Self-powered foamed aluminum impact sensing system for submarine pipeline monitoring

Abstract

The invention relates to the technical field of ocean engineering monitoring, and discloses a self-powered foamed aluminum impact sensing system for submarine pipeline monitoring, which comprises a bimodal impact sensing interface module, a multi-dimensional event feature generation module, a signal processing and cooperative communication module and an energy management and packaging module. The interface module decouples impact into low-frequency mechanical pressure and high-frequency elastic stress waves by using a closed-cell foamed aluminum material and a high-impedance elastic waveguide column; the feature generation module physically latches an energy feature vector and a modal feature through an analog circuit before the processor is awakened; the signal processing module reads features and timestamps after being awakened; the energy management module collects impact energy and provides a seal. Multi-dimensional features are physically latched before the processor is awakened, and bimodal decoupling sensing is combined, so that impact recognition under ultra-low power consumption is realized, and self power supply, long-term monitoring and accurate distinguishing of threat events in a severe seabed environment are facilitated.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of ocean engineering monitoring, in particular to a self-powered foam aluminum impact sensing system for submarine pipeline monitoring. BACKGROUND

[0002] As a key infrastructure for the development of marine oil and gas resources, the safe operation of submarine pipelines is of great significance to energy security and marine environmental protection. These pipelines are prone to threats from physical impact events such as ship anchor strikes, geological activities, or malicious damage by third parties, as they are subjected to deep-sea high pressure and corrosive environments for long periods. Therefore, developing real-time monitoring technology for submarine pipelines, especially sensing systems that can accurately identify and locate impact events, is a necessary means to ensure the integrity of the pipeline structure.

[0003] Existing submarine pipeline impact monitoring technology solutions mainly rely on distributed acoustic sensing (DAS) or piezoelectric (PZT) based acoustic monitoring arrays. Distributed optical fiber sensing involves laying special optical cables along the pipeline and demodulating backscattered signals to achieve long-distance vibration monitoring. Acoustic monitoring arrays involve deploying multiple sensor nodes at key locations on the pipeline and analyzing the collected acoustic or vibration signals. In terms of energy supply, these systems mostly use submarine cables for centralized power supply or are equipped with large-capacity disposable batteries. In terms of data processing, traditional nodes tend to high-frequency continuous sampling or local digital signal processing.

[0004] Due to the harsh restrictions of the submarine environment on system power consumption and maintainability, existing monitoring solutions face challenges in achieving long-term autonomous operation. On the one hand, continuous high-frequency sampling and complex local digital signal processing result in high static power consumption, which limits the autonomous operation time of battery-powered sensor nodes, while using submarine cable power supply is costly and complex to deploy. On the other hand, the underwater acoustic environment is complex, and impact signals are often mixed with ocean background noise and fluid noise. To ensure the capture of occasional impact events, traditional monitoring systems must keep the processor in a high-power wake-up or listening state for a long time, and it is difficult to effectively distinguish between real threat impacts and non-threat disturbances in the early stages of signal acquisition, which not only leads to high false alarm rates, but also generates a large amount of redundant data, increasing the subsequent communication and processing burden. SUMMARY

[0005] To address the shortcomings of the prior art, the present application provides a self-powered foam aluminum impact sensing system for submarine pipeline monitoring, aiming to solve the problems of high static power consumption, limited autonomous operation time of existing monitoring systems, and inaccurate impact identification in complex noise environments.

[0006] To achieve the above object, the application is implemented by the following technical solutions: a self-powered foam aluminum impact sensing system for submarine pipeline monitoring, comprising: A bimodal impact sensing interface module for responding to physical impact events on the pipeline and decoupling the impact signals into a low-frequency mechanical pressure and a high-frequency elastic stress wave; A multi-dimensional event feature generation module connected to the bimodal impact sensing interface module for receiving the low-frequency mechanical pressure and the high-frequency elastic stress wave and converting the low-frequency mechanical pressure and the high-frequency elastic stress wave into charge signals, energy feature vectors and modal features; A signal processing and cooperative communication module connected to the multi-dimensional event feature generation module for reading the energy feature vectors, the modal features and high-precision time stamps after being woken up by a hardware interrupt signal and performing cooperative communication; An energy management and packaging module connected to the multi-dimensional event feature generation module for receiving the charge signals, collecting impact energy therefrom and providing power supply to internal electronic modules of the system and providing a sealed physical barrier for the internal electronic modules.

[0007] In a preferred technical solution, the bimodal impact sensing interface module realizes physical separation of signals through specific mechanical structure design. The bimodal impact sensing interface module includes an energy capture and protection unit and a timing sensing unit.

[0008] The energy capture and protection unit includes a closed-cell foam aluminum material. When impacted, the material utilizes its elastic-plastic collapse characteristics to convert high-frequency oscillating impact kinetic energy into a low-frequency mechanical pressure signal with relatively flat waveform and long duration.

[0009] The timing sensing unit includes a high-impedance elastic waveguide column. The waveguide column physically bypasses the closed-cell foam aluminum material in structure, with one end in rigid contact with the pipeline wall being monitored. This design enables high-frequency elastic stress waves (i.e. first arrival waves) generated by impact events to bypass the foam aluminum buffer and be quickly conducted to the internal transducer element through the waveguide column.

[0010] In another key technical feature of the application, the multi-dimensional event feature generation module realizes ultra-low power feature extraction and physical latching before the processor wakes up. The module specifically includes a piezoelectric transducer unit, an energy gradient quantization unit and a timing modal discrimination unit.

[0011] The piezoelectric transduction unit (e.g. PZT) receives the low frequency mechanical pressure and high frequency elastic stress wave and converts them into charge signals. The energy gradient quantification unit, e.g. a hierarchical threshold energy storage array, quantifies the voltage peaks corresponding to the low frequency mechanical pressure. By comparing the voltage peaks to charge which level of the array, this unit physically latches in the analog domain an energy feature vector representing the impact energy level.

[0012] The timing modal discrimination unit, e.g. composed of an ultra-low power analog comparator and a digital latch, compares in real time the first arrival signal amplitude and polarity of the high frequency elastic stress wave. By such comparison, this unit physically latches in the analog domain a modal feature representing the initial phase of the impact waveform. Both the energy feature vector and the modal feature latching processes are completed before the processor of the signal processing and cooperative communication module is woken up, which helps to reduce the standby power consumption of the system.

[0013] The signal processing and cooperative communication module specifically includes an event-driven processing unit and a cooperative communication unit. The event-driven processing unit includes an ultra-low power microprocessor and a high-precision local timing unit. The multi-dimensional event feature generation module generates a hardware interrupt signal after completing the feature latching. The ultra-low power microprocessor is woken up in response to the hardware interrupt signal.

[0014] After the processor is woken up, the first task is to immediately read the count value of the high-precision local timing unit. The count value plus the global reference time of the last synchronization of the node can obtain the high-precision time stamp of the event occurrence.

[0015] Subsequently, the processor reads the energy feature vector and the modal feature that have been physically latched. In cooperative communication, the system can use the modal feature as a consistency gate to eliminate false data caused by reflected waves or noise interference, and then use the high-precision time stamp for impact positioning solution (e.g. TDoA algorithm).

[0016] To realize the long-term autonomous operation of the system, the energy management and packaging module specifically includes an energy collection and management unit and a sealing packaging unit. The energy collection and management unit includes a rectifier circuit, an energy collection management chip, a main battery and a secondary energy storage element (e.g. super capacitor).

[0017] The energy collection and management unit is used to rectify the charge signals generated by the piezoelectric transduction unit during the impact process, store the collected impact energy in the secondary energy storage element, and preferentially use the energy in the secondary energy storage element to power the system, and only switch to the main battery when the secondary energy storage element is depleted.

[0018] The sealed packaging unit provides physical protection for the internal electronic module. The unit forms a sealed cavity, and the multi-dimensional event feature generation module and the signal processing and cooperative communication module are located in the sealed cavity. In structure, the closed-cell foam aluminum material of the dual-mode impact sensing interface module is mounted outside the sealed packaging unit and can directly bear external impact. The high-impedance elastic waveguide column passes through the sealed packaging unit, one end of which is in rigid acoustic coupling with the monitored pipeline wall, and the other end is connected to the piezoelectric transducing unit in the sealed cavity.

[0019] The application provides a self-powered foam aluminum impact sensing system for submarine pipeline monitoring. 1、The multi-dimensional event feature generation module, energy gradient quantization unit and time sequence mode discrimination unit are arranged, and the energy feature vector and mode feature are physically latched by an analog circuit before the processor is woken up. This design enables the processor to remain in a deep sleep state during non-event period and switch to a working state only after a hardware interrupt is triggered, thereby helping to reduce standby power consumption of the submarine pipeline monitoring system and prolonging autonomous operation time of the equipment.

[0020] 2、The dual-mode impact sensing interface module is arranged, and the specific structural combination of the closed-cell foam aluminum material and the high-impedance elastic waveguide column decouples external impact signal matter into one low-frequency mechanical pressure and one high-frequency elastic stress wave. This physical separation mechanism avoids aliasing interference of high-energy plastic deformation signals on high-frequency first arrival wave signals, ensures that the system can capture clear time waveform features while obtaining impact energy levels, and thereby improves accuracy of subsequent impact positioning using time stamps.

[0021] 3、The energy management and packaging module is arranged, the piezoelectric charge signal is rectified and stored by the energy collection and management unit, and the internal circuit is protected in cooperation with the penetrating structure of the sealed packaging unit. This design not only realizes the self-power function of providing power supply for the system by using pipeline impact energy, but also ensures effective isolation of the internal core module from the submarine environment in the case of foam aluminum external buffering, thereby meeting the needs of long-term unattended monitoring in harsh environments. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 The system framework diagram of the application; Figure 2 The working flowchart of the dual-mode impact sensing interface module of the application; Figure 3 The working flowchart of the multi-dimensional event feature generation module of the application; Figure 4Flow chart of the signal processing and cooperative communication module of the present application; Figure 5 Flow chart of the energy management and packaging module of the present application. DETAILED DESCRIPTION

[0023] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the specification of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present application.

[0024] Referring to the drawings in the specification of the present application, Figures 1-5 The present application provides a self-powered foam aluminum impact sensing system for submarine pipeline monitoring. The system is a distributed monitoring network deployed along the submarine pipeline.

[0025] The system includes a plurality of self-powered cooperative sensing nodes in a macroscopic view. These sensing nodes form a cooperative communication network through their built-in communication units.

[0026] The sensing nodes are the basic physical units of the system and are installed along the surface of the submarine pipeline at a preset interval. The cooperative communication network is used to exchange data between adjacent nodes in real time when an event occurs, and is also used to report data between the nodes and the inspection unit during inspection.

[0027] Each sensing node is logically an integrated device and can include the following four core functional modules: A dual-mode impact sensing interface module 100; A multi-dimensional event feature generation module 200; A signal processing and cooperative communication module 300; An energy management and packaging module 400.

[0028] The working process of the system of the present application is a dynamic process of the cooperative linkage of the above four modules between a plurality of sensing nodes. The working process includes the following steps in a macroscopic view: First, when an impact event occurs, the dual-mode impact sensing interface module 100 of the sensing node responds to the high-frequency elastic stress wave and the low-frequency plastic deformation, respectively. The multi-dimensional event feature generation module 200 physically latches the energy feature E and the modal feature M through its internal analog circuit before the processor in the signal processing and cooperative communication module 300 is woken up. At the same time, the energy management and packaging module 400 uses the impact energy to power the system.

[0029] Subsequently, the processor of the signal processing and cooperative communication module 300 is woken up, immediately reads the current high-precision timestamp T and the E and M features latched by the module 200, and generates a multi-dimensional event signature vector containing T, E and M in the local memory.

[0030] Then, the woken-up adjacent sensing nodes perform near-field handshake through the communication unit of the module 300. The system elects a master node based on the comparison result of the energy feature E, that is, the node with the most serious plastic deformation of the foam aluminum. The master node broadcasts a signature collection instruction through the communication unit.

[0031] After the master node collects the event signatures of the slave nodes, the processor of the module 300 starts signature consistency gating. The signature consistency gating is used to compare whether the modal features M of the master and slave nodes are consistent. The processor discards the contaminated data with inconsistent M, that is, the nodes with incomparable timestamps T, and only uses the consistent trusted timestamp set to perform TDoA algorithm solving to determine the impact point position.

[0032] After the positioning solving is completed, the processor of the master node further analyzes the distribution of the collected energy features E to perform system-level qualitative analysis on the event, such as distinguishing between local impact and linear impact. Finally, a fusion report containing the positioning information and the qualitative result is stored in the non-volatile memory of the module 300.

[0033] Finally, all the sensing nodes of the system return to the low-power sleep state. When the underwater inspection unit inspects and issues an inquiry instruction, the master node storing the fusion report is woken up and reports the report through the communication unit.

[0034] The technical implementation details of each module will be described in detail below in combination with the specific embodiments of the application.

[0035] The dual-modal impact sensing interface module 100, as the physical sensing front end of the sensing node, is used to interact with the external physical impact event and decouples the impact signal into an energy channel for energy analysis and a timing channel for timing analysis.

[0036] Specifically, the dual-modal impact sensing interface module 100 includes an energy capture and protection unit and a timing sensing unit.

[0037] To realize energy capture and protection, the energy capture and protection unit includes a closed-cell foam aluminum material.

[0038] In a specific embodiment, the closed-cell foam aluminum material is shaped into a half-cylindrical or saddle-shaped shield structure, which is fixed through a base when installed, covers the internal electronic module of the sensing node, matches the curvature of the outer surface of the submarine pipeline, and constitutes the physical outermost layer of the sensing node.

[0039] The working principle of the closed-cell aluminum foam material is as follows: the closed-cell aluminum foam material I uses the high energy absorption characteristics of the material as a physical buffer layer and a sacrificial layer to absorb most of the impact kinetic energy to protect the internal module from physical damage caused by direct impact; the closed-cell aluminum foam material II uses the elastic-plastic collapse characteristics of the material to convert the transient and high-frequency (e.g., millisecond level) impact kinetic energy into low-frequency mechanical pressure with a relatively long action time and a relatively flat waveform (e.g., tens of milliseconds). The low-frequency mechanical pressure is transmitted to the multi-dimensional event feature generation module 200 for subsequent processing.

[0040] To realize timing perception, the timing perception unit includes a high-impedance elastic waveguide column. In a specific embodiment, the high-impedance elastic waveguide column is made of a material with high hardness and high acoustic impedance (e.g., aluminum oxide ceramic or hard alloy) to ensure minimal attenuation of the impact stress wave when propagating therein.

[0041] The high-impedance elastic waveguide column physically penetrates the closed-cell aluminum foam material (e.g., through a rigid sleeve reserved on the closed-cell aluminum foam material), and one end (the coupling end) of the high-impedance elastic waveguide column penetrates the base of the sensing node. The coupling end is rigidly acoustically coupled to the monitored pipeline wall through threaded fastening or high-strength epoxy bonding.

[0042] The working principle of the high-impedance elastic waveguide column is to use the characteristics of the high-hardness material and the rigid coupling installation method as a high-fidelity acoustic channel. This channel physically bypasses the damping buffer effect of the closed-cell aluminum foam material and is specifically used to capture high-frequency elastic stress waves (e.g., P waves or S waves) propagating at high speed in the pipeline wall without distortion. The high-frequency elastic stress wave is transmitted to the multi-dimensional event feature generation module 200 for subsequent timing feature extraction.

[0043] In this embodiment, through the structural design of the dual-mode impact sensing interface module 100, the impact signal is physically decoupled into two channels: one is the low-frequency mechanical pressure obtained through the closed-cell aluminum foam material, which represents the total energy of the impact; the other is the high-frequency elastic stress wave obtained through the high-impedance elastic waveguide column, which represents the timing of the impact. This decoupling design provides two independent and high signal-to-noise ratio signal sources for subsequent multi-dimensional event feature generation.

[0044] The multi-dimensional event feature generation module 200 is used to receive the physical signals (i.e., low-frequency mechanical pressure and high-frequency elastic stress wave) transmitted by the dual-mode impact sensing interface module 100 and convert the physical signals into latched digital features through an analog circuit before the processor is awakened.

[0045] Specifically, the multi-dimensional event feature generation module 200 includes a piezoelectric transduction unit, an energy gradient quantization unit, and a timing modal discrimination unit.

[0046] The piezoelectric transduction unit is used to convert the mechanical energy input by the bimodal impact sensing interface module 100 into an electrical signal.

[0047] In one embodiment, the piezoelectric transduction unit comprises a piezoelectric ceramic sheet, a force concentration boss, and an orthogonal micro-sensing group. The force concentration boss is designed on the lower surface of the closed-cell aluminum foam material and is tightly attached to the piezoelectric ceramic sheet. The orthogonal micro-sensing group is connected to the end of the high-impedance elastic waveguide column.

[0048] The working principle of the piezoelectric transduction unit is that the force concentration boss transmits the low-frequency mechanical pressure captured and protected by the energy capture and protection unit to the piezoelectric ceramic sheet. The piezoelectric ceramic sheet (e.g., one or more) deforms after receiving the concentrated pressure, generating an electric charge. The electric charge signal is output to the energy gradient quantization unit and the energy management and packaging module 400. The orthogonal micro-sensing group (e.g., composed of two or more pieces of micro-piezoelectric ceramic sheets perpendicular to each other) is driven by the high-frequency elastic stress wave transmitted by the time sequence sensing unit, generating a high-frequency voltage signal, and outputting the high-frequency voltage signal to the time sequence modal discrimination unit.

[0049] The energy gradient quantization unit is used to instantaneously quantify and physically latch the level of impact energy. In one embodiment, the core structure of the energy gradient quantization unit is the energy gradient quantization unit. The energy gradient quantization unit is composed of a hierarchical threshold energy storage array, which can include multiple parallel energy storage branches with different starting charging voltage thresholds .

[0050] The energy gradient quantization unit is connected to the piezoelectric ceramic sheet. The working principle of the energy gradient quantization unit is that before the processor of the signal processing and cooperative communication module 300 is awakened, multiple energy storage branches inside the energy gradient quantization unit are charged according to the voltage peak generated by the piezoelectric ceramic sheet. When the voltage peak exceeds a certain threshold , the corresponding energy storage branch is charged and latched. The charging state is read by the latch, thereby physically latching an N-bit energy feature E vector (e.g., [1, 1, 0]). The energy feature E vector represents the degree of plastic deformation of the closed-cell aluminum foam material. The energy feature E vector is output to the signal processing and cooperative communication module 300.

[0051] The time sequence modal discrimination unit is used to discriminate and physically latch the modal of the stress wave. In one embodiment, the core structure of the time sequence modal discrimination unit is the time sequence modal discrimination unit. The time sequence modal discrimination unit is composed of a super-low-power analog comparator and a digital latch (e.g., a D flip-flop).

[0052] The time sequence modal discrimination unit is connected to the orthogonal micro-sensing group.

[0053] The working principle of the timing modal discrimination unit is that before the processor is woken up, the first arrival signal amplitude and polarity of the piezoelectric sheets in different directions in the orthogonal micro-sensor group are compared in real time by an analog circuit. By using the difference in vibration characteristics of P waves (longitudinal waves) and S waves (transverse waves) in different directions (for example, the P wave has the maximum vibration component in the propagation direction, and the S wave has the maximum vibration component perpendicular to the propagation direction), the timing modal discrimination unit physically latches a modal feature M representing the waveform mode (for example, M = 1 represents that the P wave is dominant, and M = 0 represents that the S wave is dominant). The modal feature M is output to the signal processing and cooperative communication module 300.

[0054] The output of the multi-dimensional event feature generation module 200 is two sets of latched digital features: Energy feature E and modal feature M. These two sets of features are transmitted to the signal processing and cooperative communication module 300 for subsequent processing.

[0055] In this embodiment, by using the multi-dimensional event feature generation module 200, the energy feature E and the modal feature M are physically latched by the analog circuit before the processor is woken up, so that the sensor node can capture the key event signature at the moment of event occurrence, which helps the signal processing and cooperative communication module 300 to perform high-credibility gating calculation and system-level qualification.

[0056] The signal processing and cooperative communication module 300 is used to perform high-precision time service, format packaging on the digital features latched by the multi-dimensional event feature generation module 200 after being woken up in an event-driven manner, and cooperative communication with other sensor nodes in the network, to provide key data for subsequent system-level calculation.

[0057] Specifically, the signal processing and cooperative communication module 300 includes an event-driven processing unit and a cooperative communication unit.

[0058] The event-driven processing unit is used to quickly respond to impact events and perform high-precision time service at very low power consumption.

[0059] In one embodiment, the event-driven processing unit includes an ultra-low-power microprocessor and a high-precision local time service unit. The high-precision local time service unit can be composed of a 32-bit high-resolution counter driven by a high-stability temperature-compensated crystal oscillator (TCXO), to ensure the stability of the time stamp in the sea temperature change environment.

[0060] The working principle of the event-driven processing unit is as follows: when no event occurs, the ultra-low power microprocessor is in a deep sleep mode (e.g., the CPU stops working, only the RAM is kept) to save energy to the maximum extent. When the multi-dimensional event feature generation module 200 physically latches the energy feature E or the modal feature M, the multi-dimensional event feature generation module 200 generates a hardware interrupt signal (e.g., a level flip). The hardware interrupt signal is connected to an external interrupt pin of the ultra-low power microprocessor. After the ultra-low power microprocessor is woken up by the hardware interrupt signal, the ultra-low power microprocessor immediately exits the deep sleep mode and executes an interrupt service program.

[0061] The first step of the interrupt service program is to immediately read the current count value of the high-precision local time unit to capture the most accurate time of the event occurrence.

[0062] In a specific embodiment, the high-precision timestamp T of the event can be expressed as: ; In the formula, T is the final high-precision timestamp of the event; is the second-level global reference time obtained by the sensor node through network synchronization (e.g., periodic GPS time calibration or underwater acoustic clock synchronization) last time; is the high-resolution (e.g., microsecond-level) time offset accumulated by the 32-bit counter of the high-precision local time unit since the time .

[0063] After the ultra-low power microprocessor acquires the timestamp T, the ultra-low power microprocessor then reads the latched N-bit energy feature E and modal feature M from the latch of the multi-dimensional event feature generation module 200 through the data bus.

[0064] The cooperative communication unit is used for efficient exchange of event data between sensor nodes. In an embodiment, in view of the fact that the sensor nodes are deployed in an underwater environment, the cooperative communication unit includes an underwater acoustic communication machine and an underwater acoustic transducer. The ultra-low power microprocessor is connected to the underwater acoustic communication machine through a serial communication interface (e.g., UART or SPI).

[0065] The working principle of the cooperative communication unit is as follows: the ultra-low power microprocessor 301 formats the acquired local node identifier , high-precision timestamp T, energy feature E, and modal feature M into a local event data packet according to a preset communication protocol.

[0066] In a specific embodiment, the structure of the local event data packet can be defined as: ; In the formula, T is the final high-precision timestamp of the event; is the local event data packet; is a unique identifier of the sensor node in the network; T is the high-precision time stamp mentioned above; E is an energy feature vector of N bits; M is a modal feature; CRC is a cyclic redundancy check code used to ensure the integrity of data in the underwater acoustic channel transmission.

[0067] The ultra-low power microprocessor sends the local event data packet to the underwater acoustic communication machine. The underwater acoustic communication machine channel encodes and modulates the local event data packet. The underwater acoustic transducer converts the electrical signal output by the underwater acoustic communication machine into an underwater acoustic pressure wave and broadcasts the underwater acoustic pressure wave to the adjacent other sensor nodes.

[0068] After the broadcast is completed, the ultra-low power microprocessor controls the underwater acoustic communication machine to switch to a receiving mode. The underwater acoustic transducer is responsible for listening to and receiving the event data packet broadcast by other sensor nodes, and converting the received acoustic signal into an electrical signal. The underwater acoustic communication machine demodulates and decodes the electrical signal. The ultra-low power microprocessor checks the received event data packet from other nodes and stores it in the local memory for subsequent distributed TDoA (Time Difference of Arrival) positioning solution.

[0069] In this embodiment, through the signal processing and cooperative communication module 300, the physical latching feature from the multi-dimensional event feature generation module 200 is used to realize event-driven wake-up of the ultra-low power microprocessor, ensuring extremely low static power consumption of the sensor node in a non-event state. After the ultra-low power microprocessor is woken up, the event data is marked with a high-precision time stamp and packaged, and is quickly broadcast and adjacent data is collected through the cooperative communication unit, providing a high-precision and high-reliability data basis for subsequent system-level cooperative positioning and event qualification.

[0070] The energy management and packaging module 400 is used to provide long-term stable power supply for the internal electronic modules (such as the multi-dimensional event feature generation module 200 and the signal processing and cooperative communication module 300) of the sensor node, and provides a sealed physical barrier resistant to high pressure and seawater corrosion for all internal modules.

[0071] Specifically, the energy management and packaging module 400 includes an energy collection and management unit and a sealing and packaging unit.

[0072] The energy collection and management unit is used to collect impact energy from the piezoelectric ceramic sheet and manage the overall power distribution of the sensor node.

[0073] In one embodiment, the energy collection and management unit includes a rectifier circuit, an energy collection management chip, a main battery, a secondary energy storage element, and a power management circuit.

[0074] The energy harvesting and management unit works as follows: the charge signal (a high voltage, transient AC pulse) generated by the piezoelectric ceramic is delivered to a rectifier circuit. The rectifier circuit (e.g., a full-wave bridge rectifier) converts the AC pulse to a DC pulse.

[0075] The energy harvesting management chip employs an integrated circuit optimized for piezoelectric energy harvesting (e.g., LTC3588-1). A transient voltage suppression (TVS) diode is connected in parallel to the input of the full-wave bridge rectifier to clamp the high voltage pulse and protect the subsequent circuit. The output of the rectified DC pulse is connected to the supercapacitor bank through a MOSFET switch array. When the voltage of the rectified DC pulse exceeds the threshold value (e.g., 0.2 V) set internally in the chip, the energy harvesting management chip automatically activates the charging circuit to store the energy in the supercapacitors.

[0076] The energy harvesting management chip receives the DC pulse and adjusts the voltage of the DC pulse to a voltage suitable for charging the secondary energy storage element; The secondary energy storage element (e.g., one or more supercapacitors in parallel) is used to store the harvested impact energy. In one specific embodiment, the secondary energy storage element stores energy which can be represented as: wherein, E is the energy stored in the secondary energy storage element; CC is the total capacitance of the secondary energy storage element; V is the voltage of the secondary energy storage element after charging; V is the voltage of the secondary energy storage element before charging.

[0077] The primary battery (e.g., a high-energy-density lithium thionyl chloride battery) is used to provide the static power consumption of the sensor node in deep sleep mode and to supplement power when energy harvesting is insufficient.

[0078] The power management circuit (e.g., including multiple low-dropout linear regulators (LDOs) or high-efficiency DC-DC converters) connects the primary battery and the secondary energy storage element. The power management circuit is responsible for providing one or more stable operating voltages (e.g., 3.3 V or 1.8 V) to the ultra-low-power microprocessor, the analog circuits in the multi-dimensional event feature generation module 200, and the underwater acoustic communication machine.

[0079] In one embodiment, the power management circuit preferentially uses the energy in the secondary energy storage element for power supply (e.g., when the underwater acoustic communication machine performs high-power broadcasting), and only switches to the primary battery power supply when the voltage of the secondary energy storage element is below the threshold value, thereby maximizing the overall operating life of the sensor node.

[0080] The sealed packaging unit is used to isolate the internal electronic modules from the high-pressure, corrosive seabed environment.​

[0081] In one embodiment, the sealed packaging unit includes a high-pressure resistant base, a high-pressure resistant shell, and a waterproof sealing structure.

[0082] The high-pressure resistant base and the high-pressure resistant shell are made of high-strength, corrosion-resistant materials (e.g., 316L stainless steel or titanium alloy). The high-pressure resistant shell (e.g., a cylindrical sleeve) is statically sealed with the high-pressure resistant base by a waterproof sealing structure (e.g., double O-rings). The electronic components of the multi-dimensional event feature generation module 200, the signal processing and cooperative communication module 300, and the energy harvesting and management unit are mounted on the high-pressure resistant base and housed in the sealed cavity formed by the high-pressure resistant shell.

[0083] The closed-cell aluminum foam material is installed on the outer surface of the high-pressure resistant base. The high-impedance elastic waveguide column passes through the high-pressure resistant base through a sealed feed through on the high-pressure resistant base, one end of which is coupled to the pipe wall and the other end of which is connected to the orthogonal micro-sensor group in the sealed cavity. The underwater acoustic transducer is connected to the high-pressure resistant shell through a water-tight connector, and the electrical signals of the water-tight connector are transmitted to the underwater acoustic communication machine in the sealed cavity through sealed pins.

[0084] In this embodiment, the energy harvesting and management unit realizes the collection of impact energy and the charging of supercapacitors through the energy management and packaging module 400, and provides a long-life, high-reliability hybrid power supply solution for the system in combination with the main battery. The sealed packaging unit provides physical protection for the sensing node against high pressure and corrosion, ensuring the long-term stable operation of the sensing node in harsh environments such as submarine pipelines.

Claims

1. A self-powered aluminum foam impact sensing system for monitoring subsea pipelines, characterized in that, Includes the following steps: The dual-modal impact sensing interface module is used to respond to external physical impact events on the pipeline and decouples the impact signal into one low-frequency mechanical pressure and one high-frequency elastic stress wave. A multi-dimensional event feature generation module, connected to a dual-modal impact sensing interface module, is used to receive the low-frequency mechanical pressure and the high-frequency elastic stress wave, and convert the low-frequency mechanical pressure and the high-frequency elastic stress wave into charge signals, energy feature vectors and modal features; The signal processing and cooperative communication module is connected to the multi-dimensional event feature generation module. It is used to read the energy feature vector, the modal features and the high-precision timestamp after being woken up by a hardware interrupt signal, and to perform cooperative communication. The energy management and encapsulation module, connected to the multi-dimensional event feature generation module, is used to receive the charge signal, collect the impact energy from it, and provide power to the internal electronic modules of the system, providing a sealed physical barrier for the internal electronic modules.

2. The self-powered aluminum foam impact sensing system for monitoring subsea pipelines according to claim 1, characterized in that, The dual-modal impact sensing interface module specifically includes: Energy capture and protection unit; Timing-aware unit.

3. A self-powered aluminum foam impact sensing system for monitoring subsea pipelines according to claim 2, characterized in that, The energy harvesting and protection unit includes closed-cell aluminum foam material, which utilizes its elastic-plastic collapse characteristics to convert impact kinetic energy into the low-frequency mechanical pressure. The timing sensing unit includes a high-impedance elastic waveguide post that physically bypasses the closed-cell aluminum foam material to capture the high-frequency elastic stress wave.

4. The self-powered aluminum foam impact sensing system for monitoring subsea pipelines according to claim 1, characterized in that, The multi-dimensional event feature generation module specifically includes: piezoelectric transducer; Energy gradient quantization unit; Temporal mode discrimination unit.

5. A self-powered aluminum foam impact sensing system for monitoring subsea pipelines according to claim 4, characterized in that, The energy gradient quantization unit includes a hierarchical threshold energy storage array; the energy gradient quantization unit is used to physically latch the energy feature vector based on the voltage peak value generated by the piezoelectric transducer and the charging state of the hierarchical threshold energy storage array before the processor of the signal processing and cooperative communication module is woken up.

6. A self-powered aluminum foam impact sensing system for monitoring subsea pipelines according to claim 4, characterized in that, The timing mode identification unit includes an ultra-low power analog comparator and a digital latch. The timing mode identification unit is used to compare the amplitude and polarity of the first arrival signal of the piezoelectric transducer output signal in real time through the ultra-low power analog comparator before the processor of the signal processing and cooperative communication module is woken up, and to physically latch the mode features through the digital latch.

7. A self-powered aluminum foam impact sensing system for monitoring subsea pipelines according to claim 1, characterized in that, The signal processing and cooperative communication module specifically includes: Event-driven processing unit; Cooperative communication unit.

8. A self-powered aluminum foam impact sensing system for monitoring subsea pipelines according to claim 7, characterized in that, The event-driven processing unit includes an ultra-low-power microprocessor and a high-precision local time synchronization unit; the ultra-low-power microprocessor is woken up in response to a hardware interrupt signal generated by the multi-dimensional event feature generation module; after being woken up, the ultra-low-power microprocessor immediately reads the high-precision local time synchronization unit to obtain the high-precision timestamp.

9. A self-powered aluminum foam impact sensing system for monitoring subsea pipelines according to claim 1, characterized in that, The energy management and packaging module specifically includes: Energy harvesting and management unit; Sealed encapsulation unit.

10. A self-powered aluminum foam impact sensing system for monitoring subsea pipelines according to claim 9, characterized in that, The sealing and encapsulation unit forms a sealed cavity, and the multi-dimensional event feature generation module and the signal processing and collaborative communication module are both located within the sealed cavity.

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