Slurry sand content detection system based on ultrasonic attenuation and optical image bimodal fusion

Abstract

The invention discloses a slurry sand content detection system based on ultrasonic attenuation and optical image bimodal fusion, which is characterized by comprising a middle connecting pipe, a detection pipeline, an ultrasonic detection unit, an optical image acquisition unit, a diffuse reflection light source, an illumination sensor, a steady flow pump, a data processing module and a fusion early warning module. The method solves the problems of detection lag, insufficient precision, incapability of real-time monitoring and the like in the existing method for detecting the sand content of the slurry.

Description

Technical Field

[0001] This invention belongs to the field of intelligent sensing technology, specifically relating to a device and method for detecting the sand content of mud based on dual-modal fusion of ultrasonic attenuation and optical image. Background Technology

[0002] In pile foundation construction, drilling mud serves as a crucial medium for borehole wall protection and borehole stability, and its performance directly impacts pile quality and construction safety. The sand content of the drilling mud is a key parameter; excessively high sand content can lead to increased borehole wall friction, mud instability, and even borehole collapse, while excessively low sand content may affect the mud's wall protection and suspension capacity. Therefore, accurate and timely monitoring of the sand content in the drilling mud is one of the core aspects of ensuring construction quality.

[0003] Currently, the commonly used methods for detecting sand content in mud are sieving and sedimentation. Sieving requires manual sampling; the mud sample is separated through a sieve, washed, dried, and then weighed to calculate the sand content. Sedimentation utilizes the density difference between sand and mud particles, obtaining the sand ratio through natural settling or centrifugal separation. While these methods can theoretically reflect sand content, they all have significant limitations.

[0004] First, these testing methods rely on manual operation, requiring steps such as sampling, cleaning, drying, and weighing, which are complex and time-consuming. A single test typically takes tens of minutes or even longer, failing to meet the "real-time monitoring and rapid response" requirements of construction sites. Especially in large-scale pile foundation construction, where mud circulation changes frequently, delayed test results often cannot promptly guide on-site adjustments.

[0005] Secondly, traditional methods lack precision in highly turbid or fine-particle mixed mud environments. Because sand and mud particles are similar in size, and silt and other transitional particles are often present in the mud, traditional physical separation methods struggle to accurately distinguish them, leading to significant errors in test results. Particularly when the fine particle content is high, the sand content is easily underestimated, potentially causing engineering quality risks.

[0006] In summary, existing methods for detecting sand content in mud generally suffer from problems such as detection lag, limited accuracy, poor real-time performance, and insufficient environmental adaptability, making it difficult to meet the urgent needs of modern pile foundation construction for efficient and intelligent detection. Therefore, there is an urgent need to propose a new sand content detection technology that can combine the advantages of multiple detection methods to achieve real-time online monitoring, improved accuracy, and adaptability to complex environments, in order to ensure the safety and quality of pile foundation construction. Summary of the Invention

[0007] This invention proposes a mud sand content detection system based on dual-modal fusion of ultrasonic attenuation and optical image, which solves the problems of detection lag, insufficient accuracy and inability to monitor in real time in existing mud sand content detection methods.

[0008] The present invention is achieved through the following technical solution.

[0009] A mud sand content detection system based on dual-modal fusion of ultrasonic attenuation and optical imaging, characterized in that it comprises: The intermediate connecting pipe is detachably connected in series to the construction mud circulation pipeline; The detection pipeline has an inlet that is connected to the bottom of the upstream end of the intermediate pipe, and transparent windows are symmetrically arranged on the upper and lower sides of the detection pipeline. An ultrasonic detection unit, wherein the ultrasonic detection module is installed on the detection pipeline, is used to emit ultrasonic waves into the mud in the feed pipe, and collect the initial ultrasonic signal and the attenuated ultrasonic signal before and after propagation through the mud and send them to the data processing unit. An optical image acquisition unit is provided, which is positioned facing a transparent window, and is used to acquire images of mud flow within the detection pipeline and send them to a data processing unit. A diffuse reflection light source is arranged around the optical image acquisition unit to provide constant illumination to the transparent window; A light sensor is positioned on the other side of the transparent window relative to the diffuse reflection light source. It is used to collect the light intensity value of the light from the diffuse reflection light source after it passes through the mud in the detection pipeline and send it to the data processing unit. A constant flow pump is installed on the detection pipeline to pump the mud conveyed in the intermediate pipe into the detection pipeline at a constant flow rate. The data processing module includes: a function for analyzing and comparing the initial ultrasonic signal and the attenuated ultrasonic signal to obtain the change in ultrasonic characteristic parameters after the ultrasonic signal propagates through the mud, and calculating the first mud sand content P1 based on the relationship model between the change in ultrasonic characteristic parameters and the mud sand content; a function for obtaining the light intensity value and calculating the mud turbidity F based on the attenuation rate of the light intensity value; and a function for obtaining a mud flow image, performing image preprocessing on the mud flow image, identifying and marking sand particles in the mud flow image, and analyzing the area ratio of sand particles in the mud flow image to calculate the second mud sand content P2. The data fusion module includes a data fusion module for weighted fusion of the first mud sand content P1 and the second mud sand content P2 based on the mud turbidity F, to calculate the final mud sand content P3; and for comparing the final mud sand content P3 with the preset mud sand content P0, and if P3 is greater than P0, issuing an alarm message to the construction control center.

[0010] Preferably, the detection pipeline has an optical image acquisition section with a rectangular cross-section, and a transparent window is disposed on the optical image acquisition section.

[0011] Preferably, the mud turbidity F is calculated as follows: F = (L0 - L1) / L0, where L1 is the attenuated illuminance value, that is, the illuminance value after the diffuse reflection light source passes through the mud in the detection pipeline when mud is being transported in the detection pipeline, in lx; L0 is the initial illuminance value, that is, the illuminance value after the diffuse reflection light source passes through the clean water in the detection pipeline when clean water is being transported in the detection pipeline, in lx.

[0012] Preferably, the method for calculating the sand content P2 of the second mud is as follows: P 2= S1 / S0; where: S1 is the area of ​​sand particles larger than 200 mesh in the mud flow image, in cm². 3 S0 represents the area of ​​the mud flow image, in cm². 3 .

[0013] More preferably, when calculating the second mud sand content P2, the data processing module further includes classifying and marking the sand particles into true sand particles and pseudo sand particles based on their morphological characteristics, and then analyzing the area ratio of true sand particles in the mud flow image to calculate the second mud sand content P2; in this case, the calculation method for the second mud sand content P2 is: P 2= S1' / S0; where: S1' is the area of ​​true sand particles with a diameter greater than 200 mesh in the mud flow image, in cm². 3 S0 represents the area of ​​the mud flow image, in cm². 3 .

[0014] Preferably, the final mud sand content P3 is calculated as follows: P3 = (F × P1) + (1 - F) × P2, where the mud turbidity F is a percentage value.

[0015] Preferably, the system of the present invention further includes a model building module, which includes: a module for inputting the relationship model between ultrasonic characteristic parameters and mud sand content and sending it to the data processing module; and a module for analyzing the changes in ultrasonic characteristic parameters of the mud ultrasonic signal before and after propagation through the mud based on a mud sample with a known sand content, and for creating or updating the relationship model between ultrasonic characteristic parameters and mud sand content.

[0016] More preferably, the ultrasonic characteristic parameters include ultrasonic attenuation amplitude, ultrasonic phase change, and ultrasonic scattering intensity.

[0017] Preferably, the system of the present invention further includes: A mud transfer box, wherein an overflow vent is provided on the top side of the mud transfer box, and the discharge port of the detection pipeline is connected to the mud transfer box; A return pipe is provided, with one end extending to the bottom of the mud transfer box and the other end connected to the bottom of the downstream end of the intermediate pipe. A return pump is installed on the return pipe.

[0018] Preferably, the system of the present invention further includes: A mud supply chamber, the top of which is open and connected to the bottom of the upstream end of the central pipe, and the inlet of the detection pipeline is connected to the bottom of the mud supply chamber. The mixing assembly includes a rotating shaft with one end rotatably connected to the top of the central pipe and the other end extending into the mud supply chamber. The rotating shaft is connected to mixing blades and driving blades at the mud supply chamber and the central pipe, respectively.

[0019] Compared with the prior art, the beneficial effects of the present invention are as follows: 1) Detection accuracy has been significantly improved This invention integrates ultrasonic testing and optical image recognition. Ultrasonic signals have strong anti-interference capabilities and can quickly reflect particle concentration, while image recognition can accurately distinguish between sand and clay particles. The fusion of these two methods significantly improves detection accuracy, controlling the sand content detection error to within ±2%, thus meeting the high-precision testing requirements of pile foundation construction.

[0020] 2) Real-time online monitoring This invention employs a pipeline-type detection structure, which can be directly installed in the construction mud circulation system without affecting the normal circulation and transportation of the mud, enabling real-time online monitoring of sand content. Compared with traditional laboratory testing, this invention eliminates cumbersome steps such as sampling, drying, and weighing, significantly shortening the testing cycle from tens of minutes to seconds, and providing immediate data support for construction sites.

[0021] 3) High level of intelligence and visualization The detection data of this invention can be transmitted to the monitoring terminal in real time, and the sand content and dynamic changes of the mud can be intuitively displayed through a visual interface, facilitating quick understanding and decision-making by construction personnel. Simultaneously, the system has an intelligent early warning function, which can promptly alarm when the sand content exceeds the limit, preventing borehole collapse or pump blockage accidents caused by abnormal mud quality, thus improving construction safety.

[0022] 4) High promotional value This invention's system possesses excellent compatibility and portability, enabling its widespread application in various pile foundation construction projects, including railways, highways, municipal works, and building construction. Its results can be integrated with existing construction monitoring platforms to promote the intelligent and information-based upgrading of construction monitoring, demonstrating significant industrialization and application value.

[0023] In summary, this invention is superior to existing technologies in terms of detection accuracy, real-time performance, environmental adaptability, intelligence, and scalability. It can effectively improve the quality and efficiency of pile foundation construction and has significant technological advancements and broad application prospects. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the main structure of the present invention; Figure 2 for Figure 1 Cross-sectional view at point AA; Figure 3 This is the main view of the invention (part of the casing is omitted); Figure 4 This is a three-dimensional structural diagram of the optical image acquisition section in this invention; Figure 5 This is a state diagram when the present invention is in use; Figure 6 This is a schematic diagram of the system of the present invention; The meanings of the labels in the above figures are as follows: central pipe 1, detection pipe 2, transparent window 201, optical image acquisition section 202, ultrasonic detection unit 3, optical image acquisition unit 4, steady flow pump 5, return pipe 6, return pump 601, diffuse reflection light source 7, mud supply chamber 8, mixing assembly 9, rotating shaft 901, mixing blade 902, drive blade 903, light sensor 10, construction mud circulation pipe 11, mud transfer box 12, overflow vent 1201, supply pipe 13, casing 14, ventilation grille 15. Detailed Implementation

[0025] The present invention will be further described below with reference to the accompanying drawings and specific embodiments. It should be noted that the following embodiments are merely illustrative examples of the present invention, and the scope of protection of the present invention is not limited thereto. The described embodiments are only some embodiments of the present invention, 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. Example 1

[0026] This embodiment provides a mud sand content detection system based on dual-modal fusion of ultrasonic attenuation and optical imaging. Please refer to [link to relevant documentation]. Figures 1 to 6 It includes: The intermediate connecting pipe 1 is detachably connected in series to the construction mud circulation pipeline 11. The intermediate connecting pipe 1 is made of stainless steel to improve its durability. Both ends of the intermediate connecting pipe have quick-connect interfaces, such as flange interfaces and socket interfaces, to facilitate the installation of the intermediate connecting pipe on the construction mud circulation pipeline 11. The size and specifications of the intermediate connecting pipe 1 match the mainstream pipe size of the construction mud circulation pipeline 11. In use, the intermediate connecting pipe 1 is connected in series to the construction mud circulation pipeline 11, and the posture of the intermediate connecting pipe 1 is adjusted to keep it in a horizontal state so that the upstream and downstream construction mud circulation pipelines 11 are connected, so as not to affect the normal circulation and transportation of mud. The detection pipeline 2 has its inlet connected to the bottom of the upstream end of the intermediate pipe 1. Transparent viewing windows 201 are symmetrically arranged on both the upper and lower sides of the detection pipeline 2. The detection pipeline 2 is made of stainless steel or wear-resistant composite material, possessing corrosion and wear resistance properties. Its internal flow channels are optimized for fluid dynamics to ensure uniform slurry flow velocity within the cavity, reducing the impact of sedimentation or eddies on detection accuracy. To minimize the impact of the detection pipeline 2 on the normal slurry transport of the intermediate pipe 1, the cross-sectional area of ​​the flow channel of the detection pipeline 2 is controlled to be approximately one-tenth of the cross-sectional area of ​​the flow channel of the intermediate pipe 1. To improve detection stability... Qualitatively, the detection pipeline 2 is parallel to the central pipe 1; the transparent window 201 is circular or square in shape and is made of high-strength, high-transparency, and wear-resistant glass. It is symmetrically arranged on the upper and lower sides of the detection pipeline 2, thus forming a clear view; in use, a small part of the mud in the central pipe 1 is diverted and transported to the detection pipeline 2 at a constant flow rate by the constant flow pump 5. When the mud flows to the position of the transparent window 201, the diffuse reflection light source 7 can pass through the transparent window 201 and the mud and project onto the light sensor 10, so that the optical image acquisition unit 4 can acquire the mud flow image when the mud flows to the transparent window 201; The ultrasonic detection unit 3, which is installed on the detection pipeline 2, is used to emit ultrasonic waves into the mud in the feed pipe 201 and collect the initial ultrasonic wave signal and the attenuated ultrasonic wave signal before and after propagation through the mud, and send them to the data processing unit. The ultrasonic detection unit 3 can generate ultrasonic waves with a frequency of 100–500 kHz, preferably 200 kHz, and an ultrasonic power of 100–500 W to ensure the penetration intensity and resolution of the ultrasonic waves. The ultrasonic detection unit 3 is also equipped with a temperature compensation function to avoid the influence of mud temperature changes on the measurement. An optical image acquisition unit 4 is positioned facing the transparent window 201 to acquire images of the mud flow within the detection pipeline 2 and send them to the data processing unit. The optical image acquisition unit 4 uses a high-speed industrial camera with a resolution of 10 megapixels or higher and is equipped with a high-magnification microscope lens to enable it to identify sand particles larger than 74 μm in the flowing mud. At the same time, the optical image acquisition unit 4 should have high temperature resistance, dustproof and shock resistance, and be able to work stably in harsh environments such as outdoors. A diffuse reflection light source 7 is arranged around the optical image acquisition unit 4 to provide constant illumination to the transparent window 201; preferably, the diffuse reflection light source 7 is a white LED diffuse reflection light source that can provide an illumination intensity of 200-300 lux. The light sensor 10 is positioned on the other side of the transparent window 201 opposite to the LED diffuse reflection light source 7. It is used to collect the light intensity value after the light from the diffuse reflection light source 7 passes through the mud in the detection pipe 2 and send it to the data processing unit. The light sensor 10 is an industrial-grade light sensor with an accuracy of ±2% and is equipped with a temperature compensation function. A constant flow pump 5 is installed on the detection pipeline 2 and is located upstream of the ultrasonic detection unit 3 and the optical image acquisition unit 4. It is used to pump the mud conveyed in the central pipe 1 into the detection pipeline 2 at a constant flow rate. The data processing module is communicatively connected to the ultrasonic detection unit 3, the light sensor 10, the optical image acquisition unit 4, and the fusion early warning module. The data processing unit includes: functions for analyzing and comparing the initial ultrasonic signal and the attenuated ultrasonic signal to obtain the change in ultrasonic characteristic parameters after the ultrasonic signal propagates through the mud, and calculating the first mud sand content P1 based on the relationship model between the change in ultrasonic characteristic parameters and the mud sand content; functions for obtaining the light intensity value and calculating the mud turbidity F based on the attenuation rate of the light intensity value; and functions for acquiring mud flow images, performing image preprocessing such as denoising, enhancement, binarization, and edge detection to eliminate background interference, then identifying and marking sand particles in the mud flow image, analyzing the area ratio of sand particles in the mud flow image, and calculating the second mud sand content P2. The data fusion module includes a data fusion module for weighted fusion of the first mud sand content P1 and the second mud sand content P2 based on the mud turbidity F, to calculate the final mud sand content P3; and for comparing the final mud sand content P3 with the preset mud sand content P0, and if P3 is greater than P0, issuing an alarm message to the construction control center.

[0027] Furthermore, in a preferred embodiment, the system of the present invention further includes a data storage unit and a display unit; the data storage unit is used to store the first mud sand content P1, the mud turbidity F, the second mud sand content P2, and the final mud sand content P3, and the display unit is used to display the first mud sand content P1, the mud turbidity F, the second mud sand content P2, and the final mud sand content P3; wherein, the data storage unit and the display unit are both communicatively connected to the data processing module and the fusion early warning module.

[0028] Furthermore, in a preferred embodiment, the fusion early warning module further includes a function to generate a dynamic change curve of the final mud sand content P3, and to monitor the dynamic change rate of the mud sand content over a set time. When the dynamic change rate of the mud sand content exceeds a set threshold, an early warning message is sent to the construction control center. For example, for ease of understanding, if the set time for monitoring the dynamic change rate of the mud sand content is once every 0.5 minutes, the set threshold for the dynamic change rate of the mud sand content is -5% to 5%, and the preset mud sand content P0 is 4%, the system monitors the mud sand content at 0.5 minutes... The mud sand content at 1 minute, 1 minute, 1.5 minutes, 2 minutes, and 2.5 minutes were 2.32%, 2.36%, 2.30%, 2.47%, and 2.66%, respectively. The dynamic change rate of mud sand content at 1 minute, 1.5 minutes, 2 minutes, and 2.5 minutes was 1.7%, -2.5%, 7.4%, and 7.7%, respectively. If the dynamic change rate of mud sand content exceeds the set threshold at 2 minutes, the system will issue an early warning to the construction control center to alert the construction personnel that the mud sand content is abnormal and there is a risk of it continuing to rise above the preset mud sand content P0.

[0029] Furthermore, in a preferred embodiment, the ultrasonic detection unit 3 includes a transmitting transducer and a receiving transducer symmetrically arranged on both sides of the detection pipeline 2. The transmitting transducer emits ultrasonic waves into the mud in the detection pipeline 2 at a fixed frequency, and the receiving transducer receives the attenuated ultrasonic waves after propagation in the mud medium.

[0030] Furthermore, in a preferred embodiment, the detection pipeline 2 has an optical image acquisition section 202 with a rectangular cross-section, and a transparent window 201 is disposed on the optical image acquisition section 202; Preferably, the height of the optical image acquisition section 202 is 2-3 mm, and its width is such that the cross-sectional area of ​​the optical image acquisition section 202 is the same as the cross-sectional area of ​​the detection pipe 2, so as to ensure that the flow velocity of the mud remains basically unchanged when it flows through the optical image acquisition section 202. With this structure, when the mud passes through the optical image acquisition section 202, the mud passes through in the form of a thin-layer fluid, which can reduce the probability of the sand particles in the mud being layered, thereby improving the detection accuracy of the second mud sand content P2.

[0031] Furthermore, in a specific implementation scheme, the mud turbidity F is calculated as follows: F = (L0 - L1) / L0, where L1 is the attenuated illuminance value, that is, the illuminance value after the light from the diffuse reflection light source 7 passes through the mud in the detection pipe 2 when mud is being transported in the detection pipe 2, in lx; L0 is the initial illuminance value, that is, the illuminance value after the light from the diffuse reflection light source 7 passes through the clean water in the detection pipe 2 when clean water is being transported in the detection pipe 2, in lx; In the above, when the system of the present invention is initially used, L0 is the preset value of the system of the present invention; after the system of the present invention has been used for a long time, due to the attenuation of the diffuse reflection light source 7 or the change of the light transmittance of the transparent window 201, it is necessary to supply clean water into the detection pipeline 2 to measure and update L0.

[0032] Furthermore, in a specific implementation scheme, the second mud sand content P2 is calculated as follows: P 2= S1 / S0; where: S1 is the area of ​​sand particles larger than 200 mesh in the mud flow image, in cm². 3 S0 represents the area of ​​the mud flow image, in cm². 3 ; Preferably, when calculating the second mud sand content P2, the data processing module further includes classifying and marking the sand particles into true sand particles and pseudo sand particles based on their morphological characteristics, and then analyzing the area ratio of true sand particles in the mud flow image to calculate the second mud sand content P2; in this case, the calculation method for the second mud sand content P2 is: P 2= S1' / S0; where: S1' is the area of ​​true sand particles with a diameter greater than 200 mesh in the mud flow image, in cm². 3 S0 represents the area of ​​the mud flow image, in cm². 3 ; Generally, since the particle size of sand and clay particles in mud is similar, and clay particles are composed of fine silt or silt mixed with silt agglomerates, their morphological characteristics are characterized by continuous serrated outer contours, while sand particles have relatively smooth outer contours; therefore, when the morphological characteristics of sand particles are that their outer contours show continuous serrated edges, they are classified as pseudo-sand particles (i.e., clay particles), otherwise they are true sand particles. Based on the above, this invention analyzes the morphological characteristics of sand particles and classifies them into true sand particles and false sand particles. This avoids the situation where the detection result of the second mud sand content P2 is too high due to the presence of mud particles, thereby improving the detection accuracy of sand content.

[0033] Furthermore, in a specific implementation, the present invention performs weighted fusion of the first mud sand content P1 obtained by ultrasonic detection and the second mud sand content P2 obtained by image recognition method based on mud turbidity F, so as to improve the detection accuracy of mud sand content. The final mud sand content P3 is calculated as follows: P3=F×P1+(1-F)×P2, where mud turbidity F is a percentage value. When the mud turbidity F is high, the large amount of silt and sand in the mud will obscure the mud and sand, thus reducing the recognition accuracy of mud and sand in the mud flow image. Ultrasonic detection does not have this problem. Therefore, when the mud is turbid, the weight of ultrasonic detection, i.e., the first mud sand content P1, should be increased. When the mud turbidity F is low, the content of silt and sand in the mud is low, and the recognition accuracy of mud and sand in the mud flow image is high. At the same time, image recognition can also eliminate the problem of overestimation of detection results caused by mud particles. However, ultrasonic detection cannot overcome this problem. In this case, the weight of optical image recognition, i.e., the second mud sand content P2, should be increased. Based on the above, this invention integrates ultrasonic detection and optical image recognition. Ultrasonic signals have strong anti-interference capabilities and can quickly reflect particle concentration, while image recognition can accurately distinguish between sand particles and mud particles. After the two are integrated, the detection accuracy is significantly improved, and the sand content detection error can be controlled within ±2%, which can meet the high-precision detection requirements of pile foundation construction.

[0034] Furthermore, in a preferred embodiment, the system of the present invention further includes a model building module, which includes: inputting a relationship model between ultrasonic characteristic parameters and mud sand content and sending it to the data processing module; and analyzing the changes in ultrasonic characteristic parameters of a mud sample with a known sand content before and after the ultrasonic signal of the mud sample propagates through the mud, and creating or updating the relationship model between ultrasonic characteristic parameters and mud sand content; specifically, the ultrasonic characteristic parameters include ultrasonic attenuation amplitude, ultrasonic phase change, and ultrasonic scattering intensity; In this invention, the relationship model between ultrasonic characteristic parameters and mud sand content disclosed in the prior art can be entered into the system through the model building module. In order to improve the accuracy of ultra-deep detection, a new model can also be created or the entered model can be updated through the system of this invention. The specific methods are as follows: S1. The mud and sand content of each mud sample is determined by sieving or sedimentation. S2. Each mud sample is transported to the testing pipeline 2. The testing pipeline 2 should be thoroughly cleaned before replacing the mud sample. S3. Collect the initial ultrasonic signal and attenuated ultrasonic signal of each mud sample when it is transported to the detection pipeline 2, and obtain the change of ultrasonic characteristic parameters of each mud sample before and after the mud ultrasonic signal is propagated through the mud. S4. Correspond one-to-one with the changes in the mud and sand content in step S1 and the changes in the ultrasonic characteristic parameters in step S3, and establish a correspondence model using conventional data analysis methods, such as multiple regression analysis and partial least squares method.

[0035] Furthermore, in a preferred embodiment, the system of the present invention further includes: The mud transfer box 12 has an overflow vent 1201 on one side of its top, and the discharge port of the detection pipeline 2 is connected to the mud transfer box 12. Return pipe 6, one end of which extends to the bottom of mud transfer box 12 and the other end is connected to the bottom of the downstream end of central pipe 1. Return pump 601 is installed on return pipe 6. Based on the above structure, the mud in the central pipe 1 will flow into the mud transfer box 12 after being transported to the testing pipeline 2 for testing. Finally, it will be transported back to the central pipe 1 through the return pump 601 and the return pipe 6 and returned to the construction mud circulation pipeline 11, thereby preventing mud waste and avoiding direct discharge of mud that would pollute the construction site. Preferably, a discharge level sensor is installed inside the mud transfer tank 12. The discharge level sensor is electrically connected to the return pump 601. When the discharge level sensor detects that the mud stored in the mud transfer tank 12 has reached the preset level, the return pump 601 is started to pump the mud in the mud transfer tank 12 back to the central pipe 1.

[0036] When the mud flow rate in the construction mud circulation pipeline 11 is small, the mud cannot be kept full in the intermediate pipe 1, and the flow stabilizing pump may experience dry running, making it difficult to ensure a continuous mud supply to the detection pipeline 2. Therefore, real-time continuous monitoring of the mud sand content cannot be achieved. To overcome the above problems, in a preferred embodiment, the system of the present invention further includes: The mud supply chamber 8 has an opening at the top and is connected to the bottom of the upstream end of the central pipe 1. The inlet of the detection pipe 2 is connected to the bottom of the mud supply chamber 8. The stirring assembly 9 includes a rotating shaft 901 with one end rotatably connected to the top of the central pipe 1 and the other end extending into the mud supply chamber 8. The rotating shaft 901 is connected to stirring blades 902 and driving blades 903 at the positions of the mud supply chamber 8 and the central pipe 1, respectively. Based on the above structure, when the mud transport volume in the construction mud circulation pipeline 11 is small, the mud will collect in the mud supply chamber 8, thereby ensuring a continuous mud supply in the detection pipeline 2. In addition, when the mud flows in the central pipe 1, it will drive the drive blade 903 to rotate. The drive blade 903 drives the stirring blade 902 to rotate in the mud supply chamber 8 through the rotating shaft 901, thereby realizing continuous stirring of the mud stored in the mud supply chamber 8, so as to prevent the mud and sand in the mud from depositing and causing uneven mud and affecting the detection accuracy. Preferably, a supply pipe 13 is connected to the top of one side of the mud supply chamber 8, and a valve is provided on the supply pipe 13. With this structure, the valve can be opened to supply clean water into the mud supply chamber 8 through the supply pipe 13, so as to measure and update the initial illuminance value L0, or to clean the detection pipeline 2. To improve the cleaning effect, a cleaning fluid can be used instead of clean water. In addition, when using the model building module to build or update the relationship model between ultrasonic characteristic parameters and mud sand content, sample mud can be supplied into the mud supply chamber 8 through the supply pipe 13. Preferably, a feed level sensor is installed in the mud supply chamber 8. When the feed level sensor is electrically connected to the flow stabilizer pump 5, and the feed level sensor detects that the mud stored in the mud supply chamber 8 has reached the preset level, the flow stabilizer pump 5 starts to pump the mud in the mud supply chamber 8 to the detection pipeline 2.

[0037] Furthermore, in a preferred embodiment, the system of the present invention further includes: a housing 14; the housing 14 is detachably covered at the bottom of the central pipe 1, and the detection pipe 2, the mud supply chamber 8 and the mud transfer box 12 are all installed inside the housing 14; a ventilation grille 15 that can be freely opened and closed is provided on one side of the housing 14 to facilitate inspection and maintenance and heat dissipation of the various components inside the housing 14. Example 2

[0038] Based on the mud sand content detection system based on dual-modal fusion of ultrasonic attenuation and optical image provided in Example 1, this example provides its usage method or application principle: S1. Turn off the mud pump on the construction mud circulation pipeline 11, connect the intermediate pipe 1 in series to the construction mud circulation pipeline 11, adjust the attitude of the intermediate pipe 1 to be horizontal, so that the upstream and downstream construction mud circulation pipelines 11 are connected, turn on the mud pump, and the mud flows through the intermediate pipe 1 into the mud supply chamber 8. S2. After the system of the present invention is started, when the feed level sensor in the mud supply chamber 8 detects the level signal, the steady flow pump 5 starts to pump the mud in the mud supply chamber 8 to the detection pipeline 2 at a constant flow rate. The ultrasonic detection unit 3, the optical image acquisition unit 4 and the light sensor 10 continuously collect data in real time and send it to the data processing module. The data processing module calculates the mud turbidity F, the first mud sand content P1 and the second mud sand content P2. The fusion early warning module calculates the final mud sand content P3 and compares the final mud sand content P3 with the preset mud sand content P0. If P3 is greater than P0, an alarm message is sent to the construction control center. The construction personnel can immediately take measures such as cleaning mud, replenishing mud or adjusting circulation to avoid hole collapse or pump blockage caused by abnormal mud sand content. At the same time, the mud pumped out through the detection pipeline 2 is transported to the mud transfer box 12. When the discharge liquid level sensor detects the liquid level signal, the return pump 601 starts to pump the mud in the mud transfer box 12 back to the central pipe 1 and back to the construction mud circulation pipeline 11 to prevent mud waste and avoid direct discharge of mud and pollution of the construction site. S3. After the construction is completed, turn off the mud pump on the construction mud circulation pipeline 11, and send clean water or cleaning fluid into the mud supply chamber 8 through the supply pipe 13. The clean water or cleaning fluid is sent into the detection pipeline 2 through the steady flow pump to clean the detection pipeline 2. When the pipeline is cleaned, the initial illuminance value L0 can be monitored to determine whether the pipeline is thoroughly cleaned. S4. After the pipeline cleaning is completed, turn off the power of the system of the present invention and remove the intermediate connecting pipe 1 from the construction mud circulation pipeline 11.

[0039] As can be seen from the above implementation methods, the system of the present invention is operable and practical in terms of structural design, testing process and data processing method, and can ensure long-term stable operation in the complex environment of pile foundation construction, thereby improving construction quality and efficiency.

Claims

1. A mud sand content detection system based on dual-modal fusion of ultrasonic attenuation and optical imaging, characterized in that, include: The central connecting pipe (1) is detachably connected in series to the construction mud circulation pipeline (11); The detection pipeline (2) has its inlet connected to the bottom of the upstream end of the intermediate pipe (1), and transparent windows (201) are symmetrically arranged on the upper and lower sides of the detection pipeline (2). The ultrasonic detection unit (3) is set on the detection pipeline (2) to emit ultrasonic waves into the mud in the feed pipe (201) and collect the initial ultrasonic signal and the attenuated ultrasonic signal before and after propagation through the mud and send them to the data processing unit. An optical image acquisition unit (4) is arranged facing a transparent window (201) to acquire images of mud flow in the detection pipeline (2) and send them to the data processing unit. A diffuse reflection light source (7) is arranged around the optical image acquisition unit (4) to provide constant illumination to the transparent window (201); Light sensor (10) is positioned on the other side of the transparent window (201) relative to the diffuse reflection light source (7) to collect the light intensity value of the diffuse reflection light source (7) after passing through the mud in the detection pipe (2) and send it to the data processing unit. A constant flow pump (5) is installed on the detection pipeline (2) to pump the mud conveyed in the central pipe (1) into the detection pipeline (2) at a constant flow rate. The data processing module includes: a function for analyzing and comparing the initial ultrasonic signal and the attenuated ultrasonic signal to obtain the change in ultrasonic characteristic parameters after the ultrasonic signal propagates through the mud, and calculating the first mud sand content P1 based on the relationship model between the change in ultrasonic characteristic parameters and the mud sand content; a function for obtaining the light intensity value and calculating the mud turbidity F based on the attenuation rate of the light intensity value; and a function for obtaining a mud flow image, performing image preprocessing on the mud flow image, identifying and marking sand particles in the mud flow image, analyzing the area ratio of sand particles in the mud flow image, and calculating the second mud sand content P2. The data fusion module includes a data fusion module for weighted fusion of the first mud sand content P1 and the second mud sand content P2 based on the mud turbidity F, to calculate the final mud sand content P3; and for comparing the final mud sand content P3 with the preset mud sand content P0, and if P3 is greater than P0, issuing an alarm message to the construction control center.

2. The mud sand content detection system based on dual-modal fusion of ultrasonic attenuation and optical image as described in claim 1, characterized in that, The detection pipeline (2) has an optical image acquisition section (202) with a rectangular cross-section, and a transparent window (201) is set on the optical image acquisition section (202).

3. The mud sand content detection system based on dual-modal fusion of ultrasonic attenuation and optical image as described in claim 1, characterized in that, The calculation method for the mud turbidity F is: F = (L0 - L1) / L0, where L1 is the attenuated illuminance value, that is, the illuminance value after the light from the diffuse reflection light source (7) passes through the mud in the detection pipeline (2) when mud is transported in the detection pipeline (2), and the unit is lx; L0 is the initial illuminance value, that is, the illuminance value after the light from the diffuse reflection light source (7) passes through the clean water in the detection pipeline (2) when clean water is transported in the detection pipeline (2), and the unit is lx.

4. The mud sand content detection system based on dual-modal fusion of ultrasonic attenuation and optical image as described in claim 1, characterized in that, The calculation method for the second mud sand content P2 is as follows: P 2= S1 / S0; Where: S1 is the area of ​​sand particles larger than 200 mesh in the mud flow image, in cm². 3 ; S0 represents the area of ​​the mud flow image, in cm². 3 .

5. The mud sand content detection system based on dual-modal fusion of ultrasonic attenuation and optical image as described in claim 4, characterized in that, When calculating the second mud sand content P2, the data processing module further includes classifying and marking sand particles into true sand particles and pseudo sand particles based on their morphological characteristics, and then analyzing the area ratio of true sand particles in the mud flow image to calculate the second mud sand content P2. The calculation method for the second mud sand content P2 is as follows: P 2= S1' / S0; Where: S1' is the area of ​​true sand particles with a diameter greater than 200 mesh in the mud flow image, in cm². 3 ; S0 represents the area of ​​the mud flow image, in cm². 3 .

6. The mud sand content detection system based on dual-modal fusion of ultrasonic attenuation and optical image as described in claim 1, characterized in that, The final mud sand content P3 is calculated as follows: P3 = (F × P1) + (1 - F) × P2, where the mud turbidity F is a percentage value.

7. The mud sand content detection system based on dual-modal fusion of ultrasonic attenuation and optical image as described in claim 1, characterized in that, It also includes a model building module, which includes: a module for inputting the relationship model between ultrasonic characteristic parameters and mud sand content and sending it to the data processing module; and a module for analyzing the changes in ultrasonic characteristic parameters of the mud ultrasonic signal before and after propagation through the mud based on a mud sample with a known sand content, and for creating or updating the relationship model between ultrasonic characteristic parameters and mud sand content.

8. The mud sand content detection system based on dual-modal fusion of ultrasonic attenuation and optical image as described in claim 7, characterized in that, The ultrasonic characteristic parameters include ultrasonic attenuation amplitude, ultrasonic phase change, and ultrasonic scattering intensity.

9. The mud sand content detection system based on dual-modal fusion of ultrasonic attenuation and optical image as described in claim 1, characterized in that, Also includes: A mud transfer box (12) is provided with an overflow vent (1201) on one side of the top of the mud transfer box (12), and the outlet of the detection pipeline (2) is connected to the mud transfer box (12); The return pipe (6) extends one end to the bottom of the mud transfer box (12) and the other end is connected to the bottom of the downstream end of the central pipe (1). A return pump (601) is installed on the return pipe (6).

10. The mud sand content detection system based on dual-modal fusion of ultrasonic attenuation and optical image as described in claim 1, characterized in that, Also includes: The mud supply chamber (8) has an opening at the top and is connected to the bottom of the upstream end of the central pipe (1). The inlet of the detection pipeline (2) is connected to the bottom of the mud supply chamber (8). The mixing assembly (9) includes a rotating shaft (901) with one end rotatably connected to the top of the central pipe (1) and the other end extending into the mud supply chamber (8). The rotating shaft (901) is connected to a mixing blade (902) and a driving blade (903) at the mud supply chamber (8) and the central pipe (1), respectively.

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