Intelligent file cabinet remote monitoring management system and method
Patent Information
- Application Number
- CN202512050692.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-31
- Publication Date
- 2026-02-27
Smart Images
Figure CN121581079A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of intelligent sensing technology, specifically to an intelligent filing cabinet remote monitoring and management system and method. Background Technology
[0002] Intelligent record management is crucial for improving storage efficiency and security. Current intelligent record cabinet systems typically use radio frequency identification (RFID), barcode scanning, or machine vision technology to identify and manage the entry and exit of records.
[0003] In practical applications, while RFID technology enables contactless batch inventory checks, its reliance on electromagnetic waves for communication makes it difficult to impose precise physical constraints on signal propagation range. This can easily lead to signal crosstalk between adjacent levels or adjacent mobile shelving units, making it difficult to obtain the precise physical coordinates of the files on the shelf. More importantly, RFID technology can only verify the existence of the electronic tag itself and cannot sense the physical state of the physical objects inside the file box. If paper documents are removed from the file box, leaving only the tagged outer shell, or if the thickness of the file changes significantly, RFID-based systems cannot detect such missing or abnormal conditions. Although the status of the files can be inferred using a gravity sensor array, this requires placing high-precision pressure sensors in each storage unit, resulting in complex cabinet structures and difficult wiring maintenance. Optical image recognition technology, on the other hand, is limited by lighting conditions and field-of-view obstruction, making it difficult to obtain complete visual information in densely packed file storage scenarios.
[0004] Capacitive sensing technology utilizes edge electric fields to sense changes in the medium, possessing the potential to detect the presence and quantity of media such as paper. However, the electric field generated by traditional planar capacitive sensors typically radiates to the top and bottom of the sensor. Since filing cabinet shelves are generally made of metal, when such sensors are directly deployed on metal shelves, the metal shelves act as strong grounding terminals, absorbing a large amount of electric field energy and generating a severe parasitic capacitance effect. This significantly reduces the sensor's sensitivity to the files above, or even renders it inoperable. Furthermore, capacitive measurements are extremely sensitive to environmental changes. Fluctuations in ambient temperature and humidity cause background drift in the dielectric constant of the air and circuit board substrate, leading to instability in the measurement reference. Without an effective compensation mechanism, this environmental drift can drown out weak signals caused by changes in the paper inside the files, preventing the system from stably monitoring the integrity of the files over a long period. Summary of the Invention
[0005] To address the shortcomings of existing technologies, this invention provides an intelligent remote monitoring and management system and method for filing cabinets. It solves the problems that existing filing management technologies cannot simultaneously achieve high-precision positioning of files and monitoring of internal material integrity under a single detection mode, and that the low sensitivity of capacitive sensing in metal cabinet environments and the poor measurement stability caused by the susceptibility to environmental temperature and humidity drift.
[0006] To achieve the above objectives, the first aspect of this invention provides a remote monitoring and management system for an intelligent filing cabinet. This system includes an intelligent filing cabinet body, an edge electric field sensing layer, an anisotropic dielectric coded tag, a multiplexed data acquisition unit, a tomographic imaging and state inversion processing terminal, and an environmental differential reference module. The intelligent filing cabinet body provides the physical support environment for the various components of the system and internally defines several layers of storage space.
[0007] The edge electric field sensing layer, serving as the system's sensing front end, is located at the bottom of the storage space. This layer is manufactured using a multilayer printed circuit board process, and its physical structure includes a signal transmission layer and an active shielding layer beneath it. The signal transmission layer is equipped with a planar electrode array for emitting a quasi-static edge electric field. The active shielding layer is a complete copper foil plane configured to receive a voltage follower signal with the same frequency, phase, and amplitude as the excitation electrodes. By maintaining the active shielding layer and the excitation electrodes at the same potential, a zero-field region is formed between the active shielding layer and the excitation electrodes. This forces the edge electric field vector to bend unidirectionally towards the file storage area above the dielectric substrate, preventing it from diverging downwards and thus improving the system's sensing sensitivity to targets above and isolating interference from the metal cabinet.
[0008] Anisotropic dielectric coded tags are used to achieve physical layer decoupling of signals. The tag comprises alternating conductive stripe units and dielectric window units arranged in a plane. The conductive stripe units act as floating potential bodies, forcing electric field lines to terminate perpendicularly at the conductor surface, introducing an increment in coupling capacitance between the electrode pairs, forming a positional characteristic signal. The dielectric window units allow deep penetrating electric fields to freely pass through and enter the document's interior, making the measurement results dependent on the equivalent bulk dielectric constant of the paper inside the document, forming a material characteristic signal.
[0009] The multiplexed data acquisition unit is responsible for performing time-division multiplexing excitation and measurement operations. This unit includes a capacitance-to-digital converter and a multi-stage analog switch matrix, with a single-pole four-throw analog switch unit configured for each basic electrode finger unit. During acquisition, this unit executes a dynamic focusing scanning strategy: when the excitation electrode and sensing electrode are selected, it simultaneously controls the basic electrode finger units adjacent to the excitation electrode and adjacent to the sensing electrode to switch to a shielded state. The shielded electrodes physically limit the horizontal diffusion of the edge electric field, ensuring that the mutual capacitance data primarily reflects the dielectric distribution of the area directly above.
[0010] The environmental differential reference module is used to acquire the background drift of the dielectric constant caused by environmental factors. This module includes a reference electrode pair consistent with the geometry of the measurement channel, a standard dielectric reference block, and an electromagnetic shield. The system uses the data output from this module to build an environmental drift compensation model, correcting the original mutual capacitance data of the measurement channel and eliminating common-mode interference introduced by temperature and humidity changes.
[0011] The tomographic imaging and state inversion processing terminal is used to perform inverse problem solving and state analysis. This terminal calls a pre-built spatial sensitivity field model and uses a linear back-projection algorithm with regularization constraints to process the normalized mutual capacitance data, reconstructing a two-dimensional grayscale image reflecting the dielectric constant distribution above the sensing layer. In the feature decoupling stage, the terminal extracts positional feature signals by identifying high-amplitude local maxima in the image to determine the physical location of the archive; it then removes the positional feature signal response region using a mask matrix, performs weighted integration on the remaining region to extract material feature signals, calculates the total medium index, and subsequently determines the integrity status of the archive based on this index.
[0012] A second aspect of this invention provides a remote monitoring and management method for an intelligent filing cabinet. This method, based on the aforementioned system, includes the following steps: Initialization modeling is performed, and a spatial sensitivity field model is constructed based on the electrode geometric parameters and boundary conditions of the edge electric field sensing layer to define the mapping relationship between the dielectric constant perturbation and the mutual capacitance change of the electrode pair within the sensing region.
[0013] Data acquisition and modulation are performed to drive the edge electric field sensing layer to generate a quasi-static edge electric field, which is then co-modulated using anisotropic dielectric coded tags. The multiplexed data acquisition unit constructs a virtual protection ring by controlling the electrode states, and acquires mutual capacitance data containing position feature signals and material feature signals.
[0014] The image reconstruction, tomography and state inversion processing terminal receives mutual capacitance data, uses the data from the environmental differential reference module to remove environmental background noise, and uses a regularization algorithm to solve the inverse electric field problem to reconstruct a two-dimensional grayscale image reflecting the distribution of dielectric constant.
[0015] Feature decoupling and state analysis are implemented to segment the two-dimensional grayscale image into regions, separate the centroid coordinates of the high conductivity response region to determine the physical location of the archive, and separate the dielectric response intensity of the high transmittance medium region to calculate the total medium index of the archive.
[0016] The system performs monitoring, judgment, and output, comparing the parsed physical location and total media quantity indicators with a preset database. When a physical location mismatch is detected, a misalignment alarm is output. When the total media quantity indicator decreases beyond a threshold, a content missing alarm is output.
[0017] This invention provides an intelligent filing cabinet remote monitoring and management system and method. It has the following beneficial effects: 1. This invention achieves synchronous, non-contact detection of the location and internal material state of archives by combining anisotropic dielectric coded tags with multi-scale electrode driving logic. The high conductivity region on the tag, combined with a shallow electric field, generates a high signal-to-noise ratio location feature signal, while the high-transmittance dielectric region allows a deep penetrating electric field to enter the archive, generating a material feature signal reflecting the number of sheets. Parallel measurement of archive location and internal material state is achieved in a single sensing mode, solving the problems of traditional RFID technology, which can only identify IDs and cannot perceive content integrity, and the difficulty in integrating and deploying traditional weighing or optical methods.
[0018] 2. This invention suppresses interference from the metal filing cabinet to the edge electric field by integrating an active shielding layer into the edge electric field sensing layer. The active shielding layer receives a voltage follower signal at the same potential as the excitation electrodes, creating a zero electric field region below the layer, forcing the electric field energy to concentrate unidirectionally towards the upward-facing file storage area. This not only enhances the sensing sensitivity of the target but also allows the system to be directly installed on the metal layer without additional shielding structures or non-metallic modifications, improving the system's environmental adaptability and installation convenience.
[0019] 3. This invention improves the accuracy and stability of weak capacitance measurements by introducing an environmental differential reference module and a dynamic focusing scanning strategy. The environmental differential reference module quantifies the background drift of the dielectric constant caused by changes in temperature and humidity in real time, providing the processing terminal with corrections for environmental common-mode interference. Simultaneously, a virtual protection ring constructed by a multiplexed data acquisition unit actively shields adjacent electrodes, physically constraining the divergence path of the edge electric field and reducing crosstalk caused by the movement of external objects. This ensures the reliability of the system during long-term operation in complex warehousing environments. Attached Figure Description
[0020] Figure 1 This is a schematic diagram of the architecture of the intelligent filing cabinet remote monitoring and management system of the present invention; Figure 2 This is an exploded structural diagram of the edge electric field sensing layer plate and the file in this invention. Figure 3 This is a schematic diagram of the edge electric field sensing layer stack structure of the present invention; Figure 4 This is a schematic diagram of the planar electrode array topology and multi-scale detection of the present invention; Figure 5 This is a schematic diagram of the remote monitoring and management method for the intelligent filing cabinet of the present invention.
[0021] Among them, 10 is the intelligent filing cabinet body; 100 is the edge electric field sensing layer; 200 is the anisotropic dielectric coding tag; 300 is the multiplexed data acquisition unit; 400 is the tomographic imaging and state inversion processing terminal; and 500 is the environmental differential reference module. Detailed Implementation
[0022] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0023] See attached document Figure 1 -Appendix Figure 2 This invention provides a remote monitoring and management system for an intelligent filing cabinet. The system includes: an intelligent filing cabinet body 10, an edge electric field sensing layer 100, an anisotropic dielectric coding tag 200, a multiplexed data acquisition unit 300, a tomographic imaging and state inversion processing terminal 400, and an environmental differential reference module 500.
[0024] The intelligent filing cabinet body 10 forms the physical support framework of the system, and its interior contains several layers of storage space. The bottom of each storage space is replaced or covered by an edge electric field sensing layer 100.
[0025] The edge electric field sensing layer 100 serves as the core sensing front end of the system, and its surface is covered with a planar electrode array using printed circuit technology. This planar electrode array is configured to emit a quasi-static edge electric field into the half-space region above the layer under the drive of an excitation signal. This edge electric field covers the file storage area, forming a non-contact dielectric sensing field.
[0026] An anisotropic dielectric coded tag 200 is attached to the bottom outer surface of the file under test. The anisotropic dielectric coded tag 200 physically comprises alternating high conductivity regions and high transmittance dielectric regions. This structural design is used to co-modulate the incident edge electric field, enabling the position signal and material signal to exhibit separable characteristics in the frequency or spatial domain.
[0027] The multiplexed data acquisition unit 300 is electrically connected to the edge electric field sensing layer 100 via a shielded cable. The multiplexed data acquisition unit 300 includes a multi-channel capacitance-to-digital converter circuit and an analog switch matrix. The multiplexed data acquisition unit 300 is used to perform time-division multiplexing excitation and measurement operations on the electrode pairs in the planar electrode array according to a preset timing sequence, acquiring mutual capacitance data reflecting the spatial dielectric distribution characteristics.
[0028] An environmental differential reference module 500 is disposed in a non-storage area on the surface of the edge electric field sensing layer 100. The environmental differential reference module 500 includes a set of independent reference electrodes and a calibration block encapsulated with a standard reference medium. The environmental differential reference module 500 is used to monitor the background drift of the dielectric constant caused by changes in ambient temperature and humidity in real time.
[0029] The tomographic imaging and state inversion processing terminal 400 is communicatively connected to the multiplexed data acquisition unit 300. The tomographic imaging and state inversion processing terminal 400 is equipped with an algorithm for solving the inverse electric field problem and state analysis logic, which is used to receive mutual capacitance data and calculate the physical state of the file.
[0030] See attached document Figure 3 The edge electric field sensing layer 100 is manufactured using a multilayer printed circuit board (PCB) process, and its physical dimensions match the single-layer storage shelf specifications of the intelligent filing cabinet body 10. In order to achieve synchronous sensing of the location and internal status of the files, the edge electric field sensing layer 100 includes a substrate support layer, an electric field excitation / detection layer, and an active shielding layer in its hardware structure.
[0031] The edge electric field sensing layer 100 is defined from top to bottom as a surface insulating protective layer, a signal transmission layer (TopLayer), a dielectric substrate layer, and an active shielding layer (Bottom Layer).
[0032] The surface insulating protective layer uses solder resist ink or Teflon coating, with a thickness controlled between 0.1mm and 0.3mm, to isolate the file from direct electrical contact with the electrodes and eliminate contact resistance interference. The signal transmission layer is equipped with a planar electrode array. The dielectric substrate layer uses FR-4 glass fiber epoxy resin board, with a relative permittivity of [missing information]. The value ranges from 4.2 to 4.8.
[0033] The active shielding layer is a complete copper foil plane laid on the lower surface of the dielectric substrate. This active shielding layer physically isolates the signal transmission layer from the metal shelves of the filing cabinet. Electrically, the active shielding layer is not directly grounded; instead, it is connected via metallized vias inside the PCB and then via connector pins to the shielded drive terminal of the multiplexed data acquisition unit 300. This shielded drive terminal outputs a voltage follower signal with the same frequency, phase, and amplitude as the current excitation signal. This ensures that the excitation electrodes of the active shielding layer and the signal transmission layer remain at the same potential, thereby creating a zero-field region between them. This forces the edge electric field lines to bend towards the filing storage area above the dielectric substrate instead of diverging downwards, thus enhancing sensing sensitivity.
[0034] See attached document Figure 4The planar electrode array is configured as a matrix interdigitated structure. This array comprises two sets of electrodes that are physically insulated from each other but spatially alternating: the excitation electrode set... With sensing electrode assembly .
[0035] To support layered detection of the bottom label and internal paper of a document at the hardware level, the planar electrode array employs a multi-scale design with fixed physical spacing and variable logical combination. Specifically, the planar electrode array consists of multiple parallel-arranged basic electrode finger strip units, each with a width of [missing information]. (For example, 1 mm), the gap between adjacent base electrode finger units is (e.g., 1mm).
[0036] When probing shallow-layer position signals, the system controls a single basic electrode finger strip unit as the excitation source, at which point the spacing between adjacent electrodes... This creates a high-frequency, shallow electric field. According to the quasi-static edge electric field design criteria, its effective penetration depth... Spacing Proportional ( The electric field energy is mainly concentrated in the range of 0mm to 10mm above the surface of the plate.
[0037] When probing signals from deep materials, the system uses a back-end switching matrix to continuously... Each basic electrode finger strip unit is short-circuited and combined to form an equivalent wide electrode. At this point, the equivalent center-to-center distance between the excitation electrode and the sensing electrode... Increase ( This generates a deep-penetrating electric field. The effective penetration depth of this deep electric field is... Increase( It can penetrate 30mm to 100mm into the inside of the file folder, covering the main paper stacking area.
[0038] To support the active focusing function of the virtual guard ring, each individual electrode finger in the planar electrode array is led out to the edge connector via an independent trace. In the PCB routing design, ground isolation lines are inserted between adjacent signal lines to reduce crosstalk between transmission lines. The number of pins on the edge connector corresponds one-to-one with the number of basic electrode finger units, ensuring that each electrode unit can be independently configured to high-impedance, excitation, measurement, or shielded states.
[0039] The edge of the edge electric field sensing layer 100 is provided with an FPC interface or a board-to-board connector. In addition to the electrode signal lines mentioned above, this interface pins also include dedicated reference channel pins for connecting the environmental differential reference module 500. In the non-active sensing area of the layer, the PCB board has reserved mounting slots for the reference module. The active shielding layer beneath these slots is etched away to form a local electromagnetic window, allowing the reference electrodes to construct an independent local electric field loop, avoiding interference from the main array signal.
[0040] Through the hardware construction of the aforementioned multi-layer composite shielding structure and multi-scale electrode topology, the edge electric field sensing layer 100 provides the system with a directional, metal-interference-resistant, and depth-resolution physical sensing field. This physical sensing field works in conjunction with the tag structure on the file under test to achieve physical layer modulation of the signal. The specific structure of the anisotropic dielectric coded tag that works in conjunction with this layer will be described in detail below.
[0041] Anisotropic dielectric coded tag 200 is a passive device attached to the bottom of the file box. Its physical form is a layered thin film with specific electromagnetic modulation function. The tag converts the physical existence of the file into a characteristic perturbation signal of the edge electric field through the alternating arrangement of conductive and dielectric regions in space, thereby achieving decoupled measurement of the file's position coordinates and internal material properties.
[0042] The anisotropic dielectric coded label 200 comprises, from the inside out, the following layers in the thickness direction: a strong adhesive backing layer, a flexible substrate layer, a dielectric modulation layer, and a wear-resistant protective layer.
[0043] A strong adhesive backing layer, made of acrylic pressure-sensitive adhesive, is used to secure the label to the bottom surface of the file box. The flexible substrate layer is made of polyethylene terephthalate (PET) or polyimide (PI) film with a thickness of 0.05 mm to 0.1 mm. The flexible substrate layer provides mechanical support for the dielectric modulation layer above and serves as the first wave-transparent medium.
[0044] The dielectric modulation layer is the core functional layer for achieving anisotropic encoding. This layer is not a continuous uniform film, but is formed by alternating deposition of two materials with significant differences in conductivity on a plane: conductive strip units and dielectric window units.
[0045] Conductive strip units are composed of materials with a conductivity greater than 10. 6 The conductive strip is formed by printing conductive silver paste or etching aluminum foil with a thickness of S / m. In terms of physical dimensions, the width of the conductive strip unit... The electrode spacing is set to the distance between the electrodes and the positioning detector subarray in the edge electric field sensing layer 100. Matching, satisfying When the electric field lines generated by the edge electric field sensing layer 100 come into contact with the conductive strip unit, due to the physical characteristic that the electric field strength inside the conductive material is zero, the conductive strip unit, acting as a suspended potential body, will forcibly change the distribution of the surrounding electric field lines, causing the electric field lines to terminate perpendicularly at the conductor surface. This electric field coupling effect introduces an increase in coupling capacitance between the electrode pairs. In the measurement signal, it appears as an amplitude peak, which is used for precise positioning.
[0046] A dielectric window cell is either a region of flexible substrate exposed after the conductive material has been etched away, or a region filled with a low-dielectric-constant insulating material. The width of the dielectric window cell... Set to be greater than or equal to the effective span of the transmission probe subarray in the edge electric field sensing layer 100 When the deep-penetrating electric field scan reaches the dielectric window unit, due to the lack of conductive shielding, the electric field lines can freely pass through the window and enter the paper stacking area inside the upper file box. At this time, the measured change in mutual capacitance... It mainly depends on the equivalent volume dielectric constant of the paper inside the file box. This signal is a material characteristic signal that reflects the integrity of the archive.
[0047] To identify document categories, the conductive strip units and media window units are arranged along the label length according to a preset binary encoding rule. Specifically, the presence of a conductive strip unit represents logic 1, and the presence of a media window unit represents logic 0. Alternatively, pulse position modulation (PPM) can be used, by setting the length of the media window unit between two adjacent conductive strip units. To carry information. For example, when The time represents information bit 0, when The time represents a 1. This encoding structure allows the system to not only obtain the location during scanning, but also to read the file's identity ID.
[0048] An abrasion-resistant protective layer, made of matte polypropylene (PP) film with a thickness of less than 0.05 mm, covers the dielectric modulation layer. This abrasion-resistant protective layer features low dielectric loss characteristics to minimize attenuation of the transmitted electric field.
[0049] From the perspective of equivalent circuit analysis, when the anisotropic dielectric coding tag 200 is placed above the electrode array, the system forms a composite capacitor network.
[0050] In the conductive stripe unit region, the equivalent circuit behaves as two surface capacitors connected in series. Its measured capacitance value... It can be represented as: ; in, It is the vacuum permittivity; The dielectric constant of the air gap; This represents the overlap area between the electrode and the conductive strip; This refers to the air gap thickness between the label and the shelf.
[0051] because Extremely small (typically only tens of micrometers). The value is significantly higher than the background capacitance, forming a hard feature signal with a high signal-to-noise ratio.
[0052] In the dielectric window cell region, the equivalent circuit appears as a parallel structure of a paper capacitor and an air capacitor. Its measured capacitance value... Fill factor of the internal paper of the archive There is a positive correlation: ; in, The shape factor is related to its geometry; The dielectric constant of paper, is the dielectric constant of air.
[0053] Through the above structure, the anisotropic dielectric coded tag 200 achieves spatial filtering and impedance modulation of the incident electric field: it uses conductive strips to intercept high-frequency shallow electric fields to generate strong positioning signals, and uses dielectric windows to transmit low-frequency deep electric fields to generate material detection signals. This physical-level signal separation mechanism provides high signal-to-noise ratio raw data for subsequent algorithm processing. To ensure accurate measurement of the aforementioned weak capacitance changes, the system needs to introduce a stable reference benchmark. The specific configuration of the environmental differential reference module will be described below.
[0054] The environmental differential reference module 500 is configured as a common-mode interference monitoring terminal in the intelligent filing cabinet system. Its physical location is in the non-storage functional area on the surface of the edge electric field sensing layer 100. The main function of this module is to quantify in real time the systematic errors caused by fluctuations in ambient temperature and humidity, as well as circuit temperature drift, providing reference data for subsequent signal decoupling.
[0055] The environmental differential reference module 500 mainly consists of the following hardware components: a reference electrode pair, a standard dielectric reference block, and an electromagnetic shield.
[0056] The reference electrode pair maintains structural consistency with the transmission probe subarray in the edge electric field sensing layer 100 in terms of geometry, electrode spacing, and copper foil thickness. This structural consistency design ensures that the reference channel and the measurement channel have the same parasitic capacitance substrate and the same temperature drift coefficient. The reference electrode pair includes an emitter. and receiving end They are directly connected to the dedicated channel of the data acquisition unit via independent differential cables.
[0057] A standard dielectric reference block covers and is fixed to the surface of the reference electrode pair using mechanical fasteners or high-temperature epoxy adhesive. This reference block is made of a material with low hygroscopicity, low coefficient of thermal expansion, and long-term stable dielectric constant, such as polytetrafluoroethylene (PTFE) or a vitrified ceramic composite material. The thickness of the standard dielectric reference block... and equivalent dielectric constant It is pre-calibrated. In practice, to simulate the dielectric response benchmark of archival paper in a dry state, the dielectric constant of the standard dielectric reference block is... The value is set between 2.0 and 3.0. The presence of the standard dielectric reference block ensures that the measured values of the reference electrode pair mainly reflect the influence of ambient temperature on the PCB substrate and circuit parameters, as well as the background influence of air humidity on the edge electric field divergence characteristics, thereby eliminating the interference of changes in the test data.
[0058] An electromagnetic shield is a grounded metal mesh or metal shell that covers the outside of a standard dielectric reference block. The electromagnetic shield is used to isolate transient disturbances to the reference electrode pair from external moving objects, ensuring that the reference signal is only affected by ambient thermodynamic parameters.
[0059] Based on the output of the environmental differential reference module 500, the system establishes an environmental drift compensation model. The initial capacitance value of the measurement channel at a certain moment is set to... At the same time, the capacitance value of the reference channel is The system's pre-stored reference channel baseline value under standard environmental conditions (25℃, 40%RH) is... .
[0060] At this time, the capacitance drift caused by environmental factors Represented as: ; Considering the slight difference in circuit channel gain between the measurement channel and the reference channel, as well as the nonlinear temperature drift characteristics, a channel correction coefficient is introduced. and nonlinear weighting function The measured capacitance value after environmental differential correction. The calculation is as follows: ; Among them, the channel correction coefficient and nonlinear weighting function It was calibrated through temperature and humidity cycling tests before leaving the factory.
[0061] The specific calibration process is as follows: Place the system in a variable temperature and humidity environmental test chamber and record the data under no-load conditions. and The ratio to determine Record different values under standard load conditions. The drift corresponding to the value is fitted by the function. In actual runtime, the system calls the pre-stored... and The parameter table is used for real-time compensation.
[0062] In the specific circuit implementation, the driving signal of the reference electrode pair and the excitation signal of the main array originate from the same clock source, and phase noise caused by clock jitter is eliminated through synchronous sampling.
[0063] Through the hardware configuration and mathematical model of the aforementioned environmental differential reference module 500, the system can separate the common-mode error caused by environmental temperature and humidity from the weak detection signal. To achieve high-precision driving and signal extraction of the aforementioned reference electrode and main array electrode, a specific multiplexing and acquisition circuit is required. The implementation of the multiplexed data acquisition unit 300 and its virtual protection ring driving logic will be described in detail below.
[0064] The multiplexed data acquisition unit 300 is the circuit hub connecting the edge electric field sensing layer 100 and the back-end processing terminal. This unit is configured to perform the digital conversion of weak capacitance signals and provide dynamically reconfigurable electric field excitation and shielding control functions. Its core function is to actively drive the virtual protection ring through dynamic switching of hardware circuits, thereby physically constraining the divergence path of the edge electric field.
[0065] The multiplexed data acquisition unit 300 mainly includes: a main controller MCU, a high-resolution capacitor-to-digital converter (CDC), a multi-level analog switch matrix, and a shielded drive amplifier.
[0066] The main controller MCU is a 32-bit microcontroller with DMA (Direct Memory Access) function, which is responsible for generating timing control signals and buffering the acquired data.
[0067] The high-resolution capacitance-to-digital converter (CDC) is the core component of the measurement; a 24-bit resolution CDC is selected. The CDC chip is an architecture capacitor and digital-to-digital converter. It is configured to include two key input ports: an excitation output port (EXC) and a differential measurement input port (CIN). Furthermore, the CDC chip integrates a shielded drive generator to output a voltage follower signal that is in phase and has the same amplitude as the EXC port signal. .
[0068] To achieve flexible configuration of arbitrary electrode states, the multi-level analog switch matrix adopts a topology with independent gating for each channel. Specifically, for each individual electrode finger in the planar electrode array... The system is configured with a single-pole four-throw (SP4T) analog switch unit. The four inputs of this SP4T switch unit are connected to: The CDC's excitation output port EXC; CDC's measurement input port CIN; Shielding drive signal ; System ground GND. The common output terminal of the SP4T switching unit is connected to the electrode fingers. .
[0069] By encoding and driving the logic control pins of the SP4T switching unit through the main controller MCU, the system can control any electrode finger strip. Define four working states: State 1: Active TX state. Electrode It is connected to the EXC port of the CDC to transmit an AC excitation signal.
[0070] State 2: Measurement State (Active RX). Electrode It is connected to the CIN port of the CDC to receive induced charges.
[0071] State 3: Shielded State (Active Guard). Electrode Conduct to shielded drive signal At this time, the electrodes The potential of the electrode is synchronized with that of the excitation electrode, and the potential difference between them is zero, thereby eliminating parasitic capacitive coupling in this direction.
[0072] State 4: Grounded (GND). Electrode It is connected to the system ground to provide electric field isolation.
[0073] Based on the above hardware architecture, the multiplexed data acquisition unit 300 executes a dynamic focusing scanning strategy to construct a virtual protection ring that moves with the scanning window. The specific scanning steps are described below: Initialize configuration. The system resets the multi-stage analog switch matrix, placing all electrodes in the ground state.
[0074] Select the current measurement channel. Set the number of channels. Each electrode finger is an excitation electrode. , No. Each electrode bar is a sensing electrode. .
[0075] Construct a virtual protection loop. Control the analog switch matrix to... The outer adjacent first Each electrode bar and located at The outer adjacent first Each electrode finger strip switches to the shielded state. At this time, in physical space, and It is surrounded by equipotential shielding electrodes on both sides. According to the electric field boundary conditions, due to... There is no potential difference between the electric field and the outer shielding electrode, so the electric field lines cannot spread horizontally to the outside, thus limiting the divergence range of the edge electric field. This causes the electric field energy to be mainly distributed in the high impedance space above (i.e., the archive region), which improves the focusing of the electric field on the target region above.
[0076] Differential sampling and conversion. CDC chip for... and The mutual capacitance between the capacitors is oversampled multiple times, and a digital filter is applied to remove power frequency interference, outputting the original capacitance value. .
[0077] The scan window slides. The main controller MCU updates the switch matrix address, making... Repeat the above steps until the entire array has been traversed.
[0078] In addition, at the end of each full array scan cycle, the multiplexed data acquisition unit 300 independently selects and connects to the reference channel of the environmental differential reference module 500 to acquire reference data. And package it into a data frame.
[0079] Through this hardware control logic that synchronizes excitation, measurement, and shielding, the multiplexed data acquisition unit 300 not only completes data acquisition but also actively optimizes the spatial distribution of the edge electric field at the physical level, overcoming the defect of traditional capacitive sensors being easily interfered with by surrounding metal objects. The acquired raw data is then transmitted to the next-level processing unit. The next embodiment will describe in detail how the tomographic imaging and state inversion processing terminal 400 uses this data to reconstruct the spatial state of the archive.
[0080] The tomographic imaging and state inversion processing terminal 400 is the computational core of the system, typically composed of an embedded industrial computer or a high-performance server. This terminal is configured to execute inverse problem solving algorithms, transforming the one-dimensional capacitance observation vector uploaded by the multiplexed data acquisition unit 300 into a two-dimensional grayscale image or parameter set reflecting the spatial distribution and media properties of the archive.
[0081] The processing terminal 400 executes a computer program stored in non-volatile memory to perform the following sequential processing steps: Data preprocessing and normalization: Processing terminal 400 receives raw measurement data frames from the acquisition unit. and reference data frame Using the environmental compensation model constructed in Example 4, the compensated capacitance vector was calculated. .
[0082] To eliminate the fundamental capacitance bias of the measurement circuit and standardize the measurement scale, normalization is employed. The unloaded capacitance vector of the system in the fileless state is defined as follows: The full-load capacitance vector under standard full-load file conditions is: Normalized capacitance vector The calculation is as follows: ; in, Indicates the first Index of each electrode channel.
[0083] For data whose calculation results exceed the range of [0,1], the system performs a numerical truncation operation to forcibly limit them to the [0,1] interval in order to ensure the stability of subsequent imaging algorithms.
[0084] Constructing the sensitivity matrix (positive problem model): Sensitivity matrix The influence weight of the dielectric constant variation of each pixel within the detection region on the edge electric field measurement is described. In this embodiment, the detection region is discretized as follows: Grid pixels (where For the number of rows, Number of columns, total number of pixels Sensitivity matrix elements Defined as: ; in, It is the first The electric field distribution vector under electrode channel excitation; It is the adjoint field vector defined according to the reciprocity theorem, that is, assuming that when the th... The spatial electric field distribution when a unit excitation voltage is applied to the receiving electrode in the electrode channel and the transmitting electrode is grounded. It is the first A volume region of one pixel; This represents a partial derivative; Representing the The capacitance value measured against the electrode channel; In the grid representing the detection area, the first The dielectric constant of the medium within each pixel (or voxel) unit; It is a spatial integral infinitesimal element.
[0085] The matrix Pre-calculation is performed using finite element simulation (FEM) and stored in a database.
[0086] Image reconstruction (solving the inverse problem): Using normalized capacitance vector and sensitivity matrix Solve for the gray-scale vector that reflects the distribution of the dielectric constant. Because edge electric field imaging exhibits soft-field effects and ill-conditioned behavior, directly solving the linear equations is unstable. Therefore, the processing terminal 400 employs a linear back-projection algorithm with Tikhonov regularization.
[0087] The objective function is defined as: ; in, This represents the Minimize operator; This represents the grayscale distribution vector of the reconstructed image, i.e., the dielectric constant distribution value (or normalized dielectric constant) of each pixel within the detection region. This is the final image output by the algorithm; Represents the magnitude of energy or the square of the error distance; This is the sensitivity matrix; This is the normalized capacitance vector; It is the residual vector; For data fidelity items; For regularization parameters; It is the identity matrix; This is a penalty item.
[0088] The analytical solution of the objective function (the gray-level distribution vector of the reconstructed image) )for: ; in, Represents the sensitivity matrix The transpose of .
[0089] The calculated vector Reshaped into A two-dimensional grayscale image. Because the conductive strips in the anisotropic label are equipotential bodies, the resulting electric field distortion is much greater than that of the paper medium. Therefore, in the reconstructed image, the conductive strips appear as bright, hard feature areas with near-saturated grayscale values, while the paper inside the archive appears as diffuse, soft feature areas with medium to low grayscale values.
[0090] Feature decoupling and parameter inversion: This is a crucial step in achieving location and state separation. The processing terminal 400 reconstructs image vectors. Perform waveform analysis: Location decoupling (hard feature extraction): setting a high threshold (For example, taking 80% of the image's maximum grayscale value). Identify all amplitudes exceeding... The local maxima are identified. These points correspond to the conductive stripe cells in the label. The weighted centroid coordinates of these maxima are calculated. , serving as the physical location coordinates of the archive.
[0091] Identity Decoding (ID Recognition): Calculating the spatial distance between adjacent local maxima. According to the encoding rules in Example 3, the distance sequence is... The data is mapped to a binary code stream, which is then used to extract the file's unique ID.
[0092] Integrity decoupling (soft feature extraction): The system generates a mask matrix. The pixel weights corresponding to the identified hard feature regions are reset to 0, while the weights of the remaining regions are set to 1. This mask matrix is then used to reconstruct the grayscale distribution vector of the image. By performing weighted integration, the total amount of media is obtained. : ; in, For discrete summation operators, it represents the summation of all values within the imaging region. Iterate through and accumulate the discrete pixels; No. The spatial mask coefficient for each pixel typically takes the value of 0 or 1; It is the gray-level distribution vector of the reconstructed image. The first in Each element.
[0093] Through this masking operation, the algorithm mathematically eliminates the interference of the label's conductive layer on the overall dielectric measurement, thus... It only reflects the cumulative amount of archival paper.
[0094] Status determination: The processing terminal 400 will calculate the total media quantity index Compare with preset standard full box reference values and empty box reference values. If If the value is below the empty box baseline, it is determined that the file is missing; if Between these two, the thickness or page count of the archive is estimated by using a linear interpolation algorithm or by consulting a pre-stored capacitance and thickness mapping table, thereby outputting the archive's integrity status.
[0095] Through the above processing logic, the tomographic imaging and state inversion processing terminal 400 decouples the aliased electric field signal collected by a single physical channel into independent position coordinates, identity ID, and internal material state at the algorithm level, thereby realizing the digital perception of the entity inside the smart filing cabinet.
[0096] Thus far, the core hardware architecture, driving method, and signal processing logic of the intelligent filing cabinet system based on edge electric field sensing of this invention have been fully described through the above embodiments. The combination of the above embodiments constitutes a closed-loop monitoring system, effectively solving the technical problems of large metal interference and difficulty in simultaneously achieving positioning and thickness measurement in traditional technologies.
[0097] See attached document Figure 5 This invention provides a method for remote monitoring and management of intelligent filing cabinets. The overall workflow of this method is as follows.
[0098] The system executes the initialization modeling steps. The tomographic imaging and state inversion processing terminal 400 constructs a spatial sensitivity field model based on the electrode geometry parameters and boundary conditions of the edge electric field sensing layer 100. This model defines a linear mapping relationship between the dielectric constant perturbation of any pixel within the sensing region and the change in mutual capacitance between electrode pairs.
[0099] The data acquisition and modulation process then begins. The multiplexed data acquisition unit 300 drives the edge electric field sensing layer 100 to generate an alternating electric field. When the anisotropic dielectric coded tag 200 is within the sensing field, its high conductivity region causes a step increase in the coupling capacitance between electrodes, forming a positional characteristic signal; its highly transparent dielectric region allows the electric field to penetrate into the archive, forming a material characteristic signal reflecting the stacking density of the archive paper. The multiplexed data acquisition unit 300 acquires a measurement vector containing the aforementioned characteristic signals.
[0100] The image reconstruction step is performed. The tomographic imaging and state inversion processing terminal 400 receives the measurement vector and solves the inverse electric field problem using a regularization algorithm with total variational constraints. This calculation process suppresses measurement noise and reconstructs a grayscale image reflecting the dielectric constant distribution above the edge electric field sensing layer 100.
[0101] The process involves feature decoupling and state resolution. The tomographic imaging and state inversion processing terminal 400 performs region segmentation on the reconstructed grayscale image. The tomographic imaging and state inversion processing terminal 400 extracts the centroid coordinates of the high conductivity response regions to determine the physical location and arrangement order of the archives. Simultaneously, the tomographic imaging and state inversion processing terminal 400 extracts the dielectric response intensity corresponding to the high transmittance medium regions and calculates the archive integrity index.
[0102] During the calculation of the integrity index, the tomographic imaging and state inversion processing terminal 400 reads the data from the environmental differential reference module 500 and uses a differential algorithm to remove common-mode interference from environmental background noise on the dielectric response intensity.
[0103] The monitoring, judgment, and output steps are executed. The tomographic imaging and state inversion processing terminal 400 compares the parsed physical location sequence and integrity index with a preset archive information database. When a mismatch is detected between the physical location and the preset location, a misalignment alarm and the current actual coordinates are output; when the integrity index decreases by more than a preset threshold, a content missing alarm is output.
Claims
1. A remote monitoring and management system for intelligent filing cabinets, characterized in that, include: The intelligent filing cabinet body (10) has several layers of storage space inside, providing a physical support environment for the various components of the intelligent filing cabinet remote monitoring and management system; An edge electric field sensing layer (100) is disposed at the bottom of the storage space and is used to emit a quasi-static edge electric field above the storage space; An anisotropic dielectric coded tag (200) includes alternating high conductivity regions and high transmittance medium regions for co-modulating the incident quasi-static edge electric field, thereby introducing separable position feature signals and material feature signals in the electric field distribution. The multiplexed data acquisition unit (300) is used to perform time-division sampling on the modulated quasi-static edge electric field to obtain mutual capacitance data carrying the position feature signal and the material feature signal; Tomographic imaging and state inversion processing terminal (400) is used to decouple and analyze the distribution characteristics of the position feature signal and the material feature signal from the mutual capacitance data in order to reconstruct the physical position coordinates and integrity status of the archive. An environmental differential reference module (500) is used to obtain the background drift of dielectric constant caused by environmental factors, so that the tomographic imaging and state inversion processing terminal (400) can correct the environmental common-mode interference in the material feature signal.
2. The intelligent filing cabinet remote monitoring and management system according to claim 1, characterized in that, The edge electric field sensing layer (100) is manufactured using a multilayer printed circuit board process, and its physical structure includes: A signal transmission layer, on which a planar electrode array is arranged, is used to transmit and receive the quasi-static edge electric field; An active shielding layer, which is a complete copper foil plane laid below the signal transmission layer, is used to receive a voltage follower signal that is in phase and has the same amplitude as the excitation electrode in the planar electrode array; By maintaining the same potential between the active shielding layer and the excitation electrode in the signal transmission layer, a zero electric field region is formed between the active shielding layer and the excitation electrode, causing the quasi-static edge electric field to bend unidirectionally toward the file storage area above the storage space, thereby improving the sensing sensitivity of the anisotropic dielectric coded tag (200).
3. The intelligent filing cabinet remote monitoring and management system according to claim 2, characterized in that, The planar electrode array consists of multiple parallel-arranged basic electrode finger units and employs a multi-scale design with fixed physical spacing and variable logical combination to adapt to the signal characteristics of the anisotropic dielectric coded tag (200). When detecting the position feature signal, the system controls a single basic electrode finger unit as an excitation source to form a high-frequency shallow electric field. The energy of the high-frequency shallow electric field is concentrated in a first height range above the surface of the edge electric field sensing layer (100) to match the coupling characteristics of the high conductivity region in the anisotropic dielectric coding tag (200). When detecting the material characteristic signal, the system short-circuits multiple consecutive basic electrode strip units through a back-end switch matrix to form an equivalent wide electrode, thereby increasing the equivalent center distance between the excitation electrode and the sensing electrode, and generating a deep penetrating electric field. The deep penetrating electric field can enter the area of the second height range inside the file, wherein the second height range is larger than the first height range, and is used to cover the high-transmittance medium area and the file paper area above the anisotropic dielectric coding tag (200).
4. The intelligent filing cabinet remote monitoring and management system according to claim 3, characterized in that, The anisotropic dielectric coded tag (200) includes a dielectric modulation layer, which is formed by alternating conductive stripe units and dielectric window units on a plane. The conductive strip unit constitutes the high conductivity region and acts as a floating potential body to forcibly change the distribution of the surrounding electric field lines, so that the electric field lines terminate perpendicularly at the conductor surface, thereby introducing an incremental coupling capacitance between the electrode pairs and forming the position feature signal. The medium window unit constitutes the high-transmittance medium region, which allows the electric field to pass freely through and enter the upper archive, so that the measured mutual capacitance data depends on the dielectric constant of the equivalent volume of the paper inside the archive, forming the material characteristic signal; The conductive strip unit and the medium window unit are arranged along the length of the label according to a preset binary encoding rule or pulse position modulation method to carry the file's identity ID information.
5. The intelligent filing cabinet remote monitoring and management system according to claim 4, characterized in that, The multiplexed data acquisition unit (300) includes a capacitor-to-digital converter and a multi-level analog switch matrix; The multi-level analog switch matrix adopts a topology structure with independent selection for each channel. A single-pole four-throw analog switch unit is configured for each basic electrode finger unit in the edge electric field sensing layer (100), so that each basic electrode finger unit can be independently defined as one of the following four states: Excitation state: The basic electrode finger unit is turned on to the excitation output port of the capacitor-to-digital converter; Measurement state: The basic electrode finger unit is connected to the differential measurement input port of the capacitance-to-digital converter; Shielded state: The basic electrode finger unit is connected to the shielding drive signal, and the shielding drive signal is in phase and has the same amplitude as the excitation signal; Grounding state: The basic electrode finger unit is connected to the system ground.
6. The intelligent filing cabinet remote monitoring and management system according to claim 5, characterized in that, The multiplexed data acquisition unit (300) is configured as follows: When the selected basic electrode finger strip unit is in the excitation state as the excitation electrode and in the measurement state as the sensing electrode, the multi-level analog switch matrix is synchronously controlled to switch the basic electrode finger strip unit located outside the excitation electrode and the basic electrode finger strip unit located outside the sensing electrode to the shielded state. By physically surrounding the excitation electrode and the sensing electrode with the base electrode finger strip units on both sides in the shielded state, the horizontal diffusion of the quasi-static edge electric field to the outside is restricted, ensuring that the mutual capacitance data mainly reflects the dielectric distribution of the area directly above.
7. The intelligent filing cabinet remote monitoring and management system according to claim 1, characterized in that, The tomographic imaging and state inversion processing terminal (400) parses the mutual capacitance data according to the following steps: The mutual capacitance data is received, and an environmental drift compensation model is established using the dielectric constant background drift provided by the environmental differential reference module (500). The mutual capacitance data is then corrected to obtain a normalized capacitance vector. A pre-built spatial sensitivity field model is invoked, which defines a linear mapping relationship between the dielectric constant perturbation of any pixel within the sensing area and the change in mutual capacitance of the electrode pair. The inverse electric field problem is solved using a linear back-projection algorithm with total variation constraints or Tikhonov regularization to reconstruct a two-dimensional grayscale image reflecting the dielectric constant distribution above the edge electric field sensing plate (100).
8. The intelligent filing cabinet remote monitoring and management system according to claim 7, characterized in that, The tomographic imaging and state inversion processing terminal (400) decouples the position feature signal and the material feature signal from the two-dimensional grayscale image according to the following steps: Position decoupling: Identify local maxima points in the two-dimensional grayscale image whose amplitude exceeds a preset high threshold, determine the local maxima points as the position feature signal responses generated by the conductive strip units in the anisotropic dielectric coding tag (200), and calculate the weighted centroid coordinates as the physical position coordinates of the file; Integrity decoupling: Generate a mask matrix, reset the pixel weights corresponding to the identified location feature signal response areas to zero, use the mask matrix to perform weighted integration or accumulation on the two-dimensional grayscale image, extract the material feature signal response that only reflects the internal medium of the archive, and obtain the total medium index; Status determination: The total media quantity index is compared with the preset standard full box benchmark value and empty box benchmark value. If the total media quantity index is lower than the empty box benchmark value, it is determined that the file is missing. If it is between the preset standard full box benchmark value and the empty box benchmark value, the integrity status of the file is calculated.
9. The intelligent filing cabinet remote monitoring and management system according to claim 1, characterized in that: The environmental differential reference module (500) includes: a reference electrode pair, a standard dielectric reference block, and an electromagnetic shielding cover; The reference electrode pair maintains structural consistency with the electrodes in the edge electric field sensing layer (100) in terms of geometry and electrode spacing, and is used to provide a reference channel with the same parasitic parameters as the measurement channel; The standard dielectric reference block covers and is fixed to the surface of the reference electrode pair. It is made of a material with low moisture absorption and a long-term stable dielectric constant to provide a stable dielectric reference. The electromagnetic shield is a grounded metal mesh or metal shell that covers the outside of the standard dielectric reference block to isolate external object disturbances and ensure that the reference channel only reflects the background drift of the dielectric constant.
10. A method for remote monitoring and management of intelligent filing cabinets, characterized in that, The remote monitoring and management system for intelligent filing cabinets as described in any one of claims 1-9 includes the following steps: A spatial sensitivity field model is constructed based on the parameters of the edge electric field sensing plate (100); The edge electric field sensing plate (100) is driven to generate a quasi-static edge electric field. The electric field is co-modulated using an anisotropic dielectric coding tag (200), and mutual capacitance data containing position feature signals and material feature signals is collected by the multiplexed data acquisition unit (300). The tomographic imaging and state inversion processing terminal (400) receives the mutual capacitance data, performs environmental compensation using the data from the environmental differential reference module (500), and solves the electric field inverse problem using a regularization algorithm to reconstruct a two-dimensional grayscale image reflecting the dielectric constant distribution. The two-dimensional grayscale image is segmented to separate the high conductivity response region corresponding to the position feature signal to determine the physical location of the archive, and the high transmittance medium region corresponding to the material feature signal is separated to calculate the total medium index of the archive. The parsed physical location and the total media quantity index are compared with a preset database. When a mismatch is detected in the physical location, a misalignment alarm is output. When the decrease in the total media quantity index exceeds a threshold, a content missing alarm is output.