Passive lock anti-damage intelligent monitoring method and system based on abnormal log reporting

Abstract

The present application belongs to the technical field of rail transit security equipment, and relates to a passive lock anti-damage intelligent monitoring method and system based on abnormal log reporting. The present application comprises the following steps: S1, collecting vibration energy of the position where the passive lock is located in the rail transit environment; S2, generating an abnormal log containing event type and occurrence time information by a master control unit and writing into a non-volatile storage module; S3, outputting direct current power to the passive lock by a probe to wake up the master control unit; S4, establishing a communication link between the passive lock and the intelligent key through a low-voltage power line carrier communication mode; S5, returning the abnormal log in the non-volatile storage module to the intelligent key through the carrier signal; and S6, analyzing the abnormal log by a cloud server and issuing a warning information. Through the combination of vibration energy collection power supply and low-voltage power line carrier communication architecture, the effects of maintenance-free operation of the passive lock, traceability of damage events and high reliability of data transmission are realized.

Description

Technical Field

[0001] This invention belongs to the field of rail transit security equipment technology, and more specifically, relates to a passive lock anti-vandalism intelligent monitoring method and system based on abnormal log reporting. Background Technology

[0002] In the rail transit sector, locks are widely used for security in equipment cabinets, vehicle doors, and other locations. Existing smart electronic locks mostly employ an active architecture powered by built-in batteries, relying on regular battery replacements for operation. In remote and harsh environments such as tunnels and viaducts, maintenance costs are extremely high, and battery leakage and low-temperature power depletion can easily lead to lock failure, posing safety hazards. Traditional passive electronic locks only support RFID or NFC authentication and unlocking functions, lacking independent status monitoring and local log storage capabilities. In the event of vandalism, management personnel cannot promptly obtain abnormal information. Furthermore, the dense metal environment of rail transit equipment provides strong shielding for radio frequency wireless communication, making Bluetooth, LoRa, and other wireless communication methods unreliable and hindering stable reporting of vandalism logs.

[0003] Chinese patent document CN119882472A discloses a method for the linkage control of smart home appliances and access control devices. This method determines the unoccupied state of an indoor space by using access control records and biometric signals, then controls the smart home appliances to enter an automatic maintenance mode. It dynamically generates maintenance tasks and performs energy consumption optimization scheduling based on a performance degradation prediction model. While this solution addresses the linkage control between access control and home appliances in home scenarios and the automatic maintenance of devices in unoccupied states, it still relies on an active power supply system and is not applicable to outdoor lock scenarios in rail transit without external power sources. Furthermore, it lacks anti-vandalism monitoring and abnormal log reporting mechanisms for the locks themselves, failing to meet the security requirements of passive locks in rail transit.

[0004] Chinese patent document CN121033963A discloses an active smart lock system and its control method. It incorporates an environmental energy harvesting module and a dual-channel power management module to improve battery life, switches power consumption modes via a dynamic power controller, and enhances security through multi-modal authentication and blockchain-based evidence storage. While this solution addresses the battery life optimization and multi-scenario authentication issues of active smart locks, it still relies on a main energy storage battery and cannot achieve completely passive operation. Furthermore, its communication module uses wireless transmission, which is susceptible to shielding interference in the densely packed metal cabinets of rail transit environments, compromising the reliability of abnormal log reporting. Additionally, it lacks an architecture design that combines vibration energy supply with carrier communication for passive lock scenarios.

[0005] In summary, there is an urgent need to provide a smart monitoring method and system for preventing vandalism of passive locks in rail transit with anomaly log reporting function, in order to solve the problems existing in the current technology. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to address the issues mentioned in the background art, such as the high maintenance cost and low reliability of active electronic locks, the lack of anti-vandalism monitoring and log reporting capabilities of traditional passive locks, and the susceptibility of wireless communication to shielding interference in metallic environments, by combining vibration energy harvesting power supply with low-voltage power line carrier communication. This will enable the passive lock to operate without maintenance, traceable vandalism events, and highly reliable data transmission.

[0007] The technical terms related to this invention are explained as follows: Passive lock: An electronic lock that does not require a built-in battery or external power source and operates by relying on environmental energy harvesting or temporary power supply from external devices.

[0008] Low-voltage power line carrier communication: This method modulates data signals into high-frequency carrier waves and superimposes them onto DC power supply lines to achieve simultaneous power supply and communication transmission.

[0009] Vibration energy harvesting: an energy harvesting technology that converts mechanical vibration energy in the environment into electrical energy through piezoelectric or electromagnetic effects.

[0010] Non-volatile storage: storage media in which data is not lost after power failure; in this solution, it specifically refers to ferroelectric memory.

[0011] Supercapacitor: A high-power-density energy storage element used to store harvested vibration energy and provide power for short-term operation.

[0012] Mechanical tamper switch: A normally closed trigger switch installed inside the lock body. It disconnects and generates an interrupt signal when the lock body is pried open.

[0013] Carrier modulation and demodulation unit: A circuit unit that realizes the conversion between digital signals and high-frequency carrier signals.

[0014] Smart key: A handheld device with power supply, carrier communication and wireless transmission functions, used to read passive lock logs and upload them to the cloud.

[0015] The technical problem to be solved by this invention is addressed by the following technical solution. The technical problem to be solved by this invention is achieved by the following technical solution: A passive lock anti-vandalism intelligent monitoring method based on anomaly log reporting includes the following steps: S1. Collect the vibration energy at the location of the passive lock in the rail transit environment, convert the collected vibration energy into electrical energy, rectify it, and store it in the energy storage unit. S2. The main control unit is in a sleep state. The status detection module continuously monitors the lock body status. When an anti-vandalism event is detected, the main control unit is woken up by the electrical energy stored in the energy storage unit. The main control unit generates an exception log containing event type and occurrence time information and writes it to the non-volatile storage module. S3. When the smart key is inserted into the probe interface of the passive lock, the smart key outputs DC power to the passive lock through the probe to wake up the main control unit. S4. The passive lock and smart key establish a communication link through low-voltage power line carrier communication and complete identity authentication. S5. After successful identity authentication, the smart key sends a log reading command to the passive lock. The passive lock then transmits the abnormal logs from the non-volatile storage module back to the smart key via a carrier signal. S6. The smart key uploads the received abnormal logs to the cloud server, which then parses the abnormal logs and issues a warning message.

[0016] This technical solution, through the sequential coordination of the above steps, constructs a complete workflow encompassing passive standby monitoring, local anomaly storage, physical key connection, and carrier wave reading and reporting. This fundamentally eliminates reliance on built-in batteries, utilizing the continuous environmental vibrations present in rail transit scenarios as an energy source to achieve maintenance-free long-term operation of the lock. Specifically, the vibration energy harvesting and storage architecture provides a stable micro-energy supply for the lock's daily monitoring, enabling the main control unit to maintain responsiveness to abnormal events even in a very low-power sleep state. This avoids the maintenance costs and failure risks of active batteries and solves the shortcomings of traditional passive locks lacking autonomous monitoring capabilities. Simultaneously, the use of probe physical connection combined with low-voltage power line carrier communication integrates power supply and data transmission into the same set of probe contacts, eliminating the need for additional communication interfaces. Furthermore, the physical connection method completely avoids the shielding effect of the metal cabinet on wireless signals, ensuring the stability and reliability of data transmission even in environments with strong electromagnetic interference, significantly improving the success rate of anomaly log reporting under complex rail transit conditions. In addition, the design of local non-volatile storage of anomaly logs ensures that data on destructive events is not lost due to power outages, achieving traceability of destructive behavior.

[0017] In addition, the passive lock anti-vandalism intelligent monitoring method based on anomaly log reporting proposed above according to the present invention may also have the following additional technical features: Furthermore, the sabotage event in S2 is detected by at least one of the following methods: The mechanical anti-tamper switch is located between the lock cylinder back cover and the lock shell of the passive lock and is normally closed. When the lock body of the passive lock is pried, the mechanical anti-tamper switch is disconnected and an interrupt signal is generated. The vibration sensing unit detects the vibration of the passive lock in real time, and generates an interrupt signal when the vibration amplitude exceeds a preset threshold.

[0018] This technical solution employs a dual monitoring mechanism of mechanical triggering and vibration detection to achieve comprehensive identification of different types of destructive behavior. The mechanical anti-tamper switch, designed for physical acts such as prying and dismantling, uses a normally closed design so that any external force causing the lock shell and cylinder to separate will trigger the switch to open. This provides a fast response, high reliability, and is unaffected by electromagnetic interference. The vibration sensing unit, targeting violent acts such as impacts and shocks, collects vibration acceleration data in real time and compares it with preset thresholds to identify abnormal vibrations of varying intensities. It can also reuse the output signal from the vibration energy acquisition module as the basis for vibration detection, eliminating the need for additional sensors, simplifying the internal circuit structure, and reducing system power consumption and hardware costs. These two detection methods complement each other, ensuring accurate triggering of physical dismantling actions while achieving sensitive detection of impact damage, effectively improving the comprehensiveness and accuracy of anti-tamper monitoring.

[0019] Furthermore, the exception log in S2 includes the event type, the timing number of the event, and the occurrence time. The non-volatile storage module is a ferroelectric memory. After writing the exception log into the ferroelectric memory, the main control unit returns to the sleep state.

[0020] This technical solution employs ferroelectric memory as a non-volatile storage medium, leveraging its fast write speed, high write / erase cycles, and low power consumption. It is suitable for the short-term power supply scenarios of passive locks, ensuring rapid log writing under the limited power support of the energy storage unit, avoiding system power outages due to excessive power consumption during the writing process. The anomaly log uses a structured data format, including an event type field to distinguish different anomaly categories such as tamper triggering and vibration exceeding limits, a time sequence number field to ensure the log's chronological order, and an occurrence time field to record the relative or absolute time of the event, facilitating subsequent data analysis and event tracing. After completing the log writing, the main control unit immediately returns to sleep mode, minimizing energy consumption, extending the energy storage unit's runtime, and ensuring the lock can still record at least one anomaly event even in long-term vibration-free environments.

[0021] Furthermore, in step S4, the DC power supply output by the smart key to the passive lock via the probe is superimposed on the carrier communication signal and transmitted on the same electrical path. The filter isolation circuit installed in the passive lock separates the DC power supply component and the carrier communication component on the electrical path.

[0022] This technical solution employs a co-line transmission architecture for power supply and communication, enabling simultaneous DC power supply and carrier data transmission through a single set of probe contacts. This reduces the number of interface contacts, simplifies the mechanical structure of the probe interface, and improves sealing and protection performance. The filtering and isolation circuit utilizes a two-stage LC filter network structure, accurately separating the DC power supply component from the high-frequency carrier communication component. This prevents DC power supply ripple from interfering with carrier signal demodulation and avoids carrier signal interference in the power supply circuit affecting the stability of the internal circuitry, effectively improving the signal-to-noise ratio of communication and the purity of power supply. This co-line transmission design allows the smart key and lock body to complete power supply and full-duplex communication with only two contacts, significantly reducing the complexity of the physical interface and improving the reliability and lifespan of the connection.

[0023] Furthermore, in S4, the identity authentication includes at least one of the passive lock verifying the key of the smart key and the smart key verifying the device identifier of the passive lock; if authentication fails, log reading is refused.

[0024] This technical solution employs a two-way authentication mechanism to ensure data transmission security and prevent unauthorized devices from reading lock log data or forging commands to tamper with lock configurations. Specifically, the passive lock terminal stores a whitelist of authorized keys for legitimate keys and compares and verifies the authentication key sent by the smart key. The smart key terminal stores a list of device identifiers for legitimate locks and verifies the device identifiers returned by the lock. Only after both verifications are successful does the subsequent data interaction process begin. If authentication fails, the lock terminal immediately terminates communication and returns to a sleep state, refusing to respond to any read or control commands. This effectively avoids data leakage and security risks caused by unauthorized access, meeting the high security requirements of the rail transit security field.

[0025] Furthermore, in S6, the smart key uploads the abnormal log to the cloud server via its built-in 4G or 5G wireless communication module, or connects to the mobile terminal via Bluetooth, and the mobile terminal uploads the abnormal log to the cloud server.

[0026] This technical solution equips the smart key with multiple wireless upload methods to adapt to different application scenarios. The built-in 4G / 5G module allows direct access to cellular networks, enabling automatic real-time log uploads in areas with public network coverage, eliminating the need for additional equipment and improving operational efficiency. Bluetooth connectivity to mobile terminals is suitable for tunnels and underground areas with poor network signals, allowing maintenance personnel's mobile phones to act as relays for data uploads, reducing the hardware cost and power consumption of the smart key. These multiple upload methods complement each other, ensuring reliable transmission of abnormal logs to the cloud server in various rail transit operating environments, enabling centralized data management and unified early warning.

[0027] Furthermore, in S6, the cloud server parses the abnormal logs and identifies the abnormal event type. When the abnormal event type is an illegal intrusion event, an alarm is triggered on the management platform and a warning message is pushed to the management personnel's terminal.

[0028] This technical solution leverages the centralized analysis and early warning functions of a cloud server to achieve rapid response and unified management of abnormal events. Upon receiving log data uploaded by the smart key, the cloud server first performs data verification and format parsing, extracting key fields such as event type, occurrence time, and lock number. These are then correlated with lock location information in the database. When high-risk events such as unauthorized intrusion or forced entry are detected, an audible and visual alarm immediately pops up on the management platform. Simultaneously, the warning information is pushed to the management terminals of the corresponding areas via SMS and system notifications, facilitating immediate on-site response by maintenance personnel. Furthermore, the cloud server can perform statistical analysis on historical logs, generating distribution reports of sabotage events to provide data support for security strategy optimization.

[0029] Furthermore, the vibration energy in S1 is collected by a piezoelectric vibration acquisition unit or an electromagnetic vibration acquisition unit, and the converted electrical energy is rectified and stored in a supercapacitor; the main control unit is woken up in the following two ways: when a sabotage event occurs, it is woken up using the electrical energy stored in the supercapacitor, and when the smart key is inserted into the probe interface, it is woken up using the DC power provided by the smart key.

[0030] This technical solution employs either piezoelectric or electromagnetic vibration acquisition methods to adapt to different vibration environments and installation requirements. The piezoelectric vibration acquisition unit utilizes a cantilever beam structure, resulting in a small size and high integration, suitable for small locks with strict space constraints. The electromagnetic vibration acquisition unit boasts high output power and high energy conversion efficiency, ideal for applications with smaller vibration amplitudes but requiring more electrical energy. The energy storage unit uses supercapacitors, which offer advantages over traditional batteries, including faster charging and discharging speeds, longer cycle life, and better low-temperature performance. These supercapacitors can quickly collect instantaneous vibration energy and output it stably, meeting the power requirements of the main control unit for short-term operation. The main control unit features a dual wake-up source design, ensuring both autonomous triggering response during abnormal events and active wake-up upon key insertion. These two wake-up methods are independent, ensuring reliable system startup in various scenarios.

[0031] In another aspect, the present invention also provides a passive lock anti-vandalism intelligent monitoring system based on anomaly log reporting.

[0032] A passive lock anti-vandalism intelligent monitoring system based on anomaly log reporting includes: Passive lock; The vibration energy acquisition module, located inside the passive lock, is used to collect environmental vibration energy and convert it into electrical energy. The power management module, connected to the vibration energy acquisition module, is used to rectify electrical energy and store it in the energy storage unit; The status detection module, located inside the passive lock, is used to detect the status of the lock body and generate an interrupt signal when an anti-vandalism event occurs. The main control unit is connected to the power management module and the status detection module respectively, and is used to start and generate an exception log when triggered by an interrupt signal; A non-volatile storage module, connected to the main control unit, is used to store exception logs; The probe interface is located on the outside of the passive lock and is used to connect and cooperate with the probe of the smart key. The carrier communication module is connected to the main control unit and the probe interface. It is used to modulate the digital signal output by the main control unit into a carrier signal and superimpose it on the power supply line of the probe interface for transmission, and to demodulate the digital signal from the carrier signal received from the power supply line of the probe interface. The smart key is used to supply power to the passive lock via a probe and to read and upload the abnormal logs after the abnormal logs are read by the carrier communication module. The cloud server communicates with the smart key to receive and parse abnormal logs and issue warning messages.

[0033] This technical solution integrates energy harvesting, power management, status monitoring, data storage, and carrier communication functions within a passive lock through a modular system architecture design. The smart key serves as an external interactive device, enabling power supply, data reading, and data uploading. A cloud server handles data management and early warning, constructing a three-tiered architecture: the on-site passive lock, the handheld smart key, and the cloud management platform. This architecture transfers high-power wireless communication and data processing functions to the smart key and the cloud, while the lock body retains only the lowest-power monitoring and storage functions, minimizing the lock's energy consumption and allowing it to operate normally solely through vibration energy harvesting. Furthermore, the modular design facilitates independent upgrades and maintenance of each functional unit, and different lock models can use the same smart key and cloud platform, reducing system deployment and maintenance costs and making it suitable for the large-scale lock management needs of the rail transit sector.

[0034] Furthermore, the status detection module includes a mechanical anti-tamper switch and a vibration sensing unit. The mechanical anti-tamper switch is located between the lock cylinder back cover and the lock shell of the passive lock and is normally closed. The carrier communication module includes a carrier modulation and demodulation unit and a signal coupling circuit. The power management module includes a filter isolation circuit. The filter isolation circuit is connected to the probe interface, the energy storage unit and the carrier modulation and demodulation unit respectively, and is used to separate the DC power component and the carrier communication component on the power supply line.

[0035] The dual-sensor configuration of the status detection module enables multi-dimensional monitoring of destructive behavior. The normally closed design of the mechanical anti-tamper switch ensures that even if the system is completely powered off, it can still identify tampering events upon the next power-on. The vibration sensing unit allows for software adjustment of the sensitivity threshold to adapt to vibration backgrounds at different installation locations. The signal coupling circuit of the carrier communication module achieves efficient coupling and impedance matching of the carrier signal, improving communication distance and anti-interference capabilities. The design of the filtering and isolation circuit ensures that power supply and communication do not interfere with each other, guaranteeing the signal-to-noise ratio of carrier communication. The circuit design of each module follows the principle of low power consumption, retaining only the necessary detection circuits in sleep mode to minimize static power consumption and improve energy utilization efficiency.

[0036] The one or more technical solutions provided by this invention have the following advantages compared with the prior art: (1) Maintenance-free and highly reliable operation. It is powered entirely by the vibration energy of the rail transit environment, without the need for a built-in battery, thus completely eliminating problems such as battery replacement, leakage, and power loss. The lock body can operate without maintenance for a long time. The carrier communication method with probe physical connection avoids the shielding of wireless signals by the metal environment, resulting in high communication reliability and adaptability to complex working conditions such as tunnels and elevated roads.

[0037] (2) Traceable damage behavior. Breaking through the limitations of traditional passive locks that have no state memory, it records damage event logs locally through non-volatile storage. The logs are not lost when power is off, and historical abnormal data can be read through the smart key afterward, providing a basis for security investigation and responsibility determination, thus realizing the traceable management of passive locks against damage.

[0038] (3) Secure and flexible architecture. It adopts a three-level architecture of local storage in the lock body, smart key transfer, and cloud analysis and early warning. The lock body is not directly connected to the public network, which reduces the risk of network attack. The smart key has power supply, communication and upload functions. It can be read locally and uploaded remotely, adapting to different operation and maintenance scenarios and taking into account both security and flexibility. Attached Figure Description

[0039] Figure 1 This is a flowchart illustrating the principle of the present invention. Detailed Implementation

[0040] Example 1 Please refer to Figure 1 This embodiment provides an intelligent monitoring method for preventing damage to passive locks based on abnormal log reporting. It is applied to the passive lock scenario of rail transit equipment control cabinet. The specific implementation process is divided into two stages: daily monitoring and log recording, and log reporting and cloud early warning. The following is a detailed description of each step.

[0041] Vibration energy acquisition and standby energy storage during routine monitoring. The operation of rail transit trains and equipment generates continuous environmental mechanical vibrations. The vibration energy acquisition unit inside the passive lock collects the vibration energy at its location in real time. If a piezoelectric cantilever beam structure is used, when the vibration frequency approaches the natural frequency of the cantilever beam, the piezoelectric material deforms and outputs alternating induced charges, forming AC power. If an electromagnetic acquisition unit is used, the relative motion between the internal coil and the magnet cuts magnetic field lines to generate an induced electromotive force. The acquired AC power is input to the rectifier circuit of the power management module, converted into pulsating DC power by a full-bridge rectifier, and then charged by a supercapacitor after voltage regulation and filtering, storing the energy in the supercapacitor. When no abnormal events occur, the main control unit is in deep sleep mode, with only the interrupt detection circuit operating. Static power consumption is controlled at the microampere level. The energy stored in the supercapacitor can maintain the main control unit's sleep power consumption and interrupt response capability, ensuring several days of standby monitoring capability even without short-term vibration input.

[0042] Abnormal event triggering and local log recording. When destructive acts such as forced entry or impact to the lock body occur, the mechanical anti-tamper switch and vibration sensing unit of the status detection module monitor the situation. If the destructive act causes the lock shell and the back cover of the lock cylinder to separate, the normally closed mechanical anti-tamper switch located between them physically disconnects, generating an interrupt signal with a level transition. If the destructive act is a severe impact, the vibration acceleration amplitude detected by the vibration sensing unit exceeds the preset trigger threshold, also generating an interrupt signal. The interrupt signal is directly input to the external interrupt pin of the main control unit, using the electrical energy stored in the supercapacitor to wake up the main control unit. After the main control unit starts up, it first reads the interrupt source register to determine the trigger type, identifying whether it is an anti-tamper trigger or a vibration over-limit trigger. Then, it obtains the current time information from the internal real-time clock and generates an abnormal log entry according to the preset log format. The log entry includes fields such as the lock's unique ID, event type code, event timestamp, and event sequence number. After generating the log, the main control unit writes the log data to the ferroelectric memory via the serial peripheral interface. The ferroelectric memory has a write speed of nanoseconds, completing the write in a very short time, thus maximizing energy savings. After writing is complete, the main control unit clears the interrupt flag and immediately returns to deep sleep mode, waiting for the next interrupt trigger or key insertion to wake it up.

[0043] The key is inserted and power-on establishes carrier communication. When maintenance personnel conduct inspections, they insert the smart key into the probe interface on the outside of the passive lock. The gold-plated probe at the front of the key makes tight contact with the probe seat on the lock body, forming a stable physical electrical connection. The lithium battery inside the smart key outputs 3.3V DC power to the passive lock through the probe. The power is filtered and isolated by the internal filtering circuit of the lock body before supplying power to the main control unit and peripheral circuits, waking up the main control unit from its dormant state. After the main control unit is powered on and reset, it first initializes the system, configures the parameters of the carrier communication module, and then sends a connection handshake signal to the smart key. After receiving the handshake signal, the smart key replies with an acknowledgment signal. Both parties establish a full-duplex communication link through low-voltage power line carrier communication. The carrier frequency uses the standard frequency point of 115.2kHz, the modulation method is frequency shift keying, and the communication rate can reach 9600bps. After the communication link is established, two-way authentication is performed: the smart key sends its own authentication key to the lock, and the lock reads the locally stored list of authorized keys for comparison; at the same time, the lock sends its own unique device identifier to the smart key, and the smart key verifies whether the identifier is in the list of legitimate devices.

[0044] Log Reading and Cloud Alerts. After successful two-way authentication, the smart key sends a command to the passive lock to read all abnormal logs. Upon receiving the command, the main control unit sequentially reads all unuploaded abnormal log data from the ferroelectric memory, modulates the digital data into a high-frequency carrier signal via the carrier modulation and demodulation unit, and superimposes it onto the DC power supply line before sending it to the smart key. The carrier demodulation circuit inside the smart key separates the carrier signal from the power supply line, demodulates it back into digital log data, and stores it in the local storage area. After reading is complete, the smart key sends a stop command. Upon receiving this command, the lock disconnects the communication connection and returns to sleep mode after the key is removed. The smart key selects the upload method based on the current network environment: in areas with cellular network coverage, it directly uploads log data to the cloud server via the built-in 4G module; in areas without network coverage, such as tunnels, it connects to the maintenance personnel's mobile terminal via Bluetooth, and the mobile phone forwards the data to the cloud. After receiving the log data, the cloud server performs data parsing, format verification, and storage. When high-risk events such as illegal intrusion or violent destruction are detected, an audible and visual alarm is immediately triggered on the management platform, and the warning information is sent to the managers in the corresponding responsible areas via SMS, APP push, and other means. At the same time, an event handling work order is generated to track the handling progress.

[0045] This embodiment achieves passive standby monitoring through vibration energy harvesting. Abnormal events trigger local log storage, and data reading and cloud reporting are completed via carrier communication connected by the smart key. The entire process requires no built-in battery in the lock body and does not rely on on-site wireless communication, making it fully adaptable to the complex environment of rail transit. In actual testing, under typical rail transit conditions with a vibration acceleration of 0.5g and a frequency of 10Hz, the supercapacitor only needs 2 hours to charge to 3.3V, which can support the writing of logs for at least 10 abnormal events; the carrier communication has a bit error rate of less than 10% when the probe contact resistance is less than 1Ω. -6 The communication success rate can reach 100%, and it can reliably and stably complete log transmission.

[0046] Example 2 Based on the above method embodiments, this embodiment provides specific circuit parameter design and core algorithm formulas, and performs quantitative design on vibration energy acquisition power, abnormal vibration detection algorithm, carrier communication performance and storage capacity to verify the feasibility and performance indicators of the technical solution.

[0047] Parameter calculation for vibration energy harvesting and storage system. This embodiment uses a piezoelectric cantilever beam vibration harvesting unit, and its output power calculation formula is as follows:

[0048] in, The mass of the end mass block of the cantilever beam is expressed in kg. The electromechanical coupling damping ratio; The angular frequency of environmental vibration is expressed in rad / s. This represents the amplitude of vibration acceleration, in m / s². This is the stiffness coefficient of the cantilever beam, expressed in N / m.

[0049] For typical rail transit environments, vibration frequencies are selected. ,Right now Vibration acceleration Design the stiffness of the cantilever beam quality block quality Electromechanical coupling damping ratio Substituting the values ​​into the formula, the output power is approximately 120μW. This power is sufficient to meet the power consumption requirements of the main control unit during sleep mode and the energy needs for periodic monitoring. The daily accumulated energy collection can support a complete log writing process for at least 5 abnormal events.

[0050] The energy storage unit uses a 0.47F supercapacitor, and its energy storage calculation formula is as follows:

[0051] in, For capacitance, This is the highest charging voltage. This is the minimum operating voltage. (Take...) , Substituting the values ​​into the calculation, the available energy is approximately 1.53J. The main control unit has a single wake-up operating current of approximately 5mA, an operating time of approximately 100ms, and a single energy consumption of approximately 1.65mJ. Therefore, a fully charged supercapacitor can support at least 900 abnormal event recordings, fully meeting the actual usage requirements.

[0052] An adaptive threshold algorithm for abnormal vibration detection. To avoid false alarms triggered by vibrations in normal environments, an adaptive threshold algorithm is used to dynamically adjust the vibration trigger threshold. The algorithm flow is as follows: First, with a fixed sampling frequency Vibration acceleration signals are collected, and the root mean square value of the vibration is calculated using a sliding window method for N consecutive sampling points to obtain the vibration intensity value.

[0053] in, Let N be the acceleration value at the nth sampling point, and N be the length of the sliding window. Let N=50, which corresponds to a time window of 0.5 seconds.

[0054] Then, the baseline threshold is calculated based on long-term background vibration statistics:

[0055] in, This represents the average vibration intensity under normal environmental conditions. Let be the standard deviation, and k be the safety factor. Taking k=3 corresponds to a confidence level of 99.7%.

[0056] When the vibration intensity value is detected And the duration exceeds the set duration threshold. When an abnormal vibration event occurs, an interrupt signal is generated. This adaptive algorithm can automatically adjust the trigger threshold according to the background vibration level of different installation locations, ensuring sensitive detection of violent impacts while effectively reducing the false trigger rate caused by normal operational vibrations. In actual scenario testing, the false trigger rate of this algorithm is less than 0.1 times / day, and the accuracy of abnormal event detection can reach over 99%.

[0057] Signal-to-noise ratio (SNR) and transmission distance calculation for low-voltage power line carrier communication. The carrier communication system used in this embodiment employs a two-stage LC filter isolation circuit. The channel SNR calculation formula is as follows:

[0058] in, The amplitude of the carrier signal at the receiving end. This represents the noise voltage amplitude at the receiving end.

[0059] The output amplitude of the carrier signal is 2Vpp, which passes through the probe contact resistor. After the line impedance attenuation, the signal amplitude at the receiving end is about 1.5Vpp; the total noise amplitude of power supply ripple noise and electromagnetic interference noise is about 10mVpp. Substituting these values ​​into the calculation, the signal-to-noise ratio is about 43.5dB, which is much higher than the 12dB demodulation threshold required by frequency shift keying modulation. Therefore, the communication has sufficient margin.

[0060] The formula relating communication rate and bit error rate is:

[0061] Substituting SNR=43.5dB into the calculation, the theoretical bit error rate is less than 10. - ¹ 0 This ensures extremely high reliability of data transmission. In actual testing, even with a probe contact resistance of 5Ω, the signal-to-noise ratio remains above 30dB, and the bit error rate is below 10%. -6 It fully meets the reliability requirements for log data transmission.

[0062] Capacity management and wear leveling algorithms for non-volatile memory. This embodiment uses a 512KB ferroelectric memory to store exception logs. Each log entry is 32 bytes long and includes fields such as lock ID, event type, timestamp, sequence number, and checksum. The theoretical storage capacity is:

[0063] To avoid memory wear caused by frequent writes to the same address, a circular queue wear leveling algorithm is employed. The storage space is divided into contiguous log blocks, maintaining a write pointer and a read pointer. Each time a new log is written, the write pointer moves forward, automatically returning to the beginning when it reaches the end of the storage space, cyclically overwriting the oldest historical logs. The algorithm also records the start and end sequence numbers of valid logs, ensuring that all valid logs are output in chronological order during reading. This algorithm ensures that all storage units in the entire storage space are used evenly. The ferroelectric memory's erase / write lifespan can reach 10¹² cycles. Based on 10 abnormal events per day, its lifespan can exceed 270,000 years, fully meeting the product's lifecycle requirements.

[0064] This embodiment verifies, through quantitative formula calculations and algorithm design, that the power of vibration energy acquisition is sufficient to support system operation, the anomaly detection algorithm can accurately identify destructive events, the carrier communication has extremely high reliability, and the storage capacity and lifespan meet the requirements for long-term use. All performance indicators are superior to existing technical solutions, providing clear parameter basis and design reference for engineering implementation.

[0065] Example 3 Please refer to Figure 1 This embodiment provides a passive lock anti-vandalism intelligent monitoring system based on abnormal log reporting, which specifically includes three parts: passive lock terminal device, smart key and cloud server. The following provides a detailed description of the structure, connection relationship and working principle of each part.

[0066] The passive lock features an industrial-grade protective shell with an IP67 protection rating, suitable for humid and dusty outdoor environments. Internally, it integrates a vibration energy acquisition module, power management module, status detection module, main control unit, non-volatile storage module, carrier communication module, and probe interface components. The vibration energy acquisition module employs a piezoelectric cantilever beam structure, fixed to a mounting post inside the lock shell with screws. The fixed end of the cantilever beam is rigidly connected to the lock shell, while the free end carries a mass block, enabling sensitive sensing of vibrations experienced by the lock body. The power management module, integrated on the main control circuit board, includes a full-bridge rectifier circuit, a voltage regulator circuit, a supercapacitor energy storage unit, and a filter isolation circuit. The input of the rectifier circuit connects to the output of the vibration energy acquisition module, and the output connects to the supercapacitor and the voltage regulator circuit. The voltage regulator circuit outputs a 3.3V system power bus to power the main control unit and other digital circuits. The filter isolation circuit connects the probe interface to the internal power supply and carrier module, achieving DC-DC and carrier separation. The main control unit uses an ultra-low-power MCU, model STM32L011, with a sleep current of only 0.5μA. It has multiple external interrupt sources and can quickly respond to trigger signals. The non-volatile memory module uses ferroelectric memory and is connected to the main control unit via an I2C bus. The status detection module includes a mechanical tamper switch and a vibration sensing unit. The mechanical tamper switch is a normally closed membrane switch, clamped between the lock cylinder back cover and the inner wall of the lock shell. The switch automatically disconnects when the lock shell is pried open, and its output is connected to the interrupt pin of the main control unit. The vibration sensing unit multiplexes the output signal of the vibration acquisition module and connects it to the ADC pin of the main control unit through a voltage divider circuit to realize vibration amplitude detection.

[0067] The carrier communication module and probe interface are structurally designed as follows: The carrier communication module is integrated on the main control circuit board, including a carrier modulation and demodulation unit and a signal coupling circuit. The carrier modulation and demodulation unit uses a dedicated PLC modulation and demodulation chip, supporting a 115.2kHz carrier frequency and frequency shift keying modulation. It has a built-in digital signal processing unit and error correction mechanism, enabling reliable half-duplex or full-duplex communication. The signal coupling circuit consists of coupling capacitors and inductors, achieving coupling and isolation between the carrier signal and the DC power supply line. The probe interface is located on the side end face of the lock body, using a countersunk sealed base structure. Two gold-plated probe contacts are embedded inside the base, and the contacts use a flexible pin design to ensure tight contact with the key probe. A sealing rubber ring is provided on the outside of the base. When the smart key is inserted, the rubber ring is compressed to achieve a waterproof seal, preventing moisture and dust from entering the interface. The lock body probe holder is fixedly installed on the lock cylinder shell. The two probe contacts inside are respectively connected to the input terminal of the filter isolation circuit of the power management module, and simultaneously connected to the signal terminal of the carrier communication module through a coupling capacitor, realizing the co-line transmission of power supply and carrier signal. The probe contact surface is gold-plated with a thickness of not less than 2μm, which can withstand tens of thousands of insertions and removals while maintaining good conductivity, making it suitable for frequent inspection scenarios.

[0068] The smart key is a handheld portable device with a built-in rechargeable lithium battery, power management circuit, carrier communication unit, microcontroller, local storage unit, and 4G / Bluetooth wireless communication module. The front of the key has two gold-plated probes that mate with the lock body probe interface, and an internal spring structure ensures contact pressure during docking. The core controller of the smart key uses an ARM Cortex-M4 core microcontroller, responsible for controlling power output, carrier communication, data storage, and wireless upload. When the key is inserted into the lock body, the controller controls the power supply to output 3.3V DC voltage, and simultaneously activates the carrier communication module to establish a connection with the lock body, completing identity authentication and log reading. The read log data is stored in local Flash memory. The side of the key has function buttons and status indicator lights, which can manually trigger log reading and upload operations. The indicator lights display the connection status, data transmission status, and battery status. The smart key's lithium battery has a capacity of 1000mAh, supporting at least 500 lock log reading operations on a full charge, with a battery life of more than one month, meeting daily inspection needs.

[0069] System Architecture and Functions of the Cloud Server. The cloud server is deployed on a cloud platform, employing a B / S architecture management platform, comprising a data access layer, a data storage layer, a business logic layer, and a front-end presentation layer. The data access layer supports 4G cellular network and internet access, receiving log data uploaded by smart keys, performing data verification and protocol parsing, and then storing it in the database. The data storage layer uses a relational database to store basic lock information, log data, user information, and alarm records, and a time-series database to store historical vibration data and statistical data. The business logic layer implements core functions such as log parsing, event recognition, alarm management, and statistical reports. It can automatically identify high-risk events based on preset alarm rules and trigger corresponding alarm processes. The front-end presentation layer provides a web management interface, supporting functions such as electronic map display of lock distribution, real-time alarm pop-ups, historical log queries, and data statistical reports. Administrators can log in to the platform through a browser to view the operating status and abnormal events of all locks. The cloud server also supports integration with existing rail transit operation and maintenance management systems, synchronizing alarm information to the existing operation and maintenance work order system for integrated management.

[0070] The overall workflow of this system embodiment is as follows: Under normal conditions, the passive lock relies on vibration energy collection to maintain standby monitoring, and automatically records logs when a tampering event occurs. During maintenance personnel's inspections, a smart key is inserted into the lock body probe interface to complete power supply, authentication, and log reading. After the inspection, the smart key uploads all collected lock logs to the cloud server in batches. The cloud platform parses the data and generates alarms and reports for centralized management. This system is completely passive, requiring no wiring or battery maintenance, offering reliable communication and high security. It is ideal for the security management of numerous equipment cabinets and control cabinets distributed along rail transit lines, effectively improving maintenance efficiency and reducing management costs.

[0071] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the technical solutions of the present invention, and are not intended to limit the specific implementation of the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the claims of the present invention should be included within the protection scope of the claims of the present invention.

Claims

1. A passive lock anti-vandalism intelligent monitoring method based on anomaly log reporting, characterized in that, Includes the following steps: S1. Collect the vibration energy at the location of the passive lock in the rail transit environment, convert the collected vibration energy into electrical energy, rectify it, and store it in the energy storage unit. S2. The main control unit is in a sleep state. The status detection module continuously monitors the lock body status. When an anti-vandalism event is detected, the main control unit is woken up by the electrical energy stored in the energy storage unit. The main control unit generates an exception log containing event type and occurrence time information and writes it to the non-volatile storage module. S3. When the smart key is inserted into the probe interface of the passive lock, the smart key outputs DC power to the passive lock through the probe to wake up the main control unit. S4. The passive lock and smart key establish a communication link through low-voltage power line carrier communication and complete identity authentication. S5. After successful identity authentication, the smart key sends a log reading command to the passive lock. The passive lock then transmits the abnormal logs from the non-volatile storage module back to the smart key via a carrier signal. S6. The smart key uploads the received abnormal logs to the cloud server, which then parses the abnormal logs and issues a warning message.

2. The passive lock anti-vandalism intelligent monitoring method based on anomaly log reporting according to claim 1, characterized in that, The anti-vandalism event in S2 is detected by at least one of the following methods: The mechanical anti-tamper switch is located between the lock cylinder back cover and the lock shell of the passive lock and is normally closed. When the lock body of the passive lock is pried, the mechanical anti-tamper switch is disconnected and an interrupt signal is generated. The vibration sensing unit detects the vibration of the passive lock in real time, and generates an interrupt signal when the vibration amplitude exceeds a preset threshold.

3. The passive lock anti-vandalism intelligent monitoring method based on anomaly log reporting according to claim 1, characterized in that, The exception log in S2 includes the event type, the timing number of the event, and the occurrence time. The non-volatile storage module is a ferroelectric memory. After writing the exception log into the ferroelectric memory, the main control unit returns to the sleep state.

4. The passive lock anti-vandalism intelligent monitoring method based on anomaly log reporting according to claim 1, characterized in that, In step S4, the DC power supply output by the smart key to the passive lock via the probe is superimposed on the carrier communication signal and transmitted on the same electrical path. The filter isolation circuit installed in the passive lock separates the DC power supply component and the carrier communication component on the electrical path.

5. The passive lock anti-vandalism intelligent monitoring method based on anomaly log reporting according to claim 1, characterized in that, In step S4, the identity authentication includes at least one of the passive lock verifying the key of the smart key and the smart key verifying the device identifier of the passive lock. If authentication fails, log reading is refused.

6. The passive lock anti-vandalism intelligent monitoring method based on anomaly log reporting according to claim 1, characterized in that, In S6, the smart key uploads the abnormal log to the cloud server through the built-in 4G or 5G wireless communication module, or connects to the mobile terminal through the Bluetooth module, and the mobile terminal uploads the abnormal log to the cloud server.

7. The passive lock anti-vandalism intelligent monitoring method based on anomaly log reporting according to claim 1, characterized in that, In S6, the cloud server parses the abnormal logs and identifies the abnormal event type. When the abnormal event type is an illegal intrusion event, an alarm is triggered on the management platform and a warning message is pushed to the management personnel terminal.

8. The passive lock anti-vandalism intelligent monitoring method based on anomaly log reporting according to claim 1, characterized in that, The vibration energy in S1 is collected by a piezoelectric vibration acquisition unit or an electromagnetic vibration acquisition unit, and the converted electrical energy is rectified and stored in a supercapacitor. The main control unit is woken up in the following two ways: when a sabotage event occurs, it is woken up using the electrical energy stored in the supercapacitor, and when the smart key is inserted into the probe interface, it is woken up using the DC power provided by the smart key.

9. A passive lock anti-vandalism intelligent monitoring system based on anomaly log reporting, employing the passive lock anti-vandalism intelligent monitoring method based on anomaly log reporting as described in any one of claims 1-8, characterized in that, include: Passive lock; The vibration energy acquisition module, located inside the passive lock, is used to collect environmental vibration energy and convert it into electrical energy. The power management module, connected to the vibration energy acquisition module, is used to rectify electrical energy and store it in the energy storage unit; The status detection module, located inside the passive lock, is used to detect the status of the lock body and generate an interrupt signal when an anti-vandalism event occurs. The main control unit is connected to the power management module and the status detection module respectively, and is used to start and generate an exception log when triggered by an interrupt signal; A non-volatile storage module, connected to the main control unit, is used to store exception logs; The probe interface is located on the outside of the passive lock and is used to connect and cooperate with the probe of the smart key. The carrier communication module is connected to the main control unit and the probe interface. It is used to modulate the digital signal output by the main control unit into a carrier signal and superimpose it on the power supply line of the probe interface for transmission, and to demodulate the digital signal from the carrier signal received from the power supply line of the probe interface. The smart key is used to supply power to the passive lock via a probe and to read and upload the abnormal logs after the abnormal logs are read by the carrier communication module. The cloud server communicates with the smart key to receive and parse abnormal logs and issue warning messages.

10. The passive lock anti-vandalism intelligent monitoring system based on anomaly log reporting according to claim 9, characterized in that, The status detection module includes a mechanical anti-tamper switch and a vibration sensing unit. The mechanical anti-tamper switch is located between the lock cylinder back cover and the lock shell of the passive lock and is normally closed. The carrier communication module includes a carrier modulation and demodulation unit and a signal coupling circuit. The power management module includes a filter isolation circuit. The filter isolation circuit is connected to the probe interface, the energy storage unit and the carrier modulation and demodulation unit respectively, and is used to separate the DC power component and the carrier communication component on the power supply line.

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