Storage tank intelligent monitoring and sampling integrated system and method

Abstract

The invention relates to the technical field of storage tank monitoring and sampling, and discloses a storage tank intelligent monitoring and sampling integrated system and method.The system comprises a reducing winch module, a sensing detection module, an isolation replacement module, a sampling verification module, a ground transfer module and a control calculation module; the variable-diameter winch module eliminates the self-weight load of a cable through a non-linearly changed winding radius and is matched with the sensing detection module to collect high-signal-to-noise-ratio mechanical data; the control resolving module inverts the medium density and viscosity based on the net load moment, identifies the layering position and generates a sampling plan; after the sampling verification module executes sampling, the sampling verification module is matched with the variable-diameter winch module to verify the sampling quality by utilizing mechanical frequency sweep excitation and frequency domain response characteristics; the ground transfer module calls the inversion density data to convert the standard sampling volume into the target filling mass; according to the invention, the online inversion of the rheological property of the medium, the non-contact verification of the sampling quality and the full-flow closed automatic operation are realized.

Description

Technical Field

[0001] This invention relates to the field of storage tank monitoring and sampling technology, specifically to an integrated intelligent monitoring and sampling system and method for storage tanks. Background Technology

[0002] Large storage tanks are core facilities in petrochemical storage and transportation systems, used to store crude oil, refined oil products, and various liquid chemical raw materials. During long-term storage, the media inside the tank often undergoes stratification, emulsification, or property drift due to changes in ambient temperature, media settling, and loading / unloading operations. To ensure inventory safety and the accuracy of measurement during trade transactions, regularly monitoring the physical properties of the media inside the tank through vertical profiles and obtaining representative samples from specific layers is a critical operational step in production management.

[0003] Existing tank inspection and sampling operations typically rely on winch mechanisms mounted on the tank top. These mechanisms use a motor to drive a rotating drum, which lowers the sensor-equipped detection unit or mechanical sampler to a predetermined depth by winding up and down a flexible cable. The winch mechanisms often employ a drum design with a constant diameter, and the control system controls the probe's lifting and lowering position based on length data fed back from the encoder. The typical operating procedure involves the operator setting a target height, the equipment performing single-point parameter measurements or opening a sampling bottle at a designated point, and then retrieving the equipment to the tank top. Samples are then manually removed or data is read to complete the inspection of the tank's internal condition.

[0004] However, in existing tank detection and sampling operations, especially in deep liquid level scenarios, the weight of the cable itself accumulates linearly with increasing descent depth. This load increment often far exceeds the slight buoyancy or viscous resistance changes experienced by the probe in the fluid. A constant-diameter drum structure cannot eliminate this background load interference. The system struggles to extract the rheological properties of the medium from the mixed torque, making it difficult to accurately identify the oil-water interface or emulsion layer online. This leads to the selection of sampling depth often relying on empirical blind measurements, leaving the downhole sampling process in a blind zone. Surface detection of whether the sampling container is full of medium is difficult, and situations of empty sampling or insufficient sampling volume are usually only discovered after the equipment is fully recovered and the sealed chamber is opened, resulting in low operational efficiency. The probe recovery process lacks a robust physical isolation and gas replacement mechanism, allowing high concentrations of harmful gases to easily be carried out with the equipment and diffuse into the environment. Furthermore, data from high-altitude sampling and surface packaging are disconnected, lacking real-time medium parameter support. Therefore, this invention provides an integrated intelligent monitoring and sampling system and method for tanks to address the shortcomings of existing technologies. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides an integrated intelligent monitoring and sampling system and method for storage tanks, solving the problems in existing technologies such as the difficulty in online inversion of medium rheological properties due to interference from the self-weight of cables during deep well exploration, the difficulty in non-contact real-time verification of downhole sampling quality, and the lack of data closed-loop linkage between high-altitude sampling and ground dispensing.

[0006] To achieve the above objectives, the present invention provides the following technical solution: The first aspect of this invention provides an integrated intelligent monitoring and sampling system for storage tanks, comprising: The variable diameter winch module is installed on the top of the storage tank and is used to drive the cable to rise and fall and output load torque data; The sensing and detection module includes a composite detection component suspended at the end of a cable for collecting liquid level data; The isolation and replacement module has a transition chamber inside and is connected to the top interface of the storage tank. It is used to establish a physical isolation barrier for the entry and exit of the composite detection component and to perform gas replacement on the transition chamber. The sampling verification module, integrated within the sensing and detection module, is used to extract the target medium as a sample and cooperate with the variable diameter winch module to perform quality verification. The ground transfer module, connected to the isolation and replacement module via a sealed pipeline, is used to receive the transported samples and perform dispensing based on the characteristics of the target medium; The control and calculation module is connected to the above modules and is used to calibrate the starting point of the liquid phase stroke using the liquid level height data; to invert the rheological parameter distribution of the target medium based on the load torque data, and to generate a sampling plan based on the rheological parameter distribution to regulate the actions of the above modules.

[0007] Preferably, the quality verification includes quality verification based on frequency domain response.

[0008] Preferably, the variable diameter winch module is used to monitor changes in cable length and match the compensating torque to eliminate the cable's self-weight load, thereby driving the cable to rise and fall and outputting load torque data.

[0009] Preferably, the sensing and detection module is also used to collect hydrostatic pressure data; the control and calculation module is also used to perform redundancy verification based on the hydrostatic pressure data.

[0010] Preferably, the dispensing device is for quantitative dispensing; the sensing and detection module is also used to collect tensile force data.

[0011] Preferably, the tensile data is used to characterize the direct stress state of the composite detection component in the medium, and serves as the mechanical input for the control calculation module to invert rheological property parameters such as the density and viscosity of the medium inside the tank.

[0012] Preferably, the load torque data is used to characterize the comprehensive stress state of the variable diameter hoist module under the action of the medium, and serves as system-level mechanical input data for the control calculation module to invert rheological characteristic parameters such as the density and viscosity of the medium inside the tank.

[0013] In this invention, the generation of medium density and viscosity data is primarily based on the load torque data output by the variable-diameter hoist module. This is because the load torque data reflects the comprehensive mechanical response of the hoist system under the action of the medium, making it suitable for system-level inversion. Simultaneously, the tension data collected by the sensing and detection module serves as an independent mechanical observation, used to constrain the inversion model or perform redundancy checks on the inversion results, thereby improving the reliability of the inversion results.

[0014] Preferably, the control solution module includes a deep analysis unit, a rheological parameter inversion unit, and a hierarchical identification and decision unit; The depth analysis unit is used to construct and output the depth data of the composite detection component based on the rotation angle fed back by the variable diameter winch module, combined with the geometric mapping model of the winding characteristics of the variable diameter drum assembly in the variable diameter winch module and the cable elasticity correction algorithm. The rheological parameter inversion unit is used to receive the depth data and the load torque data output by the variable diameter hoisting module. After deducting the friction baseline, it calculates and generates the medium density data and viscosity data corresponding to the depth data using Archimedes' principle and the fluid resistance principle, respectively. The hierarchical identification and decision unit is used to monitor the vertical gradient change of the medium density data and the viscosity data in real time. After identifying the two-phase interface, it generates an adaptive sampling plan containing the target depth set and converts the adaptive sampling plan into instructions to drive the sampling verification module to act.

[0015] Preferably, the variable diameter winch module includes a variable diameter drum assembly, a forced rope laying mechanism, and a dynamic torque sensor; The forced rope feeding mechanism includes a reciprocating screw structure mechanically coupled to the variable diameter drum assembly; The reciprocating screw structure is used to drive the cable guide to perform synchronous reciprocating motion, and to lay the cable in the cable guide groove of the variable diameter drum assembly to maintain a preset radius function relationship. The dynamic torque sensor is used to collect the load torque data.

[0016] Preferably, the sampling verification module includes an automatic sampling mechanism, a sample container, and a frequency domain response verification logic unit; The automatic sampling mechanism is equipped with a pressure balancing circuit, which is used to balance the internal and external pressure difference and establish a fluid channel when the target depth is reached, so as to introduce the medium into the sample container. The sample container can be connected to the detection component through a rigid structure to form an integral mass block. After sampling, it is lifted with the detection component to the gas phase region inside the storage tank and receives mechanical frequency sweep excitation applied by the variable diameter winch module. The frequency domain response verification logic unit is used to receive the vibration response signal of the dynamic torque sensor of the variable diameter winch module during mechanical frequency sweep excitation, perform spectrum analysis, identify the first natural angular frequency, and use the inverse square relationship between mass and frequency to calculate the total suspended mass, thereby determining whether the sample collection amount falls within the qualified range.

[0017] Preferably, the isolation and replacement module includes a transition chamber, the bottom of which is integrated with a lower isolation valve group. A position sensor is installed inside the transition chamber, and the transition chamber is also connected to a gas replacement circuit and a differential pressure monitoring unit.

[0018] Preferably, the position sensor is used to detect the position of the composite detection component; The lower isolation valve assembly is used to perform a closing action to disconnect the connection with the storage tank when the composite detection component is in a safe position within the transition chamber; The condition that the composite detection component is in a safe position within the transition chamber includes: when the composite detection component is completely retracted into the transition chamber and the position of the composite detection component is higher than a preset safe plane within the transition chamber; The gas replacement circuit is used to obtain inert gas from an external inert gas source, inject it into the transition chamber through the inlet, and discharge the mixed gas inside the transition chamber to the waste gas treatment facility through the exhaust port. The injection and discharge process is controlled according to the minimum replacement time generated by the dilution mixing model until the environment inside the transition chamber meets the safety standards. The differential pressure monitoring unit is used to monitor the pressure difference between the inside and outside of the transition chamber in real time, drive the gas injection valve in the gas replacement circuit to establish a micro-positive pressure environment in the transition chamber, and unlock the top interface of the storage tank only when the actual gas replacement time reaches the minimum replacement time and the micro-positive pressure environment has been established.

[0019] This dilution-mixing model uses precise mathematical calculations to determine the minimum replacement time required to reduce the concentration of harmful gases (such as volatile organic compounds, toxic or flammable gases) in the isolation chamber from a known initial value to below a preset safety threshold. During the gas replacement process, the newly injected inert gas can mix instantaneously and uniformly with the original gas in the chamber, ensuring that the gas concentration at any point in the chamber is the same at any given time. By introducing an adjustable safety redundancy coefficient based on this theory, non-ideal factors are compensated for, thereby ensuring the safety and reliability of the final replacement effect.

[0020] Preferably, the ground transfer module includes an automated dispensing workstation, and the automated dispensing workstation includes; The precision weighing and filling unit is used to call the control calculation module to invert the generated rheological parameter distribution and extract the medium density data from it. Based on the extracted medium density data, the preset standard sampling volume is dynamically converted into the target filling mass. An automated dispensing unit is used to control the timing of the filling valves according to the target filling quality, so that the deviation between the actual increment fed back by the weighing sensor inside the precision weighing filling unit and the target value is kept within the error threshold. The automatic capping unit includes a servo motor and capping claws connected to the output shaft of the servo motor, which are used to monitor the output torque of the servo motor after filling to ensure that the capping quality meets the preset torque range.

[0021] Preferably, the automated dispensing workstation further includes a robot interaction interface unit and a waste liquid switching circuit; The robot interaction interface unit is used to set a visual positioning target on the finished product temporary storage platform, so that the external transportation equipment can identify it to calculate the relative pose matrix between itself and the sample, and plan the motion trajectory according to the relative pose matrix to carry out unmanned transfer of the sample. The waste liquid switching circuit is used to control the flow direction at the end of the pipeline during non-sampling conditions, and to guide the waste liquid into the collection device in conjunction with the cleaning action.

[0022] Preferably, the composite detection component adopts a fixed cross-section rotating body structure; the composite detection component maintains a stable fluid resistance coefficient during vertical movement through its streamlined shape.

[0023] Preferably, the pressure sensor integrated within the composite detection component is used to collect hydrostatic pressure data and transmit the hydrostatic pressure data to the depth data of the control calculation module for redundancy comparison, in order to identify cable slippage or abnormal operation of the composite detection component due to stranding. Stranding of the composite detection component refers to a state where, while the cable continues to be deployed or retrieved, the actual spatial position of the composite detection component cannot change as expected due to obstruction from the internal structure of the storage tank, sediment, or the bottom of the container.

[0024] Preferably, the control calculation module further includes a system self-calibration unit; The system self-calibration unit is used to collect operating resistance data during the gas phase stroke, construct a dynamic friction baseline and calculate the average friction torque; the average friction torque is fed back to the rheological parameter inversion unit as a reference value for subtraction, and the mechanical health status is determined based on the fluctuation variance of the average friction torque.

[0025] The mechanical health status refers to the health status of the mechanical transmission system directly related to the cable lifting movement in the integrated intelligent monitoring and sampling system of the storage tank.

[0026] A second aspect of this invention provides a method for intelligent monitoring and sampling of storage tanks, comprising the following steps: The control and calculation module drives the variable diameter winch module to operate in the gas phase stroke, using the change in the winding radius of the variable diameter drum structure to offset the cable's self-weight load, while collecting running resistance data to construct a dynamic friction baseline. After the sensing and detection module enters the liquid phase, the control and calculation module uses the net load torque after removing the gravity component and dynamic friction baseline to invert the medium density and viscosity data in real time, and generates an adaptive sampling plan based on the vertical gradient change. The sampling verification module responds to the command to extract the medium at the target depth, and then is lifted to the gas phase region by the sensing and detection module. The variable diameter winch module applies mechanical frequency sweep excitation, and the control calculation module determines the sample collection amount by analyzing the first natural angular frequency of the vibration response signal. After successful verification, the sensing and detection module is retracted into the internal cavity of the isolation and replacement module, the lower isolation valve group is disconnected from the storage tank, the gas replacement circuit performs gas replacement and the micro differential pressure monitoring unit maintains a micro positive pressure environment; The sample is transported to the ground transfer module through a closed pipeline. The automated dispensing workstation calls the inverted media density data, converts the standard sampling volume into the target filling mass, and performs quantitative dispensing.

[0027] The present invention provides an integrated intelligent monitoring and sampling system and method for storage tanks, which has the following beneficial effects: This invention utilizes a variable-diameter drum for mechanical gravity compensation combined with rheological parameter inversion technology. The drum's radius, changing nonlinearly with rotation angle, automatically offsets the gravitational increment during cable release at a physical level, enabling the servo drive unit to sensitively sense the subtle fluid buoyancy and viscous resistance experienced by the detection components. Through high signal-to-noise ratio mechanical measurement conditions, the system can accurately invert the density and viscosity distribution of the medium based on Archimedes' principle and fluid resistance formulas without the need for expensive online analysis instruments, thereby accurately identifying the oil-water interface or emulsion layer location inside the storage tank.

[0028] After the sampling process is completed, the system raises the detection component to the gas phase region and applies a slight mechanical excitation. By analyzing the change in the first-order natural angular frequency of the vibration response, the total suspended mass is calculated, thereby determining whether the sample container is properly filled. This overcomes the drawback of traditional equipment that requires recovery and opening of the sealed chamber before the sampling results can be confirmed. It effectively avoids invalid recovery and repeated operations due to sampling failure, and improves operational efficiency while ensuring the system remains sealed and isolated.

[0029] The precision weighing and filling unit of the ground transfer module of this invention directly calls upon real-time density data obtained from high-altitude sounding, dynamically converting the standard volume required in the laboratory into a target filling quality that is easy to execute in industry, thus solving the problem that traditional constant-volume filling cannot adapt to media density fluctuations. Combined with the gas replacement mechanism of the isolation and replacement module and the automation interface of the ground robot, it achieves fully unmanned, closed-loop operation from sampling to dispensing, effectively preventing the diffusion of toxic and harmful gases into the external environment and ensuring operational safety. Attached Figure Description

[0030] Figure 1 This is a system architecture diagram of an embodiment of the present invention; Figure 2 This is a flowchart of a method according to an embodiment of the present invention; Figure 3 This is a schematic diagram of the variable diameter hoist module structure according to an embodiment of the present invention; Figure 4 This is a schematic diagram of the sampling verification module according to an embodiment of the present invention; Figure 5 This is a schematic diagram of the sensing and detection module according to an embodiment of the present invention.

[0031] Among them, 100 is the variable diameter winch module; 101 is the bidirectional reciprocating lead screw; 102 is the cable guide; 103 is the absolute multi-turn encoder; 104 is the servo motor; 105 is the precision planetary reducer; 106 is the drum spindle; 107 is the dynamic torque sensor; 200 is the sensing and detection module; 300 is the isolation and replacement module; 400 is the sampling and verification module; 500 is the ground transfer module; and 600 is the control calculation module. Detailed Implementation

[0032] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0033] See Figure 1 , Figure 1 This is a system architecture diagram according to an embodiment of the present invention. The present invention provides an integrated intelligent monitoring and sampling system for storage tanks, including a variable diameter winch module 100, a sensing and detection module 200, an isolation and replacement module 300, a sampling verification module 400, a ground transfer module 500, and a control calculation module 600.

[0034] A variable-diameter winch module 100 is located at the top of the storage tank. This module features a drum structure with variable diameter characteristics, and its winding radius changes with the rotation angle according to a preset geometric function. During cable winding and unwinding, the variable-diameter winch module 100 continuously adjusts the physical lever arm to output a compensating torque that matches the change in cable sag length, eliminating the linear load increment caused by the cable's own weight and ensuring the drive motor maintains a constant torque output reference throughout its entire stroke. One end of the cable is wound and unwound onto the drum of the variable-diameter winch module, while the other end extends vertically downwards, with a sensing and detection module 200 (including composite detection components, etc.) suspended at the end. The variable-diameter winch module 100 is the driving, winding, unwinding, and control mechanism for the cable.

[0035] The sensing and detection module 200 includes a composite detection component suspended at the end of the cable and a laser ranging unit installed on the top of the storage tank. This module 200 is used to construct a multi-dimensional data sensing network. By fusing the spatial reference coordinates provided by the laser ranging unit with the mechanical and media state data collected in real time by the composite detection component, it builds a spatiotemporally synchronized, multi-parameter correlated sensing information system for the system. The laser ranging unit is used to acquire the absolute height data of the liquid level of the medium stored inside the storage tank, providing a spatial position reference for the system. The composite detection component integrates a mechanical sensing unit and a media parameter sensing unit, used to collect high-precision tension data, media temperature data, and pressure data in real time during the cable raising and lowering process. The mechanical sensing unit is used to measure the high-precision tension data of the cable in real time during the cable raising and lowering process, providing mechanical input for the control calculation module to invert the rheological properties of the medium, such as density and viscosity. The media parameter sensing unit is used to measure the temperature and pressure data of the medium in the storage tank in real time, providing direct physical property parameters for media state monitoring, characteristic analysis, and environmental assessment of sampling points.

[0036] The isolation and replacement module 300 is located at the equipment installation port on the top of the storage tank, between the variable-diameter hoist module 100 and the internal gas phase space of the storage tank. This isolation and replacement module 300 constructs a physical cavity structure capable of independent pressure bearing and sealing. The module integrates a hard-seal valve assembly and a gas replacement interface to establish a physical isolation barrier during the entry and exit of the composite detection component from the storage tank, and to perform inert gas replacement of the gas trapped within the cavity, preventing the leakage of toxic and harmful gases from the storage tank. Specifically, the hard-seal valve assembly controls the communication and isolation between the cavity of the isolation and replacement module 300 and the internal and external environments of the storage tank, thereby establishing or removing the physical isolation barrier during the entry and exit of the composite detection component. The gas replacement interface connects to an external gas source and exhaust device to perform inert gas replacement and discharge operations on the trapped gas within the cavity of the isolation and replacement module.

[0037] The sampling verification module 400 is integrated within the composite detection component and is used to open or close the sampling channel in response to control commands, introducing the target depth medium into the sampling container. The sampling verification module 400 is also configured to work with the variable diameter hoist module 100 to perform mechanical vibration excitation, and to physically verify the actual filling quality of the sampling container by detecting the frequency domain response characteristics of the detection system under specific conditions.

[0038] A ground transfer module 500 is located at the bottom of the storage tank and connected to the isolation and replacement module 300 via a sealed pipeline. This ground transfer module 500 includes an automatic filling mechanism and a mobile robot interface, used to receive liquid samples transported from above and dispense them into standard reagent bottles. The ground transfer module 500 also interacts with automated guided transport equipment to complete automated sample collection and transfer. The automatic filling mechanism performs precise metering and dispensing operations on the received liquid samples, filling them into standard reagent bottles. The mobile robot interface is used for positioning, docking, and signal interaction with the automated guided transport equipment to achieve automated transfer and transport of dispensed reagent bottles. The automated guided transport equipment is an unmanned transport device capable of autonomously navigating along a preset path or through environmental perception, and automatically docking with the mobile robot interface to receive and transport dispensed sample bottles.

[0039] The control and calculation module 600 establishes bidirectional data communication with the aforementioned hardware modules to coordinate the timing of their actions. The control and calculation module 600 internally includes a mechanical inversion algorithm and a frequency domain analysis algorithm. These algorithms are used to invert the rheological characteristic parameters of the medium based on the collected mechanical data and the depth data from the composite detection component, and to determine the completion status of the sampling task based on the frequency domain response characteristics. Specifically, the mechanical inversion algorithm calculates the distribution of rheological parameters of the medium inside the tank using a mechanical model based on the tensile data collected by the sensing and detection module and the depth data from the composite detection component. The rheological parameters include medium density and medium viscosity. Medium density is used to identify different liquid stratifications, while medium viscosity is used to distinguish different grades of medium or identify sludge sediment. The frequency domain analysis algorithm processes the system response signal generated by the vibration excitation of the sampling verification module, and determines the filling status of the sampling container and whether the sampling task is completed by analyzing its frequency domain characteristics.

[0040] See Figure 2 , Figure 2 This is a flowchart of a method according to an embodiment of the present invention. The present invention provides an intelligent monitoring and sampling method for storage tanks, comprising the following steps: S10, the control calculation module 600 drives the variable diameter winch module 100 to operate. During the gas phase stroke when the sensing and detection module 200 is not in contact with the liquid surface, it continuously collects system operating resistance data and constructs a dynamic friction baseline. During this process, the variable diameter winch module 100 offsets the cable gravity through the variable diameter structure to ensure the stability of the friction baseline data. The inside of the variable diameter winch module is a variable diameter drum with a specially designed profile. The rotation radius of the drum is not constant, but changes continuously with the rotation angle of the drum according to a preset geometric function (e.g., Archimedean spiral or logarithmic spiral).

[0041] S20, as the sensing and detection module 200 enters below the liquid surface, the system enters the rheological characteristic scanning stage. The variable diameter winch module 100 continuously eliminates the change in cable gravity caused by the increase in depth. The control calculation module 600 uses the net tension residual after deducting the gravity term and the friction baseline term, combined with the current movement speed, to calculate the medium density and viscosity data at the current depth in real time, and thereby identify the oil-water interface or material stratification location in the storage tank. S30, after determining the target sampling location, the sampling verification module 400 performs a medium extraction operation at a specified depth; S40, after the sampling action is completed, the sensing and detection module 200 is lifted to the stable gas phase region above the liquid surface. In this gas phase region, the variable diameter winch module 100 applies a micro-mechanical excitation to control the calculation module 600 to analyze the change of the system's natural frequency and confirm whether the sample has been successfully collected. S50, after verification, the sensing and detection module 200 is recycled into the internal cavity of the isolation and replacement module 300. The isolation and replacement module 300 closes the lower valve to cut off the connection with the storage tank and fills inert gas for environmental replacement. After the cavity environment reaches the safety standard, the sample is transported to the ground transfer module 500 through the pipeline, and finally transported away from the site by the automatic guidance equipment, completing the unmanned monitoring and sampling process.

[0042] See Figure 3 The variable diameter winch module 100 is installed at the equipment flange interface on the top of the storage tank and adopts an explosion-proof design. The variable diameter winch module 100 mainly includes a variable diameter drum assembly, a forced rope winding mechanism, a servo drive unit, and a precision sensing assembly.

[0043] The variable-diameter drum assembly is a key component for achieving mechanical gravity compensation. This assembly includes a CNC-machined drum body with a continuous helical cable guide groove on its circumferential surface to accommodate the cable. To address the issue of linear load increase caused by the cable's own weight during long-distance sampling, the winding radius of the helical cable guide groove is... Designed to change non-linearly with the rotation angle, the spiral cable guide groove has its maximum winding radius at the initial position where the cable is fully retracted (with the composite detection component at its highest point); as the drum rotates and the cable is lowered, the winding radius gradually decreases. This is achieved by utilizing the torque balance formula. (Torque = Force × Lever arm), as the length of the cable increases, gravity... When the load increases, decrease the lever arm. (i.e., the winding radius) ensures that the product of the two remains stable, thereby automatically offsetting the effect of gravity changes on the drive shaft at the mechanical structure level.

[0044] To quantify the aforementioned compensation logic and guide drum processing, the drum profile curve of the variable diameter hoist module 100 is designed based on a gravity balance model. Let the drum's rotation angle be... (Radians), when the composite detection component is at its highest point The linear density (mass per unit length) of the cable is: The inherent mass of the composite detection component is The winding radius of the spool The following moment balance constraint equations must be satisfied: ; In the formula, Represents gravitational acceleration; This represents the integral variable, corresponding to the rotation angle; Indicates the rotation angle Total length of cable already released ; This indicates the pre-set target constant torque value. This target constant torque value is selected based on the rated torque and optimal efficiency range of the servo motor 104, and is set as the holding torque required in the cable retraction state (minimum load but maximum radius). By solving the above integral equation using a numerical iteration method, the radius coordinate data corresponding to each angle of the cable guide groove can be obtained, which can be used to guide the machining path of the CNC machine tool.

[0045] The variable-diameter winch module 100 is equipped with a forced rope-laying mechanism in conjunction with the variable-diameter drum assembly. Because the drum uses a variable-diameter design, if the cable entry angle deviates, it is very easy for the cable to slip out of the groove. Therefore, the forced rope-laying mechanism uses a bidirectional reciprocating screw 101 mechanically coupled to the drum spindle 106. To ensure the reliability of the mechanical implementation, the pitch of the helical cable guide groove in the drum axial direction (i.e., the axial distance between two adjacent grooves) is designed to be a constant value. The pitch of the bidirectional reciprocating screw 101 matches this constant axial pitch. Gear transmission ensures that for each rotation of the drum, the axial movement of the follower cable guide 102 is precisely equal to one cable guide groove pitch. The cable passes through the cable guide 102 to prevent the cable from deviating from the helical cable guide groove of the drum. The cable guide 102 has a wear-resistant alloy guide sleeve inside to limit the radial runout of the cable, ensuring that the cable always falls vertically into the bottom of the cable guide groove of the current radius, maintaining... The physical validity of the functional relationship.

[0046] The servo drive unit uses a servo motor 104, which is connected to the drum spindle 106 via a precision planetary reducer 105. The servo motor 104 receives control commands to drive the drum rotation. At the end of the drive chain, between the drum spindle 106 and the precision planetary reducer 105, a dynamic torque sensor 107 is installed in series. This dynamic torque sensor 107 is used to collect the total load torque during actual operation in real time. Since the variable diameter drum has eliminated the main component of gravity variation, this The values ​​mainly include the inherent frictional torque of the mechanical system, the buoyancy torque of the fluid on the probe, and the viscous drag torque of the fluid, providing a high signal-to-noise ratio physical basis for subsequent algorithms to extract weak media rheological features.

[0047] The precision sensing assembly also includes an absolute multi-turn encoder 103 mounted on the end of the drum shaft for real-time feedback of the absolute rotation angle of the drum. The control and calculation module is based on this absolute rotation angle. By querying the pre-stored "angle-depth" mapping table (which is based on the aforementioned...) (Generate integral relationship) to determine the current precise depth of the detection component.

[0048] To address the frictional interference introduced by the sealing structure, the variable-diameter winch module 100 employs a low-friction sealing component at the interface where the cable exits the storage tank. Preferably, a magnetohydrodynamic seal or a multi-stage non-contact labyrinth seal structure is used to reduce the dry frictional resistance at the seal to below the level of the system torque measurement accuracy, or to ensure high repeatability and stability of the frictional resistance. This, combined with subsequent gas-phase calibration steps, enables effective differentiation of fluid viscous resistance.

[0049] See Figure 5 The sensing and detection module 200 constructs a physical sensing network for the internal environment of the storage tank, which includes a laser ranging unit installed on the top of the storage tank, a composite detection component suspended at the end of a cable, and a signal transmission and communication unit connecting the two.

[0050] The laser ranging unit, serving as the system's absolute spatial position reference source, is rigidly fixed to an independent mounting flange or sight glass window (a transparent observation window or a dedicated interface with a transparent observation window) on the top of the storage tank. This laser ranging unit employs a phase-type or pulse-type explosion-proof laser rangefinder, with its emitted beam directed vertically downwards towards the liquid surface inside the tank. The laser ranging unit is configured to independently measure the vertical distance from the emission point at the top of the tank to the gas-liquid interface, thereby obtaining the real-time absolute liquid level height. The absolute liquid level height is related to the probe rope insertion depth fed back by the variable diameter winch module 100. Together, they form the system's dual positioning coordinate system. The control and calculation module calculates the current height of the probe's bottom in real time. (in (for installation height), and with Compare: when When the system is in the "gas phase" stage, the fluid resistance is zero, and the system automatically executes the friction baseline extraction algorithm. when When the system enters the "liquid phase" stage, the rheological property inversion algorithm is activated. To overcome the problem of lens contamination caused by the volatilization and condensation of oil and gas inside the storage tank, a gas purging interface is configured outside the viewing window of the laser ranging unit. Clean instrument air or nitrogen is used to form a positive pressure air knife to keep the measurement optical path clean.

[0051] The composite detection component is the sensing and execution end point that directly contacts the medium. Its physical structure includes a streamlined counterweight housing, an internal sensor array, and an anti-torsion connector at the top. The streamlined counterweight housing is preferably made of corrosion-resistant stainless steel or titanium alloy, and its outline is designed as a rotating structure with a fixed maximum cross-sectional area (e.g., a cylinder with conical ends). The technical purpose of this design is to ensure that the flow field remains stable when the probe moves vertically up and down in the liquid, thus minimizing the fluid drag coefficient. At the set scanning speed The value is approximated as a constant, thus satisfying the linearization solution prerequisite of the fluid viscous resistance equation.

[0052] For the fluid dynamics calculations involved, the geometric parameters of the composite detection component must satisfy the definition of the following fluid resistance equation: ; In the formula, This refers to the fluid viscous resistance experienced by the probe during its movement; This is the fluid resistance coefficient, which is obtained through a pre-calibration experiment of the probe in a standard viscosity fluid; The maximum projected cross-sectional area of ​​the composite detection component perpendicular to the direction of motion; For fluid density; This represents the vertical movement speed of the probe.

[0053] The composite detection assembly integrates a medium parameter sensing unit, including a high-precision temperature sensor and a pressure sensor. The probe portion of the temperature sensor (e.g., a PT100 RTD) penetrates the housing wall to directly contact the medium, enabling real-time acquisition of the medium temperature. To compensate for the drift of rheological parameters with temperature, a pressure sensor is mounted at the bottom of the composite detection assembly to sense the current hydrostatic pressure. The hydrostatic pressure data is configured as a redundant verification parameter for depth. The control calculation module has a preset pressure-depth verification threshold. Real-time calculation If the calculation result exceeds... The system determines that the cable has slipped or the composite detection component has become stranded in the storage tank, triggering the emergency stop protection.

[0054] To support the density inversion function, the total mass of the composite detector assembly... and drainage volume After manufacturing, the components undergo precise weighing and drainage volume calibration, and are pre-stored as system constants in the control unit. The total mass of the composite detection assembly... Configured to satisfy ,in The mass constraint, representing the maximum theoretical density of the medium allowed to be stored in the tank, ensures that the probe can always sink under its own weight under all operating conditions, maintaining cable tension. Its buoyancy calculation follows Archimedes' principle: ; In the formula, This refers to the buoyancy generated when the probe is completely submerged. Depth to be measured The density of the medium at that location; The acceleration due to gravity is taken as the local standard acceleration due to gravity. This represents the effective drainage volume of the composite detection component.

[0055] The signal transmission communication unit transmits the analog signals acquired by the composite detection component to the top of the tank. The cable is a composite armored cable containing multiple load-bearing steel wires and embedded shielded conductors. The central conductor layer of the cable is wrapped with a tensile fiber reinforcement layer (e.g., aramid fiber) and a chemically resistant insulating sheath (e.g., polytetrafluoroethylene), enabling it to withstand the maximum tensile force generated by the probe's own weight and viscous resistance. The cable is connected to the composite detection component via an anti-torsion rotary joint, which allows the probe to rotate freely relative to the cable, eliminating the influence of rotational torque generated by the cable's helical structure under tension on the probe's attitude. The composite detection component also integrates a signal conditioning circuit, converting the weak analog sensor signals into digital signals (e.g., Modbus protocol signals) and uploading them via differential transmission to ensure data integrity in the tank's electromagnetic environment.

[0056] The isolation and replacement module 300 serves as a transitional device connecting the internal environment of the storage tank with the external operating environment. Its main body is a vertical cavity structure with independent pressure-bearing capacity. The transition chamber structure is located between the variable-diameter hoist module 100 and the process installation port on the top of the storage tank, forming a temporary storage and purification space for the composite detection components. Considering the acidic gas corrosion or high-pressure conditions present inside the storage tank, the shell of the isolation and replacement module 300 and key components in contact with the medium are made of corrosion-resistant alloy materials. Its wall thickness and the design pressure rating of the connecting flanges must exceed the maximum working pressure of the storage tank to meet the safety regulations for pressure vessels.

[0057] The isolation and replacement module 300 integrates a lower isolation valve assembly, an upper sealing interface assembly, and a gas replacement circuit in its mechanical structure. The lower isolation valve assembly is located at the flange connecting the bottom of the cavity to the storage tank. It employs a full-bore pneumatic hard-seal gate valve or ball valve, with a diameter designed to be larger than the maximum outer diameter of the composite detection component, ensuring unobstructed passage of the detection component. The control logic of the lower isolation valve assembly uses a position interlock mechanism: a non-contact proximity switch (e.g., an inductive sensor) is installed inside the valve body or on the cavity wall, or the control calculation module directly performs logical judgments based on the height data fed back by the laser ranging unit. Only when the system confirms the bottom height of the detection component... Safety closing plane above the valve plate Only then is the pneumatic actuator allowed to perform the closing action, using the metal hard seal structure to sever the physical connection between the cavity and the gas phase space inside the storage tank.

[0058] The gas replacement circuit includes an inert gas injection unit and a waste gas recovery and emission unit, each connected to the side wall interface of the cavity. The inert gas injection unit is connected to the on-site nitrogen pipeline network via a pressure reducing valve assembly to inject high-purity nitrogen into the sealed cavity; the waste gas recovery and emission unit is connected to the waste gas treatment main pipe. Based on the gas dilution and replacement theory, after the lower isolation valve is closed, a high concentration of volatile gases of the same origin as those in the storage tank remains in the cavity. At this time, by injecting oxygen-free inert gas and continuously venting, the partial pressure of flammable or toxic gases in the cavity is reduced, lowering their concentration to below the safe limit, thereby preventing gas escape or flash explosion accidents when the upper interface is opened to remove the sample.

[0059] To quantify the displacement process and precisely control the displacement time, avoiding safety hazards or nitrogen waste caused by empirical estimation, the control and calculation module calculates the minimum displacement time required in real time based on a fully mixed flow model. Assume the net free volume of the cavity is The volumetric flow rate of the injected inert gas is The formula for calculating the replacement time required to meet safety emission standards is as follows: ; In the formula, The net gas volume is the total geometric volume of the isolation chamber minus the physical volume of the detection component. The standard volumetric flow rate for the inert gas injection pipeline is set and fed back through a gas mass flow controller; This is the initial gas concentration before replacement. This value can be determined in two ways: one is to directly read the measured value from the gas concentration sensor installed in the cavity; the other is, to ensure intrinsic safety, to directly take the theoretical concentration value corresponding to the saturated vapor pressure of the medium in the tank at the current temperature. The preset safe concentration threshold is set to 10% of the lower explosive limit of the gas or the occupational health exposure limit (e.g., the permissible concentration of benzene) based on the characteristics of the medium. This is a safety redundancy factor used to correct for non-ideal mixing deviations caused by dead angles in the cavity; its value range is set from 1.2 to 1.5.

[0060] The isolation and replacement module 300 also integrates a differential pressure monitoring unit to construct a positive pressure protection system. This differential pressure monitoring unit includes an explosion-proof differential pressure transmitter to monitor the internal pressure of the cavity in real time. With external atmospheric pressure The difference During sample transfer or before the maintenance door is opened, the system enters a pressure-holding mode: the opening of the inert gas injection valve is adjusted using a PID algorithm to maintain the internal pressure of the chamber slightly higher than the external atmospheric pressure. Within a preset micro-positive pressure range (e.g., 50 Pa to 200 Pa), this micro-positive pressure environment prevents external oxygen-containing air from backflowing into the cavity, avoiding the formation of an explosive gas mixture. Simultaneously, if there is a slight internal leak in the lower isolation valve, the positive pressure environment can inhibit the reverse diffusion of toxic gases from the storage tank into the cavity. The system has a strict unlocking logic: only when the "replacement time" is simultaneously met... "and the establishment of micro-positive pressure" "Two conditions must be met for the electronic lock on the upper discharge port or maintenance door to be automatically released."

[0061] To address the potential dripping issue with high-viscosity media, the bottom of the isolation and replacement module 300 is designed with a liquid collection tank and a return drainage pipeline. When the composite detection component is lifted, any adhering residual liquid drips into the collection tank under gravity and is then drained back into the storage tank or waste liquid collection network via the drainage valve, preventing residual liquid accumulation from affecting the sealing performance of the lower isolation valve. For sampling scenarios involving high-purity or easily crystallizing media, the inner wall of the chamber is also equipped with a spray cleaning nozzle that sprays a compatible solvent during gas replacement to perform online cleaning of the probe surface and the lower section of the cable.

[0062] See Figure 4 The sampling verification module 400 is integrated into the internal cavity of the composite detection component and mainly includes an automatic sampling mechanism, a sample container, and a frequency domain response verification logic unit that works with it.

[0063] The automatic sampling mechanism is located at the center of the composite detection assembly and controls the fluid channel for external media to enter the internal sample container. To adapt to the high-pressure environment of deep liquids in the storage tank and ensure safety, the automatic sampling mechanism adopts a magnetically coupled needle valve or high-pressure solenoid ball valve structure. This valve body has a normally closed characteristic; in the absence of power or control signal, the valve core is pressed tightly against the valve seat by the return spring, maintaining the sealed state of the sample container. When the composite detection assembly reaches the target sampling depth determined by the rheological inversion algorithm... At this time, the control and calculation module sends an opening command through the communication line inside the cable, driving the valve core to open the inlet. The external medium flows into the sample container under the action of hydrostatic pressure difference or auxiliary micro pump. In order to prevent cavitation or container rupture due to excessive internal and external pressure difference, a pressure balancing valve is connected in series in the liquid inlet circuit of the sampling mechanism to balance the static pressure inside and outside the container before the sample inlet valve is opened.

[0064] The sample container is used to store the collected medium and is fixed to the frame of the composite detection component by a rigid chuck or threaded connection. This structure ensures that when the cable transmits vibration excitation, the sample container and the detection component can move as a whole mass block, avoiding local modal or nonlinear damping caused by loose connection, thereby ensuring the signal-to-noise ratio of frequency domain analysis.

[0065] The sampling verification module 400 employs a non-contact verification method based on the "mass-frequency" mapping relationship to perform closed-loop verification of the sampled data. By treating the "hoisting system-cable-detection assembly" as a single-degree-of-freedom spring-mass damped system, under a given stiffness, the system's natural frequency is inversely proportional to the square root of the total mass. When the sample container successfully collects liquid, the total mass of the detection assembly increases, causing an observable shift (frequency shift) in the system's natural frequency towards lower frequencies.

[0066] The specific verification process is as follows: After the sampling action is completed, the variable diameter winch module 100 lifts the detection component to a safe gas phase area above the liquid surface. At this time, the detection component is completely freed from the viscous damping environment of the liquid and is in a free-suspension state, eliminating the interference of fluid-added mass and viscous damping on vibration characteristics. The servo motor 104 of the variable diameter winch module 100 switches to torque control mode and applies a small-amplitude sweep frequency excitation signal (e.g., a sine wave with a frequency range of 0.1Hz to 10Hz and an amplitude of 5% to 10% of the rated torque). The control calculation module acquires the position response signal fed back by the encoder or the force signal fed back by the tension sensor, uses Fast Fourier Transform (FFT) to convert the time-domain signal into a frequency-domain spectrum, and identifies the frequency corresponding to the fundamental wave with the largest amplitude through a peak search algorithm, which is the first-order natural angular frequency of the current system. .

[0067] Based on the dynamic equations, the control solution module uses the identified frequency to inversely calculate the current total suspension mass. : ; In the formula, The total mass of the system participating in the vibration; This is the measured first-order natural angular frequency of the system; This represents the equivalent axial stiffness at the current cable release length.

[0068] For steel wire ropes or multi-layer composite cables, their equivalent stiffness The calculation formula varies with cable length as follows: ; In the formula, This is the overall elastic modulus of the cable material, a value provided by the cable manufacturer and corrected through factory tensile testing; This refers to the effective load-bearing cross-sectional area of ​​the cable. The current cable sag length is fed back in real time by the encoder of the variable diameter winch module 100.

[0069] After calculating the total mass Then, the system calculates the actual mass of the sample obtained from sampling by subtracting the known baseline mass. : ; In the formula, The known mass of the unloaded detection component; The effective mass of the cable participating in the vibration is calculated. According to the Rayleigh energy approximation, for a homogeneous cable, its effective mass participating in the vibration is approximately 1 / 3 of the total mass of the current suspension cable.

[0070] To determine whether sampling was successful, the control and calculation module pre-sets a quality verification logic based on the medium density. If the calculated... Sampling is considered successful if the following conditions are met: ; In the formula, and These are the minimum and maximum theoretical densities of the medium inside the storage tank (for example, for crude oil storage tanks, the density of the light component and the density of water-containing heavy oil are taken respectively). This refers to the standard geometric volume of the sample container; The minimum allowable fill rate coefficient is set to a value of 0.85 to 0.90 to exclude insufficient sampling volume caused by air bubbles occupying space or inadequate filling.

[0071] like If the sample size is below the lower threshold, the system determines that sampling has failed and automatically triggers the resampling logic; if If the abnormal value exceeds the upper limit threshold, it is determined that there may be probe wall adhesion or external foreign object adhesion, the system triggers an abnormality alarm and stops the retrieval process. Through this frequency domain verification method, the system achieves quantitative confirmation of sampling quality without opening the isolation chamber.

[0072] The ground transfer module 500 is located in a safe area at the bottom of the storage tank and is connected to the isolation and replacement module 300 located at the top of the storage tank via physical pipelines. The ground transfer module 500 mainly consists of a closed conveying pipeline system, an automated dispensing workstation, and a robot interaction interface unit.

[0073] A closed-loop delivery pipeline system connects the top of the storage tank to the ground, undertaking the vertical transport of samples. The pipeline uses 316L stainless steel tubing with an electrolytically polished inner wall or high-pressure flexible tubing lined with PTFE to reduce media residue. For power delivery, this closed-loop pipeline utilizes the liquid's own gravitational potential energy and the inert gas micro-positive pressure established within the isolation and displacement module 300 to ensure smooth flow of high-viscosity media. To prevent the media from solidifying due to temperature drops during long-distance pipeline travel, the entire delivery pipeline is wrapped with an electric heating tape and insulation layer. The control and calculation module incorporates temperature closed-loop logic to maintain the pipe wall temperature. The temperature is always above the freezing point or wax precipitation point of the medium (e.g., maintained between 40°C and 60°C). At the end of the pipeline entering the dispensing station, a buffer tank and a flow regulating valve are installed to eliminate fluid shock and stabilize the filling flow rate.

[0074] The automated dispensing workstation adopts a rotary multi-station turntable structure or a linear chain conveyor line structure, integrating empty bottle supply, precision weighing and filling, automatic capping and labeling units. The precision weighing and filling unit is located below the filling station and is equipped with a high-precision electronic weighing sensor. Since laboratory analysis usually requires a fixed sample volume, while industrial filling is difficult to directly measure small volumes, this embodiment utilizes the measured medium density to dynamically convert the target volume into a target weight, thereby achieving high-precision quantitative filling.

[0075] The specific control logic for filling cutoff is as follows: The system sets the standard sampling volume to be... It also calls the real-time density of the medium calculated by the control calculation module 600. Calculate the corresponding target net weight. The system closes the filling valve when the following mass balance relationship is met: ; In the formula, The current total weight (including bottle weight) is fed back in real time by the weighing sensor. The tare weight of the empty bottle measured before filling; The preset standard sampling volume (e.g., 500ml); This is the density value of the medium derived from the cable tension data. Here, this process data is directly used as the filling parameter, achieving a closed-loop application of the detection data at the execution end, eliminating the need for manual input of the density again. The permissible filling error threshold is typically set to a percentage of the target filling quality. to This accuracy is determined by the response speed of the filling valve and the resolution of the weighing sensor.

[0076] The automatic capping unit is located downstream of the filling station and includes a servo-driven capping head. To ensure a tight seal on the sample vials without damaging the cap threads, the capping process employs a dual torque-angle control mode. Servo motor 104 monitors the output torque in real time. Set the acceptable torque range The motor stops when the feedback torque reaches the set value. If the final torque exceeds this range, the system automatically marks the sample as defective and rejects it at a subsequent workstation.

[0077] The robot interaction interface unit is used to realize unmanned sample transfer. This unit includes a finished product storage platform and a communication module. The storage platform is equipped with a mechanical alignment clamp to fix the packaged reagent bottles in a unified retrieval position. To address navigation errors in mobile robots, high-contrast visual positioning targets (such as AprilTag or ArUco codes) are set on the surface or sides of the storage platform. Visual sensors on the automated guided vehicle or autonomous mobile robot identify these targets, calculate the relative pose matrix, and guide the robotic arm or vehicle chassis to achieve sub-millimeter-level end-effector alignment for precise grasping.

[0078] The communication module connects to the AGV scheduling system via industrial Ethernet or wireless LAN, executing standard signal interaction logic. Once the sample is packaged and locked on the temporary storage platform, the ground transfer module 500 sends a "ready" signal and workstation ID. After the AGV arrives and identifies the target, it sends a "in position" signal. The temporary storage platform clamps release upon receiving the signal, cooperating with the AGV to complete the retrieval. After retrieval, the AGV sends a "complete" signal, the system resets, and prepares for the next operation.

[0079] To address pipeline cleaning needs, the ground transport module 500 integrates a waste liquid switching loop. Between different batches of sampling tasks, the system controls the three-way valve at the end of the delivery pipeline to switch to the waste liquid collection position. In conjunction with the spray cleaning function, the waste solvent generated during cleaning is discharged into the waste liquid collection tank through this pipeline until the cleaning is qualified (which can be determined by the color or conductivity sensor of the cleaning solution), preventing cross-contamination of samples.

[0080] The physical carrier of the control calculation module 600 is an industrial control computer or a high-performance programmable logic controller installed in an explosion-proof electrical control box. This control calculation module 600 establishes a bidirectional communication connection with the servo driver of the variable diameter hoist module 100, the signal conditioning circuit of the sensing and detection module 200, and other actuators via an industrial real-time bus (such as EtherCAT or Profinet). The control calculation module 600 runs a real-time operating system and integrates a deep analysis unit, a rheological parameter inversion unit, a hierarchical identification and decision-making unit, and a system self-calibration unit.

[0081] The depth analysis unit maps the rotation angle fed back by the variable-diameter hoist module 100 to a linear depth. Because the drum employs a non-linear variable-diameter design, the depth analysis unit incorporates a geometric mapping model that strictly corresponds to the drum's machining curve. This geometric mapping model, based on calculus principles, maps minute angle increments fed back by the encoder. Multiply by the instantaneous radius corresponding to the current angle The results are accumulated. Simultaneously, to eliminate elastic elongation errors caused by the cable's own weight and load during deep well operations, an elastic correction algorithm based on Hooke's law is introduced. The final accurate depth of the detection component is then determined. The calculation formula is as follows: ; In the formula, The function represents the relationship between the drum radius and the rotation angle. This function is determined by the mechanical design parameters and stored using a lookup table. The current absolute cumulative angle fed back by the encoder; This is the actual tension force borne by the cable at the current moment, which is obtained by subtracting the drum inertia from the torque sensor data. The theoretical release length without elastic correction, calculated by integration; The tensile stiffness (i.e., modulus of elasticity) of the cable With effective cross-sectional area (the product of the two values), which is obtained through the cable's factory tensile test.

[0082] The rheological parameter inversion unit indirectly calculates the density and viscosity of the medium by utilizing the dynamic response of the probe component when it moves in the medium. The calculation process of the rheological parameter inversion unit is divided into two steps: static density inversion and dynamic viscosity inversion.

[0083] In the static density inversion step, calculations are performed using Archimedes' principle of buoyancy. When the probe is fully submerged and suspended at a specific depth, the decrease in cable tension is precisely equal to the weight of the liquid displaced by the probe. The control and calculation module controls the probe at the target depth. Remain stationary (speed) The density of the medium at the current depth is calculated based on the torque balance equation. : ; In the formula, This value is obtained during the device initialization phase as a reference gravitational torque for detecting components when they are hovering in the air (ignoring air buoyancy). The actual output holding torque of the servo motor 104 when it is suspended in the medium; This is the inherent static friction torque of the system, which was obtained through low-speed testing during the gas phase stroke; It is the acceleration due to gravity; The calibration drainage volume for the detection components; This is the drum radius corresponding to the current hovering depth.

[0084] In the dynamic viscosity inversion step, calculations are performed based on the principle of fluid resistance. When the probe component moves at a constant speed, in addition to overcoming gravity and buoyancy, the servo motor 104 needs to provide additional torque to overcome the viscous resistance of the fluid. This resistance is related to the dynamic viscosity of the medium and the speed of movement. The control and calculation module controls the probe component to move at a constant speed. A vertical scan is performed, and the rheological parameter inversion unit calculates the dynamic viscosity of the medium. : ; In the formula, The total torque output by the motor in real time during the constant speed scanning process; This is the equivalent hovering moment at the same depth (i.e., the gravity term after deducting buoyancy). This is the mechanical dynamic friction torque under motion conditions, which is obtained by looking up the "velocity-friction force" characteristic curve of the system during no-load operation. To detect the vertical movement speed of the component; This is the geometry factor. For the standard cylindrical probe used in this embodiment, based on a modification of the Stokes fluid resistance formula, this geometry factor is approximately... (in For diameter, For length, (For fluid shape coefficients). The system calibration coefficient is determined through calibration experiments using standard viscosity oils and is used to map torque values ​​to standard viscosity units (e.g., mPa·s).

[0085] The hierarchical identification decision unit is based on the density curve obtained from the above inversion. and viscosity curve A media distribution model inside the storage tank is constructed, and the hierarchical identification decision unit uses a gradient detection algorithm to identify the interfaces between different media layers. The system presets a hierarchical discrimination threshold: a density gradient threshold. (For example, a value of 0.02 to 0.05 g / cm³) 3 ( / m) and viscosity gradient threshold (For example, a change rate of 10% / m). When the vertical change rate of the monitored data exceeds the above threshold, it is considered satisfactory. or The system determines that the current depth is a two-phase interface (such as oil-water interface, oil-gas interface, or emulsion layer interface).

[0086] Based on the identified hierarchical structure, the hierarchical identification decision unit automatically generates an adaptive sampling plan, which includes a set of discrete target sampling depths. The specific decision-making process is as follows: A sampling point is generated at the geometric center of each identified homogeneous layer (i.e., the region where the data gradient is below a threshold); for homogeneous layers with a thickness exceeding a preset standard (e.g., 3 meters), sampling points are added at equal intervals; for abnormal emulsified or transitional layers identified through gradient analysis, an additional sampling point is forcibly added for focused analysis. This sampling plan is sent to the execution mechanism as a subsequent action instruction.

[0087] The system self-calibration unit is used to eliminate systematic errors caused by mechanical wear and environmental changes during the gas phase travel phase before each detection mission begins (i.e., The system's self-calibration unit collects torque data from the servo motor 104 in real time and updates the system's friction model. The system calculates the average friction torque. This is then used as the baseline deduction value for the current task. If the variance of the self-detected frictional torque fluctuation... If the value exceeds a safety threshold (e.g., 20% of the baseline value), the system will determine that there is a risk of mechanical structure jamming or lubrication failure, issue a maintenance warning, and prohibit subsequent liquid entry detection actions.

[0088] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. An integrated intelligent monitoring and sampling system for storage tanks, characterized in that, include: The variable diameter winch module is installed on the top of the storage tank and is used to drive the cable to rise and fall and output load torque data; The sensing and detection module includes a composite detection component suspended at the end of a cable for collecting liquid level data; The isolation and replacement module has a transition chamber inside and is connected to the top interface of the storage tank. It is used to establish a physical isolation barrier for the entry and exit of the composite detection component and to perform gas replacement on the transition chamber. The sampling verification module, integrated within the sensing and detection module, is used to extract the target medium as a sample and cooperate with the variable diameter winch module to perform quality verification. The ground transfer module, connected to the isolation and replacement module via a sealed pipeline, is used to receive the transported samples and perform dispensing based on the characteristics of the target medium; The control calculation module is used to calibrate the starting point of the liquid phase stroke using the liquid level height data; The rheological parameter distribution of the target medium is inverted based on the load torque data, and a sampling plan is generated based on the rheological parameter distribution to regulate the actions of the above modules.

2. The system according to claim 1, characterized in that, The control calculation module includes: The depth analysis unit is used to construct and output the depth data of the composite detection component based on the rotation angle fed back by the variable diameter winch module, combined with the geometric mapping model of the variable diameter drum assembly in the variable diameter winch module and the cable elasticity correction algorithm. The rheological parameter inversion unit is used to receive the depth data and the load torque data, and after subtracting the friction baseline, calculates and generates the medium density data and viscosity data corresponding to the depth data using Archimedes' principle and the fluid resistance principle, respectively. The hierarchical identification and decision unit is used to monitor the vertical gradient change of the medium density data and the viscosity data in real time. After identifying the two-phase interface, it generates an adaptive sampling plan containing the target depth set and converts the adaptive sampling plan into instructions to drive the sampling verification module to act.

3. The system according to claim 1, characterized in that, The variable diameter winch module includes a variable diameter drum assembly, a forced rope laying mechanism, and a dynamic torque sensor; The forced rope feeding mechanism includes a reciprocating screw structure mechanically coupled to the variable diameter drum assembly; The reciprocating screw structure is used to drive the cable guide to perform synchronous reciprocating motion, and to lay the cable in the cable guide groove of the variable diameter drum assembly to maintain a preset radius function relationship. The dynamic torque sensor is used to collect the load torque data.

4. The system according to claim 3, characterized in that, The sampling verification module includes: An automatic sampling mechanism is provided with a pressure balancing circuit to balance the internal and external pressure difference and establish a fluid channel when the target depth is reached, so as to introduce the target medium into the sample container; The sample container, connected to the composite detection component as an integral mass block, is lifted to the gas phase region inside the storage tank after sampling, along with the composite detection component, and receives mechanical frequency sweep excitation applied by the variable diameter winch module. The frequency domain response verification logic unit is used to receive the vibration response signal of the dynamic torque sensor during mechanical frequency sweep excitation, perform spectrum analysis, identify the first natural angular frequency, calculate the total suspension mass using the inverse square relationship between mass and frequency, and determine whether the sample collection amount falls within the qualified range.

5. The system according to claim 1, characterized in that, The isolation and replacement module includes a transition chamber, the bottom of which is integrated with a lower isolation valve group. A position sensor is installed inside the transition chamber, and the transition chamber is also connected to a gas replacement circuit and a differential pressure monitoring unit.

6. The system according to claim 5, characterized in that, The position sensor is used to detect the position of the composite detection component; The lower isolation valve assembly is used to perform a closing action to disconnect the connection with the storage tank when the composite detection component is in a safe position within the transition chamber; The gas replacement circuit is used to obtain inert gas from an external inert gas source, inject it into the transition chamber through the inlet, and discharge the mixed gas inside the transition chamber through the exhaust port. The differential pressure monitoring unit is used to monitor the pressure difference between the inside and outside of the transition chamber in real time and drive the gas injection valve in the gas replacement circuit to establish a micro-positive pressure environment in the transition chamber.

7. The system according to claim 2, characterized in that, The ground transfer module includes an automated dispensing workstation, which includes; A precision weighing and filling unit is used to dynamically convert a preset standard sampling volume into a target filling mass based on the medium density data. An automated dispensing unit is used to control the timing of the filling valves based on the target filling quality. The automatic capping unit is used to monitor the output torque of the servo motor after filling to ensure that the capping quality meets the preset torque range.

8. The system according to claim 7, characterized in that, The automated packaging workstation also includes: The robot interaction interface unit is used to set a visual positioning target on the finished product temporary storage platform, so that the external transportation equipment can identify it to calculate the relative pose matrix between itself and the sample, and plan the motion trajectory based on the relative pose matrix. The waste liquid switching circuit is used to control the flow direction at the end of the closed pipeline in non-sampling conditions, and to guide the waste liquid into the collection equipment in conjunction with the cleaning action.

9. The system according to claim 1, characterized in that, The pressure sensor integrated inside the composite detection component is used to collect hydrostatic pressure data, and the hydrostatic pressure data is redundantly compared with the depth data of the control calculation module to identify operational abnormalities.

10. A method for intelligent monitoring and sampling of storage tanks, applied to the integrated intelligent monitoring and sampling system for storage tanks as described in any one of claims 1-9, characterized in that, Includes the following steps: The control and calculation module drives the variable diameter winch module to operate in the gas phase stroke, using the change in the winding radius of the variable diameter drum structure to offset the cable's self-weight load, while collecting running resistance data to construct a dynamic friction baseline. After the sensing and detection module enters the liquid phase, the control and calculation module uses the net load torque after removing the gravity component and dynamic friction baseline to invert the medium density and viscosity data in real time, and generates an adaptive sampling plan based on the vertical gradient change. The sampling verification module responds to the command to extract the medium at the target depth. It is then lifted to the gas phase region inside the storage tank by the sensing and detection module. The variable diameter winch module applies mechanical frequency sweep excitation, and the control calculation module determines the sample collection amount by analyzing the first natural angular frequency of the vibration response signal. After successful verification, the sensing and detection module is retracted into the internal cavity of the isolation and replacement module, the lower isolation valve group is disconnected from the storage tank, the gas replacement circuit performs gas replacement and the micro differential pressure monitoring unit maintains a micro positive pressure environment; The sample is transported to the ground transfer module through a closed pipeline, where the inverted medium density data is called up to convert the standard sampling volume into the target filling mass and then the sample is dispensed.

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