Preparation and quality detection device and detection method for uniformly layered granular materials with different densities

Abstract

The invention discloses a preparation and quality detection device and method for uniformly layered granular materials with different compactness, and belongs to the technical field of geotechnical test equipment.The device comprises a receiving container arranged on an inner supporting frame, the receiving container is connected with a diffuser through a control valve, and a miniature CPT device is arranged between the diffuser and the inner supporting frame; the top of the receiving container is connected with a hopper through a flexible hose, and the hopper is arranged on the top of the outer supporting frame. A porous plate structure in the diffuser is used for controlling the deposition strength, particle distribution is monitored through a micro pressure sensor and a high-speed camera, the aperture is adjusted, multi-dimensional characteristic in-situ detection is achieved by means of multiple sensors of a micro CPT device, and parameters are optimized and optimal deposition parameters are predicted through a controller. According to the preparation and quality detection device and detection method for the layered uniform granular materials with the different compactness, the deposition strength and particle distribution can be accurately controlled, multi-dimensional detection and automatic control are achieved, the test precision and efficiency are improved, and manual errors are reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of geotechnical test equipment, and particularly to a device and a method for preparing and quality detecting different-density stratified uniform granular materials. Background Art

[0002] In laboratory and physical model experiments of geotechnical engineering or granular material engineering, it is extremely difficult to obtain stratified undisturbed sand or other granular sediment samples with different densities, resulting in the common need for reconstructing sand samples or granular materials. Currently, sand sample preparation methods such as vibration method, dry and wet ramming method, and sand rain method coexist. However, the sand rain method has attracted much attention in the field of large-scale dry granular material preparation because it can efficiently produce sand samples with large volume, good stratification uniformity at different densities. With the increasing requirements for test accuracy and efficiency in physical modeling, it is urgent to develop a granular material preparation and property testing system with high automation and excellent performance. Most traditional systems have defects such as cumbersome operation, rough control of deposition parameters, and one-sided test analysis, and are difficult to fully meet the strict requirements of modern geotechnical engineering or granular material engineering physical modeling for accurate research on the quality, stress distribution, and boundary effect of granular materials, seriously restricting the development of scientific research and engineering practice. Traditional CPT test equipment is large in volume and complex in operation, and it is difficult to integrate with an automated granular material preparation system. Most existing laboratory CPT devices rely on manual operation, with low test efficiency, and can only obtain a single mechanical parameter (such as tip resistance), unable to meet the in-situ detection requirements for multi-dimensional characteristics (water content, resistivity) of the sand bed. In addition, the real-time linkage mechanism between test data and the deposition control system is not yet mature, resulting in lag in test optimization. Therefore, it is of great significance to develop a deposition system for different-density stratified granular materials with automated and precise control of flow rate and position. Summary of the Invention

[0003] To solve the above problems, the present invention provides a device and a method for preparing and quality detecting different-density stratified uniform granular materials, aiming to precisely control the deposition intensity and particle distribution by setting structures such as a diffuser, a micro CPT device, and a controller, realize multi-dimensional detection and automated control, improve test accuracy and efficiency, and reduce human error.

[0004] To achieve the above object, the present invention provides a device for preparing and quality detecting different-density stratified uniform granular materials, which includes a receiving container arranged on an inner support frame. The receiving container is connected to a diffuser through a control valve. The bottom of the diffuser is arranged in a test box. A micro CPT device is arranged between the diffuser and the inner support frame. The top of the receiving container is connected to a hopper through a flexible hose. One end of the hose is arranged at the top of the hopper, and the other end is provided with a sand suction device. The sand suction device is arranged in the test box. The hopper is arranged on the top of an outer support frame through a fixing frame. The test box is connected to the bottom of the outer support frame through a weighing sensor.

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

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

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

[0008] Preferably, a gate valve is arranged at one end of the flexible hose close to the hopper, and a flow control valve is arranged at one end close to the receiving container.

[0009] The detection method of the device for preparing and detecting the quality of granular materials with different compactness stratified uniformly includes the following steps:

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

[0011] S2: The granular materials in the receiving container enter the diffuser through the control valve. A perforated plate is installed above the control valve to ensure the uniform stratified flow of the granular materials. The perforated plate in the diffuser is arranged as a variable-diameter mesh structure composed of embedded shape memory alloys. The perforated plate moves up and down under the action of the micro slide rail to control the deposition intensity. The vibrating plate strips the adhered granular materials through high-frequency vibration. A micro pressure sensor and a high-speed camera are integrated at the outlet of the diffuser. A timing cleaning program is set, and if it is blocked, an emergency cleaning mode is triggered;

[0012] S3: The micro pressure sensor and the high-speed camera monitor the uniformity of the distribution of the granular materials in real time, dynamically adjust the aperture parameters, ensure the best flow state under different compactness requirements, capture the distribution of the granular materials through the high-speed camera, and calculate the uniformity index U:

[0013]

[0014] where ρ i is the density of the granular materials in each region, ρ is the average density, and n is the total number of divided regions.

[0015] If U < 0.95, increase the aperture of the low-density area and reduce the moving speed of the diffuser;

[0016] S4: The actuator is installed on two crossbars connected to linear bearings and is used to move the diffuser. The moisture sensor collects the moisture content of the granular material, the resistivity probe collects the resistivity, and the triaxial sensor synchronously measures the tip resistance, sidewall friction resistance, and tilt angle. The actuator dynamically adjusts the penetration rate through the PID algorithm and compensates for the change in the resistance of the granular material in real time. The actuator speed v(t) is dynamically adjusted through the 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 represents the set speed, v curren represents the current actual speed, K p , K i and K d represent the proportional, integral, and derivative coefficients respectively, and are set to K p = 1.2, K i = 0.3, K d = 0.5, represents the rate of change of the error with respect to time;

[0019] S5: The controller optimizes the flow rate, humidity, and model compaction degree of the granular material through algorithms, analyzes the relationship between historical CPT data and the density of the granular material through machine learning algorithms, and predicts the optimal deposition parameters:

[0020] Resistance mutation detection: If dq c represents the rate of change of the tip resistance with respect to time, dt represents the time interval, trigger the emergency stop protection, retract the cone by 5 mm, and re-penetrate; Temperature and humidity compensation: Correct q c and f s : where α = 0.005, in the formula T ref is the reference temperature, q c represents the original tip resistance, and T represents the current temperature;

[0021] S6: The test chamber is placed on four push-button load cells to continuously measure the deposited sand amount;

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

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

[0024] S21: The triggering mechanism is based on multi-sensor collaboration for determination. The micro pressure sensor integrated at the diffuser outlet monitors the pressure value in real time. When the detected pressure exceeds the dynamic threshold and lasts for 2 seconds, it is preliminarily determined as a blockage. If the flow rate of the granular 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 that the local density standard deviation σ > 0.15ρ av , triggering the dual-confirmation mechanism, and manually starting the emergency mode through the controller interface;

[0025] S22: The cleaning operation is divided into three-level strategies: primary cleaning, intermediate cleaning, and advanced cleaning;

[0026] After the controller closes the control valve and the flow control valve, the conveyance of the granular material is paused, and the sand suction device is started to draw back the undeposited particles into the hopper, entering the primary cleaning stage. The vibrating piece is driven by a micro motor to vibrate at a high frequency to peel off the tiny adhered particles;

[0027] If the primary cleaning fails to meet the standard, and the uniformity index U < 0.9, it is upgraded to intermediate cleaning. The shape memory alloy is electrified and heated, the pore diameter of the porous plate shrinks, and the servo motor drives the porous plate to reciprocate to remove the stuck large particles;

[0028] If the blockage is still not removed, advanced cleaning is started, and the rotatable nozzle motor drives the rotatable nozzle to spray compressed air for purging;

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

[0030] k p = ΔP / Δt;

[0031] where, ΔP represents the pressure difference between two adjacent samplings, Δt represents the time difference. When Δt = 100 ms, the camera updates the uniformity index U every 0.5 s. If U ≥ 0.98 and k p <0.1 kPa / s, it is determined that the cleaning is completed, the diffuser parameters are reset, and the deposition is resumed in stages:

[0032] If the blockage is repeatedly triggered within 30 seconds, the fault code is recorded and manual maintenance is prompted.

[0033] Therefore, the present invention adopts the above-mentioned device and detection method for preparing and detecting granular materials with different compactness layers, and has the following beneficial effects:

[0034] (1) By setting a diffuser and embedding 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 a micro slide rail, accurately controlling the deposition intensity, ensuring the uniform flow of granular materials in layers, and meeting the requirements of different compactness layers;

[0035] (2) The present invention integrates a micro pressure sensor and a high-speed camera at the outlet of the diffuser to monitor the uniformity of the granular material distribution in real time. By calculating the uniformity index U, the aperture parameter is dynamically adjusted to ensure the optimal flow state under different compaction degree requirements and guarantee the uniform distribution of the granular material.

[0036] (3) The present invention integrates a variety of sensors through a micro CPT device. The moisture sensor collects the moisture content of the granular material, the resistivity probe collects the resistivity, and the triaxial sensor synchronously measures the tip resistance, sidewall friction resistance and inclination angle, realizing the in-situ detection of multi-dimensional characteristics of the granular material and comprehensively understanding the quality and characteristics of the granular material.

[0037] (4) The present invention connects the controller with the diffuser, the temperature and humidity sensor, the triaxial sensor, etc., and optimizes the flow rate, humidity and model compaction degree of the granular material through algorithms. Using machine learning algorithms to analyze the relationship between historical CPT data and the compaction degree of the granular material, predicting the optimal deposition parameters, realizing automatic control, improving the test accuracy and efficiency, and reducing manual operation errors.

[0038] The technical solution of the present invention will be further described in detail below through the accompanying drawings and embodiments. Description of the Drawings

[0039] Figure 1 It is a schematic structural diagram of a device for preparing and detecting the quality of stratified uniform granular materials with different compaction degrees according to the present invention;

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

[0041] Figure 3 It is a structural diagram inside the diffuser according to the present invention;

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

[0043] Figure 5 It is a schematic structural diagram of the micro CPT device according to the present invention.

[0044] The reference numerals in the drawings are: 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, micro 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, outer support frame; 20, inner support frame; 21, fixing frame; 71, porous plate; 72, rotatable nozzle motor; 73, rotatable nozzle; 74, micro motor; 75, vibrating plate; 76, micro slide rail; 711, shape memory alloy; 712, servo motor. Detailed implementation manners

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

[0046] Unless otherwise defined, the technical terms or scientific terms used in the present invention shall have the ordinary meanings understood by those of ordinary skill in the field to which the present invention belongs. The terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the present application; the terms "including" and "having" and any variations thereof in the specification and the above-mentioned drawings of the present application are intended to cover non-exclusive inclusion.

[0047] Embodiment

[0048] As Figure 1 shown, a device for preparing and quality detecting stratified uniform granular materials with different compactness includes a receiving container 5 arranged on an inner support frame 20. The receiving container 5 is connected to a diffuser 7 through a control valve 6. A perforated plate is installed above the control valve 6 to ensure uniform stratified flow of the granular materials. The bottom of the diffuser 7 is arranged in a test chamber 8. The diffuser 7 and the test chamber 8 are installed on four linear bearings and there is a horizontal actuator, allowing it to travel at different speeds in the horizontal direction and being supported by four vertical actuators to control the movement in the vertical direction. The top of the receiving container 5 is connected to a hopper 1 through a flexible hose 3. A gate valve 2 is arranged at one end of the flexible hose 3 close to the hopper 1, and a flow control valve 4 is arranged at one end close to the receiving container 5. The flow rate of the granular materials is controlled through the gate valve 2 and the flow control valve 4. The hopper 1 is arranged on the top of an outer support frame 19 through a fixing frame 21. The test chamber 8 is connected to the bottom of the outer support frame 19 through a weighing sensor 9 to continuously measure the deposited sand amount. One end of a hose 16 is arranged at the top of the hopper 1, and the other end is provided with a sand suction device 15 which is arranged in the test chamber 8.

[0049] The granular materials in the hopper 1 are transported to the receiving container 5 through the flexible hose 3. The gate valve 2 can cut off or allow the flow of the granular materials, and the flow control valve 4 precisely controls the flow rate of the granular materials entering the receiving container 5, thereby ensuring that the amount of granular materials entering the subsequent device is adjustable and stable. The receiving container 5 is connected to the diffuser 7 through the control valve 6. The perforated plate above the control valve 6 enables the granular materials to flow in a uniform stratified manner when entering the diffuser 7. The test chamber 8 is connected to the bottom of the outer support frame 19 through the weighing sensor 9, and can continuously measure the deposited sand amount in the test chamber 8 to monitor the deposition situation of the granular materials. After the test is completed, the sand suction device 15 extracts the granular materials in the test chamber 8 to the hopper 1 through the hose 16 for recycling and reuse of the granular materials.

[0050] As Figures 2 - 4As shown, a perforated plate 71 is provided inside the diffuser 7. The perforated plate 71 is set as a variable-diameter structure composed of embedded shape memory alloys 711. The shape memory alloys 711 have the two-phase characteristics of austenite and martensite. In the low-temperature martensite phase, the shape memory alloys 711 can be plastically deformed; when heated to the austenite phase transformation temperature, the shape memory alloys 711 restore the preset shape (such as contraction). The shape memory alloys 711 in each grid unit are designed for "shrinkage-expansion" bidirectional action. When energized, an electric current passes through the shape memory alloys 711 to generate Joule heat, and the temperature rises to the austenite phase. The contraction of the shape memory alloys 711 drives the displacement of the grid baffles, and the aperture shrinks. After power-off, it naturally cools to the martensite phase, and the aperture expands. The perforated plate 71 is arranged on the micro slide rail 76, and the perforated plate 71 moves up and down under the action of the micro slide rail 76. The moving distance and speed of the perforated plate 71 are accurately controlled through the servo motor 712, so as to realize the accurate control of the deposition intensity; a rotatable nozzle motor 72 is arranged at the bottom end of the micro slide rail 76. The rotatable nozzle motor 72 is connected to the rotatable nozzle 73. The rotation angle of the rotatable nozzle 73 is set to 0-45°, supporting fan-shaped, annular, and spiral deposition modes. The rotatable nozzle motor 72 and the micro motor 74 are symmetrically arranged. The micro motor 74 is connected to the vibrating plate 75, and the vibrating plate 75 peels off the adhered particulate material through high-frequency vibration.

[0051] The perforated plate 71 inside the diffuser 7 is composed of shape memory alloys 711 to form a variable-diameter structure, which can control the passing amount and passing speed of the particulate material. At the same time, the perforated plate 71 can move up and down on the micro slide rail 76, and the moving distance and speed of the perforated plate 71 can be accurately controlled through the servo motor 712, further realizing the accurate control of the deposition intensity of the particulate material. The rotatable nozzle motor 72 drives the rotatable nozzle 73, enabling the particulate material to be evenly deposited in the test chamber 8 according to different modes.

[0052] As Figure 1 , Figure 5 As shown, a micro CPT device is provided between the diffuser 7 and the inner support frame 20. The micro CPT device includes a micro CPT motor 10 and an actuator 11 arranged below the micro CPT motor 10. A temperature and humidity sensor 14 is arranged at the bottom end of the actuator 11. A three-axis sensor 13 is arranged between the temperature and humidity sensor 14 and the potentiometer 12. Both the potentiometer 12 and the three-axis sensor 13 are arranged on the actuator 11, and a resistivity probe is also embedded in the potentiometer 12. A power supply box 18 and a controller 17 are respectively arranged 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 three-axis sensor 13.

[0053] The temperature and humidity sensor 14 in the micro CPT device monitors the temperature and humidity environment in the test chamber 8 in real time. The resistivity probe embedded in the potentiometer 12 can measure the electrical properties such as the resistivity of granular materials, and the triaxial sensor 13 can synchronously measure the tip resistance, sidewall friction resistance and inclination angle to comprehensively evaluate the mechanical properties of granular materials. These sensors transmit data to the controller 17, enabling a comprehensive understanding of the environmental factors and physical property changes of granular materials during the preparation process, so as to timely adjust the preparation parameters and ensure that the quality and performance of granular materials meet the requirements.

[0054] The detection method of the device for preparing and detecting the quality of granular materials with different compactness and uniform stratification includes the following steps:

[0055] S1: The hopper 1 discharges granular materials into the receiving container 5 through the flexible hose 3, and the flow rate of the granular materials is controlled by the gate valve 2 and the flow control valve 4;

[0056] S2: The granular materials in the receiving container 5 enter the diffuser through the control valve 6. A perforated plate is installed above the control valve 6 to ensure the uniform stratified flow of granular materials. The perforated plate 71 in the diffuser 7 is set as a variable-diameter mesh structure composed of embedded shape memory alloys 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 piece 75 strips the adhered granular materials through high-frequency vibration. A micro pressure sensor and a high-speed camera are integrated at the outlet of the diffuser 7. A timed cleaning program is set. If a blockage occurs, an emergency cleaning mode is triggered. This process realizes fully automated operation through a multi-modal detection and hierarchical cleaning strategy. Specifically:

[0057] S21: The micro pressure sensor integrated at the outlet of the diffuser 7 monitors the pressure value in real time. When it is detected that the pressure exceeds the dynamic threshold and lasts for 2 seconds, it is initially determined as a blockage; if the flow rate of the granular materials fed back by the flow control valve 4 is lower than 70% of the set value, the high-speed camera (integrated at the outlet of the diffuser 7) analyzes the image through the convolutional neural network (CNN) and detects the local density standard deviation (σ > 0.15ρ avg ), triggering a double confirmation mechanism, and manually starting the emergency mode through the controller 17 interface;

[0058] S22: The controller closes the control valve 6 and the flow control valve 4, pauses the conveyance of granular materials, starts the sand suction device 15 to suck back the undeposited particles through the hose 16 into the hopper 1, enters the primary cleaning stage, the micro-motor 74 drives the vibrating plate 75 to vibrate at a high frequency of 200 - 300 Hz, and strips the fine particles (particle size < 0.5 mm) adhering to the surface of the porous plate 71 through the frequency sweeping mode; if the uniformity index U < 0.95 after the primary cleaning, it is upgraded to the intermediate cleaning, the shape memory alloy 711 is energized and heated to the austenite phase at 80 °C, the aperture of the porous plate 71 shrinks by 15%, the servo motor 712 drives the porous plate 71 to reciprocate 3 times along the micro-slide rail 76 at a speed of 5 mm / s to remove the stuck large particles (particle size > 2 mm); if the blockage is still not relieved, start the advanced cleaning, the rotatable nozzle motor 72 switches to the spiral scanning mode, drives the rotatable nozzle 73 to spray compressed air at 0.3 - 0.5 MPa to achieve purging;

[0059] S23: The micro pressure sensor samples once every 100 ms and calculates the pressure drop slope (k p = ΔP / Δt, where ΔP represents the pressure difference between two adjacent samplings, Δt represents the time difference, and Δt = 100 ms); the camera updates the uniformity index U every 0.5 s. If U ≥ 0.98 and k p <0.1 kPa / s, it is determined that the cleaning is completed. The controller 17 resets the parameters of the diffuser 7 and resumes deposition in stages. The flow control valve 4 is opened 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 the blockage is repeatedly triggered within 30 seconds, a fault code is recorded and manual maintenance is prompted;

[0060] S3: The micro pressure sensor and the high-speed camera monitor the uniformity of the granular material distribution in real time, dynamically adjust the aperture parameters to ensure the best flow state under different density requirements, capture the granular material distribution through the high-speed camera, and calculate the uniformity index U:

[0061]

[0062] where ρ i is the density of the granular material in each region, ρ is the average density, and n is the total number of regions divided.

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

[0064] The diffuser 7 adjusts the uniformity of the granular material through multi-parameter PID control. The opening u(t) of the control valve 6, the core control equation is:

[0065]

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

[0067] Intelligent step calculation: Input parameters: area A of the diffuser 7, target dry unit weight γ d , bottom area S of the test box 8, deposition time T. The calculation formula for the step length L is: Drive the diffuser 7 to move in steps of L through a linear bearing, Q target represents the target flow rate, which is dynamically set by the controller 17 according to the deposition parameters.

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

[0069]

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

[0071] S5: The controller 17 optimizes the flow rate, humidity, and model compaction degree of the granular material through algorithms, analyzes the relationship between historical CPT data and the density of the granular material through machine learning algorithms, and predicts the optimal deposition parameters:

[0072] Resistance mutation detection: If (where dq crepresents the change rate of the cone tip resistance with time, dt represents the time interval), trigger the emergency stop protection, retract the cone by 5 mm, and re-penetrate; Temperature and humidity compensation: correct q according to temperature / humidity c and f s : where α = 0.005, and T in the formula ref is the reference temperature, set according to the experimental standard, q c represents the original cone tip resistance, and T represents the current temperature (unit: °C);

[0073] S6: The test chamber 8 is placed on four button-type load cells 9, and the deposited sand amount is continuously measured;

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

[0075] Therefore, the present invention adopts the above device and method for preparing and quality detecting layered uniform granular materials with different compactness. By setting 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 a micro slide rail to accurately control the deposition intensity, ensure the layered uniform flow of the granular material, and meet the requirements of different compactness layers; By integrating a micro pressure sensor and a high-speed camera at the diffuser outlet, the distribution uniformity of the granular material is monitored in real time. By calculating the uniformity index, the aperture parameters are dynamically adjusted to ensure the best flow state under different compactness requirements and ensure the uniform distribution of the granular material; By integrating a variety of sensors in the micro CPT device, the moisture content of the granular material is collected by the temperature and humidity sensor, the resistivity is collected by the resistivity probe, and the cone tip resistance, sidewall friction resistance and tilt angle are synchronously measured by the triaxial sensor, realizing the in-situ detection of multi-dimensional characteristics of the granular material, comprehensively understanding the quality and characteristics of the granular material; The controller is connected to the diffuser, the temperature and humidity sensor and the triaxial sensor, and optimizes the flow rate, humidity and model compaction degree of the granular material through algorithms. Using machine learning algorithms to analyze the relationship between historical CPT data and the compactness of the granular material, predicting the optimal deposition parameters, realizing automatic control, improving the test accuracy and efficiency, and reducing manual 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 are not intended to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that: They can still modify or equivalently replace the technical solutions of the present invention, and these modifications or equivalent replacements cannot make the modified technical solutions 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 by: It includes a receiving container arranged on an inner support frame, the receiving container is connected to a diffuser through a control valve, the bottom of the diffuser is arranged in a test box, a micro CPT device is arranged between the diffuser and the inner support frame, the top of the receiving container is connected to a hopper through a flexible hose, one end of the hose is arranged on the top of the hopper, and the other end is provided with a sand absorber, the sand absorber is arranged in the test box, the hopper is arranged on the top of the outer support frame through a fixed frame, and the test box is connected to the bottom of the outer support frame through a weighing sensor.

2. The device for preparing and testing the quality of stratified uniform granular materials with different densities according to claim 1, characterized in that: A porous plate is arranged inside the diffuser, and the porous plate is arranged as a variable diameter structure composed of an embedded shape memory alloy. The porous plate is arranged on a micro slide rail, and a rotatable nozzle motor is arranged at the bottom end 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 vibration plate.

3. The device for preparing and testing the quality of stratified uniform granular materials with different densities according to claim 1, characterized in that: The micro CPT device includes a micro CPT motor and an actuator arranged below the micro CPT motor. A temperature and humidity sensor is arranged at the bottom of the actuator. A three-axis sensor is arranged between the temperature and humidity sensor and the potentiometer. The potentiometer and the three-axis sensor are both arranged on the actuator. A resistivity probe is also embedded in the potentiometer.

4. The device for preparing and testing the quality of stratified uniform granular materials with different densities according to claim 1, characterized in that: A power box and a controller are respectively arranged on both sides of the outer support frame, and the controller is connected with the diffuser, the temperature and humidity sensor and the three-axis sensor.

5. The device for preparing and testing the quality of stratified uniform granular materials with different densities according to claim 1, characterized in that: A gate valve is arranged at one end of the flexible hose close to the hopper, and a flow control valve is arranged at one end of the flexible hose close to the receiving container.

6. The detection method of the device for preparing and detecting the quality of stratified uniform granular materials with different densities according to any one of claims 1 to 5, characterized in that: The following steps are involved: S1: The hopper discharges the 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 granular material in the receiving container enters the diffuser through the control valve. A porous plate is installed above the control valve to ensure that the granular material flows evenly in layers. The porous plate in the diffuser is set to a variable-diameter mesh structure composed of embedded shape memory alloys. The porous plate moves up and down under the action of a micro-slide to control the deposition intensity. The vibrating plate peels off the adhered granular material through high-frequency vibration. A micro pressure sensor and a high-speed camera are integrated at the outlet of the diffuser to set a timed cleaning program. If it is blocked, the emergency cleaning mode is triggered; S3: Micro pressure sensor and high-speed camera, real-time monitoring of the uniformity of particle material distribution, dynamic adjustment of aperture parameters, to ensure the best flow state under different density requirements, capture the particle material distribution through high-speed camera, calculate the uniformity index U: Among them, ρ i is the density of granular materials in each region, ρ is the average density, n is the total number of divided regions, if U<0.95, increase the aperture of the low-density region and reduce the moving speed of the diffuser; S4: The actuator is mounted on two crossbars connected to linear bearings and is used to move the diffuser. The temperature and humidity sensor collects the moisture content of the granular material, the resistivity probe collects the resistivity, and the triaxial sensor synchronously measures the cone tip resistance, side wall friction and inclination angle. The actuator dynamically adjusts the penetration rate through the PID algorithm and compensates for the change in granular material resistance in real time. The actuator speed v(t) is dynamically adjusted through the PID algorithm: Where e(t) = v target -v current , e(t) is the error signal, which indicates the difference between the set value and the actual value, v target Indicates the set speed, v curren Indicates the current actual speed, K p , K i and K d Represent the proportional, integral and differential coefficients respectively, set to K p =1.2, K i =0.3, K d =0.5, Represents the rate of change of error over time. S5: The controller uses algorithms to optimize the particle material flow rate, humidity, and model compaction degree, and uses machine learning algorithms to analyze the relationship between historical CPT data and particle material density to predict the optimal deposition parameters: Resistance mutation detection: If dq c It indicates the rate of change of cone tip resistance over time, dt indicates the time interval, triggers the emergency stop protection, retracts the cone 5mm, and re-inserts; Temperature and humidity compensation: corrects q according to temperature / humidity c and f s : Where α = 0.005, where T ref is the reference temperature, q c represents the original cone tip resistance, T represents the current temperature; S6: The test chamber is placed on four push-button load cells to continuously measure the amount of deposited sand; S7: After the test, the sand suction device extracts the granular material into the hopper through the hose.

7. The detection method according to the device for preparing and detecting the quality of stratified uniform granular materials with different densities as claimed in claim 6, characterized in that: In step S2, the specific steps of triggering the emergency cleaning mode are as follows: S21: The trigger mechanism is based on multi-sensor collaborative judgment. The micro 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 particle material flow rate fed back by the flow control valve is lower than 70% of the set value, the high-speed camera analyzes the image through the convolutional neural network and detects that the local density standard deviation σ>0.15ρ av , triggering the double confirmation mechanism and manually starting the emergency mode through the controller interface; S22: Cleaning operations are divided into three levels of strategy: primary cleaning, intermediate cleaning and advanced cleaning; After the controller closes the control valve and the flow control valve, the particle material delivery is suspended, and the sand suction device is started to draw back the undeposited particles to the hopper, entering the primary cleaning stage, and the micro-motor drives the vibration plate to vibrate at a high frequency to peel off the tiny sticky particles; If the primary cleaning fails to meet the standard and the uniformity index U<0.9, it is upgraded to the intermediate cleaning. The shape memory alloy is electrically heated, the aperture of the porous plate is shrunk, and the servo motor drives the porous plate to reciprocate to remove the stuck large particles. If the blockage is still not removed, start the advanced cleaning, and the rotatable nozzle motor drives the rotatable nozzle to spray compressed air for cleaning; S23: Dynamic feedback and optimization, the micro pressure sensor samples once every 100ms and calculates the pressure drop slope: k p =ΔP / Δt; Among them, ΔP represents the pressure difference between two adjacent samples, Δt represents the time difference, and when Δt = 100ms, the camera updates the uniformity index U every 0.5s. If U ≥ 0.98 and k p <0.1kPa / s, the cleaning is considered complete, the diffuser parameters are reset, and the deposition is resumed in stages: If the jam is triggered repeatedly within 30 seconds, the fault code will be recorded and a manual maintenance prompt will be given.

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