An adaptive geotechnical sampling disturbance suppression system and method

Abstract

This invention relates to the field of geotechnical mining technology, and in particular to an adaptive geotechnical sampling disturbance suppression system and method. It calculates the foundation volume replacement flow rate by simultaneously collecting drilling speed and pressure inside and outside the pipe; constructs a dynamic hydraulic impedance model; uses a state observation algorithm to identify the equivalent annular gap width online; and quantifies the annular gap leakage compensation flow rate accordingly; finally, the superimposed flow rate drives the actuator to perform active fluid throughput. This invention effectively solves the pressure imbalance problem caused by neglecting dynamic gap leakage between the pipe wall and the soil sample; achieves millisecond-level adaptive balance of internal pipe pressure; constructs a dynamic hydraulic barrier without mechanical seals; and completely eliminates the squeezing or suction damage to the soil sample skeleton caused by instantaneous pressure difference through precise compensation for microscopic leakage, significantly improving the original state and integrity of geotechnical samples in complex strata.

Description

Technical Field

[0001] This invention relates to the field of rock and soil mining technology, and in particular to an adaptive rock and soil sampling disturbance suppression system and method. Background Technology

[0002] In geotechnical engineering exploration and deep geological science research, obtaining undisturbed soil and rock samples that maintain in-situ stress state and microstructure is a key prerequisite for accurately evaluating the physical and mechanical properties of strata. Traditional double-tube sampling techniques usually rely on passive one-way valve drainage or simple geometric volume replacement logic to control the fluid in the tube during operation, maintaining the pressure balance in the tube by discharging fluid equal to the volume of soil sample entering.

[0003] However, existing technologies have significant limitations when dealing with complex fluid-structure interaction environments. They are usually designed based on the assumption of an ideal seal, while ignoring the annular gap that objectively exists between the inner wall of the sampling tube and the incoming soil and rock sample, and which dynamically changes with the properties of the strata. In actual sampling, this annular gap will form a "leakage channel" connecting the high-pressure area inside the tube and the low-pressure area outside the tube, resulting in a non-negligible deviation between the actual fluid volume inside the tube and the theoretical calculation value.

[0004] Because existing technologies lack the ability to perceive this dynamic annular gap in real time, and cannot quantify and compensate for fluid leakage through this gap, it is difficult to achieve precise synchronization between the fluid pressure inside the sampling tube and the in-situ pore pressure. This loss of fluid dynamics can easily trigger instantaneous positive pressure squeezing or negative pressure suction inside the tube: positive pressure will damage the skeleton structure of weak soil samples, while negative pressure will cause the bottom of the sample to crack or detach from the tube wall. This sampling disturbance caused by the imbalance of the hydraulic environment inside the tube seriously reduces the sampling rate and the integrity of the sample, making it difficult to meet the needs of high-precision geotechnical engineering investigation. Summary of the Invention

[0005] The main objective of this invention is to provide an adaptive soil and rock sampling disturbance suppression system, which aims to solve the technical problem that existing soil and rock sampling techniques neglect the dynamic annular gap between the inner wall of the sampling tube and the soil sample and the fluid leakage effect caused by it, resulting in the fluid pressure inside the tube failing to maintain a real-time balance with the in-situ pressure of the formation, thus causing damage to the microstructure of the sample.

[0006] To achieve the above objectives, the present invention provides an adaptive soil and rock sampling disturbance suppression system, the system comprising:

[0007] A dual-layer sampling assembly, comprising a coaxially nested outer rotating tube and an inner stationary tube, wherein a sealed pressure regulating cavity is formed at the top of the inner stationary tube, and the inner stationary tube is used to contain the incoming soil and rock samples.

[0008] The data acquisition module is used to simultaneously acquire the instantaneous penetration velocity of the sampling tube, the current sampling depth, the fluid pressure inside the inner stationary tube, and the in-situ pore pressure outside the outer rotating tube during the process of the sampling tube penetrating the soil and rock.

[0009] Impedance observation module, which is used to obtain the basic fluid volume flow rate that needs to be discharged due to the drill bit cutting into the rock and soil based on the instantaneous penetration velocity and the inner cross-sectional area of ​​the inner stationary tube, and use it as the volume displacement flow rate component.

[0010] The model building module is used to build a dynamic hydraulic impedance model. The fluid pressure value in the inner static pipe is used as the observed output of the system and compared with the predicted pressure value output by the dynamic hydraulic impedance model. Based on the deviation between the two, the current equivalent annular gap width is corrected in reverse through the state observation algorithm.

[0011] The disturbance compensation module is used to obtain the cross-boundary pressure difference based on the fluid pressure in the inner stationary tube and the in-situ pore pressure, and to obtain the leakage flow rate through the annular gap based on the cube value of the equivalent annular gap width, the current sampling depth and the cross-boundary pressure difference, and to use it as the compensation flow rate component for the annular gap leakage.

[0012] The disturbance suppression module is used to superimpose the volume displacement flow component with the compensation flow component of the annular gap leakage to obtain a fluid throughput control command, so as to drive the actuator to actively inject or pump fluid into the pressure regulating chamber at the top of the inner stationary tube, so as to dynamically balance the pressure fluctuation in the tube.

[0013] Optionally, the data acquisition module includes:

[0014] A pressure sensing unit is embedded in the inner wall of the bottom edge of the inner stationary tube and the outer wall of the outer rotating tube, respectively, for obtaining the fluid pressure inside the inner stationary tube and the in-situ pore pressure outside the outer rotating tube.

[0015] A motion monitoring unit is installed on one side of the drill string within the dual-layer sampling assembly. It is used to acquire the displacement signal of the drill string at a preset high sampling frequency and to preprocess the displacement signal to obtain the instantaneous penetration velocity.

[0016] Optionally, the model building module is configured with a state observation algorithm;

[0017] The state observation algorithm is used to compare the observed output with the predicted pressure value, and iteratively update the estimated value of the equivalent annular gap width based on the deviation between the two through the error feedback gain matrix within the state observation algorithm.

[0018] Optionally, the disturbance compensation module uses calculation logic based on the fluid gap flow characteristics when acquiring the compensation flow component of the annular gap leakage;

[0019] The calculation logic is configured to: call the equivalent annular gap width output by the model building module, perform a cubic operation on the equivalent annular gap width, determine the current gap flow resistance characteristics based on the current sampling depth and dynamic viscosity, and then perform calculations with the cross-boundary pressure difference to quantify and obtain the leakage flow rate occurring through the annular gap.

[0020] Optionally, the impedance observation module includes an entry rate correction unit, which is used to characterize the ratio between the actual volume of soil and rock entering the inner stationary tube and the theoretical geometric volume during the cutting process of the double-layer sampling component. The corresponding soil and rock entry rate correction factor is selected according to the preset soil and rock type parameters, so as to correct the volumetric flow rate of the basic fluid according to the soil and rock entry rate correction factor.

[0021] Optionally, the actuator includes:

[0022] The servo hydraulic station is installed on the ground and is connected to the pressure regulating chamber of the inner stationary tube through a pressure pipeline.

[0023] A piezoelectric proportional servo valve, integrated within the servo hydraulic station, is used to adjust the valve opening in response to the fluid throughput control command, thereby achieving continuous regulation of fluid flow.

[0024] The disturbance suppression module further includes a liquid resistance characteristic query unit, which is used to convert the fluid throughput control command into a corresponding opening voltage signal based on the differential pressure flow characteristics of the piezoelectric proportional servo valve.

[0025] Optionally, the disturbance suppression module further includes a pressure servo correction unit;

[0026] The pressure servo correction unit is used to set a target differential pressure threshold and compare the cross-boundary differential pressure with the target differential pressure threshold to obtain a pressure feedback adjustment component; the disturbance suppression module superimposes the pressure feedback adjustment component into the fluid throughput control command to eliminate the accumulated static pressure error.

[0027] Optionally, the inner wall of the inner stationary tube is coated, and the inner diameter of the inner stationary tube is larger than the inner diameter of the drill bit cutting edge to form a preset gap; the model building module uses the preset gap as the initial iterative reference value of the equivalent annular gap width.

[0028] Optionally, the system further includes an abnormal circuit breaker module;

[0029] The abnormal fuse module is used to monitor the rate of change of the equivalent annular gap width. When the equivalent annular gap width is detected to exceed the preset safety threshold within a preset time, it is determined to be an abnormality of soil sample detachment or pipe wall rupture, triggering the disturbance suppression module and stopping the drive actuator to perform active injection or suction, while issuing an alarm signal.

[0030] To achieve the above objectives, the present invention also provides an adaptive soil and rock sampling disturbance suppression method, the method comprising the following steps:

[0031] During the process of the sampling tube penetrating the soil and rock, the instantaneous penetration velocity of the sampling tube, the current sampling depth, the fluid pressure inside the inner stationary tube, and the in-situ pore pressure outside the outer rotating tube are simultaneously acquired.

[0032] Based on the instantaneous penetration velocity and the inner cross-sectional area of ​​the inner stationary tube, the volumetric flow rate of the basic fluid that needs to be discharged due to the drilling tool cutting into the rock and soil is obtained, and used as the volume displacement flow rate component.

[0033] A dynamic hydraulic impedance model is constructed, and the fluid pressure value in the inner static pipe is used as the observed output of the system. The model is compared with the predicted pressure value output by the dynamic hydraulic impedance model. Based on the deviation between the two, the current equivalent annular gap width is corrected in reverse through the state observation algorithm.

[0034] The cross-boundary pressure difference is obtained based on the fluid pressure inside the inner stationary tube and the in-situ pore pressure. The leakage flow rate through the annular gap is obtained based on the cube value of the equivalent annular gap width, the current sampling depth, and the cross-boundary pressure difference, and is used as the compensation flow rate component for annular gap leakage.

[0035] The volume displacement flow component is superimposed with the compensation flow component of the annular gap leakage to obtain a fluid throughput control command, which drives the actuator to actively inject or pump fluid into the pressure regulating chamber at the top of the inner stationary tube to dynamically balance the pressure fluctuations inside the tube.

[0036] This invention constructs an adaptive soil and rock sampling disturbance suppression system that includes a dual-layer sampling component, multi-dimensional data acquisition, and multi-level closed-loop control logic. Based on real-time acquisition of drill bit movement status and pressure data inside and outside the pipe, it not only calculates the volume displacement flow required for the drill bit to cut into the soil and rock, but more importantly, it constructs a dynamic hydraulic impedance model. By utilizing the deviation between the measured pressure inside the static pipe and the model prediction, the equivalent annular gap width, which cannot be directly measured, is corrected online through a state observation algorithm. Based on the cubic value of this width and the cross-boundary pressure difference, the leakage flow rate occurring through the annular gap is accurately quantified. Finally, the volume displacement amount and the leakage compensation amount are superimposed to drive the actuator to perform active fluid throughput control.

[0037] The system achieves millisecond-level adaptive dynamic balance of the pressure environment inside the pipe throughout the sampling process. By mapping changes in micro-gap in real time into quantifiable fluid leakage compensation commands, the system can automatically adjust the fluid injection or suction rate in the pressure regulating chamber at the moment when the drill bit passes through strata with different permeability or when there are slight fluctuations in the gaps between the soil sample sidewalls. This dual compensation mechanism completely eliminates the control blind zone caused by single geometric volume replacement. It effectively prevents the compression damage to the weak soil sample skeleton caused by the instantaneous positive pressure due to untimely fluid discharge from the pipe, and avoids the suction cracking or suction damage to the sample caused by the negative pressure inside the pipe due to gap leakage. Thus, without the need for manual intervention and without relying on mechanical seals, it significantly improves the integrity and original state of the obtained soil and rock samples, providing a reliable technical guarantee for high-precision geotechnical engineering exploration. Attached Figure Description

[0038] Figure 1 This is a structural block diagram of the system in Embodiment 1 of the present invention.

[0039] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0040] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0041] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indication will also change accordingly.

[0042] In this invention, unless otherwise explicitly specified and limited, the terms "connection," "fixed," etc., should be interpreted broadly. For example, "fixed" can mean a fixed connection, a detachable connection, or an integral part; it can mean a mechanical connection or an electrical connection; it can mean a direct connection or an indirect connection through an intermediate medium; it can mean the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0043] Furthermore, if the embodiments of this invention involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the meaning of "and / or" throughout the text includes three parallel solutions; for example, "A and / or B" includes solution A, solution B, or a solution where both A and B are satisfied simultaneously. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0044] Example 1:

[0045] As attached Figure 1 As shown, this embodiment provides an adaptive soil and rock sampling disturbance suppression system, the system comprising:

[0046] A dual-layer sampling assembly, comprising a coaxially nested outer rotating tube and an inner stationary tube, wherein a sealed pressure regulating cavity is formed at the top of the inner stationary tube, and the inner stationary tube is used to contain the incoming soil and rock samples.

[0047] The data acquisition module is used to simultaneously acquire the instantaneous penetration velocity of the sampling tube, the current sampling depth, the fluid pressure inside the inner stationary tube, and the in-situ pore pressure outside the outer rotating tube during the process of the sampling tube penetrating the soil and rock.

[0048] Impedance observation module, which is used to obtain the basic fluid volume flow rate that needs to be discharged due to the drill bit cutting into the rock and soil based on the instantaneous penetration velocity and the inner cross-sectional area of ​​the inner stationary tube, and use it as the volume displacement flow rate component.

[0049] The model building module is used to build a dynamic hydraulic impedance model. The fluid pressure value in the inner static pipe is used as the observed output of the system and compared with the predicted pressure value output by the dynamic hydraulic impedance model. Based on the deviation between the two, the current equivalent annular gap width is corrected in reverse through the state observation algorithm.

[0050] The disturbance compensation module is used to obtain the cross-boundary pressure difference based on the fluid pressure in the inner stationary tube and the in-situ pore pressure, and to obtain the leakage flow rate through the annular gap based on the cube value of the equivalent annular gap width, the current sampling depth and the cross-boundary pressure difference, and to use it as the compensation flow rate component for the annular gap leakage.

[0051] The disturbance suppression module is used to superimpose the volume displacement flow component with the compensation flow component of the annular gap leakage to obtain a fluid throughput control command, so as to drive the actuator to actively inject or pump fluid into the pressure regulating chamber at the top of the inner stationary tube, so as to dynamically balance the pressure fluctuation in the tube.

[0052] In existing geotechnical engineering investigations, traditional double-tube sampling techniques typically employ passive one-way valve drainage or fluid control methods based on geometric volume replacement logic to maintain pressure balance within the tube. During sampling, the annular gap acts as a leakage channel connecting the high-pressure zone inside the tube with the low-pressure zone outside, causing a deviation between the actual fluid volume inside the tube and the theoretically calculated value. Furthermore, due to the lack of real-time sensing and quantitative compensation capabilities for the dynamic annular gap, it is difficult to directly synchronize the fluid pressure inside the tube with the in-situ pore pressure. Positive pressure compression can easily damage the skeleton structure of weak soil samples, while negative pressure suction can easily cause the bottom of the sample to detach from the tube wall, reducing the sampling rate and the integrity of the sample.

[0053] Based on the above problems, this embodiment aims to solve the problem of pressure instability inside the sampling tube caused by leakage of invisible dynamic gaps between the inner wall of the sampling tube and the soil sample. In terms of physical structure, the double-layer sampling assembly serves as the main actuator, consisting of an outer rotating tube and an inner stationary tube coaxially nested. The outer rotating tube is responsible for transmitting torque to cut the strata, while the inner stationary tube is in a relatively stationary state, used to receive and protect the cut soil sample. The top of the inner stationary tube is constructed with a sealed pressure regulating chamber, which is connected to the hydraulic actuator on the ground through a pipeline, forming the physical boundary for active fluid pressure control.

[0054] Throughout the entire process of the sampling tube penetrating the soil and rock, multi-dimensional physical field data is collected simultaneously. Specifically, a high-frequency displacement sensor (such as a magnetostrictive displacement sensor) installed at the drill rig's power head is used to acquire the displacement signal of the drill bit at a millisecond-level sampling rate. After preprocessing (such as differential calculation and Kalman filtering for noise reduction), the instantaneous penetration velocity of the sampling tube is calculated. At the same time, a miniature pressure sensor embedded in the inner wall of the cutting edge at the bottom of the inner stationary tube monitors the fluid pressure inside the tube in real time, while a pressure sensor installed on the outer wall of the outer rotating tube monitors the in-situ pore pressure of the formation.

[0055] The impedance monitoring module is primarily responsible for calculating the theoretical rigid displacement flow rate. Under ideal, completely sealed sampling conditions, the volume of fluid displaced by the drill bit penetrating the formation should be strictly equal to the volume of soil sample entering the inner tube. Therefore, based on the principle of fluid continuity, the impedance monitoring module calculates the basic fluid volumetric flow rate, defining it as the volumetric displacement flow rate component. This calculation process is based on the following volumetric displacement formula: ;

[0056] in, The volumetric flow rate at time t represents the basic fluid volumetric flow rate, i.e., the volumetric displacement flow rate component, in cubic meters per second.

[0057] This represents the instantaneous penetration velocity of the sampling tube at time t, and the data comes from the real-time calculation of the displacement signal by the data acquisition module.

[0058] This represents the inner cross-sectional area of ​​the inner stationary tube, and the data comes from the preset geometric parameters of the inner stationary tube at the factory.

[0059] Understandably, during the sampling process, the movement of the drill bit is the active source of pressure changes inside the pipe. By multiplying the real-time velocity by the cross-sectional area, the system can pre-calculate the theoretical displacement required to maintain volume balance before the pressure sensor detects pressure fluctuations. This feedforward mechanism can significantly improve the system's response speed to sudden changes in drilling speed and prevent instantaneous high pressure caused by hysteresis from damaging the soft soil structure.

[0060] However, an ideal seal does not exist in actual working conditions; a small and dynamically changing annular gap objectively exists between the soil sample and the pipe wall. To address this, the model building module introduces a dynamic hydraulic impedance model and a state observation algorithm. The core task of this module is to obtain the relatively small gap width. Since the annular gap cannot be directly measured, the system constructs a mathematical model that incorporates the gap's flow resistance characteristics and uses the measured fluid pressure inside the stationary inner pipe as the system's observed output. The state observation algorithm (such as an extended Kalman filter or a Luenberger observer) compares the measured pressure with the pressure value predicted by the model based on the current state in real time. When a deviation occurs, the algorithm determines that it is due to an inaccurate equivalent annular gap width parameter in the model. It then corrects this parameter through an error feedback mechanism until the predicted value approximates the measured value. This process achieves online parameter identification of unknown geometric parameters.

[0061] Based on the identified gap parameters, the disturbance compensation module is responsible for quantifying the leakage flow rate through the gap. When the pressure inside the pipe is higher or lower than the formation pressure, the fluid will flow through the annular gap under the pressure difference, resulting in a subtle increase or decrease in the total amount of fluid inside the pipe. This module calculates the compensation flow rate component of the annular gap leakage according to the laminar flow motion law of the fluid in the slender annular gap (a variant of Poiseuille flow). The calculation follows the following leakage quantification formula:

[0062] ;

[0063] In the formula, This represents the leakage flow rate occurring through the annular gap at time t, i.e., the compensation flow rate component of the annular gap leakage.

[0064] This represents the inner diameter of the stationary tube, and the data comes from the preset geometric parameters of the stationary tube.

[0065] This represents the equivalent annular gap width obtained by the reverse correction of the state observation algorithm at time t, which comes from the real-time output of the model building module;

[0066] This represents the fluid pressure inside the stationary tube at time t, and the data comes from the measured values ​​of the data acquisition module.

[0067] This represents the in-situ pore pressure outside the rotating tube at time t, and the data comes from the measured values ​​of the data acquisition module.

[0068] μ represents the dynamic viscosity of the fluid (usually mud or water) inside the pipe, which is derived from preset fluid property parameters or real-time monitoring values.

[0069] This represents the current sampling depth at time t, which is the length of the flow channel through the annular gap, derived from the displacement monitoring of the data acquisition module.

[0070] It should be noted that in micron-level interstitial flow, extremely small changes in geometry can lead to an exponential change in flow resistance. For example, when the sampling object changes from cohesive soil (with extremely small interstitial spaces) to sandy soil (with slightly larger interstitial spaces), although the interstitial space width increases only slightly, the leakage will increase dramatically. Without introducing a cubic term for compensation, the system cannot prevent instantaneous backflow or loss of fluid through linear adjustment alone. It is also understandable that, based on the above formula, when the system encounters highly permeable strata or when soil shrinkage causes an increase in interstitial spaces, it will automatically calculate a large compensation flow command, driving the actuator to rapidly inject fluid or pump at a high flow rate, thereby forming a hydraulic seal and effectively preventing sand sample loss or soft soil collapse.

[0071] Finally, the disturbance suppression module synthesizes the control command, algebraically superimposing the volume displacement flow component calculated by the impedance observation module and the annular leakage compensation flow component calculated by the disturbance compensation module to generate the final fluid throughput control command. This command drives the actuator (such as a piezoelectric proportional servo valve) connected to the pressure regulating chamber to precisely inject or pump the fluid within the chamber. Through this composite control strategy of feedforward volume displacement and feedback leakage compensation, the system can maintain the pressure inside the pipe in balance with the in-situ formation pressure during the dynamic process of continuously increasing sampling depth and changing flow resistance characteristics, thus achieving truly adaptive and disturbance-free sampling.

[0072] Example 2:

[0073] In this embodiment, the data acquisition module includes:

[0074] A pressure sensing unit is embedded in the inner wall of the bottom edge of the inner stationary tube and the outer wall of the outer rotating tube, respectively, for obtaining the fluid pressure inside the inner stationary tube and the in-situ pore pressure outside the outer rotating tube.

[0075] A motion monitoring unit is installed on one side of the drill string within the dual-layer sampling assembly. It is used to acquire the displacement signal of the drill string at a preset high sampling frequency and to preprocess the displacement signal to obtain the instantaneous penetration velocity.

[0076] It should be noted that the pressure sensor inside the inner stationary tube is preferably positioned within an annular groove only a few millimeters from the cutting edge, and the sensor surface is covered with a high-hardness, wave-transparent ceramic or wear-resistant resin layer. This effectively ensures that the sensor can directly contact the interface between the fluid and soil sample just entering the tube, accurately acquiring the fluid pressure inside the inner stationary tube, while avoiding sensor damage due to severe friction when penetrating hard strata. The pressure sensor outside the outer rotating tube is located in the stabilization section behind the drill bit, used to directly sense the original stress state of the strata, i.e., the in-situ pore pressure outside the outer rotating tube. Both sensors are high-frequency response MEMS piezoresistive or piezoelectric sensors, capable of synchronously acquiring pressure signals at a frequency of not less than 1000Hz, thereby ensuring that the system can capture millisecond-level pressure pulses generated when the drill bit traverses different soil layer interfaces.

[0077] It should also be noted that the motion monitoring unit is installed on the drive end of the double-layer sampling assembly or on the side of the drill rig's power head. In actual operation, the movement of the drill bit is not uniform linear motion, but a complex nonlinear motion accompanied by mechanical vibration and changes in formation resistance. In order to accurately capture this motion state, the motion monitoring unit uses a non-contact laser rangefinder or magnetostrictive displacement sensor to continuously collect the absolute position information of the drill bit relative to the borehole opening at a preset high sampling frequency (e.g., 2kHz) to generate the original displacement signal sequence.

[0078] Since the original displacement signal inevitably contains high-frequency noise generated by drilling rig vibration, directly performing differentiation would greatly amplify the noise interference, leading to distortion of the calculated velocity signal. Therefore, the data acquisition module in this embodiment incorporates a dedicated signal preprocessing algorithm to filter and differentiate the displacement signal to obtain a smooth and accurate instantaneous penetration velocity. This processing is based on the following discrete differentiation and filtering formulas:

[0079] ;

[0080] In the formula, This represents the instantaneous penetration velocity of the sampling tube at the k-th sampling time, calculated after preprocessing. This data is the direct input basis for the subsequent impedance observation module to calculate the volume displacement flow component.

[0081] This represents the original drill string displacement signal (i.e., the current penetration depth) directly acquired by the motion monitoring unit at the k-th sampling time.

[0082] This represents the original drill string displacement signal collected by the motion monitoring unit at the (k-1)th sampling time;

[0083] This indicates the preset sampling time interval of the motion monitoring unit, which is the reciprocal of the sampling period. It is determined by the hardware clock of the data acquisition module and is usually set to the millisecond level (e.g., 0.001s).

[0084] This represents the first-order low-pass filter coefficient (or smoothing factor), which is a dimensionless constant between 0 and 1, used to adjust the balance between the system's response sensitivity to sudden speed changes and its noise suppression capability.

[0085] This represents the instantaneous penetration velocity that the system has calculated and output at the (k-1)th sampling time.

[0086] It should be noted that the above expression combines the logic of the finite difference method and the exponentially weighted moving average (EWMA) filter. This term represents the instantaneous velocity in the physical sense, that is, the displacement increment per unit time. This is the original basis for calculating the volume displacement flow rate. However, simple differential calculation is extremely sensitive to noise. Even the slightest mechanical vibration of the drilling rig will produce a huge velocity spike in this term.

[0087] Therefore, by introducing coefficients The recursive filtering logic for control is designed to simulate the inertial characteristics of actual physical systems. During the soil and rock sampling process, although the penetration speed of the drill bit will change with the hardness of the formation, it is impossible for a step change to occur. By introducing the velocity value of the previous moment into the current calculation, high-frequency vibration noise can be effectively smoothed out, while the low-frequency velocity trend reflecting the change of formation resistance can be preserved.

[0088] It should also be noted that when the sampling tube suddenly encounters a hard interlayer (such as a nodule) causing drilling to be obstructed, the original displacement difference term will instantly return to zero or become negative (bounce). At this time, the above expression can quickly capture this sudden drop in velocity, making the calculated... The rapid reduction in flow rate is immediately transmitted to the impedance monitoring module, causing it to significantly decrease the calculated value of the volumetric displacement flow component, which in turn drives the actuator to reduce the discharge rate. This rapid response mechanism prevents the system from continuing to discharge at the original rate when the drill string is stationary, thus preventing the formation of negative pressure suction on the hard soil surface and protecting the integrity of the sample. Simultaneously, The value of gives the system strong adaptability: when drilling rapidly in soft formations, it can be increased. To improve tracking sensitivity; when drilling in hard rock with severe vibrations, the sensitivity can be reduced. This enhances anti-interference capabilities and ensures the smooth and reliable operation of control commands.

[0089] Example 3:

[0090] In this embodiment, the model building module is configured with a state observation algorithm;

[0091] The state observation algorithm is used to compare the observed output with the predicted pressure value, and iteratively update the estimated value of the equivalent annular gap width based on the deviation between the two through the error feedback gain matrix within the state observation algorithm.

[0092] It should be noted that in actual operation, the gap width fluctuates in real time due to multiple factors such as soil rheology, particle size distribution, and sampling tube vibration. It is the most critical parameter that determines the amount of leakage. Therefore, this embodiment adopts a state observer architecture based on control theory (such as an extended Kalman filter or Luenberger observer) to construct a digital mirror that runs parallel to the actual sampling process. By continuously comparing the pressure difference between the virtual and real samples, the implicit state variables can be identified online.

[0093] Specifically, the state observation algorithm operates based on the fluid dynamics constitutive equation and error feedback correction mechanism. First, it uses the gap width estimated at the previous moment and combines it with the current drilling state to predict the theoretical pressure value that should be in the pipe. Then, it compares the predicted value with the actual pressure value measured by the sensor and uses the deviation between the two to drive the iterative update of the estimated value.

[0094] The expression for the iterative update process satisfies:

[0095] ;

[0096] In the formula, This represents the current estimated value of the equivalent annular gap width after algorithm correction at the k-th calculation time.

[0097] This means that the estimated equivalent annular gap width, which has been calculated and stored at the (k-1)th calculation time (i.e. the previous time), is used as prior knowledge in the calculation at the current time.

[0098] The error feedback gain matrix (simplified to scalar gain coefficients in a single-variable system) is preset during the system design phase based on the fluid system's response time constant and the sensor's noise level, or adaptively adjusted according to operating conditions. It is used to control the speed and stability of the convergence of the estimated value to the true value.

[0099] This represents the actual measured value of fluid pressure that is directly acquired and transmitted to the system by the pressure sensing unit installed inside the inner stationary tube at the k-th calculation time.

[0100] This represents the system's internal prediction function, which is based on the gap estimate from the previous moment and the current system input vector (including instantaneous penetration velocity, servo valve flow command, etc.), and uses a fluid dynamics model to calculate the theoretical prediction value of the fluid pressure inside the pipe.

[0101] In actual system operation, if the assumed gap width in the model is exactly the same as the actual physical gap, then the theoretical predicted pressure should be exactly equal to the measured pressure, the residual should be zero, and the estimated value should remain unchanged. However, in special scenarios, such as when the drill bit suddenly cuts into a sandy layer from a clay layer, the actual physical gap increases instantaneously due to the shear expansion effect of the sand particles. At this time, the fluid in the pipe will leak rapidly through the enlarged gap, causing the measured pressure to drop rapidly, significantly lower than the predicted pressure calculated based on the old gap value. The above logic captures this negative deviation (i.e., the residual is negative) and, through the action of the gain matrix, forces... exist The changes are based on the previous ones; it is understandable that the gain here needs to be matched according to the direction of the derivative of the physical model. Usually, the pressure drop corresponds to the increase in leakage, and the increase in leakage corresponds to the large gap. Therefore, logically, it is necessary to ensure that the deviation can correctly drive the direction of the increase in gap.

[0102] Based on the above, the system in this embodiment does not need to know the specific parameters of the formation (such as the permeability coefficient) in advance. Instead, it uniformly maps all unknown environmental disturbances (such as pipe wall wear, soil shrinkage, and particle blockage) as pressure deviations and forces these deviations to be attributed to changes in the equivalent gap width. This allows the system to automatically acquire the failure of the soil sample sidewall sealing within a millisecond timescale and quickly adjust the gap parameters, thereby providing accurate targeted data for subsequent calculation of accurate leakage compensation flow and ensuring the robustness of sampling disturbance suppression in complex and variable formations.

[0103] Example 4:

[0104] In this embodiment, the disturbance compensation module uses calculation logic based on the fluid gap flow characteristics when acquiring the compensation flow component of the annular gap leakage.

[0105] The calculation logic is configured to: call the equivalent annular gap width output by the model building module, perform a cubic operation on the equivalent annular gap width, determine the current gap flow resistance characteristics based on the current sampling depth and dynamic viscosity, and then perform calculations with the cross-boundary pressure difference to quantify and obtain the leakage flow rate occurring through the annular gap.

[0106] It should be noted that after the system successfully reverse-corrects and obtains the equivalent annular gap width between the sampling tube and the soil sample at the current moment through the state observation algorithm, the disturbance compensation module converts this microscopic geometric parameter into a macroscopic fluid flow command. In actual deep soil sampling operations, even a micrometer-sized annular gap can generate fluid leakage or backflow sufficient to disrupt the soil sample's microenvironment under a pressure difference of hundreds of kilopascals. To eliminate this disturbance source, the disturbance compensation module is equipped with calculation logic based on fluid gap flow characteristics (i.e., generalized Cuyet-Poiseuille flow theory), aiming to construct a dynamic hydraulic compensation barrier.

[0107] Specifically, the calculation logic is essentially a real-time solution program. The program first calls the equivalent annular gap width output in real time by the model building module as the core input variable and performs a cubic operation on it. This is because in narrow gap flow, the flow rate is highly sensitive to changes in the gap height. At the same time, the module combines the current sampling depth (characterizing the length of the fluid leakage path) obtained from the data acquisition module with preset or online measured fluid dynamic viscosity parameters to determine the flow resistance characteristics of the annular gap at the current moment. Finally, the flow resistance characteristics are calculated with the cross-boundary pressure difference inside and outside the inner stationary pipe to quantify the instantaneous leakage flow rate through the annular gap and define it as the compensation flow rate component of the annular gap leakage.

[0108] The specific calculation process satisfies:

[0109] ;

[0110] In the formula, This represents the annular leakage compensation flow component that the system needs to execute at time t;

[0111] The inner diameter of the stationary tube is derived from the geometric parameter library of the system hardware and is used to determine the circumference reference of the annular gap.

[0112] This represents the estimated equivalent annular gap width output by the model building module at time t;

[0113] It represents the cross pressure difference between the fluid pressure inside the stationary tube and the in-situ pore pressure outside the rotating tube at time t.

[0114] Indicates the dynamic viscosity of the fluid (such as mud or water) inside the pipe;

[0115] The current sampling depth at time t is derived from the real-time integration of the drill string displacement by the data acquisition module, and physically represents the frictional resistance length of the fluid flowing through the annular leakage channel.

[0116] In practical technical application scenarios, when the sampling object is soft clay with extremely low permeability and tightly adheres to the pipe wall, the observed gaps... The leakage flow rate is extremely small, and its cubic value approaches zero. The flow rate component is almost negligible, and the system mainly relies on volume displacement to operate, which is consistent with the undrained characteristics of clay sampling.

[0117] However, when the drill bit cuts into loose silt or shell-bearing debris layers, insufficient sidewall support in the soil sample leads to gaps. A slight increase (e.g., from 0.1 mm to 0.3 mm), although only doubling the geometric dimensions, will instantly increase the flow-carrying capacity of the leakage channel by 27 times according to cubic logic. At this point, if the system continues to inject fluid at the original flow rate, the fluid inside the pipe will rapidly leak out, causing negative pressure to abrade the soil sample. This formula can accurately detect this minute geometric change, calculate a huge compensation flow command, and drive the actuator to inject fluid at a high flow rate.

[0118] In addition, the introduction As a multiplicative term, it endows the system with the ability to automatically determine the flow direction: when the pressure inside the pipe is greater than the pressure outside the pipe (positive pressure difference), the calculation result is positive, and the system is instructed to replenish the lost liquid; when the pressure inside the pipe is less than the pressure outside the pipe (negative pressure difference, i.e. backflow), the calculation result is negative, and the system is instructed to extract the excess liquid. This logic enables the technical solution to construct a dynamic zero-pressure differential hydraulic seal between the sampling pipe wall and the soil sample through hydraulic servo without any mechanical seals, thereby achieving ultimate protection of the microstructure of rock and soil samples under various complex geological conditions.

[0119] Example 5:

[0120] In this embodiment, the impedance observation module includes an entry rate correction unit. The entry rate correction unit is used to characterize the ratio between the actual volume of soil and rock entering the inner stationary tube and the theoretical geometric volume during the cutting process of the double-layer sampling component. The corresponding soil and rock entry rate correction factor is selected according to the preset soil and rock type parameters, so as to correct the basic fluid volume flow rate according to the soil and rock entry rate correction factor.

[0121] It should be noted that in the description of Example 1, the basic fluid volumetric flow rate is calculated based on the ideal cutting assumption, that is, it is assumed that the soil and rock within the geometric volume swept by the bottom of the drill bit can completely enter the inner stationary tube. However, in actual soil and rock sampling engineering practice, due to the inevitable crowding effect (i.e., area ratio effect) of the sampling tube wall thickness and the differences in the rheological properties of different soil and rock media, the actual volume of soil and rock entering the inner stationary tube is often not strictly equal to the theoretical geometric volume. Specifically, when drilling high-density sand layers, some soil will be squeezed to the outside of the tube wall; while when drilling high-sensitivity soft soil, the soil may be compressed due to tube wall friction. In order to eliminate the calculation error caused by this physical phenomenon, the entry rate correction unit is configured to correct the basic fluid volumetric flow rate calculated in advance in real time based on preset soil and rock type parameters.

[0122] The correction process is achieved by querying and calling the soil and rock entry rate correction factors stored in the system database. Before the start of the operation or during drilling, the operator can input the soil and rock type of the current stratum (such as silty clay, silty clay, fine sand, etc.) through the human-machine interface, or the system can automatically identify the stratum type based on the drilling parameters. The entry rate correction unit selects the corresponding correction factor based on the type parameter and uses the factor to perform weighted processing on the product of instantaneous penetration velocity and internal cross-sectional area.

[0123] Example 6:

[0124] The implementing mechanism includes:

[0125] The servo hydraulic station is installed on the ground and is connected to the pressure regulating chamber of the inner stationary tube through a pressure pipeline.

[0126] A piezoelectric proportional servo valve, integrated within the servo hydraulic station, is used to adjust the valve opening in response to the fluid throughput control command, thereby achieving continuous regulation of fluid flow.

[0127] The disturbance suppression module further includes a liquid resistance characteristic query unit, which is used to convert the fluid throughput control command into a corresponding opening voltage signal based on the differential pressure flow characteristics of the piezoelectric proportional servo valve.

[0128] It should be noted that the actuator in this embodiment adopts a separate architecture that combines a surface servo hydraulic station with a downhole pressure regulating chamber. The servo hydraulic station is deployed on a stable base on the surface and is connected to the pressure regulating chamber located at the top of the inner stationary pipe underground through a rigid pressure pipeline (or a steel wire braided high-pressure hose) with high pressure resistance and low expansion coefficient.

[0129] This embodiment also integrates a high-frequency response piezoelectric proportional servo valve. This valve is driven by the inverse piezoelectric effect of piezoelectric ceramic materials. Compared with traditional electromagnet drive, its frequency response characteristics can usually reach hundreds of hertz, which can match the millisecond-level pressure pulse suppression requirements in this embodiment. The piezoelectric proportional servo valve is integrated into the precision pressure regulating circuit of the servo hydraulic station. Its core function is to continuously adjust the opening area of ​​the valve core according to the received electrical signal, thereby precisely controlling the flow rate of fluid flowing through the valve port.

[0130] In hydraulic control theory, the relationship between valve opening and flow rate is not a simple linear one, but a nonlinear one that is greatly affected by the pressure difference across the valve. Although the preceding disturbance suppression module calculates the precise fluid throughput control command (i.e., the target flow rate), directly sending this flow rate value to the servo valve cannot execute it accurately. Therefore, the disturbance suppression module is further equipped with a hydraulic resistance characteristic query unit. This unit stores the PQ (pressure-flow) characteristic curve data of this specific model of piezoelectric proportional servo valve under different pressure difference conditions. Then, combined with the current system pressure difference state, the target flow rate is mapped inversely to the corresponding valve core drive voltage.

[0131] Example 7:

[0132] The disturbance suppression module also includes a pressure servo correction unit;

[0133] The pressure servo correction unit is used to set a target differential pressure threshold and compare the cross-boundary differential pressure with the target differential pressure threshold to obtain a pressure feedback adjustment component; the disturbance suppression module superimposes the pressure feedback adjustment component into the fluid throughput control command to eliminate the accumulated static pressure error.

[0134] In the aforementioned embodiments, volume displacement control based on instantaneous penetration velocity is a type of feedforward control, which has a fast response but its accuracy is limited by geometric parameters; leakage compensation based on state observers is a type of model reference control, whose accuracy depends on the accuracy of the hydraulic impedance model. However, in long-term deep-hole sampling operations, systematic cumulative errors inevitably exist, such as zero-point temperature drift of pressure sensors, slight changes in fluid dynamic viscosity due to rising deep geothermal temperatures, or internal leakage of hydraulic actuators. These factors cause the pipe pressure to fluctuate with formation pressure, but there is always a constant deviation value (i.e., static error). To eliminate this hidden danger, a pressure servo correction unit is further integrated into the disturbance suppression module, constructing the outermost closed-loop negative feedback control loop.

[0135] Specifically, the pressure servo correction unit is first used to set the target differential pressure threshold. This threshold is preset based on the soil mechanical properties of the sampling object. For highly sensitive soft clay, the target differential pressure is usually set to zero to prevent disturbance; while for loose sand, in order to provide a weak hydraulic wall protection effect to prevent piping, the target differential pressure can be set to a small positive value (e.g., +0.5 kPa). During system operation, this unit receives the cross-boundary pressure difference (i.e., the difference between the fluid pressure inside the inner stationary pipe and the in-situ pore pressure outside the outer rotating pipe) calculated by the data acquisition module in real time, and continuously compares this real-time cross-boundary pressure difference with the set target differential pressure threshold to calculate the pressure deviation signal. Subsequently, the pressure deviation signal is processed using a proportional-integral (PI) control algorithm or a more advanced robust control algorithm to generate a pressure feedback adjustment component.

[0136] Example 8:

[0137] The inner wall of the inner stationary tube is coated, and the inner diameter of the inner stationary tube is larger than the inner diameter of the drill bit cutting edge to form a preset gap; the model building module uses the preset gap as the initial iteration reference value of the equivalent annular gap width.

[0138] The inner wall surface of the inert tube is coated with a micron-sized hydrophobic low-friction coating (such as polytetrafluoroethylene (PTFE) or diamond-like carbon (DLC) coating) using chemical vapor deposition or spraying. The presence of this coating significantly reduces the coefficient of friction between the tube wall and the soil sample, allowing the soil sample column entering the tube to slide upward more smoothly and reducing axial compressive deformation caused by frictional resistance.

[0139] Example 9:

[0140] The system also includes an abnormal circuit breaker module;

[0141] The abnormal fuse module is used to monitor the rate of change of the equivalent annular gap width. When the equivalent annular gap width is detected to exceed the preset safety threshold within a preset time, it is determined to be an abnormality of soil sample detachment or pipe wall rupture, triggering the disturbance suppression module and stopping the drive actuator to perform active injection or suction, while issuing an alarm signal.

[0142] Understandably, when a sudden failure occurs due to non-geological factors, such as a soil or rock sample suddenly detaching from the inner stationary tube (sample drop), or the sampling tube wall fracturing due to fatigue, the state observation algorithm will detect an extremely drastic change in the equivalent annular gap width. If the system lacks the ability to identify this, the disturbance compensation module may mistakenly interpret this large gap caused by the failure as a signal requiring large compensation, and thus instruct the actuator to inject or aspirate liquid into the tube at full speed. This erroneous and forceful intervention is highly likely to cause secondary damage to the sample remaining at the bottom of the borehole, or even damage to the hydraulic equipment. Therefore, this embodiment introduces an abnormal fuse module, which acts as a monitoring unit independent of the conventional control loop, and monitors the dynamic evolution characteristics of the equivalent annular gap width in parallel.

[0143] Specifically, the abnormal fuse module does not focus on the absolute size of the gap width (because the gap in sand is naturally larger than that in clay), but rather on its rate of change over time. In the normal process of stratigraphic change, even when transitioning from clay to sand, the change in gap is a gradual process with physical inertia; while sample detachment or equipment damage manifests as a mathematical step signal.

[0144] Example 10:

[0145] In this embodiment, an adaptive soil and rock sampling disturbance suppression method is provided, the method comprising the following steps:

[0146] During the process of the sampling tube penetrating the soil and rock, the instantaneous penetration velocity of the sampling tube, the current sampling depth, the fluid pressure inside the inner stationary tube, and the in-situ pore pressure outside the outer rotating tube are simultaneously acquired.

[0147] Based on the instantaneous penetration velocity and the inner cross-sectional area of ​​the inner stationary tube, the volumetric flow rate of the basic fluid that needs to be discharged due to the drilling tool cutting into the rock and soil is obtained, and used as the volume displacement flow rate component.

[0148] A dynamic hydraulic impedance model is constructed, and the fluid pressure value in the inner static pipe is used as the observed output of the system. The model is compared with the predicted pressure value output by the dynamic hydraulic impedance model. Based on the deviation between the two, the current equivalent annular gap width is corrected in reverse through the state observation algorithm.

[0149] The cross-boundary pressure difference is obtained based on the fluid pressure inside the inner stationary tube and the in-situ pore pressure. The leakage flow rate through the annular gap is obtained based on the cube value of the equivalent annular gap width, the current sampling depth, and the cross-boundary pressure difference, and is used as the compensation flow rate component for annular gap leakage.

[0150] The volume displacement flow component is superimposed with the compensation flow component of the annular gap leakage to obtain a fluid throughput control command, which drives the actuator to actively inject or pump fluid into the pressure regulating chamber at the top of the inner stationary tube to dynamically balance the pressure fluctuations inside the tube.

[0151] This embodiment provides an adaptive soil and rock sampling disturbance suppression method. This method achieves active servo control of the pressure environment inside the pipe during complex geological sampling by real-time fusion of multi-physics field data and closed-loop feedback of the fluid dynamics model.

[0152] When the dual-layer sampling assembly begins to penetrate the soil and rock medium, the system immediately initiates a synchronous data acquisition process. During this process, through a high-frequency sensor array deployed on the drill string and pipe wall, the instantaneous penetration velocity of the sampling pipe relative to the formation, the current sampling depth, the fluid pressure inside the inner stationary pipe, and the in-situ pore pressure outside the outer rotating pipe are acquired synchronously. This ensures that the control system can perceive the motion state of the drill string (disturbance source) and the hydraulic boundary conditions inside and outside the pipe (controlled object and environment) in real time, providing an accurate physical input reference for subsequent flow calculation.

[0153] Subsequently, the control algorithm performs a product calculation based on the real-time instantaneous penetration velocity and the preset inner cross-sectional area of ​​the inner stationary pipe to calculate the volume of fluid that must theoretically be discharged due to the space occupied by the drill bit cutting into the soil layer. This calculation result is defined as the basic fluid volume flow rate and used as the volume displacement flow rate component. This component constitutes the basic benchmark for fluid control, which aims to deal with the most important volume displacement effect during drilling and ensure the balance of fluid volume in the pipe under ideal sealing conditions.

[0154] However, considering the inherent non-ideal contact between the pipe wall and the soil sample during actual sampling, a model-reference-based gap observation step is further executed in parallel. The system constructs a dynamic hydraulic impedance model in the processor, which describes the flow characteristics of the fluid inside the pipe and in the annular gap. The measured internal static pipe fluid pressure is used as the system's observed output, and a theoretical predicted pressure value is calculated based on the current state using the dynamic hydraulic impedance model. Next, the algorithm continuously compares the deviation between the observed output and the predicted pressure value. If a deviation exists, it indicates that the gap parameters set in the model do not match the actual physical gap. At this point, the error correction mechanism of the state observation algorithm (such as Kalman filtering or Luenberger observer) is used to reverse-correct the key state variables in the model based on the magnitude and direction of the deviation, thereby iteratively calculating the current equivalent annular gap width. This step essentially achieves online identification of the width of micron-level leakage channels through mathematical means in a downhole environment where direct measurement is not possible.

[0155] Based on the identified gap parameters, the difference between the fluid pressure inside the inner stationary tube and the in-situ pore pressure of the outer tube is calculated to obtain the cross-boundary pressure difference driving the fluid flow. Subsequently, according to the flow law of fluid in a slender annular gap, combined with the current sampling depth (characterizing the flow resistance length) and the cubic value of the equivalent annular gap width, the instantaneous leakage flow rate through the annular gap driven by this pressure difference is quantitatively calculated. The introduction of cubic value calculation logic enables this method to extremely sensitively capture and compensate for huge flow fluctuations caused by small changes in the gap.

[0156] Finally, the volumetric displacement flow component (for rigid displacement) calculated previously is algebraically superimposed with the flow component compensated for annular leakage (for flexible leakage) to generate the final fluid throughput control command. This command is converted into a physical electrical signal, driving an actuator (such as a piezoelectric servo valve) connected to the top of the inner stationary pipe to adjust the valve opening, thereby actively injecting or pumping fluid into the pressure regulating chamber at the millisecond level. Based on the above steps, various disturbance factors can be dynamically offset throughout the drilling process, maintaining the pressure inside the pipe in a state of dynamic equilibrium with the in-situ formation pressure, thus ensuring the natural integrity of the microstructure of the soil and rock samples.

[0157] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or system that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or system. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or system that includes that element.

[0158] The sequence numbers of the embodiments in this application are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0159] Through the above description of the embodiments, those skilled in the art can clearly understand that the methods of the above embodiments can be implemented by means of software plus necessary general-purpose hardware platforms. Of course, they can also be implemented by hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product is stored in a storage medium (such as read-only memory / random access memory, magnetic disk, optical disk) and includes several instructions to cause a multimedia terminal device (which may be a mobile phone, computer, television receiver, or network device, etc.) to execute the methods described in the various embodiments of this application.

[0160] The above are merely preferred embodiments of the present invention and do not limit the scope of the patent. Any equivalent structural or procedural transformations made based on the description and drawings of the present invention, or direct or indirect applications in other related technical fields, are similarly included within the scope of patent protection of the present invention.

Claims

1. An adaptive soil and rock sampling disturbance suppression system, characterized in that, The system includes: A dual-layer sampling assembly, comprising a coaxially nested outer rotating tube and an inner stationary tube, wherein a sealed pressure regulating cavity is formed at the top of the inner stationary tube, and the inner stationary tube is used to contain the incoming soil and rock samples. The data acquisition module is used to simultaneously acquire the instantaneous penetration velocity of the sampling tube, the current sampling depth, the fluid pressure inside the inner stationary tube, and the in-situ pore pressure outside the outer rotating tube during the process of the sampling tube penetrating the soil and rock. Impedance observation module, which is used to obtain the basic fluid volume flow rate that needs to be discharged due to the drill bit cutting into the rock and soil based on the instantaneous penetration velocity and the inner cross-sectional area of ​​the inner stationary tube, and use it as the volume displacement flow rate component. The model building module is used to build a dynamic hydraulic impedance model. The fluid pressure value in the inner static pipe is used as the observed output of the system and compared with the predicted pressure value output by the dynamic hydraulic impedance model. Based on the deviation between the two, the current equivalent annular gap width is corrected in reverse through the state observation algorithm. The disturbance compensation module is used to obtain the cross-boundary pressure difference based on the fluid pressure in the inner stationary tube and the in-situ pore pressure, and to obtain the leakage flow rate through the annular gap based on the cube value of the equivalent annular gap width, the current sampling depth and the cross-boundary pressure difference, and to use it as the compensation flow rate component for the annular gap leakage. The disturbance suppression module is used to superimpose the volume displacement flow component and the compensation flow component of the annular leakage to obtain a fluid throughput control command, so as to drive the actuator to actively inject or pump fluid into the pressure regulating chamber at the top of the inner stationary tube, so as to dynamically balance the pressure fluctuation in the tube. The model building module is equipped with a state observation algorithm. The state observation algorithm is used to compare the observed output with the predicted pressure value, and iteratively update the estimated value of the equivalent annular gap width based on the deviation between the two through the error feedback gain matrix within the state observation algorithm.

2. The adaptive soil and rock sampling disturbance suppression system as described in claim 1, characterized in that, The data acquisition module includes: A pressure sensing unit is embedded in the inner wall of the bottom edge of the inner stationary tube and the outer wall of the outer rotating tube, respectively, for obtaining the fluid pressure inside the inner stationary tube and the in-situ pore pressure outside the outer rotating tube. A motion monitoring unit is installed on one side of the drill string within the dual-layer sampling assembly. It is used to acquire the displacement signal of the drill string at a preset high sampling frequency and to preprocess the displacement signal to obtain the instantaneous penetration velocity.

3. The adaptive soil and rock sampling disturbance suppression system as described in claim 1, characterized in that, When the disturbance compensation module obtains the compensation flow component of the annular gap leakage, it adopts calculation logic based on the fluid gap flow characteristics. The calculation logic is configured to: call the equivalent annular gap width output by the model building module, perform a cubic operation on the equivalent annular gap width, determine the current gap flow resistance characteristics based on the current sampling depth and dynamic viscosity, and then perform calculations with the cross-boundary pressure difference to quantify and obtain the leakage flow rate occurring through the annular gap.

4. The adaptive soil and rock sampling disturbance suppression system as described in claim 1, characterized in that, The impedance observation module includes an entry rate correction unit, which is used to characterize the ratio between the actual volume of soil and rock entering the inner stationary tube and the theoretical geometric volume during the cutting process of the double-layer sampling component. The corresponding soil and rock entry rate correction factor is selected according to the preset soil and rock type parameters, so as to correct the volumetric flow rate of the basic fluid according to the soil and rock entry rate correction factor.

5. The adaptive soil and rock sampling disturbance suppression system as described in claim 1, characterized in that, The implementing mechanism includes: The servo hydraulic station is installed on the ground and is connected to the pressure regulating chamber of the inner stationary tube through a pressure pipeline. A piezoelectric proportional servo valve, integrated within the servo hydraulic station, is used to adjust the valve opening in response to the fluid throughput control command, thereby achieving continuous regulation of fluid flow. The disturbance suppression module further includes a liquid resistance characteristic query unit, which is used to convert the fluid throughput control command into a corresponding opening voltage signal based on the differential pressure flow characteristics of the piezoelectric proportional servo valve.

6. The adaptive soil and rock sampling disturbance suppression system as described in claim 1, characterized in that, The disturbance suppression module also includes a pressure servo correction unit; The pressure servo correction unit is used to set a target differential pressure threshold and compare the cross-boundary differential pressure with the target differential pressure threshold to obtain a pressure feedback adjustment component; the disturbance suppression module superimposes the pressure feedback adjustment component into the fluid throughput control command to eliminate the accumulated static pressure error.

7. The adaptive soil and rock sampling disturbance suppression system as described in claim 1, characterized in that, The inner wall of the inner stationary tube is coated, and the inner diameter of the inner stationary tube is larger than the inner diameter of the drill bit cutting edge to form a preset gap; the model building module uses the preset gap as the initial iteration reference value of the equivalent annular gap width.

8. The adaptive soil and rock sampling disturbance suppression system as described in claim 1, characterized in that, The system also includes an abnormal circuit breaker module; The abnormal fuse module is used to monitor the rate of change of the equivalent annular gap width. When the equivalent annular gap width is detected to exceed the preset safety threshold within a preset time, it is determined to be an abnormality of soil sample detachment or pipe wall rupture, triggering the disturbance suppression module and stopping the drive actuator to perform active injection or suction, while issuing an alarm signal.

9. An adaptive method for suppressing disturbances in soil and rock sampling, characterized in that, The method is based on an adaptive soil and rock sampling disturbance suppression system according to any one of claims 1 to 8, and the method includes the following steps: During the process of the sampling tube penetrating the soil and rock, the instantaneous penetration velocity of the sampling tube, the current sampling depth, the fluid pressure inside the inner stationary tube, and the in-situ pore pressure outside the outer rotating tube are simultaneously acquired. Based on the instantaneous penetration velocity and the inner cross-sectional area of ​​the inner stationary tube, the volumetric flow rate of the basic fluid that needs to be discharged due to the drilling tool cutting into the rock and soil is obtained, and used as the volume displacement flow rate component. A dynamic hydraulic impedance model is constructed, and the fluid pressure value in the inner static pipe is used as the observed output of the system. The model is compared with the predicted pressure value output by the dynamic hydraulic impedance model. Based on the deviation between the two, the current equivalent annular gap width is corrected in reverse through the state observation algorithm. The cross-boundary pressure difference is obtained based on the fluid pressure inside the inner stationary tube and the in-situ pore pressure. The leakage flow rate through the annular gap is obtained based on the cube value of the equivalent annular gap width, the current sampling depth, and the cross-boundary pressure difference, and is used as the compensation flow rate component for annular gap leakage. The volume displacement flow component is superimposed with the compensation flow component of the annular gap leakage to obtain a fluid throughput control command, which drives the actuator to actively inject or pump fluid into the pressure regulating chamber at the top of the inner stationary tube to dynamically balance the pressure fluctuations inside the tube.

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