dead zone mask, calculates the net radio frequency penetration rate after deducting the dead zone effect, characterizing the degree of media stacking congestion within the region.

[0025] The allocation execution module 400 is connected to the feature analysis module 300 and configured to generate physical allocation instructions. Based on the net radio frequency penetration rate determination result, the allocation execution module 400 generates book removal and spacing adjustment instructions for the core browsing area, and media isolation unit insertion instructions for the dynamic buffer. The insertion instructions do not specify a specific serial number for the media isolation unit, allowing the use of any idle unit.

[0026] The feedback verification module 500 is connected to the allocation execution module 400 and configured to confirm the validity of the allocation operation. The feedback verification module 500 performs status confirmation through a multi-level funnel logic: comparing newly added tags during the regular scan cycle; triggering a high-power excitation scan when no new tags are detected; and generating a manual review signal when there is no feedback from the excitation scan.

[0027] See attached document Figure 2 This invention provides an intelligent inventory and allocation management method for library collections, comprising the following steps: S100, the radio frequency sensing module 100 performs near real-time polling to collect the original received signal strength indication and carrier phase data of the tags in the bookshelf area; S200, the topology inference module 200 constructs a logical adjacency sequence based on phase and frequency characteristics, triggers micro-translation perturbation in low-signal regions, and updates the structural dead zone mask based on signal variation characteristics; S300, the feature analysis module 300 calls the structural dead zone mask, performs dual-mode phase calibration and background de-embedding, and calculates the net radio frequency penetration and differential phase entropy of each physical segment; S400, the allocation execution module 400 compares the net radio frequency penetration rate with a preset threshold. If it is lower than the threshold, it is determined to be a media congestion, and generates a corresponding media isolation unit insertion instruction or book relief instruction according to the area type. After the dispatch command is executed, the S500 feedback verification module 500 starts multi-level verification, sequentially performing new identifier retrieval, high-power disturbance scanning, and manual review prompts, until the work order is closed.

[0028] To further clarify the implementation of each technical aspect of the present invention, the following will provide a detailed description of the implementation of each functional module involved above and its internal processing flow.

[0029] See attached document Figure 1 The radio frequency sensing module 100, serving as the physical layer data entry point of the system, is primarily configured to construct a standardized electromagnetic sensing environment and acquire high-fidelity raw radio frequency signals. In this embodiment, the multi-beam read / write unit does not employ high-cost custom-designed underlying radio frequency circuits; instead, it utilizes commercially available UHF RFID discrete components conforming to the ISO-18000-6C (EPC-Gen2) standard. This read / write unit is coupled to a layered antenna array via a radio frequency multiplexer and configured to perform a quasi-real-time polling mode. This means it performs time-division multiplexing scanning of passive tags in space according to a preset time-slice strategy, thereby reducing hardware deployment costs while ensuring coverage.

[0030] Considering the strong reflection and detuning effects of metal shelves on radio frequency signals, an anti-metal printed circuit board (PCB) electronic tag is deployed at the physical geometric center of each bookshelf shelf in the reference unit. To maintain input impedance matching stability, the tag is electrically isolated from the metal base plate by a dielectric pad with a thickness of 2mm to 5mm. During system initialization and environmental calibration, this fixed reference anchor point is defined as the physical reference system for absolute phase. By reading the response signal of this anchor point, the system can not only calibrate the path loss constant of the antenna array, but also calculate the phase null offset caused by differences in feeder length and temperature drift, thus providing a unified calibration benchmark for subsequent inference of the relative positions of books.

[0031] To address signal congestion issues in high-density book stacking scenarios, this embodiment introduces a dielectric isolation unit composed of several distributed dielectric isolation blocks. To minimize the interference loss of the isolation blocks themselves on the RF field distribution, the main body of the dielectric isolation blocks is selected with a relative permittivity. Low-loss materials with a loss ratio between 1.03 and 1.10, such as expanded polypropylene (EPP) or high-density polystyrene (EPS), are used. Notably, considering the blind operation needs of frontline library staff in non-line-of-sight scenarios—that is, randomly inserting the isolation block into the book seams without precise visual alignment—an omnidirectional RFID inlay layer is embedded within the media isolation block. This inlay layer employs an orthogonal double dipole or three-dimensional antenna structure, configured to have low axial ratio radiation components in all three principal axes of the Cartesian coordinate system. This spatial diversity design eliminates the polarization blind spots of traditional single dipole antennas, ensuring that regardless of whether the media isolation block is placed horizontally, vertically, or at any tilt angle into the gaps between densely stacked books, its antenna polarization direction maintains an effective coupling coefficient with the reader antenna polarization direction. Accordingly, the system sets the radar cross section (RCS) threshold for the media isolation block. The value is -15dB, meaning that under any physical placement orientation, its backscattering power will not be lower than this threshold, thereby preventing missed readings due to angle mismatch.

[0032] Based on physical layer signal acquisition, the system establishes a mathematical model of the received signal that includes environmental noise and multipath effects. At time... The reader / writer communicates through a specific antenna port. Received the Complex baseband signals of an electronic tag The signal follows the following channel response equation: ; In the formula, Indicates from reader antenna To tag The round-trip channel impulse response, which includes path loss, multipath fading, and transmitter-receiver leakage; The modulation data symbol representing the backscattering of an electronic tag; This represents the thermal noise at the receiver front end and the ambient additive white Gaussian noise.

[0033] The reader receives complex baseband signals. By performing orthogonal demodulation and calculating the magnitude and argument of the complex vector, two key original feature vectors are extracted: the received signal strength indicator. phase with carrier The specific mapping relationship is as follows: ; ; In the formula, and These represent the real and imaginary parts of the complex signal, respectively. Due to the periodicity of the arctangent function, the extracted phase value... There exists an ambiguity of 2π, the value of which is restricted to the interval [0, 2π).

[0034] To ensure the time-invariant assumption of the aforementioned radio frequency propagation characteristics holds true, the system sets strict environmental control parameters: the ambient temperature in the bookshelf area must be maintained between -10 degrees Celsius and 45 degrees Celsius, and the relative humidity must be maintained between 10% and 90%. These environmental constraints aim to prevent drastic changes in temperature and humidity from causing drift in the dielectric constant of the dielectric material and dimensional deformation of the metal components, thereby affecting the channel response. Stability.

[0035] See attached document Figure 1 The topology inference module 200 establishes a communication connection with the radio frequency sensing module 100. Its core logic configuration is to process the raw radio frequency signal to construct the logical topology of the books and identify fixed interference sources in the bookshelf environment. In this embodiment, the system adopts a sequence construction method based on phase-frequency gradient, combined with an active micro-translation perturbation strategy, aiming to effectively distinguish between random occlusion and structural dead zones, thereby improving the spatial resolution of inventory counting.

[0036] The sequence construction unit executes ranging logic based on multi-frequency phase slope. Considering the inherent periodic ambiguity of single-frequency phase data, the reader is configured to operate in the UHF band. (For example, frequency hopping within 902MHz to 928MHz) to acquire the same electronic tag. exist Different discrete carrier frequencies The following phase response set To eliminate the 2π periodic jumps in phase measurements, the system first unwinds the original phase set to generate a continuous phase-frequency response curve. Then, utilizing the physical property that the phase of a radio frequency signal changes linearly with frequency, the system fits the slope of this curve using the least squares method and calculates the tag value according to the following formula. Radial distance estimate relative to the antenna phase center : ; In the formula, The speed at which electromagnetic waves propagate in free space. The slope of the fitted phase frequency. Despite the influence of multipath effects, this distance estimate... There may be absolute error, but it exhibits monotonicity in relative comparisons within the same layer. System based on... The size of the identified label set is used to sort the data, and the continuous distance intervals are discretized into several logical space indices. This allows us to construct a topological sequence vector representing the relative adjacency order of books. This step effectively maps discrete tag IDs to continuous logical location indices, providing a coordinate basis for subsequent spatial feature analysis.

[0037] The micro-perturbation determination unit monitors the signal quality at each logical location in the topology sequence. The system sets a signal strength threshold. (e.g., -75dBm) and phase variance threshold .in, The value range is set to 0.5 to 1.5 radians squared. This threshold is used to define whether the signal is in an unstable state with severe multipath jitter. At a specific logic location... The average received signal strength of the tag at that location over multiple consecutive polling cycles is lower than [a certain value]. Or the variance of its phase measurement exceeds When this occurs, the system determines that there is a signal anomaly at that location and marks it as a "suspected structural dead zone." Such anomalies are usually caused by the coherent cancellation of electromagnetic waves at the joints of the metal bookshelf's uprights, beams, or shelves.

[0038] To confirm whether the suspected area is an inherent structural dead zone in the environment, rather than a malfunction in the book labels or a temporary obstruction, the system generates a micro-translation disturbance command. This command instructs the actuator or operator to uniformly translate all books on the current shelf by a certain horizontal displacement. In this embodiment, the displacement amount The distance is strictly set between 3cm and 5cm. The physical basis for this value is the wavelength of the UHF RFID signal. Approximately 32cm, with a displacement of 3cm to 5cm corresponding to approximately to The phase change path is sufficient to trigger signal amplitude and phase jumps in multipath fading channels; at the same time, the distance is usually less than or equal to the thickness of two regular books, ensuring that the translation operation will not damage the overall physical layout of the bookshelf, making it feasible in engineering implementation.

[0039] The system acquires a new round of scan data after the translation operation is completed and executes dead zone feature matching logic. This logic generates a structural dead zone mask vector by tracking the signal change rate between the removed and inserted tags. The specific decision logic is as follows: Assume the logical position before the translation is... Books tagged as The book label that was moved to this position after translation is The system calculates the change in received signal strength between the two tags before and after the translation: ; ; In the formula, and These represent the timestamps before and after the translation operation, respectively. If... If the value is greater than a preset recovery threshold (e.g., 6 dB), it indicates that the tag has left its location. The signal quality improved afterward; and at the same time A drop of less than a preset drop threshold (e.g., -6dB) indicates a newly entered location. The tag signal quality deteriorates. At this point, the system determines the logical location. The signal attenuation at that location is location-dependent, not tag-dependent.

[0040] Based on the above dual verification judgment, the system will determine the logical location. It was identified as a structural dead zone, and the mask vector was adjusted. Corresponding index The elements of the mask vector are set to 1, while the rest of the normal regions are set to 0. The environmental characteristic parameters are stored and transmitted to the feature analysis module. These parameters are used to eliminate the spatial weight of invalid regions when calculating radio frequency penetration rates, preventing false inventory reports due to environmental blind spots. The signal strength thresholds involved in the above process... Its value is set according to the noise floor level of the on-site environment. It is usually the noise floor value plus a safety margin of 6dB to 10dB to ensure the robustness of the judgment.

[0041] See attached document Figure 1 The feature analysis module 300 establishes data interaction with the topology inference module 200 and the radio frequency sensing module 100, and is mainly configured to perform deep feature extraction based on environment perception. In order to solve the problem of nonlinear distortion of radio frequency signals caused by changes in the stacking density of books in a metal bookshelf environment, this embodiment constructs a dual-mode reference adaptive switching logic based on neighborhood density and proposes a method for calculating net radio frequency penetration, aiming to eliminate the negative impact of physical blind spots on the accuracy of inventory counting.

[0042] The feature analysis module 300 is internally equipped with a reference adaptive unit, which monitors changes in the electromagnetic environment complexity surrounding the target electronic tag in real time. Considering the mutual impedance characteristics of UHF RFID tags under near-field coupling effects, the system defines a physical influence radius. (For example, 15cm to 20cm corresponds to the thickness of approximately 5 to 10 books). To quantify this radius at the logical level, the system uses a spatial attenuation model based on the received signal strength indication to statistically analyze all data related to the target label. signal strength difference The number of neighboring labels less than a preset neighborhood threshold (e.g., 3dB) is denoted as the neighborhood density. This indicator directly reflects the density of books in the current area and the potential electromagnetic coupling strength.

[0043] Based on the calculated neighborhood density, the system dynamically switches between two phase calibration modes. A neighborhood density threshold is preset in the system. In this embodiment, The threshold is preferably set to 5. This threshold selection is based on statistical principles, namely, at least 5 sample points are needed to construct a statistically significant local constellation diagram for effective median filtering. At this point, the system determines that it is currently in a "sparse island state." In this state, due to the lack of sufficient neighboring tag references and relatively weak multipath interference in the environment, the system forcibly reverts to the fixed anchor point mode. This mode directly uses the phase of the reference reference unit (PCB tag) in the RF sensing module as the absolute reference. Through calculation To eliminate systematic phase drift caused by the reader itself and the feeder.

[0044] Conversely, when At this point, the system determines that it is currently in a "high-density mutual coupling state." In this state, due to the strong mutual coupling effect between the densely stacked book tags, and the potential failure of a single fixed anchor point due to distance or viewpoint obstruction, the system activates the constellation median mode. This mode no longer relies on a single physical anchor point; instead, it first maps the phase values ​​of all tags in the neighborhood to the same period or performs unwinding processing, and then calculates their statistical median as a local floating reference. This processing method eliminates the periodic discontinuity of phase data at the boundary between 0 radians and 2π radians. Utilizing the robustness of the median to outliers, this method can effectively offset phase abrupt changes caused by uneven adhesion media of individual tags or local multipath reflections, thereby obtaining a calibrated phase that better reflects the overall trend of the area. .

[0045] After completing the phase calibration, the thermal extraction unit further analyzes the temporal characteristics of the calibrated phase. The system calculates the calibrated phase. Within the preset time window The differential phase entropy (e.g., over the past 24 hours) is calculated. To quantify this metric, the system first calculates the phase difference sequence between adjacent time steps. Construct the phase change probability distribution And calculate the heat index based on the Shannon entropy formula. : ; In the formula, This is the discretized phase difference value. This entropy value serves as a behavioral heat index that quantifies the frequency of book touching. Its physical meaning is that when a book is taken down, flipped through, or returned by a reader, the slight change in its position causes disordered phase jitter, thereby increasing the entropy value of the phase distribution; conversely, the phase difference distribution of a book that has been stationary for a long time tends to be a narrow pulse near zero, with a lower entropy value.

[0046] To accurately assess the remaining load-bearing capacity of the bookshelf and avoid false alarms, the penetration rate calculation unit performs a net radio frequency penetration rate calculation. Traditional penetration rate calculations only consider the ratio of read count to total capacity, which can easily misclassify missed reads caused by structural dead zones as "empty slots." This embodiment introduces a dead zone mask correction mechanism, calculating the area based on the following formula. Net radio frequency penetration : ; In the formula, Indicates in the region The total number of valid book tags actually read; Indicates based on the physical width of the bookshelf Divide by the preset average thickness of a single book The theoretical maximum number of books that can be accommodated is calculated using a method that converts a measurement of 2.5cm (e.g., 2.5cm). It is a structural dead zone mask vector generated by the topology inference module, where each logical position index In physical space, this is mapped to a width equal to the average thickness of a single book. Discretized slots. When the logic position Its value is 1 when it is determined to be a dead zone, and 0 otherwise; at this time, the summation term Item represents a region The equivalent number of book slots occupied by structural dead zones that are identified as unusable.

[0047] The physical meaning of this formula lies in calculating the "net" congestion after deducting environmental disturbances by removing known physical dead zones from the theoretical total expected inventory. This calculation method ensures that the system's congestion alarms are based on actually available physical space, rather than spurious empty spaces blocked by metal. Furthermore, to guarantee the algorithm's numerical stability under extreme conditions, the system is configured with denominator overflow prevention logic: when the denominator term... When the calculated result is less than the minimum effective capacity threshold (e.g., 1), the system determines that there is no effective physical storage space in that area and directly... Set the saturation value to 1.0 and trigger a maintenance alarm to prompt administrators to check for serious hardware obstruction or configuration errors.

[0048] See attached document Figure 1The allocation execution module 400 establishes instruction interaction with the feature analysis module 300 and the physical layer execution mechanism. The allocation execution module 400 is configured to generate targeted physical intervention strategies based on quantified congestion and behavioral heat indicators. To address the inefficiency of traditional warehouse management where instructions and physical goods must be strictly pre-bound, and to improve the electromagnetic propagation environment of high-density storage areas, this embodiment proposes a core area dynamic optimization strategy based on electromagnetic breathing gaps, as well as a buffer anonymous scheduling mechanism that supports on-demand use.

[0049] The allocation execution module 400 adjusts the net radio frequency penetration rate output by the feature analysis module 300. Execute real-time monitoring logic. The system has a congestion warning threshold set. In this embodiment, the threshold is set to 0.85 to 0.90. When detected... When the value exceeds this threshold, it indicates that the effective physical space occupancy rate in the area is close to saturation. At this time, the close fit between books is very likely to cause antenna detuning and frequency offset. The system then triggers the allocation logic and executes different physical intervention strategies according to the functional attributes of the area.

[0050] For the core browsing area, considering that this area requires not only high inventory accuracy but also convenient access for readers, the core area scheduling unit implements a heat-based distribution strategy. The system uses differential phase entropy... The books within the area are sorted, and a few "unpopular books" with the lowest entropy values ​​are selected for removal. Simultaneously, the system calculates the optimal physical spacing required for the remaining books, known as the "electromagnetic breathing gap." To ensure this gap is sufficient to disrupt the parasitic capacitive coupling formed by tightly stacked books, a target average spacing is determined. Determined according to the following formula: ; In the formula, This represents the physical effective width of the shelf. The number of books retained after the removal operation. For the first This retains the measured or standard thickness of the book. To prevent calculation errors due to zero or negative denominators, a formula is introduced... The protection logic; when At this time, the system defaults to not requiring air gap setting. If the calculated... If the distance is less than the minimum decoupling threshold (e.g., 2mm), the system will automatically increase the number of less popular books to be removed until the spacing requirement is met. The physical meaning of this strategy is that by forcibly creating a millimeter-level air gap between the parallel media plates of adjacent books, according to the parallel plate capacitance formula... This reduces the real part of the mutual impedance caused by near-field coupling, thereby preventing antenna detuning and ensuring that the labels of each book are in a better radiation state.

[0051] For the dynamic buffer zone, which primarily faces high-frequency logistics throughput and demands extremely high operational efficiency, the buffer scheduling unit employs a media isolation strategy to generate instructions for inserting media isolation blocks. Unlike the strongly bound mode in traditional logistics systems, which requires specifying "place the isolation block with ID X at position Y," this embodiment innovatively adopts an anonymous scheduling mode. The system-generated instructions only contain physical segment information (e.g., "insert any Type-A isolation block between the 5th and 6th books") and media type requirements, completely decoupling the pre-bound relationship between physical entities and digital identities.

[0052] This anonymous scheduling relies on the system's post-hoc binding logic. When an operator responds to a command, randomly grabs a media isolation block from the spare parts warehouse that is not registered and inserts it into the designated slot, the reader will detect a newly added media isolation block located at the logical position in the next scan cycle. (i.e., the separator tag between the original 5th and 6th books) The system then automatically triggers an identity registration event, which will... A temporary spatiotemporal mapping relationship is established with this logical location. To ensure system stability after anonymous insertion, the system executes the following posterior verification logic: ; In the formula, This is the estimated logical position of the new label inferred based on the phase slope. Insert the center position for the target specified by the instruction. This parameter, which sets the allowable logical insertion deviation tolerance (e.g., ±0.5 logical index units), is used to verify at a fine-grained level whether the media isolation unit is accurately inserted into the specified book adjacency gap. It is a media type identifier code read from a specific address range in the tag's user storage area. The media type required by the instruction. Only when When the task is completed, the system confirms its completion and closes the command; otherwise, if a positional deviation or type mismatch occurs, the system will generate a correction prompt. This mechanism supports a "ready-to-use" operation mode, reducing redundant steps for operators to scan and match codes on-site and improving overall scheduling efficiency.

[0053] See attached document Figure 1The feedback verification module 500 establishes a communication connection with the allocation execution module 400 and the radio frequency sensing module 100. The feedback verification module 500 is mainly configured to execute a multi-level funnel-shaped closed-loop confirmation mechanism. In order to solve the problem of "instruction execution uncertainty" caused by the random fading characteristics of signals in traditional passive RFID systems, especially for the posterior correlation between physical objects and instructions in anonymous scheduling scenarios, this embodiment constructs a consistency verification logic between the physical state of inventory and the digital twin model by hierarchically deploying passive observation, active perturbation and manual review strategies.

[0054] The hierarchical review unit of the feedback verification module 500 is configured to perform first-level verification, i.e., passive observation and reverse binding logic, using the next day's quasi-real-time polling cycle after the allocation command is issued. During this stage, the system maintains monitoring of the target area. During routine monitoring, the reader maintains standard transmission power. (e.g., 27dBm to 30dBm) and standard stay To achieve automatic archiving under anonymous scheduling, the system monitors the field of view for any newly added, unregistered electronic tags. And its three-dimensional physical position is calculated based on the phase array. .

[0055] Based on the principle of location consistency, this embodiment decouples the serial dependency of "scanning and recording before shelving" in traditional logistics, and adopts a parallel operation mode of "physical shelving before system registration". Considering that multiple tags may be entered into the warehouse at the same time in actual operation, if multiple new tags are detected in the target area, the system prioritizes the tag with the closest Euclidean distance to the work order center coordinates as the candidate. The system determines the instruction according to the following state machine logic. Execution status: ; In the formula, This is the collection of currently registered inventory databases; To allocate work orders The specified expected physical coordinate center; A physical area matching tolerance (e.g., ±10cm) is provided, which is greater than the logical deviation tolerance in the allocation execution module 400. The design aims to comprehensively consider the Cramer-Rhodes boundary of RFID phase positioning and the physical dimensions of the shelf unit in order to adapt to coarse-grained area attribution determination.

[0056] In particular, for multi-target concurrent scenarios, if there are multiple candidate labels All satisfy the above distance constraints (i.e.) The system executes the nearest neighbor arbitration logic: selecting the nearest neighbor that results in a Euclidean distance of 1 / 2. The smallest tag is used as the unique match. The system automatically extracts the match only if the result is "Completed" and arbitration is successful. The user area metadata is written into the database and permanently associated with the current work order, thereby closing the mapping chain between physical entities and digital instructions.

[0057] If the state function returns "Pending" within the preset passive observation window (e.g., 2 hours after the command is issued or at the end of the first polling cycle), the system determines that it is currently in a "verification pending state" and automatically activates the secondary verification process, i.e., the active perturbation scanning logic. Considering that high-power electromagnetic radiation may cause electromagnetic interference to the human body or the regular borrowing process, this mode is strictly limited to non-business hours (e.g., from 23:00 to 06:00 the next day) or long off-peak periods determined by the system through infrared sensors to be unattended.

[0058] In this mode, the scrambling scanning unit takes over the control of the RF front-end and performs scrambling parameter reconstruction. The system will adjust the reader's transmit power. Increase to the maximum saturation power permitted by the area's radio regulations. (e.g., 33 dBmE.IRP), while also reducing the carrier dwell time of a single frequency point. Extended to a multiple of the standard value (e.g.) times, (Values ​​range from 2 to 4). The physical purpose of this strategy is to improve the link budget by maximizing transmit power to overcome dielectric losses and by utilizing long-term integral gain to improve the signal-to-noise ratio at the receiver. Cumulative energy injection efficiency in active excitation mode. Defined by the following formula: ; In the formula, This refers to the gain of the transmitting antenna; The multipath channel transmission coefficient, which varies with time, characterizes the fading properties in the environment. The physical meaning of this formula indicates that in densely metal environments with multipath effects, extending the upper limit of the integration time can mitigate the fading. The system can increase the capture of channel transmission coefficients. The probability of being at the peak of "constructive interference" is used to forcibly activate tags in a critical edge state, causing them to transition from a "silent state" to a "responsive state." If a target tag that meets the position constraints is successfully read under this high-energy disturbance, the system will retroactively execute the above reverse binding logic and record the location as a "weak signal area" for subsequent feature analysis modules to optimize antenna beam pointing.

[0059] As the final line of defense in closed-loop verification, if the system still fails to detect the expected feedback signal in the target area after multiple rounds (e.g., 3) of active perturbation scanning, it is determined that the allocation task has encountered a physical anomaly (such as the isolation block not being placed, the label being physically damaged, or the presence of impenetrable metal obstruction). At this point, the system generates a three-level manual review work order, pushing the specific shelf code, shelf location, and expected operation content to the manager's handheld terminal, prompting on-site physical verification and manual intervention to ensure the absolute accuracy of the system data.

[0060] To more intuitively illustrate this embodiment, a high-density circulation stack environment of a municipal public library was selected as a typical application scenario. This scenario was intentionally chosen to avoid the relatively enclosed environment and fixed borrowing patterns of campus libraries, aiming to verify the system's robustness in a complex electromagnetic interference environment open to the public with high personnel mobility. It should be noted that although this embodiment uses a high-density circulation stack environment of a municipal public library as an example, the scope of application of this invention is not limited to this. The technical solution provided by this invention is also applicable to complex sensing scenarios involving high-density stacking of items, metal shelf reflections, and radio frequency identification interference, such as archives, warehousing and logistics centers, and retail stores.

[0061] This specific embodiment was constructed in the circulation stacks environment of a municipal public library, and a double-sided metal compact bookshelf numbered A-103 was selected as the experimental object. The effective width of a single layer of this bookshelf... The shelf is 90cm long and is primarily used to store bound volumes of back issues with high paper density that are highly susceptible to radio frequency (RF) signal absorption. In terms of hardware configuration, to achieve physical layer sensing without altering the main structure of the bookshelf, the RF sensing module 100 uses a commercially available four-channel reader compliant with the EPC-C1G2 standard, deployed along the side rails of the bookshelf with a circularly polarized flat panel antenna, and a transmission power of 30dBm.

[0062] It is worth noting that, considering the multipath reflection effect of the metal layers on electromagnetic waves, this embodiment pre-places an anti-metal PCB label at the geometric center of each layer as a physical reference system for the absolute phase (i.e., an anchor label). This anchor point is isolated from the metal layers by a 3mm thick EVA dielectric pad, and its position coordinates... It is precisely calibrated during system initialization. For the dielectric isolation unit, this embodiment selects a relative permittivity. The L-shaped bookend is made of EPP foamed polypropylene material of approximately 1.05, and encapsulates an electronic tag with three-dimensional omnidirectional radiation characteristics inside to ensure reading sensitivity under non-line-of-sight blind operation.

[0063] During the initial sensing phase of system operation, the reader performed a full scan of the third layer board. At this time, the system detected the logical location. A signal discontinuity is observed (approximately 55cm from the left). Although the phase continuity of adjacent tags at this location is acceptable, the received signal strength of the echo signal at this point is significantly reduced. The mean has been hovering around -78dBm for a long time, and the phase variance... Up to 1.4 rad 2 It exhibits highly unstable multipath jitter characteristics.

[0064] Faced with this "suspected structural dead zone," the system did not directly determine it as a device malfunction, but instead triggered a micro-translation perturbation strategy. Upon receiving the instruction, the actuator or tester shifted the entire layer of books to the right by a specified amount of displacement. cm. The physical significance of this operation lies in changing the length of the propagation path of electromagnetic waves between the pages of a book. For example... Figure 3 As shown in the figure, this graph displays the RSSI time-domain response curves of the label at different positions before and after translation. It can be observed that the label originally located at... After the tag at the location was moved out of that position (dashed line), its RSSI value quickly returned to the normal level of -60dBm; while the signal strength of the new tag that was moved into the physical location (solid line) dropped sharply the moment it entered the area, with a drop of more than 7dB.

[0065] Based on equations Calculations showed that the drop was below a preset threshold. This phenomenon, where "position determines signal quality," confirmed the existence of a coherent destructive standing wave point at physical coordinates 55cm, caused by the metal beam. Based on this, the system generated a mask vector. The coordinates are marked as unusable invalid space, thus avoiding false empty space reports in subsequent calculations.

[0066] After establishing the validity of the physical topology, the feature analysis module 300 further quantifies the congestion of the bookshelf. In this embodiment, by calculating the neighborhood density, it was found that on average, there are 7 neighboring labels within a 3dB range around each label in the target area, i.e. Far exceeding the threshold This indicates that the current state is one of "high-density mutual coupling," where the tight stacking of the books leads to parasitic capacitance, causing severe antenna detuning.

[0067] To visually demonstrate the impact of this mutual coupling effect on phase ranging, see [link to relevant documentation]. Figure 4 The circular data points and their corresponding dashed fitted lines in the figure show the phase-frequency response in the traditional close-stacked mode. It exhibits obvious nonlinear fluctuations, and the goodness of fit is... Only 0.72, which leads to a low phase slope Calculated distance estimate There is an average error of 18.2cm, which cannot meet the needs of refined management.

[0068] To address this issue, the 400 allocation and execution module is based on the popularity index. Unused books that had not been read for a long time were removed from the core area. Then, an "electromagnetic breathing gap" strategy was calculated and implemented to force a physical gap of approximately 3mm to 5mm between the remaining books. This operation effectively reduced the capacitance of the parallel plates. The capacitance value in the image. For example... Figure 4 As shown by the square data points and their corresponding solid line fitting lines, the phase-frequency response recovers good linearity after the air gap is introduced. (Increased to 0.98), the phase slope became smooth and monotonic, verifying the decisive role of the air gap in improving the radio frequency propagation environment.

[0069] In the scheduling phase of the dynamic buffer, this invention demonstrates its unique "ready-to-use" characteristic. The system generates an instruction to insert an isolation block between the 5th and 6th books, but does not specify a specific isolation block ID. The operator randomly selects a Type-A isolation block and inserts it into the designated gap. In a subsequent polling cycle, the reader captures a new tag signal. .

[0070] The system uses posterior verification logic Verification: The logical position derived from the phase slope of the new tag was detected. Deviation tolerance for accurately landing in the target gap Inside, and type code Matching. At this point, the feedback verification module 500 automatically binds and registers the physical entity with the digital instruction, completing the task loop. Actual testing shows that this parallel operation mode reduces the response time for a single task from 2 minutes using traditional barcode scanning to less than 30 seconds.

[0071] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. An intelligent inventory and allocation management system for library collections, characterized in that, include: The radio frequency sensing module is configured to acquire the original radio frequency signal of the electronic tag through a multi-beam read / write unit, wherein the original radio frequency signal includes a received signal strength indication and a carrier phase; The topology inference module is configured to construct the logical topology of the book based on the phase frequency gradient and use a micro-translation perturbation strategy to identify structural dead zones in order to generate structural dead zone mask vectors. The feature analysis module is configured to use a neighborhood density-switching phase calibration mode and calculates the net radio frequency penetration rate in conjunction with the structural dead zone mask vector. The scheduling execution module is configured to generate electromagnetic breathing air gap adjustment commands or anonymous scheduling commands for the media isolation unit based on the net radio frequency penetration rate. The feedback verification module is configured to perform closed-loop confirmation of the electromagnetic breathing air gap adjustment command or anonymous scheduling command by combining passive observation and active perturbation.

2. The intelligent inventory and allocation management system for library collections according to claim 1, characterized in that, The radio frequency sensing module also includes a reference unit and a medium isolation unit; The reference unit is an anti-metal printed circuit board electronic tag deployed at the physical geometric center of the bookshelf shelf, used to provide a physical reference system for absolute phase; The medium isolation unit consists of multiple medium isolation blocks, and an omnidirectional radio frequency identification (RFID) inlay layer is embedded inside the medium isolation block. The omnidirectional RFID inlay layer is configured such that the backscattering power is not lower than a preset radar cross section threshold under any physical placement posture.

3. The intelligent inventory and allocation management system for library collections according to claim 1, characterized in that, The specific method by which the topology inference module constructs the logical topology of the book is as follows: The multi-beam read / write unit is controlled to perform frequency switching within the ultra-high frequency operating band to obtain the phase response set of the same electronic tag under different carrier frequencies. The phase response set is unwound, and the slope of the phase frequency response curve is fitted using a linear fitting algorithm. The radial distance estimate of the electronic tag relative to the antenna phase center is calculated based on the slope, and the identified electronic tag set is sorted and discretized based on the radial distance estimate to generate a topological sequence vector representing the relative adjacency order of the books.

4. The intelligent inventory and allocation management system for library collections according to claim 1, characterized in that, The specific method by which the topology inference module identifies structural dead zones using the micro-translation perturbation strategy is as follows: Monitor the signal quality of logical locations in the logical topology of the book. When the received signal strength is detected to be lower than the received signal strength threshold or the phase variance exceeds the phase variance threshold, mark the logical location as a suspected structural dead zone. Generate a micro-translation excitation command to instruct the shelf books to be translated by a preset displacement in the horizontal direction; acquire the scan data after the translation operation is completed, and calculate the change in the received signal strength of the removed and inserted tags before and after the translation. If the received signal strength of the removed tag improves while the received signal strength of the inserted tag deteriorates, then the logical location is determined to be a structural dead zone, and the corresponding index in the structural dead zone mask vector is set to a valid state.

5. The intelligent inventory and allocation management system for library collections according to claim 1, characterized in that, The specific method by which the feature analysis module is based on the neighborhood density switching phase calibration mode is as follows: The neighborhood density is obtained by counting the number of adjacent tags within the preset signal strength difference range of the target electronic tag; When the neighborhood density is less than the preset neighborhood density threshold, it is determined to be a sparse island state, and the phase of the reference reference unit in the radio frequency sensing module is used as the absolute reference for calibration. When the neighborhood density is greater than or equal to the preset neighborhood density threshold, it is determined to be a high-density mutually coupled state, and the median of the phase statistical characteristics of all electronic tags in the neighborhood is calculated as a local floating reference for calibration.

6. The intelligent inventory and allocation management system for library collections according to claim 1, characterized in that, The feature analysis module is also configured to calculate a popularity index, specifically as follows: Obtain the differential phase sequence of the calibration phase within a preset time window; Construct the probability distribution of the differential phase sequence, and calculate the differential phase entropy based on the information entropy logic. Use the differential phase entropy as a popularity index to quantify the frequency of book touches.

7. The intelligent inventory and allocation management system for library collections according to claim 1, characterized in that, The specific method by which the feature analysis module calculates the net radio frequency penetration rate is as follows: Get the total number of valid book tags actually read in the area; calculate the theoretical maximum number of books that can be held based on the physical width of the bookshelf and the average thickness of a single book. The equivalent number of books occupying space that are identified as structural dead zones is counted using the structural dead zone mask vector. The net radio frequency penetration rate is obtained by calculating the ratio of the total number of valid book tags to the theoretical maximum book capacity after deducting the number of equivalent book occupants.

8. The intelligent inventory and allocation management system for library collections according to claim 1, characterized in that, The electromagnetic breathing air gap adjustment command generated by the allocation execution module is specifically used for: When the net radio frequency penetration rate is higher than the congestion warning threshold, the books with the lowest popularity index are selected as the removal targets. Calculate the average physical spacing required for the remaining books within the effective physical width of the shelf after the removal operation, to ensure that the average physical spacing can reduce parasitic capacitive coupling between adjacent books.

9. The intelligent inventory and allocation management system for library collections according to claim 1, characterized in that, The scheduling execution module generates anonymous scheduling instructions for the media isolation unit and executes the post-hoc binding logic: The anonymous scheduling instruction only includes physical segment information and media type requirements, and does not specify a unique identifier for the media isolation unit; The post-hoc binding logic is configured as follows: when a new media isolation unit tag is detected, it is determined whether the logical position inferred from the phase slope of the media isolation unit tag falls within the deviation tolerance of the target insertion center position specified by the anonymous scheduling instruction, and whether the media type matches; if they match, the media isolation unit tag is associated with the physical segment information.

10. The intelligent inventory and allocation management system for library collections according to claim 1, characterized in that, The feedback verification module, which combines passive observation with active perturbation, specifically includes: Passive observation is performed during the polling cycle after the electromagnetic breathing air gap adjustment command or anonymous scheduling command is issued. If a new electronic tag that meets the position consistency constraint is detected, it is determined that the electromagnetic breathing air gap adjustment command or anonymous scheduling command is completed. If the determination is not completed within the passive observation window, active interference is triggered in the preset idle window to increase the transmit power of the multi-beam read / write unit and extend the carrier dwell time, so as to increase the probability of capturing the channel transmission coefficient at the constructive interference peak. If no feedback signal is detected after active perturbation, a manual review work order is generated.

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