Device and method for preparing and testing quality of different density layered uniform granular material

Abstract

The application discloses a different density layered uniform particle material preparation and quality detection device and method, and belongs to the technical field of soil test equipment. The device comprises a receiving container arranged on an inner support frame, the receiving container is connected with a diffuser through a control valve, a micro CPT device is arranged between the diffuser and the inner support frame, the top of the receiving container is connected with a hopper through a flexible hose, and the hopper is arranged at the top of an outer support frame. The deposition intensity is controlled by using the porous plate structure in the diffuser, the particle distribution is monitored and the aperture is adjusted by using a micro pressure sensor and a high-speed camera, multi-dimensional characteristics are in-situ detected by using the multi-sensor micro CPT device, and the parameters are optimized and the optimal deposition parameters are predicted by using a controller. The application can precisely control the deposition intensity and the particle distribution, realize multi-dimensional detection and automatic control, improve the test precision and efficiency, and reduce the manual error by using the above different density layered uniform particle material preparation and quality detection device and method.

Description

Technical Field

[0001] This invention relates to the field of geotechnical testing equipment technology, specifically to a device and testing method for preparing and testing quality of layered uniform granular materials with different densities. Background Technology

[0002] In laboratory and physical model experiments of geotechnical engineering or granular materials engineering, obtaining stratified undisturbed sand or other granular sediment samples with different densities is extremely difficult, making sand sample or granular material reconstruction a common requirement. Currently, various sand sample preparation methods exist, including vibration method, wet-dry compaction method, and sand rain method. However, the sand rain method has attracted much attention in the field of large-volume dry granular material preparation due to its ability to efficiently produce large-volume, well-uniform stratified sand samples of different densities. With the increasing demands for experimental accuracy and efficiency in physical modeling, the development of highly automated and high-performance granular material preparation and property testing systems is urgently needed. Traditional systems often suffer from drawbacks such as cumbersome operation, coarse control of sedimentation parameters, and one-sided test analysis, making it difficult to fully meet the stringent requirements of modern geotechnical engineering or granular materials engineering physical modeling for accurate research on granular material quality, stress distribution, and boundary effects. This severely restricts the development of scientific research and engineering practice. Traditional CPT testing equipment is bulky and complex to operate, making it difficult to integrate with automated granular material preparation systems. Existing laboratory CPT devices largely rely on manual operation, resulting in low testing efficiency and the ability to acquire only single mechanical parameters (such as cone tip resistance), failing to meet the in-situ testing requirements for multi-dimensional characteristics of sand beds (moisture content, resistivity). Furthermore, the real-time linkage mechanism between test data and the deposition control system is not yet mature, leading to delays in experimental optimization. Therefore, developing an automated deposition system for layered granular materials with varying densities, capable of precisely controlling flow rate and location, is of great significance. Summary of the Invention

[0003] To address the aforementioned challenges, this invention provides a device and method for preparing and testing uniformly granular materials with varying densities. By incorporating structures such as diffusers, micro CPT devices, and controllers, the invention aims to precisely control deposition intensity and particle distribution, enabling multi-dimensional detection and automated control, thereby improving experimental accuracy and efficiency, and reducing human error.

[0004] To achieve the above objectives, the present invention provides a device for preparing and testing the quality of layered uniform granular materials with different densities. The device includes a receiving container mounted on an inner support frame, which is connected to a diffuser via a control valve. The bottom of the diffuser is located inside a test chamber. A micro CPT device is installed between the diffuser and the inner support frame. The top of the receiving container is connected to a hopper via a flexible hose. One end of the hose is located on top of the hopper, and the other end is equipped with a sand suction device, which is located inside the test chamber. The hopper is mounted on top of an outer support frame via a fixing frame. The test chamber is connected to the bottom of the outer support frame via a weighing sensor.

[0005] Preferably, the diffuser has a perforated plate inside, which is a variable diameter structure made of embedded shape memory alloy. The perforated plate is set on a micro slide rail, and a rotatable nozzle motor is set at the bottom of the micro slide rail. The rotatable nozzle motor is connected to the rotatable nozzle, and the rotation angle of the rotatable nozzle is set to 0-45°. The rotatable nozzle motor and the micro motor are symmetrically arranged, and the micro motor is connected to the vibrating plate.

[0006] Preferably, the miniature CPT device includes a miniature CPT motor and an actuator disposed below the miniature CPT motor. A temperature and humidity sensor is disposed at the bottom of the actuator. A triaxial sensor is disposed between the temperature and humidity sensor and the potentiometer. Both the potentiometer and the triaxial sensor are disposed on the actuator. A resistivity probe is also embedded in the potentiometer.

[0007] Preferably, a power supply box and a controller are respectively provided on both sides of the outer support frame, and the controller is connected to the diffuser, temperature and humidity sensor and triaxial sensor.

[0008] Preferably, a gate valve is provided at the end of the flexible hose near the hopper, and a flow control valve is provided at the end near the receiving container.

[0009] A detection method for a quality testing device for the preparation of layered uniform granular materials with different densities includes the following steps:

[0010] S1: The hopper discharges granular material into the receiving container through a flexible hose, and the flow rate of the granular material is controlled by a gate valve and a flow control valve.

[0011] S2: The particulate material in the receiving container enters the diffuser through the control valve. A perforated plate is installed above the control valve to ensure that the particulate material flows in layers and uniformly. The perforated plate in the diffuser is set as a variable diameter mesh structure composed of embedded shape memory alloy. The perforated plate moves up and down under the action of micro slide rails to control the deposition intensity. The vibrating plate peels off the adhering particulate material through high-frequency vibration. The outlet of the diffuser integrates a micro pressure sensor and a high-speed camera to set a timed cleaning program. If it is blocked, an emergency cleaning mode is triggered.

[0012] S3: A miniature pressure sensor and a high-speed camera monitor the uniformity of particulate material distribution in real time, dynamically adjust pore size parameters to ensure optimal flow under different density requirements, and capture particulate material distribution through the high-speed camera to calculate the uniformity index U.

[0013]

[0014] Where, ρ i Let ρ be the density of the granular material in each region, ρ be the average density, and n be the total number of regions.

[0015] If U < 0.95, increase the aperture in the low-density region and decrease the diffuser moving speed;

[0016] S4: The actuator is mounted on two crossbars connected to linear bearings to move the diffuser. A temperature and humidity sensor collects the moisture content of the granular material, a resistivity probe collects the resistivity, and a triaxial sensor simultaneously measures the cone tip resistance, sidewall friction, and tilt angle. The actuator dynamically adjusts the penetration rate using a PID algorithm and compensates for changes in granular material resistance in real time. The actuator speed v(t) is dynamically adjusted using a PID algorithm.

[0017]

[0018] Where, e(t) = v target -v current e(t) is the error signal, representing the difference between the set value and the actual value, v target Indicates the set speed, v curren K represents the current actual speed. p K i and K d Let K represent the proportional, integral, and differential coefficients, respectively. p =1.2,K i =0.3,K d =0.5, This represents the rate of change of error over time.

[0019] S5: The controller optimizes particulate material flow rate, humidity, and model compaction through algorithms, and analyzes the relationship between historical CPT data and particulate material density using machine learning algorithms to predict optimal deposition parameters.

[0020] Resistance mutation detection: If dq c The cone tip resistance represents the rate of change over time, dt represents the time interval, triggering emergency stop protection, retracting the cone by 5mm, and re-entering; temperature and humidity compensation: q is corrected based on temperature / humidity. c and f s : Where α = 0.005, and T ref For reference temperature, q c This represents the original cone tip resistance, and T represents the current temperature;

[0021] S6: The test chamber is placed on four button-type weighing sensors to continuously measure the amount of deposited sand;

[0022] S7: After the test, the sand suction device will extract the granular material into the hopper through the hose.

[0023] Preferably, in step S2, the specific steps for triggering the emergency cleaning mode are as follows:

[0024] S21: The triggering mechanism is based on multi-sensor collaborative judgment. The miniature pressure sensor integrated at the diffuser outlet monitors the pressure value in real time. When the pressure exceeds the dynamic threshold and lasts for 2 seconds, it is initially judged as a blockage. If the flow rate of the particulate material fed back by the flow control valve is lower than 70% of the set value, the high-speed camera analyzes the image through a convolutional neural network and detects a local density standard deviation σ > 0.15ρ. av This triggers a dual confirmation mechanism, allowing you to manually activate the emergency mode via the controller interface.

[0025] S22: Cleaning operations are divided into three levels of strategy: basic cleaning, intermediate cleaning and advanced cleaning;

[0026] After the controller closes the control valve and flow control valve, it stops the conveying of granular materials, starts the sand suction device to pull back the undeposited particles to the hopper, and enters the primary cleaning stage. The micro motor drives the vibrating plate to vibrate at high frequency to peel off the tiny adhering particles.

[0027] If the initial cleaning does not meet the standard and the uniformity index U < 0.9, it is upgraded to intermediate cleaning. The shape memory alloy is heated by electricity, the aperture of the perforated plate shrinks, and the servo motor drives the perforated plate to reciprocate to remove stuck large particles.

[0028] If the blockage is still not cleared, activate advanced cleaning, which uses a rotating nozzle motor to drive the rotating nozzle to spray compressed air for cleaning.

[0029] S23: Dynamic feedback and optimization, miniature pressure sensor samples once every 100ms, calculates the pressure drop slope:

[0030] k p =ΔP / Δt;

[0031] Where ΔP represents the pressure difference between two adjacent samples, Δt represents the time difference, and when Δt = 100 ms, the camera updates the uniformity index U every 0.5 s. If U ≥ 0.98 and k p If the pressure is less than 0.1 kPa / s, cleaning is considered complete. The diffuser parameters are then reset, and the deposition is restored in stages.

[0032] If the blockage is triggered repeatedly within 30 seconds, the fault code will be recorded and a manual inspection will be requested.

[0033] Therefore, the present invention employs the above-mentioned apparatus and method for preparing and testing uniformly granular materials with different densities, which has the following beneficial effects:

[0034] (1) The present invention sets up a diffuser and embeds a variable diameter porous plate structure composed of shape memory alloy inside the diffuser. This structure can move up and down under the action of micro slide rails, precisely control the deposition intensity, ensure uniform flow of granular material in layers, and meet the needs of different density layers.

[0035] (2) This invention integrates a miniature pressure sensor and a high-speed camera at the diffuser outlet to monitor the uniformity of particle material distribution in real time. By calculating the uniformity index U, the aperture parameters are dynamically adjusted to ensure the optimal flow state under different density requirements and to ensure uniform particle material distribution.

[0036] (3) This invention integrates multiple sensors through a micro CPT device. The temperature and humidity sensor collects the moisture content of the granular material, the resistivity probe collects the resistivity, and the triaxial sensor simultaneously measures the cone tip resistance, side wall friction and tilt angle, thereby realizing in-situ detection of multi-dimensional characteristics of granular materials and gaining a comprehensive understanding of the quality and characteristics of granular materials.

[0037] (4) The present invention connects the controller with the diffuser, temperature and humidity sensor and triaxial sensor, and optimizes the flow rate, humidity and compaction degree of the particulate material through the algorithm. It uses machine learning algorithm to analyze the relationship between historical CPT data and particulate material density, predicts the optimal deposition parameters, realizes automated control, improves experimental accuracy and efficiency, and reduces human operation error.

[0038] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0039] Figure 1 This is a schematic diagram of the device for preparing and testing the quality of layered uniform particulate materials with different densities according to the present invention.

[0040] Figure 2 This is a schematic diagram of the diffuser system of the present invention;

[0041] Figure 3 This is a structural diagram of the diffuser of the present invention;

[0042] Figure 4 This is a structural diagram of the porous plate diffuser of the present invention;

[0043] Figure 5 This is a schematic diagram of the structure of the micro CPT device of the present invention.

[0044] The labels in the attached diagram are as follows: 1. Hopper; 2. Gate valve; 3. Flexible hose; 4. Flow control valve; 5. Receiving container; 6. Control valve; 7. Diffuser; 8. Test chamber; 9. Weighing sensor; 10. Miniature CPT motor; 11. Actuator; 12. Potentiometer; 13. Triaxial sensor; 14. Temperature and humidity sensor; 15. Sand suction device; 16. Hose; 17. Controller; 18. Power supply box; 19. External support frame; 20. Internal support frame; 21. Fixing frame; 71. Perforated plate; 72. Rotatable nozzle motor; 73. Rotatable nozzle; 74. Miniature motor; 75. Vibrating plate; 76. Miniature slide rail; 711. Shape memory alloy; 712. Servo motor. Detailed Implementation

[0045] The technical solution of the present invention will be further described below with reference to the accompanying drawings and embodiments.

[0046] Unless otherwise defined, the technical or scientific terms used in this invention shall have the ordinary meaning understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of this application; the terms "comprising" and "having," and any variations thereof, in the specification and foregoing description of the drawings, are intended to cover non-exclusive inclusion.

[0047] Example

[0048] like Figure 1 As shown, the device for preparing and testing uniformly layered granular materials with different densities includes a receiving container 5 mounted on an inner support frame 20. The receiving container 5 is connected to a diffuser 7 via a control valve 6. A perforated plate is installed above the control valve 6 to ensure uniform flow of the granular material in layers. The bottom of the diffuser 7 is located inside a test chamber 8. The diffuser 7 and the test chamber 8 are mounted on four linear bearings and have a horizontal actuator that allows movement at different speeds in the horizontal direction. The device is supported by four vertical actuators that control the movement in the vertical direction. The top of the receiving container 5 is connected to a hopper 1 via a flexible hose 3. A gate valve 2 is installed at one end of the flexible hose 3 near the hopper 1, and a flow control valve 4 is installed at the other end near the receiving container 5. The flow rate of the granular material is controlled by the gate valve 2 and the flow control valve 4. The hopper 1 is mounted on top of an outer support frame 19 via a fixed frame 21. The test chamber 8 is connected to the bottom of the outer support frame 19 via a weighing sensor 9 to continuously measure the amount of deposited sand. One end of a hose 16 is located on top of the hopper 1, and the other end is equipped with a sand suction device 15, which is located inside the test chamber 8.

[0049] The granular material in hopper 1 is conveyed to receiving container 5 via flexible hose 3. Gate valve 2 can cut off or allow the flow of granular material, and flow control valve 4 precisely controls the flow rate of granular material entering receiving container 5, thereby ensuring that the amount of granular material entering subsequent devices is adjustable and stable. Receiving container 5 is connected to diffuser 7 via control valve 6. The perforated plate above control valve 6 allows the granular material to flow evenly in layers when entering diffuser 7. Test chamber 8 is connected to the bottom of outer support frame 19 via weighing sensor 9, which can continuously measure the amount of deposited sand in test chamber 8 to monitor the deposition of granular material. After the test, sand suction device 15 extracts the granular material in test chamber 8 into hopper 1 via hose 16 for recycling and reuse.

[0050] like Figure 2-4As shown, the diffuser 7 has a perforated plate 71 inside. The perforated plate 71 is a variable diameter structure composed of embedded shape memory alloy 711. The shape memory alloy 711 has two-phase characteristics of austenite and martensite. In the low-temperature martensite phase, the shape memory alloy 711 can be plastically deformed. When heated to the austenite phase transformation temperature, the shape memory alloy 711 restores the preset shape (such as shrinking). The shape memory alloy 711 of each grid unit is designed to have a bidirectional "shrink-expand" action. When energized, the current passes through the shape memory alloy 711 to generate Joule heat, and the temperature rises to the austenite phase. The shape memory alloy 711 shrinks and drives the grid baffle to move, and the aperture shrinks. After the power is turned off, it naturally cools to the martensite phase, and the aperture expands. A porous plate 71 is mounted on a micro slide rail 76. The porous plate 71 moves up and down under the action of the micro slide rail 76. The moving distance and speed of the porous plate 71 are precisely controlled by a servo motor 712, thereby achieving precise control of the deposition intensity. A rotatable nozzle motor 72 is mounted at the bottom of the micro slide rail 76. The rotatable nozzle motor 72 is connected to a rotatable nozzle 73. The rotation angle of the rotatable nozzle 73 is set to 0-45°, supporting fan-shaped, ring-shaped, and spiral deposition modes. The rotatable nozzle motor 72 and the micro motor 74 are symmetrically arranged. The micro motor 74 is connected to a vibrating plate 75. The vibrating plate 75 peels off the adhered particulate material through high-frequency vibration.

[0051] The porous plate 71 inside the diffuser 7 is composed of a shape memory alloy 711 with a variable diameter structure, which can control the amount and speed of particulate material passing through. Simultaneously, the porous plate 71 can move up and down on a micro-slide rail 76, and the moving distance and speed of the porous plate 71 can be precisely controlled by a servo motor 712, further achieving precise control over the deposition intensity of the particulate material. A rotatable nozzle motor 72 drives a rotatable nozzle 73, enabling the particulate material to be uniformly deposited in the test chamber 8 according to different patterns.

[0052] like Figure 1 , Figure 5 As shown, a miniature CPT device is disposed between the diffuser 7 and the inner support frame 20. The miniature CPT device includes a miniature CPT motor 10 and an actuator 11 disposed below the miniature CPT motor 10. A temperature and humidity sensor 14 is disposed at the bottom of the actuator 11. A triaxial sensor 13 is disposed between the temperature and humidity sensor 14 and the potentiometer 12. Both the potentiometer 12 and the triaxial sensor 13 are disposed on the actuator 11. A resistivity probe is also embedded in the potentiometer 12. A power supply box 18 and a controller 17 are respectively disposed on both sides of the outer support frame 19. The controller 17 is connected to the diffuser 7, the temperature and humidity sensor 14, and the triaxial sensor 13.

[0053] The temperature and humidity sensor 14 in the miniature CPT device monitors the temperature and humidity environment inside the test chamber 8 in real time. The resistivity probe embedded in the potentiometer 12 can measure the resistivity and other electrical properties of the particulate material. The triaxial sensor 13 can simultaneously measure the cone tip resistance, sidewall friction, and tilt angle to comprehensively evaluate the mechanical properties of the particulate material. These sensors transmit data to the controller 17, which provides a comprehensive understanding of the environmental factors and physical property changes of the particulate material during the preparation process, allowing for timely adjustment of preparation parameters to ensure that the quality and performance of the particulate material meet the requirements.

[0054] A detection method for a quality testing device for the preparation of layered uniform granular materials with different densities includes the following steps:

[0055] S1: Hopper 1 discharges granular material into receiving container 5 through flexible hose 3, and controls the flow rate of granular material through gate valve 2 and flow control valve 4.

[0056] S2: The particulate material in the receiving container 5 enters the diffuser through the control valve 6. A perforated plate is installed above the control valve 6 to ensure that the particulate material flows in layers and uniformly. The perforated plate 71 in the diffuser 7 is set as a variable diameter mesh structure composed of embedded shape memory alloy 711. The perforated plate 71 moves up and down under the action of the micro slide rail 76 to control the deposition intensity. The vibrating plate 75 peels off the adhered particulate material through high-frequency vibration. The outlet of the diffuser 7 integrates a micro pressure sensor and a high-speed camera. A timed cleaning program is set. If blockage occurs, an emergency cleaning mode is triggered. This process achieves fully automated operation through multimodal detection and graded cleaning strategies. Specifically:

[0057] S21: The miniature pressure sensor integrated at the diffuser 7 outlet monitors the pressure value in real time. When the pressure exceeds the dynamic threshold and persists for 2 seconds, a preliminary judgment of blockage is made. If the particulate material flow rate fed back by the flow control valve 4 is lower than 70% of the set value, the high-speed camera (integrated at the diffuser 7 outlet) analyzes the image through a convolutional neural network (CNN) and detects the local density standard deviation (σ>0.15ρ). avg This triggers a dual confirmation mechanism, allowing the emergency mode to be manually activated via the controller 17 interface;

[0058] S22: The controller closes control valve 6 and flow control valve 4, suspends the delivery of particulate material, and starts the sand suction device 15 to draw back undeposited particles to hopper 1 through hose 16, entering the primary cleaning stage. The micro motor 74 drives the vibrating plate 75 to vibrate at a high frequency of 200-300Hz, and peels off the small particles (particle size <0.5mm) adhering to the surface of the porous plate 71 through the frequency sweep mode. If the uniformity index U <0.95 after primary cleaning, it is upgraded to intermediate cleaning. The shape memory alloy 711 is heated to 80℃ austenitic phase, and the pore size of the porous plate 71 shrinks by 15%. The servo motor 712 drives the porous plate 71 to reciprocate along the micro slide rail 76 at a speed of 5mm / s 3 times to remove stuck large particles (particle size >2mm). If the blockage is still not cleared, advanced cleaning is started. The rotatable nozzle motor 72 switches to the spiral scanning mode and drives the rotatable nozzle 73 to spray 0.3-0.5MPa compressed air to achieve purging.

[0059] S23: The miniature pressure sensor samples once every 100ms and calculates the pressure drop slope (k). p =ΔP / Δt, where ΔP represents the pressure difference between two adjacent samples, and Δt represents the time difference (Δt = 100 ms); the camera updates the uniformity index U every 0.5 s. If U ≥ 0.98 and k p If the pressure is less than 0.1 kPa / s, cleaning is considered complete. Controller 17 resets the parameters of diffuser 7 and restores the deposit in stages. Flow control valve 4 opens at 20% of the initial flow rate. If the pressure fluctuation is less than 5% within 5 seconds, it is gradually increased to full speed. If blockage is triggered repeatedly within 30 seconds, a fault code is recorded and manual inspection is prompted.

[0060] S3: A miniature pressure sensor and a high-speed camera monitor the uniformity of particulate material distribution in real time, dynamically adjust pore size parameters to ensure optimal flow under different density requirements, and capture particulate material distribution through the high-speed camera to calculate the uniformity index U.

[0061]

[0062] Where, ρ i Let ρ be the density of the granular material in each region, ρ be the average density, and n be the total number of regions.

[0063] If U < 0.95, increase the aperture of the low-density region and decrease the moving speed of diffuser 7;

[0064] Diffuser 7 uses multi-parameter PID control to adjust the uniformity of particulate material, controlling the opening degree u(t) of valve 6. The core control equation is:

[0065]

[0066] Where e(t) is the deviation between the set value and the actual value, K pK i and K d Let K represent the proportional, integral, and differential coefficients, respectively. p =0.5, K i =0.1, K d =0.2;

[0067] Intelligent step size calculation: Input parameters: diffuser 7 area A, target dry weight γ d Formulas for calculating the bottom area S of test chamber 8, deposition time T, and step size L: The diffuser 7 is moved in steps L by a linear bearing, Q target The target flow rate is dynamically set by controller 17 based on deposition parameters.

[0068] S4: Actuator 11 is mounted on two crossbars connected to linear bearings. Actuator 11 is a linear actuator used to move diffuser 7. Temperature and humidity sensor 14 collects the moisture content of the granular material, resistivity probe collects resistivity, and triaxial sensor 13 simultaneously measures cone tip resistance, sidewall friction, and tilt angle. Linear actuator 11 dynamically adjusts the penetration rate through a PID algorithm and compensates for changes in granular material resistance in real time. The speed v(t) of linear actuator 11 is dynamically adjusted through a PID algorithm.

[0069]

[0070] Where, e(t) = v target -v current e(t) is the error signal, representing the difference between the setpoint (target value) and the actual value (current value), v target This is represented as the target speed (set value), which is dynamically set by controller 17 according to test requirements. curren The current actual speed is calculated by measuring the depth difference using potentiometer 12, K. p K i and K d Let K represent the proportional, integral, and differential coefficients, respectively. p =1.2,K i =0.3,K d =0.5, This represents the rate of change of error over time.

[0071] S5: Controller 17 optimizes particulate material flow rate, humidity, and model compaction through algorithms, and analyzes the relationship between historical CPT data and particulate material density using machine learning algorithms to predict optimal deposition parameters.

[0072] Resistance mutation detection: If (where dq) cThe cone tip resistance is expressed as the rate of change over time (dt represents the time interval), triggering emergency stop protection, retracting the cone by 5mm, and re-entering; temperature and humidity compensation: q is corrected according to temperature / humidity. c and f s : Where α = 0.005, and T ref As a reference temperature, q is set according to experimental standards. c The initial cone tip resistance is represented by T, and the current temperature is represented by °C.

[0073] S6: The test chamber 8 is placed on four button-type weighing sensors 9 to continuously measure the amount of deposited sand;

[0074] S7: After the test, the sand suction device 15 will draw the granular material into the hopper 1 through the hose 16.

[0075] Therefore, this invention employs the aforementioned apparatus and method for preparing and testing uniformly layered granular materials with different densities. By setting up a diffuser and embedding a variable-diameter porous plate structure composed of shape memory alloy inside the diffuser, the variable-diameter porous plate structure moves up and down under the action of micro-rails, precisely controlling the deposition intensity and ensuring uniform flow of the granular material in layers to meet the requirements of different densities. Furthermore, by integrating a micro-pressure sensor and a high-speed camera at the diffuser outlet, the uniformity of the granular material distribution is monitored in real time. By calculating the uniformity index and dynamically adjusting the pore size parameters, the optimal flow state under different density requirements is ensured, guaranteeing uniform distribution of the granular material. Uniformity; by integrating multiple sensors through a micro CPT device, a temperature and humidity sensor collects the moisture content of the granular material, a resistivity probe collects the resistivity, and a triaxial sensor simultaneously measures the cone tip resistance, sidewall friction resistance, and tilt angle, it realizes in-situ detection of multi-dimensional characteristics of the granular material, and comprehensively understands the quality and characteristics of the granular material; the controller is connected to the diffuser, temperature and humidity sensor, and triaxial sensor, and optimizes the flow rate, humidity, and model compaction degree of the granular material through algorithms. It uses machine learning algorithms to analyze the relationship between historical CPT data and granular material density, predicts the optimal deposition parameters, realizes automated control, improves experimental accuracy and efficiency, and reduces human operation errors.

[0076] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the technical solutions of the present invention, and these modifications or equivalent substitutions cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A device for preparing and testing the quality of stratified uniform granular materials with different densities, characterized in that: It includes a receiving container mounted on an inner support frame, which is connected to a diffuser via a control valve. The bottom of the diffuser is located inside the test chamber. A miniature CPT device is installed between the diffuser and the inner support frame. The top of the receiving container is connected to a hopper via a flexible hose. One end of the hose is located on the top of the hopper, and the other end is connected to a sand suction device, which is located inside the test chamber. The hopper is mounted on the top of an outer support frame via a fixed frame. The test chamber is connected to the bottom of the outer support frame via a weighing sensor. The diffuser has a perforated plate inside, which is a variable diameter structure made of embedded shape memory alloy. The perforated plate is set on a micro slide rail, and a rotatable nozzle motor is set at the bottom of the micro slide rail. The rotatable nozzle motor is connected to the rotatable nozzle, and the rotation angle of the rotatable nozzle is set to 0-45°. The rotatable nozzle motor and the micro motor are symmetrically arranged, and the micro motor is connected to the vibrating plate. The miniature CPT device includes a miniature CPT motor and an actuator located below the miniature CPT motor. A temperature and humidity sensor is located at the bottom of the actuator. A triaxial sensor is located between the temperature and humidity sensor and the potentiometer. Both the potentiometer and the triaxial sensor are located on the actuator. A resistivity probe is also embedded in the potentiometer. A power supply box and a controller are respectively installed on both sides of the external support frame. The controller is connected to the diffuser, temperature and humidity sensor and triaxial sensor. A miniature pressure sensor and a high-speed camera are integrated at the outlet of the diffuser; The controller optimizes the flow rate, humidity, and compaction degree of particulate material through algorithms, and analyzes the relationship between historical CPT data and particulate material density through machine learning algorithms to predict the optimal deposition parameters.

2. The apparatus for preparing and testing quality of layered uniform granular materials with different densities as described in claim 1, characterized in that: A gate valve is installed at the end of the flexible hose near the hopper, and a flow control valve is installed at the end near the receiving container.

3. The detection method of the apparatus for preparing and detecting the quality of layered uniform granular materials with different densities according to any one of claims 1-2, characterized in that: Includes the following steps: S1: The hopper discharges granular material into the receiving container through a flexible hose, and the flow rate of the granular material is controlled by a gate valve and a flow control valve. S2: The particulate material in the receiving container enters the diffuser through the control valve. A perforated plate is installed above the control valve to ensure that the particulate material flows in layers and uniformly. The perforated plate in the diffuser is set as a variable diameter mesh structure composed of embedded shape memory alloy. The perforated plate moves up and down under the action of micro slide rails to control the deposition intensity. The vibrating plate peels off the adhering particulate material through high-frequency vibration. The outlet of the diffuser integrates a micro pressure sensor and a high-speed camera to set a timed cleaning program. If it is blocked, an emergency cleaning mode is triggered. S3: A miniature pressure sensor and a high-speed camera monitor the uniformity of particulate material distribution in real time, dynamically adjust pore size parameters to ensure optimal flow under different density requirements, and capture particulate material distribution through the high-speed camera to calculate the uniformity index U. ； in, For the density of granular materials in each region, U is the average density, and n is the total number of regions. If U < 0.95, increase the aperture of the low-density region and decrease the diffuser moving speed. S4: The actuator is mounted on two crossbars connected to linear bearings to move the diffuser. A temperature and humidity sensor collects the moisture content of the granular material, a resistivity probe collects the resistivity, and a triaxial sensor simultaneously measures the cone tip resistance, sidewall friction, and tilt angle. The actuator dynamically adjusts the penetration rate using a PID algorithm and compensates for changes in granular material resistance in real time. The actuator speed v(t) is dynamically adjusted using a PID algorithm. ； Where, e(t) = v target -v current e(t) is the error signal, representing the difference between the set value and the actual value, v target Indicates the set speed, v curren K represents the current actual speed. p K i and K d Let K represent the proportional, integral, and differential coefficients, respectively. p =1.2, K i =0.3, K d =0.5, This represents the rate of change of error over time. S5: The controller optimizes particulate material flow rate, humidity, and model compaction through algorithms, and analyzes the relationship between historical CPT data and particulate material density using machine learning algorithms to predict optimal deposition parameters. Resistance mutation detection: If , This represents the rate of change of the cone tip resistance over time. Indicates a time interval, triggers emergency stop protection, retracts the cone by 5mm, and re-inserts; Temperature and humidity compensation: corrects q according to temperature / humidity. c and f s : Where α = 0.005, in the formula For reference temperature, q c This represents the original cone tip resistance, and T represents the current temperature; S6: The test chamber is placed on four button-type weighing sensors to continuously measure the amount of deposited sand; S7: After the test, the sand suction device will extract the granular material into the hopper through the hose.

4. The detection method of the device for preparing and detecting quality of layered uniform granular materials with different densities as described in claim 3, characterized in that: In step S2, the specific steps for triggering the emergency cleaning mode are as follows: S21: The triggering mechanism is based on multi-sensor collaborative judgment. The miniature pressure sensor integrated at the diffuser outlet monitors the pressure value in real time. When the pressure exceeds the dynamic threshold and lasts for 2 seconds, it is initially judged as a blockage. If the flow rate of the particulate material fed back by the flow control valve is lower than 70% of the set value, the high-speed camera analyzes the image through a convolutional neural network and detects a local density standard deviation σ > 0.15ρ. av This triggers a dual confirmation mechanism, allowing you to manually activate the emergency mode via the controller interface. S22: Cleaning operations are divided into three levels of strategy: basic cleaning, intermediate cleaning and advanced cleaning; After the controller closes the control valve and flow control valve, it stops the conveying of granular materials, starts the sand suction device to pull back the undeposited particles to the hopper, and enters the primary cleaning stage. The micro motor drives the vibrating plate to vibrate at high frequency to peel off the tiny adhering particles. If the initial cleaning does not meet the standard and the uniformity index U < 0.9, it is upgraded to intermediate cleaning. The shape memory alloy is heated by electricity, the aperture of the perforated plate shrinks, and the servo motor drives the perforated plate to reciprocate to remove stuck large particles. If the blockage is still not cleared, activate advanced cleaning, which uses a rotating nozzle motor to drive the rotating nozzle to spray compressed air for cleaning. S23: Dynamic feedback and optimization, miniature pressure sensor samples once every 100ms, calculates the pressure drop slope: ； in, This represents the pressure difference between two adjacent samples. Indicates time difference, At that time, the camera updates the uniformity index U every 0.5 seconds. If U ≥ 0.98 and k p If the pressure is less than 0.1 kPa / s, cleaning is considered complete. The diffuser parameters are then reset, and the deposition is restored in stages. If the blockage is triggered repeatedly within 30 seconds, the fault code will be recorded and a manual inspection will be requested.

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