Bottom mud columnar sampler operation control test system and method thereof

Abstract

The invention relates to the technical field of geotechnical engineering detection and geological exploration, in particular to a bottom mud columnar sampler operation control test system and method, and the method comprises the steps: collecting operation state feedback data, and recognizing the current operation stage and resistance state of a sampler; when it is recognized that the sampler is in the extraction stage and the cable traction tension exceeds a preset tension threshold value, frequency conversion excitation control logic is triggered; identifying a resonant frequency point of the current pipe wall and an external medium system; generating a vibration control instruction to reduce the friction resistance of the interface; the change rate of the environment pressure outside the pipe is monitored in real time; generating a pneumatic compensation instruction, adjusting the pressure of the cavity in the tube, and maintaining the difference value between the pressure of the environment outside the tube and the pressure of the cavity in the tube to be within a preset allowable error range of the sample maintaining pressure difference; according to the invention, sample slippage or bedding damage caused by pressure imbalance is effectively avoided, and the integrity of the columnar sample is guaranteed.

Description

Technical Field

[0001] This invention relates to the field of geotechnical engineering testing and geological exploration technology, specifically to a sediment column sampler operation control testing system and method. Background Technology

[0002] In the field of sediment sampling and physicochemical property analysis, column samplers are key equipment for obtaining undisturbed underwater samples. The control precision during their operation directly determines the integrity of the samples and the reliability of subsequent analysis results. Existing sediment sampling methods typically rely on winch cables for forced lifting and extraction. However, in complex geological environments such as high sand content, compacted clay, or deep water under high pressure, there is often significant interfacial frictional resistance between the sampling tube wall and the external sediment. This traditional mechanical extraction method has significant limitations: on the one hand, relying solely on mechanical pulling force to forcibly lift the sampler can easily cause it to jam due to high friction, or even lead to engineering accidents such as cable breakage or equipment loss; on the other hand, the conventional fixed-frequency vibration used to overcome resistance is often inefficient in energy transfer because it cannot adapt to the acoustic impedance differences of different substrates, and the violent, ineffective vibration can easily damage the stratification structure of the sediment; in addition, as the sampler is lifted from deep water to the surface, the gas sealed in the cavity inside the tube expands according to the law of physical expansion as the external hydrostatic pressure decreases, generating a downward piston thrust; this internal thrust caused by pressure change and the high external frictional resistance form a complex coupling contradiction, and traditional technology cannot effectively reduce the extraction resistance of the tube wall while dynamically balancing the pressure inside the tube to prevent sample slippage or loss; therefore, how to achieve real-time sensing of the sampler's operating resistance state in complex underwater environments, and how to reduce interfacial frictional resistance while ensuring the integrity and original state of the sample through decoupling control strategies, has become an urgent technical problem to be solved. Summary of the Invention

[0003] The purpose of this invention is to provide a system and method for controlling the operation of a sediment column sampler. This system effectively resolves the coupling contradiction between sample tube jamming and sample slippage in high-sand or compacted sediment sampling scenarios. It significantly reduces interfacial frictional resistance by identifying resonant frequency points to drive radial micro-vibration of the tube wall, and dynamically adjusts the internal cavity pressure according to the external environmental pressure to maintain the pressure difference for sample retention, thereby ensuring the integrity and original state of the column sediment sample. Specifically, the technical solution of this invention is as follows: The test method for the operation control of the sediment column sampler includes: Collect operational status feedback data; the operational status feedback data includes the sampler's cable tension, the pressure inside the tube cavity, and the environmental pressure outside the tube; analyze the operational status feedback data to identify the sampler's current operating stage and resistance status; When the sampler is identified as being in the extraction stage and the cable tension exceeds a preset tension threshold, the variable frequency excitation control logic is triggered. Based on the variable frequency excitation control logic, the sampler tube wall is scanned to identify the resonant frequency point between the current tube wall and the external medium system. A vibration control command is generated to drive the sampler tube wall to perform radial micro-amplitude vibration at the resonant frequency point to reduce interface friction resistance. Simultaneously, during the extraction stage, the rate of change of the external environmental pressure is monitored in real time; based on the external environmental pressure and the preset sample holding pressure difference, the target internal pressure is calculated; a pneumatic compensation command is generated to adjust the internal cavity pressure so that it dynamically follows the change of the external environmental pressure and maintains the difference between the external environmental pressure and the internal cavity pressure within the preset allowable error range of the sample holding pressure difference.

[0004] Preferably, the method for performing a frequency scan on the sampler tube wall to identify the resonant frequency point between the current tube wall and the external medium system includes: determining a preset frequency scan range; and controlling the piezoelectric ceramic excitation array embedded in the sampler tube wall to output a frequency conversion excitation signal within the frequency scan range. The vibration response amplitude of the sampler tube wall at different excitation frequencies is collected; a frequency-response amplitude curve is constructed; and the frequency corresponding to the peak in the frequency-response amplitude curve is marked as the resonance frequency point. The vibration control command is used to lock the operating frequency of the excitation unit at the resonant frequency point and control the vibration mode to be the radial shear wave mode.

[0005] Preferably, the method for identifying the current operating stage and resistance state of the sampler includes: monitoring the value of the external environmental pressure; if the external environmental pressure remains stable and is greater than atmospheric pressure, it is determined to be a static state at the bottom of the water. Monitor the rate of change of the cable traction tension; if the rate of change of the cable traction tension is positive, determine that the extraction start-up state has been reached. In the extraction start state, the real-time value of the cable traction tension is compared with the tension threshold; if the cable traction tension is greater than the tension threshold, the resistance state is determined to be a high friction jam state; if the cable traction tension is less than or equal to the tension threshold, the resistance state is determined to be a normal extraction state.

[0006] Preferably, the method further includes control logic for the penetration phase: monitoring the deceleration speed of the sampler; when the absolute value of the deceleration speed exceeds a preset penetration determination threshold, the method determines that the process has entered the penetration phase. A longitudinal excitation command is generated to drive the sampler tube wall to vibrate longitudinally at a low frequency until a preset sampling depth is reached; wherein, the frequency of the longitudinal low-frequency vibration is lower than the resonant frequency point, and the vibration direction is parallel to the axis of the sampler.

[0007] Preferably, the method for calculating the target tube pressure based on the external environmental pressure and the preset sample holding pressure difference includes: obtaining a preset sample density parameter and an estimated sample length; calculating the product of the sample density parameter, the gravitational acceleration constant and the estimated sample length to obtain the minimum adsorption pressure value that can overcome the gravity of the sample, and setting the minimum adsorption pressure value as the sample holding pressure difference; Obtain the current external environmental pressure; subtract the sample holding pressure difference from the external environmental pressure to obtain the target internal pressure of the tube; The pneumatic compensation command is used to control the opening of the bidirectional air pump or proportional valve to adjust the actual intra-pipe cavity pressure to approximate the target intra-pipe pressure.

[0008] Preferably, the step of generating pneumatic compensation commands further includes: calculating the pressure deviation between the cavity pressure inside the pipe and the target pipe pressure; inputting the pressure deviation into a PID controller; and outputting an adjustment signal through the PID controller to control the on / off state and flow rate of the pneumatic system. When the external environmental pressure decreases as the sampler rises, the pneumatic compensation command controls the gas path system to discharge the gas inside the tube to prevent the gas inside the tube from expanding and causing the sample to slip. When the pressure deviation caused by the change in the external environmental pressure exceeds the safety threshold, the emergency lockout mode is triggered, and the pressure difference of the sample is forcibly increased to maintain the pressure difference.

[0009] Preferably, the method further includes safety protection logic: real-time monitoring of the vibration acceleration data of the sampler; if the vibration acceleration data collected by the acceleration sensor indicates that the pipe wall amplitude exceeds the preset structural safety limit, then the driving amplitude in the vibration control command is forcibly reduced; If, after performing the frequency scan, the cable tension still does not drop below the tension threshold and the duration exceeds the preset timeout threshold, a stop extraction command is generated and an alarm is issued.

[0010] Preferably, generating vibration control commands includes: generating a sinusoidal excitation signal based on the resonant frequency point; and analyzing the change in equivalent acoustic impedance at the contact surface between the sampler and the medium based on the vibration data collected by the accelerometer. Based on the change in equivalent acoustic impedance, the frequency of the sinusoidal excitation signal is finely adjusted in real time to maintain the liquefaction state of the pipe wall and the medium boundary layer; wherein, the liquefaction state refers to the rheological state in which the contact stress between medium particles decreases and the pore water pressure increases.

[0011] Preferably, the operating status feedback data also includes the sampler's attitude angle data; the method further includes: acquiring the attitude angle data through an accelerometer to determine the tilt degree of the sampler; If the degree of tilt exceeds a preset tilt angle threshold, the calculated value of the pressure inside the target pipe is corrected to compensate for the uneven distribution of hydrostatic pressure caused by the tilt.

[0012] A sediment column sampler operation control test system, applied to the sediment column sampler operation control test method according to any one of claims 1-9, comprising: A data acquisition module is used to collect operational status feedback data. The data acquisition module includes an intelligent sensing system, which comprises: a tension sensor located at the sampler's traction cable to monitor the cable's traction tension in real time; an internal pressure sensor located at the top of the sampler tube to monitor the pressure inside the tube's cavity; an external pressure sensor located at the bottom of the sampler tube to monitor the external environmental pressure; and an acceleration sensor located on the sampler tube wall to monitor the sampler's vibration acceleration and attitude angle data. The status analysis module is used to analyze the operating status feedback data and identify the current operating stage and resistance status of the sampler. The vibration control module, including a piezoelectric ceramic excitation array, is used to perform frequency scanning and generate vibration control commands when a high friction jamming state is detected, driving the pipe wall to generate radial micro-amplitude vibration at the resonant frequency point. The pressure compensation module includes a pneumatic compensation unit, which is used to monitor the external environmental pressure in real time, calculate the target internal pressure based on the preset sample pressure difference, and generate a pneumatic compensation command to adjust the internal cavity pressure and maintain the internal and external pressure difference within the preset allowable range.

[0013] Compared with the prior art, the present invention has the following beneficial effects: 1. This invention automatically identifies high-resistance jamming by monitoring cable tension, triggers variable frequency excitation and locks the resonance frequency point between the pipe wall and the medium; it effectively cuts off the interlocking effect between the pipe wall and the sediment by using the shear wave generated by radial micro-amplitude vibration, significantly reduces the interface friction resistance, solves the risk of equipment jamming and cable breakage caused by traditional forced extraction in complex geological environments, and greatly improves the safety and passability of deep-water operations. 2. This invention constructs a depth-dependent pneumatic compensation mechanism that monitors the external environmental pressure in real time and dynamically adjusts the internal cavity pressure to accurately follow changes in external water pressure. This mechanism eliminates the piston thrust generated by the expansion of gas inside the tube during the lifting process, ensuring that the negative pressure at the top of the sample remains constant and is only used to overcome gravity. This effectively avoids sample slippage or stratification damage caused by pressure imbalance and ensures the integrity of the columnar sample. 3. This invention introduces an adaptive control logic based on acoustic impedance feedback, which can finely adjust the excitation frequency in real time according to different substrate environments such as fine sand and clay, and maintain the optimal liquefaction state of the pipe wall and the medium boundary layer. This not only solves the problem of low drag reduction efficiency of fixed frequency under different geological conditions and achieves maximum drag reduction with minimum energy consumption, but also avoids the compression of the sample by longitudinal vibration through radial shear mode, ensuring the original state of the sediment. 4. This invention establishes a phased control strategy for the entire process. In the penetration stage, longitudinal low-frequency vibration is used to assist in cutting, which solves the problem of insufficient penetration depth in hard mud layers. In the extraction stage, the radial resonance mode is switched to reduce drag and prevent the sample from being compressed. Combined with attitude perception and pressure correction algorithms, the error of equipment tilt on pressure control is eliminated, which significantly improves the sampling depth and control accuracy in complex water flow and geological environments. Attached Figure Description

[0014] The present invention will be further explained below with reference to the accompanying drawings and embodiments: Figure 1 This is a flowchart of the method of the present invention; Figure 2 This is a structural diagram of the system of the present invention. Detailed Implementation

[0015] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments.

[0016] Example 1: Please see Figure 1 A test method for the operation control of a sediment column sampler, comprising: Collect operational status feedback data; the operational status feedback data includes the sampler's cable tension, the pressure inside the tube cavity, and the environmental pressure outside the tube; analyze the operational status feedback data to identify the sampler's current operating stage and resistance status; When the sampler is identified as being in the extraction stage and the cable tension exceeds the preset tension threshold, the variable frequency excitation control logic is triggered. Based on the variable frequency excitation control logic, the sampler tube wall is scanned to identify the resonant frequency point between the current tube wall and the external medium system. A vibration control command is generated to drive the sampler tube wall to perform radial micro-amplitude vibration at the resonant frequency point to reduce the interface friction resistance. Meanwhile, during the extraction stage, the rate of change of the external environmental pressure is monitored in real time; based on the external environmental pressure and the preset sample holding pressure difference, the target internal pressure is calculated; a pneumatic compensation command is generated to adjust the internal cavity pressure so that it dynamically follows the change of the external environmental pressure and maintains the difference between the external environmental pressure and the internal cavity pressure within the preset allowable error range of the sample holding pressure difference.

[0017] This embodiment discloses a test method for the operation control of a sediment column sampler based on rheological impedance feedback. This method aims to solve the coupling contradiction between sampling tube jamming and sample slippage and loss caused by traditional forced extraction in high sand or compacted sediment sampling scenarios. The core concept of this embodiment is to construct a dual closed-loop control system, in which one closed loop is responsible for reducing the drag at the interface and the other closed loop is responsible for the internal adsorption and locking. The system performs a data acquisition step, obtaining operational status feedback data through a multi-source sensor network integrated on the sampler; among which, the cable traction tension originates from the tension sensor. The physical meaning is the vertical lifting resistance experienced by the sampler, measured in N; it originates from the pressure inside the tube cavity of the tube top pressure sensor. The physical meaning is the absolute pressure of the air chamber acting on the top of the sample, measured in Pa; the external environmental pressure originates from the external pressure sensor at the bottom of the tube. The physical meaning is the sum of the hydrostatic pressure and atmospheric pressure at the current depth, with the unit being Pa; The system analyzes the operational status feedback data to identify the current operating stage and resistance status of the sampler; the controller determines whether it is currently in the lowering, stationary, or extraction stage based on the characteristics of the sensor data stream. In response to the identification that the sampler is in the extraction phase and the cable tension is low Exceeding the preset tension threshold This indicates a high-resistance stuck state, triggering the variable frequency excitation control logic of the system. Based on this, the system drives the excitation unit to perform a frequency scan on the sampler tube wall, identifying the resonant frequency point between the current tube wall and the external medium system. ; Generate vibration control commands to drive the sampler tube wall at the resonant frequency point. Radial micro-vibration is performed; radial micro-vibration is used here instead of longitudinal vibration, in order to generate shear waves to effectively break the interlocking effect between the pipe wall and the external deposits; Meanwhile, to prevent the sample from falling off due to gravity or changes in internal and external pressure during drag reduction or lifting, the system monitors the external environmental pressure in real time during the extraction stage. The rate of change; based on the current and the preset sample holding pressure difference The system calculates a dynamically changing target pipe pressure. This generates pneumatic compensation commands, controlling the pneumatic circuit unit to adjust the actual intra-pipe cavity pressure. Make it dynamically follow Changes; It should be noted that the sediment column sampler of the present invention is applicable to various geological environments such as terrestrial soft soil, deep-pore soil and rock, and underwater sediments; in particular, the system can establish the target tube pressure in response to changes in environmental pressure under different environments. The pressure balance model achieves sample preservation; This embodiment achieves physical and logical decoupling of pipe wall drag reduction and pipe sample locking through dual closed-loop control; in the deep-water sediment sampling scenario, radial micro-amplitude vibration significantly reduces external friction through shear effect, solving the problem of high-viscosity sediment being unable to be lifted. Meanwhile, the dynamic tracking aerodynamic compensation logic ensures that no matter how the external water pressure changes, the negative pressure applied to the top of the sample is always just enough to overcome the sample's weight, avoiding damage to the stratification due to excessive negative pressure or slippage due to insufficient pressure, thus ensuring the integrity and original state of the columnar sediment sample.

[0018] Example 2: The method for performing a frequency scan on the sampler tube wall to identify the resonant frequency point between the current tube wall and the external medium system includes: determining a preset frequency scan range; The piezoelectric ceramic excitation array embedded in the sampler tube wall is controlled to output a frequency conversion excitation signal within the frequency scanning range; The vibration response amplitude of the sampler tube wall at different excitation frequencies was collected; frequency-response amplitude curves were constructed. The frequency corresponding to the peak in the frequency-response amplitude curve is marked as the resonant frequency point; the vibration control command is used to lock the operating frequency of the excitation unit at the resonant frequency point and control the vibration mode to be the radial shear wave mode.

[0019] This embodiment details the specific implementation process of performing frequency scanning on the sampler tube wall to identify resonant frequency points; The system determines the preset frequency scanning range. For example, 50Hz to 2000Hz; The controller controls the piezoelectric ceramic excitation array embedded in the sampler tube wall to output a frequency-modulated excitation signal within the frequency scanning range; during the scanning process, an accelerometer located on the tube wall synchronously acquires the vibration response amplitude of the sampler tube wall at different excitation frequencies. ; Based on this, the system constructs a frequency-response amplitude curve using the collected data; on this curve, the frequency corresponding to the peak is marked as the resonant frequency point. Resonant frequency points derived from frequency sweep analysis results The physical meaning is the frequency point where the mechanical impedance of the sampling tube wall and the surrounding soil system is the minimum and the energy transfer efficiency is the highest, and the unit is Hz; The generated vibration control commands are used to lock the operating frequency of the excitation unit at the resonant frequency point. Furthermore, the vibration mode is specifically controlled to be a radial shear wave mode. Specifically, the excitation control module controls multiple piezoelectric ceramic units arranged around the sampler tube wall to adopt the same phase drive mode (i.e., the phase difference of the drive signals of each unit is 0), so that the tube wall as a whole synchronously undergoes radial expansion and contraction, thereby generating a micro-amplitude high-frequency shear motion perpendicular to the contact surface at the interface between the tube wall and the deposit. This embodiment utilizes real-time frequency sweeping technology to solve the impedance matching problem under different geological environments. When facing different substrates such as fine sand, coarse sand, or clay, their acoustic impedances vary significantly, and fixed-frequency vibration is often inefficient. By locking the resonant frequency point, the system can adaptively find the optimal excitation frequency under the current geological conditions, ensuring that the thixotropy of the boundary layer soil is excited with minimal energy consumption, thereby maximizing the drag reduction effect.

[0020] Example 3: Methods for identifying the current operating stage and resistance state of a sampler include: Monitor the external environmental pressure value. If the external environmental pressure is within a preset time judgment window, for example... The standard deviation of the fluctuation within the range is less than the preset stability threshold, for example... And the value is significantly greater than atmospheric pressure, for example It was determined to be in a static state at the bottom of the water; Monitor the rate of change of cable tension. If the rate of change of cable tension is positive, it is determined to be an extraction start-up state. In the extraction start-up state, the real-time value of cable tension is compared with the tension threshold. If the cable tension is greater than the tension threshold, the resistance state is determined to be a high friction jamming state. If the cable tension is less than or equal to the tension threshold, the resistance state is determined to be the normal extraction state.

[0021] This embodiment elaborates on the logical determination method for identifying the current operating stage and resistance state of the sampler, which is based on the temporal characteristics of multi-dimensional sensor data; The system performs the underwater static state determination step and monitors... The value; in response to If the sampler remains stable within a preset time window and the value is significantly greater than atmospheric pressure, the system determines that the sampler has reached its bottom and has transitioned from dynamic to static. The system executes the startup status determination step and monitors... rate of change ; in response to A positive value, meaning a positive increase in tension, indicates that the winch has started to take in the cable, and the system determines that it has entered the extraction start state; The system executes the resistance state determination step, and in the extracted startup state, it will... The real-time value and the preset tension threshold Perform comparison; respond to Greater than This indicates that the simple mechanical lifting force encountered abnormal resistance, and the system is judged to be in a high-friction jamming state; conversely, in response to Less than or equal to This indicates that the resistance is within a safe range, and the system determines that the extraction state is normal. This embodiment establishes a precise finite state machine logic to enable on-demand intervention of vibration control. During routine extraction operations, the system remains silent to avoid unnecessary vibration disturbance to the sample structure. The excitation logic is activated only when a clear high friction jamming state is detected. This strategy not only effectively saves onboard energy but also protects the layered structure of the sediment sample to the greatest extent possible.

[0022] Example 4: The method also includes control logic for the penetration phase: The system monitors the lowering speed of the sampler; the time derivative of the lowering speed is calculated as the deceleration. When the absolute value of the deceleration of the lowering speed is detected... Exceeding the preset penetration threshold At that time, it is determined that the penetration phase has begun; A longitudinal excitation command is generated to drive the sampler tube wall to vibrate longitudinally at a low frequency until the preset sampling depth is reached; wherein, the frequency of the longitudinal low-frequency vibration is lower than the resonant frequency point, and the vibration direction is parallel to the axis of the sampler.

[0023] This embodiment supplements the control logic of the sampler during the penetration phase, forming a complete end-to-end control; The system monitors the sampler descent speed from the winch encoder or the onboard inertial measurement unit (IMU). ; The system calculates the deceleration of the lowering speed; in response to detection absolute value of deceleration Exceeding the preset penetration threshold This indicates that the bottom of the sampler has contacted the mud surface and is blocked, and the system determines that it has entered the penetration stage. The system generates a longitudinal excitation command. By controlling the phase of the driving signal of each piezoelectric ceramic unit distributed along the sampler axis, it generates an axial phase gradient or traveling wave excitation, thereby generating a longitudinal excitation command to drive the sampler tube wall to perform longitudinal low-frequency vibration until the preset sampling depth is reached. In this process, the longitudinal low-frequency vibration from the excitation control module means a vibration mode with a frequency significantly lower than the aforementioned resonance frequency point and a vibration direction parallel to the sampler axis, such as 20Hz to 50Hz. This embodiment achieves targeted optimization of downward cutting and upward drag reduction by distinguishing the vibration modes of the penetration stage and the extraction stage. When penetrating the hard plate layer, the longitudinal low-frequency vibration uses the principle of a vibrating hammer to assist the sampling tube in cutting in, which solves the problem of insufficient gravity penetration depth. During extraction, the radial vibration is switched to avoid the compression effect of longitudinal vibration on the sample, thereby maintaining the sample quality while ensuring the sampling depth.

[0024] Example 5: Methods for calculating the target tube pressure based on the external environmental pressure and the preset sample holding pressure difference include: Obtain the preset sample density parameters and estimated sample length; calculate the product of the sample density parameters, the gravitational acceleration constant and the estimated sample length to obtain the minimum adsorption pressure value that can overcome the sample gravity, and set the minimum adsorption pressure value as the sample holding pressure difference; Obtain the current external environmental pressure; subtract the sample holding pressure difference from the external environmental pressure to obtain the target internal pressure; among which, the pneumatic compensation command is used to control the working speed of the bidirectional air pump or the opening of the proportional valve to adjust the actual internal cavity pressure to approximate the target internal pressure.

[0025] This embodiment details the calculation of target pipe pressure based on a physical model. The specific algorithm; The system obtains preset parameters: sample density parameters. and estimated sample length Among them, to ensure safety and redundancy during the sampling process, the sample density parameter... The preferred configuration is the actual physical density of the sediment and a safety factor of, for example, 1.1 to 1.2. The product of these parameters allows for the provision of a safety margin at the parameter level. The system calculates the minimum adsorption pressure that can overcome the sample's gravity and sets it as the sample holding pressure difference. The product calculation logic strictly corresponds to the embodiment, and the calculation formula is as follows: ; In each control cycle, the system acquires the current ambient pressure outside the pipe. Based on this, the pressure inside the target pipe is calculated. Pneumatic compensation commands control the opening of the bidirectional air pump or proportional valve to adjust... Approximating the calculated ; This embodiment employs a pressure difference following strategy based on a physical model to solve the gas expansion problem caused by Boyle's law in deep-water sampling; As the sampler is lifted from the deep water area, the external water pressure decreases. This scheme allows the pressure inside the pipe to decrease synchronously, maintaining a constant net pressure difference that is only used to overcome the weight of the sample. This dynamic adjustment mechanism eliminates the piston effect caused by the expansion of gas inside the pipe that pushes the sample out, significantly improving the sampling success rate of loose sediments.

[0026] Example 6: The steps for generating aerodynamic compensation commands also include: Calculate the pressure deviation between the cavity pressure inside the tube and the target tube pressure; input the pressure deviation into the PID controller; the PID controller outputs an adjustment signal to control the on / off state and flow rate of the gas circuit system; When the external environmental pressure decreases as the sampler rises, the pneumatic compensation command controls the gas path system to discharge the gas inside the tube to prevent the gas inside the tube from expanding and causing the sample to slip. When changes in external environmental pressure cause the pressure deviation to exceed the safety threshold, the emergency lockout mode is triggered, forcibly increasing the sample pressure to maintain the differential pressure.

[0027] This embodiment further refines the closed-loop feedback control mechanism of the pneumatic compensation command; the system calculates the cavity pressure inside the pipe. With target pipe pressure Pressure deviation between ; The deviation is input into the PID controller; the PID controller outputs an adjustment signal to control the on / off state and flow rate of the air circuit system; to prevent the actuator from frequently operating near the equilibrium point, a pressure dead zone is set in the control logic, for example... The specific control logic is as follows: If the absolute value of the pressure deviation Keep the control gas system closed; like When the pressure inside the pipe is significantly higher than the target value, the PID outputs a positive signal to drive the exhaust proportional valve to open and release the excess gas inside the pipe. like When the pressure inside the pipe is significantly lower than the target value, the PID outputs a negative signal to drive the bidirectional air pump to perform air replenishment. Based on this, in response to external environmental pressures As the sampler rises, it decreases, resulting in target pressure. As the deviation decreases, the system detects a positive deviation and initiates a pneumatic compensation command to control the gas path system to actively expel the gas inside the tube to prevent the gas from expanding and causing the sample to slip. In addition, pressure deviations exceeding safety thresholds are caused by changes in external environmental pressure. ,For example For example, when passing through the turbulent layer, the system triggers an emergency lockout mode; in this mode, the system forcibly increases the sample pressure to maintain the differential pressure. For example, increase the speed by 20% and adjust the PID parameters to high response mode, i.e., increase the proportional gain. And reduce the integration time constant This is to achieve rapid suppression of pressure surges and prioritize ensuring that the sample does not shift.

[0028] Example 7: The method also includes security protection logic: The vibration acceleration data of the sampler is monitored in real time; if the vibration acceleration data collected by the acceleration sensor indicates that the pipe wall amplitude exceeds the preset structural safety limit, the driving amplitude in the vibration control command is forcibly reduced. If the cable tension does not drop below the tension threshold after frequency scanning and the duration exceeds the preset timeout threshold, a stop extraction command will be generated and an alarm will be issued.

[0029] This embodiment specifically implements the system's security protection logic; The system executes structural safety protection procedures and monitors the vibration acceleration data of the sampling tube wall in real time. ; In response to detection This indicates that the pipe wall vibration amplitude exceeds the preset structural safety limit, which is set based on the physical characteristics of the piezoelectric ceramic sheet. The controller will ignore the drag reduction requirement and forcibly reduce the drive amplitude in the vibration control command. The system executes the timeout protection procedure, and monitors the cable tension after frequency scanning and excitation. ; in response It has not yet dropped to the tension threshold. The following applies, and the duration of this state exceeds a preset timeout threshold. The system determines that the situation is an unrecoverable deadlock; the system generates a stop extraction command, stops the winch operation, and issues an alarm. This embodiment provides a graded equipment protection mechanism to prevent hardware damage under extreme working conditions; by limiting the maximum amplitude, it avoids the piezoelectric ceramic from cracking due to overload; and by using timeout shutdown logic, it prevents the risk of cable breakage or equipment loss caused by forced lifting, thereby significantly improving the reliability and safety of deep-sea operations.

[0030] Example 8: The generation of vibration control commands includes: Based on the resonant frequency point, a sinusoidal excitation signal is generated; Based on vibration data collected by accelerometers, the equivalent acoustic impedance change at the contact surface between the sampler and the medium is analyzed; according to the equivalent acoustic impedance change, the frequency of the sinusoidal excitation signal is finely adjusted in real time to maintain the liquefaction state of the boundary layer between the pipe wall and the medium. The liquefied state refers to the rheological state in which the contact stress between medium particles decreases and the pore water pressure increases.

[0031] This embodiment further optimizes the generation method of vibration control commands by introducing equivalent acoustic impedance feedback; The system generates a sinusoidal excitation signal based on the resonant frequency point; based on the vibration data collected by the accelerometer, it analyzes the change in the equivalent acoustic impedance of the sampler-medium contact surface. Here, the controller uses a simplified electromechanical coupling model to calculate the equivalent acoustic impedance modulus. The calculation formula is: ; in, : This represents the effective value of the driving voltage for the piezoelectric ceramic; : This represents the effective value of the pipe wall vibration velocity; : This represents the root mean square value of the vibration acceleration of the pipe wall; : This represents the current driving frequency; Pi is the constant. : This is the electromechanical conversion coefficient of the piezoelectric ceramic exciter, in N / V. This coefficient is a preset constant, obtained by force-voltage calibration of the piezoelectric exciter in the laboratory, and is used to map the electrical drive voltage into the mechanical output force. This formula physically represents the driving force required per unit vibration velocity. The lower the impedance, the higher the degree of decoupling between the pipe wall and the soil, and the higher the energy transfer efficiency. The system fine-tunes the frequency of the sinusoidal excitation signal in real time based on changes in equivalent acoustic impedance; specifically, it employs a perturbation-observation algorithm. The controller is used every preset period For example, apply a frequency perturbation amount for 50ms. The disturbance amount Adopting an adaptive step size strategy, i.e. The magnitude of this is proportional to the gradient of the current impedance change; when the rate of impedance change approaches zero, it decreases. To lock the frequency; If the frequency increases, it will cause impedance Decline, i.e. If the current direction of change is favorable to liquefaction, the frequency will be increased in the next moment; otherwise, the frequency will be adjusted in the opposite direction. In response to the detected impedance The initial rise indicates that the liquefied boundary layer has remodeled and solidified or deviated from the resonance point. The controller automatically searches for a new local optimum frequency through the aforementioned optimization logic to maintain the liquefaction state between the pipe wall and the medium boundary layer. Here, the physical meaning of the liquefaction state is a rheological state in which the contact stress between medium particles decreases and the pore water pressure increases. In the algorithm, this is represented by acoustic impedance. It remains within the 10% error band of the historical minimum.

[0032] Example 9: The operational status feedback data also includes the sampler's attitude angle data; The method also includes: collecting attitude angle data through an accelerometer to determine the tilt of the sampler; if the tilt exceeds a preset tilt angle threshold, correcting the calculated value of the pressure inside the target pipe to compensate for the uneven distribution of hydrostatic pressure caused by the tilt.

[0033] This embodiment involves compensation control of the sampler's attitude; The system acquires pitch and roll attitude angle data through accelerometers or inertial measurement units (IMUs); The controller determines the tilt of the sampler in real time. , The calculation is based on the principle of gravity vector projection, and the formula is: ; in, The pitch angle relative to the horizontal plane, measured by an accelerometer, in degrees; The roll angle is relative to the horizontal plane, in degrees. Pi is a constant. Based on this, in response to If the tilt angle exceeds the preset threshold, such as 15 degrees, it indicates that the sampler has tilted significantly, causing a change in the component of the sample gravity along the axis of the sampling tube. The system performs a pressure correction step to correct the calculated value of the target pipe pressure; the correction formula is: ; in, This is the theoretical pressure difference required to overcome the sample's gravity in a vertical position. The cosine of the tilt angle; This correction logic is based on physical facts: when the sampling tube is tilted, the gravitational component of the sample sliding down the tube wall decreases, so the required adsorption negative pressure, i.e., the pressure difference between the inside and outside of the tube, should be reduced accordingly to avoid excessive negative pressure from drawing in too much sample or damaging the stratification. This embodiment eliminates the error influence of tilt attitude on hydrostatic pressure calculation by using attitude sensing and pressure correction. In actual sea conditions, the sampler often tilts due to water flow impact, resulting in inconsistent water pressure on both sides of the nozzle and changes in the effective gravity component. This solution ensures that the accurate pressure balance point can still be calculated in the tilted state, avoiding excessive sample intake or insufficient suction caused by calculation errors, and ensuring sampling accuracy under non-ideal attitude conditions.

[0034] Example 10: Please see Figure 2 A sediment column sampler operation control and testing system, comprising: The data acquisition module is used to collect operational status feedback data. The data acquisition module includes an intelligent sensing system, which comprises: a tension sensor located at the sampler's traction cable to monitor the cable's traction tension in real time; an internal pressure sensor located at the top of the sampler tube to monitor the pressure inside the tube cavity; an external pressure sensor located at the bottom of the sampler tube to monitor the external environmental pressure; and an acceleration sensor located on the sampler tube wall to monitor the sampler's vibration acceleration and attitude angle data. The status analysis module is used to analyze the operational status feedback data and identify the current operating stage and resistance status of the sampler. The vibration control module, including a piezoelectric ceramic excitation array, is used to perform frequency scanning and generate vibration control commands when a high friction jamming state is detected, driving the pipe wall to generate radial micro-amplitude vibration at the resonant frequency point. The pressure compensation module includes a pneumatic compensation unit, which is used to monitor the external environmental pressure in real time, calculate the target internal pressure based on the preset sample pressure difference, and generate a pneumatic compensation command to adjust the internal cavity pressure and maintain the internal and external pressure difference within the preset allowable range.

[0035] This embodiment describes a specific hardware architecture for a sediment column sampler operation control and testing system, which is used to execute the method of any of the above embodiments. The system's hardware architecture specifically includes: The data acquisition module, which serves as the system's sensory nerve, includes an intelligent sensing system; among which, a tension sensor is installed at the cable connection point of the sampler head; and an internal pressure sensor is located at the top of the sampling tube, directly contacting the air chamber. The external pressure sensor is located at the bottom of the outer wall of the sampling tube, near the cutting edge; the acceleration sensor is rigidly coupled to the wall of the sampling tube. A state analysis module running in an embedded processor is configured to identify the current operating stage and resistance state of the sampler; An excitation control module comprising a piezoelectric ceramic excitation array arranged around the wall of a sampling tube is configured to generate mechanical waves of specific frequencies and modes in response to control commands. The pneumatic compensation module includes a pneumatic compensation unit, which integrates a miniature bidirectional air pump, a proportional solenoid valve and an air storage buffer tank. It is configured to monitor the external environmental pressure in real time and adjust the internal cavity pressure. This embodiment achieves full-dimensional perception and active intervention of the sampling process through a specific sensor layout and actuator integration; in particular, the sensor distribution of internal pressure at the top, external pressure at the bottom, tension on the cable, and vibration on the wall maximizes the signal-to-noise ratio and the correlation of the physical field; together with the piezoelectric excitation and pneumatic compensation actuator, an intelligent entity with adaptive capabilities is constructed, providing a solid hardware foundation for high-quality sampling in complex underwater environments.

[0036] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. A method for controlling and testing the operation of a sediment column sampler, characterized in that, include: Collect operational status feedback data; the operational status feedback data includes the sampler's cable tension, the pressure inside the tube cavity, and the environmental pressure outside the tube. The operational status feedback data is analyzed to identify the current operating stage and resistance status of the sampler; When the sampler is identified as being in the extraction stage and the cable tension exceeds a preset tension threshold, the variable frequency excitation control logic is triggered. Based on the variable frequency excitation control logic, the sampler tube wall is scanned to identify the resonant frequency point between the current tube wall and the external medium system. A vibration control command is generated to drive the sampler tube wall to perform radial micro-amplitude vibration at the resonant frequency point to reduce interface friction resistance. Simultaneously, during the extraction stage, the rate of change of the external environmental pressure is monitored in real time; based on the external environmental pressure and the preset sample holding pressure difference, the target internal pressure is calculated; a pneumatic compensation command is generated to adjust the internal cavity pressure so that it dynamically follows the change of the external environmental pressure and maintains the difference between the external environmental pressure and the internal cavity pressure within the preset allowable error range of the sample holding pressure difference.

2. The method for operation control and testing of a sediment column sampler according to claim 1, characterized in that, The method for performing frequency scanning on the sampler tube wall to identify the resonant frequency point between the current tube wall and the external medium system includes: determining a preset frequency scanning range; and controlling the piezoelectric ceramic excitation array embedded in the sampler tube wall to output a frequency conversion excitation signal within the frequency scanning range. The vibration response amplitude of the sampler tube wall at different excitation frequencies is collected; a frequency-response amplitude curve is constructed; and the frequency corresponding to the peak in the frequency-response amplitude curve is marked as the resonance frequency point. The vibration control command is used to lock the operating frequency of the excitation unit at the resonant frequency point and control the vibration mode to be the radial shear wave mode.

3. The method for controlling and testing the operation of a sediment column sampler according to claim 2, characterized in that, The method for identifying the current operating stage and resistance state of the sampler includes: monitoring the value of the external environmental pressure; if the external environmental pressure remains stable and is greater than atmospheric pressure, it is determined to be a static state at the bottom of the water. Monitor the rate of change of the cable traction tension; if the rate of change of the cable traction tension is positive, determine that the extraction start-up state has been reached. In the extraction start state, the real-time value of the cable traction tension is compared with the tension threshold; if the cable traction tension is greater than the tension threshold, the resistance state is determined to be a high friction jam state; if the cable traction tension is less than or equal to the tension threshold, the resistance state is determined to be a normal extraction state.

4. The method for controlling and testing the operation of a sediment column sampler according to claim 3, characterized in that, The method also includes control logic for the penetration phase: monitoring the deceleration speed of the sampler; when the absolute value of the deceleration speed exceeds a preset penetration determination threshold, the method determines that the process has entered the penetration phase. A longitudinal excitation command is generated to drive the sampler tube wall to vibrate longitudinally at a low frequency until a preset sampling depth is reached; wherein, the frequency of the longitudinal low-frequency vibration is lower than the resonant frequency point, and the vibration direction is parallel to the axis of the sampler.

5. The method for operation control and testing of a sediment column sampler according to claim 1, characterized in that, The method for calculating the target tube pressure based on the external environmental pressure and the preset sample holding pressure difference includes: obtaining a preset sample density parameter and an estimated sample length; calculating the product of the sample density parameter, the gravitational acceleration constant and the estimated sample length to obtain the minimum adsorption pressure value that can overcome the gravity of the sample, and setting the minimum adsorption pressure value as the sample holding pressure difference; Obtain the current external environmental pressure; subtract the sample holding pressure difference from the external environmental pressure to obtain the target internal pressure of the tube; The pneumatic compensation command is used to control the opening of the bidirectional air pump or proportional valve to adjust the actual intra-pipe cavity pressure to approximate the target intra-pipe pressure.

6. The method for operation control and testing of a sediment column sampler according to claim 5, characterized in that, The step of generating pneumatic compensation commands further includes: calculating the pressure deviation between the cavity pressure inside the pipe and the target pipe pressure; inputting the pressure deviation into a PID controller; and outputting an adjustment signal through the PID controller to control the on / off state and flow rate of the pneumatic system. When the external environmental pressure decreases as the sampler rises, the pneumatic compensation command controls the gas path system to discharge the gas inside the tube to prevent the gas inside the tube from expanding and causing the sample to slip. When the pressure deviation caused by the change in the external environmental pressure exceeds the safety threshold, the emergency lockout mode is triggered, and the pressure difference of the sample is forcibly increased to maintain the pressure difference.

7. The method for operation control and testing of a sediment column sampler according to claim 1, characterized in that, The method also includes safety protection logic: real-time monitoring of the vibration acceleration data of the sampler; if the vibration acceleration data collected by the acceleration sensor indicates that the pipe wall amplitude exceeds the preset structural safety limit, the driving amplitude in the vibration control command is forcibly reduced. If, after performing the frequency scan, the cable tension still does not drop below the tension threshold and the duration exceeds the preset timeout threshold, a stop extraction command is generated and an alarm is issued.

8. The method for operation control and testing of a sediment column sampler according to claim 1, characterized in that, The vibration control command includes: generating a sinusoidal excitation signal based on the resonant frequency point; and analyzing the change in equivalent acoustic impedance of the sampler-medium contact surface based on the vibration data collected by the accelerometer. Based on the change in equivalent acoustic impedance, the frequency of the sinusoidal excitation signal is finely adjusted in real time to maintain the liquefaction state of the pipe wall and the medium boundary layer; wherein, the liquefaction state refers to the rheological state in which the contact stress between medium particles decreases and the pore water pressure increases.

9. The method for operation control and testing of a sediment column sampler according to claim 1, characterized in that, The operational status feedback data also includes the sampler's attitude angle data; the method further includes: acquiring the attitude angle data through an accelerometer to determine the sampler's tilt degree; If the degree of tilt exceeds a preset tilt angle threshold, the calculated value of the pressure inside the target pipe is corrected to compensate for the uneven distribution of hydrostatic pressure caused by the tilt.

10. A sediment column sampler operation control and testing system, applied to the sediment column sampler operation control and testing method according to any one of claims 1-9, characterized in that, include: The data acquisition module is used to collect operational status feedback data; The data acquisition module includes an intelligent sensing system, which comprises: a tension sensor installed at the traction cable of the sampler for real-time monitoring of the cable tension; an internal pressure sensor installed at the top of the sampler tube for monitoring the pressure inside the tube cavity; an external pressure sensor installed at the bottom of the sampler tube for monitoring the external environmental pressure; and an acceleration sensor installed on the sampler tube wall for monitoring the sampler's vibration acceleration and attitude angle data. The status analysis module is used to analyze the operating status feedback data and identify the current operating stage and resistance status of the sampler. The vibration control module, including a piezoelectric ceramic excitation array, is used to perform frequency scanning and generate vibration control commands when a high friction jamming state is detected, driving the pipe wall to generate radial micro-amplitude vibration at the resonant frequency point. The pressure compensation module includes a pneumatic compensation unit, which is used to monitor the external environmental pressure in real time, calculate the target internal pressure based on the preset sample pressure difference, and generate a pneumatic compensation command to adjust the internal cavity pressure and maintain the internal and external pressure difference within the preset allowable range.

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