Pile hole detection device, system and method based on ultrasonic imaging

Abstract

The invention discloses a pile hole detection device, system and method based on ultrasonic imaging. The device comprises a telescopic mechanical arm, multiple sets of telescopic arms radially distributed on the mechanical arm and ultrasonic sensors installed at the tail ends of the telescopic arms, and a mechanical arm driving device drives the multiple sets of telescopic arms to stretch out and draw back. The system comprises a detection device, a central shaft setting assembly, a lifting driving device, a position information acquisition unit, a three-dimensional coordinate correction unit and a data processing terminal. When the detection device and system are used for detecting the pile hole, the telescopic mechanical arm can adjust the probe to be close to the side wall of the pile hole, the propagation distance of ultrasonic waves in mud liquid is reduced, and echo signals are clearer; by adjusting the position of the support, it is ensured that the mechanical arm drives the ultrasonic sensors arranged in an annular array to conduct 360-degree complete coverage scanning on the pile hole along the center axis, and the magnetic north pole sensor and the gyroscope are matched to conduct dynamic correction on three-dimensional coordinates, so that the detection precision and the imaging integrity and reliability are further improved.

Description

Technical Field

[0001] This invention relates to the field of pile hole detection technology, and in particular to an ultrasonic imaging technology that achieves high-precision imaging in a turbid mud slurry environment in pile holes. Background Technology

[0002] In construction engineering, pile foundations are widely used as an important type of foundation. During pile hole construction, quality inspection of the pile holes is crucial, and ultrasonic imaging technology is one of the commonly used inspection methods. However, existing ultrasonic imaging technologies have many problems in the pile hole environment. The space inside a pile hole is usually quite small, which makes ultrasonic waves prone to diffuse reflection during propagation. The chaotic echoes generated by diffuse reflection severely interfere with image quality, resulting in blurred images and low resolution. Simultaneously, the pile hole is filled with turbid mud, a medium that strongly attenuates ultrasonic waves, greatly shortening the propagation distance and weakening the echo signal. This echo signal is also easily masked by diffuse reflection background radiation, further reducing the clarity and accuracy of the image. Current technology struggles to effectively solve these problems and cannot meet the demand for high-precision imaging inspection of pile holes. Summary of the Invention

[0003] To overcome the shortcomings and defects of the existing technology, this invention provides a pile hole detection device, system, and method based on ultrasonic imaging. It aims to solve problems in existing pile hole ultrasonic imaging technology, such as ultrasonic diffuse reflection interference caused by the confined space of the pile hole, and the large attenuation, short propagation distance, and weak echo that is easily masked by turbid mud. This invention achieves clear and accurate imaging of the pile hole sidewall, providing reliable data support for pile hole quality inspection. This invention is achieved through the following scheme: A pile hole detection device based on ultrasonic imaging, comprising, A telescopic robotic arm assembly includes a central rod and multiple sets of telescopic arms arranged radially on the central rod; An ultrasonic testing unit includes ultrasonic sensors installed at the ends of each telescopic arm. A robotic arm drive device is used to drive the extension and retraction of the multiple sets of telescopic arms.

[0004] By adopting the above technical solution, ultrasonic sensors are installed at the end of each telescopic arm. During scanning, the distance between the ultrasonic sensor and the sidewall of the pile hole can be flexibly adjusted by driving the telescopic arm to extend and retract. This allows the ultrasonic sensor to be close to the sidewall of pile holes of different diameters, which can significantly reduce the propagation distance of ultrasonic waves in turbid mud and reduce the attenuation effect of mud on ultrasonic waves, thereby obtaining stronger and clearer echo signals. In addition, the telescopic umbrella frame structure is easy to fold and store, making it convenient to carry and deploy on site.

[0005] As an improvement of the present invention, the telescopic arm includes a first frame and a second frame; one end of the first frame is hinged to the lower part of the central rod, and the other end is fixedly connected to the ultrasonic sensor; a middle ring is slidably sleeved on the central rod, and one end of the second frame is hinged to the middle part of the first frame, and the other end is fixed to the middle ring.

[0006] Using the above technical solution, the robotic arm has a simple and compact structure that is easy to implement. The robotic arm is designed as a telescopic umbrella frame structure, which facilitates overall storage and carrying.

[0007] As an improvement of the present invention, the robotic arm driving device is an electric push rod; the electric push rod includes a push rod motor and a push rod; the push rod motor is fixed to the central rod, the push rod is fixed to the middle ring, and the electric push rod drives the middle ring to slide back and forth on the central rod to extend and retract the telescopic arm.

[0008] The above technical solution results in a compact and easy-to-implement detection device with a small size and light weight, making it easy to deploy and carry on-site.

[0009] Preferably, the telescopic arms are configured in six or eight groups and are evenly distributed along the circumference of the central rod.

[0010] By adopting the above technical solution, the telescopic arm is set at equal intervals of six or eight groups along the circumference of the central rod, so that the ultrasonic sensors are arranged in a ring on the same plane, ensuring complete coverage of the pile hole sidewall during scanning, avoiding detection blind spots, and improving the integrity and accuracy of imaging.

[0011] Preferably, the ultrasonic sensor is connected to the ball joint of the telescopic arm.

[0012] Using the above technical solution, the ultrasonic sensor can achieve an angle adjustment of ±15 degrees, ensuring that the ultrasonic sensor fits the arc of the pile hole sidewall. By adjusting the ball joint structure, the beam angle direction of each ultrasonic sensor can be adjusted so that the overlap width of the beam angle edges of adjacent sensors is not less than 10% of the beam width, ensuring complete 360-degree scanning coverage of the pile hole sidewall.

[0013] A pile hole detection system based on ultrasonic imaging includes a lifting drive device and the aforementioned pile hole detection device, and further includes: The central axis setting assembly includes a bracket, a traction rope, and a centering lead block; the bracket is erected above the pile hole, and a wire hole is opened in the center of the bracket; one end of the traction rope is connected to the centering lead block, and the other end passes through the central rod and is fixed to the output end of the lifting drive device; the lifting drive device drives the pile hole detection device to reciprocate along the central axis perpendicular to the pile bottom inside the pile hole; The location information acquisition unit includes a location sensor for acquiring distance information of the ultrasonic sensor relative to the central axis; The three-dimensional coordinate correction unit includes a magnetic north pole sensor for determining the orientation angle of the robotic arm and a gyroscope for monitoring changes in the posture of the robotic arm. The data processing terminal processes the data collected by the system and creates images.

[0014] By adopting the above technical solution, the verticality of the central axis and the center positioning accuracy are ensured by bracket calibration and centering lead block. Combined with the dynamic correction of three-dimensional coordinates by magnetic north pole sensor and gyroscope, the measurement accuracy of position and attitude is further improved. The signal can be accurately mapped to the specific position of the pile hole sidewall, which improves the accuracy of imaging and positioning accuracy, and provides more reliable data for pile hole quality inspection.

[0015] A pile hole detection method based on ultrasonic imaging, applied to the aforementioned pile hole detection system based on ultrasonic imaging, includes the following steps: Step 1: Adjust the position of the support to ensure that the traction rope is located in the center of the pile hole, forming a scanning center axis perpendicular to the bottom of the pile, and ensure that the robotic arm moves along the center axis; Step 2: Based on the diameter of the pile hole, drive the telescopic arm to extend using the mechanical arm drive device, so that the ultrasonic sensor installed at the end of the telescopic arm is close to the side wall of the pile hole. Step 3: Start the lifting drive device to pull the robotic arm to move along the central axis, so that the robotic arm drives the ultrasonic sensor to perform reciprocating scanning along the central axis; at the same time, the position sensor collects the distance information of the ultrasonic sensor relative to the central axis, the magnetic north pole sensor collects the azimuth information of the robotic arm, and the gyroscope collects the tilt angle information of the robotic arm. Step 4: Transmit the collected echo signal from the ultrasonic sensor, the position information of the ultrasonic sensor relative to the central axis, the azimuth information of the robotic arm, and the tilt angle information of the robotic arm to the data processing terminal. Step 5: The data processing terminal stores the data in real time and processes it using a specific algorithm to finally create an image.

[0016] The data processing terminal stores the data in real time and processes it using a specific algorithm to ultimately create an image, including the following steps: Step 1: Coordinate correction. Based on the tilt angle output by the gyroscope, attitude compensation is performed on the distance measured by the position sensor. Combined with the azimuth angle of the magnetic north pole sensor, the relative position of the ultrasonic sensor is converted into absolute three-dimensional coordinates with the central axis of the pile hole as the origin and due north as the reference. Step 2: Distance calculation. Based on the propagation speed of ultrasonic waves in mud and the propagation time of the echo signal, calculate the straight-line distance between the ultrasonic sensor and the reflection point on the side wall of the pile hole. Step 3: Image generation. The absolute three-dimensional coordinates of the reflection point are correlated with the echo signal intensity. A voxel reconstruction algorithm is used to generate a three-dimensional image of the pile hole sidewall. The image is then enhanced with grayscale to improve its contrast.

[0017] The method for attitude compensation of the distance measured by the position sensor based on the tilt angle output by the gyroscope is to calculate and correct the actual horizontal distance using trigonometric functions based on the tilt angle. In the absolute three-dimensional coordinate system, the X-axis represents the east-west direction, the Y-axis represents the north-south direction, and the Z-axis represents the depth direction of the pile hole. The propagation speed of the ultrasonic wave in the mud can be obtained through preliminary experimental measurements.

[0018] The distance between the ultrasonic sensor and the sidewall of the pile hole is controlled to be 5-10cm. The robotic arm drives the ultrasonic sensor to reciprocate along the central axis at a speed of 5-10 cm / s.

[0019] The beneficial effects of this invention are as follows: 1. Improved imaging clarity and adaptability: The telescopic umbrella-shaped robotic arm can flexibly adjust the probe position to get close to the sidewall of pile holes of different sizes, effectively reducing the ultrasonic wave propagation distance and mud attenuation, making the echo signal clearer, significantly improving the clarity and resolution of the image, and adapting to various pile hole diameters, thus expanding the application range of the technology.

[0020] 2. Achieve comprehensive coverage scanning: The ring array arrangement of ultrasonic probes ensures complete coverage of the scanning area, eliminates blind spots, and enables accurate detection of all parts of the pile hole sidewall, improving the integrity and reliability of imaging.

[0021] 3. Improved ease of use: The telescopic umbrella-shaped robotic arm can be folded and stored, making it small in size and light in weight. This facilitates transportation and on-site deployment, reducing preparation time and labor intensity for testing operations and improving testing efficiency.

[0022] 4. Precise positioning and imaging: The verticality of the central axis and the center positioning accuracy are ensured by bracket calibration and plumb bob. Combined with the magnetic north pole sensor and gyroscope for dynamic correction of three-dimensional coordinates, the measurement accuracy of position and attitude is further improved. The signal can be accurately mapped to the specific position of the pile hole sidewall, which improves the accuracy of imaging and positioning accuracy, and provides more reliable data for pile hole quality inspection. Attached Figure Description

[0023] Figure 1 This is a partial schematic diagram of the pile hole detection system of the present invention; Figure 2 This is an assembly perspective view of the pile hole detection device of the present invention; Figure 3 for Figure 1 A magnified view of a portion of point A in the middle; Figure 4 for Figure 2 A magnified view of a portion of point B in the middle; Figure 5 This is a top view of the pile hole detection device inside the pile hole.

[0024] In the diagram: 1. Central rod; 2. Telescopic arm; 21. First frame; 22. Second frame; 3. Ultrasonic sensor; 4. Bracket; 5. Traction rope; 6. Centering lead block; 7. Lifting drive device; 8. Electric push rod; 81. Push rod motor; 82. Push rod; 10. Middle ring; 11. Mounting box; 12. Position sensor; 13. Magnetic north pole sensor; 14. Gyroscope; 15. Main control board; 100. Pile hole; 101. Pile opening; 200. Central through hole; 400. Threading hole. Detailed Implementation

[0025] To better understand the present invention, it will be further described below with reference to the accompanying drawings. It should be noted that the following embodiments are provided to aid in understanding the present invention, but do not constitute a limitation thereof.

[0026] In the description of this application, it should be understood that the terms "upper", "lower", "upper part", "lower part", "middle part", "bottom", etc., indicate the orientation or positional relationship based on the orientation shown in the accompanying drawings or the orientation of the object in the use state. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0027] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature.

[0028] In this application, unless otherwise expressly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0029] A pile hole detection device based on ultrasonic imaging includes a telescopic robotic arm assembly, an ultrasonic detection unit, and a robotic arm drive device.

[0030] like Figure 1 and 2 As shown, the telescopic robotic arm assembly includes a central rod 1 and multiple sets of telescopic arms 2 arranged radially on the central rod 1; each set of telescopic arms 2 includes a first frame 21 and a second frame 22; a central ring 10 is slidably sleeved on the central rod 1; one end of the first frame 21 is hinged to the lower part of the central rod 1, and the other end is fixed to the ultrasonic sensor 3; one end of the second frame 22 is hinged to the middle part of the first frame 21, and the other end is fixedly connected to the central ring 10.

[0031] like Figure 2 As shown, the robotic arm assembly is also equipped with a robotic arm drive device, which can drive multiple sets of telescopic arms 2 to achieve synchronous extension and retraction.

[0032] Preferably, the robotic arm drive device is an electric push rod 8, which includes a push rod motor 81 and a push rod 82. The push rod motor 81 is fixed to the upper part of the central rod 1, and the push rod 82 is fixed to the middle ring 10. The electric push rod 8 is longitudinally arranged on the central rod 1, and the axis of the push rod 82 is parallel to the axis of the central rod 1. The push rod motor 81 drives the push rod 82 to reciprocate along the axis of the central rod 1, thereby causing the middle ring 10 to slide back and forth on the central rod 1, thus realizing the synchronous extension and retraction of multiple sets of telescopic arms 2.

[0033] In this embodiment, the central rod 1 is made of a high-strength, lightweight alloy (such as aerospace-grade aluminum alloy 6061); the electric actuator 8 is a TGA-100 electric actuator with a stroke of 500-800mm and a thrust of 500N. The overall length of the robotic arm assembly is controlled within 1.2m, and the weight does not exceed 8kg. The electric actuator 8 on the central rod 1 drives multiple sets of telescopic arms 2 to achieve synchronous extension and retraction, thereby forming a telescopic umbrella-like structure robotic arm. In the non-working state, the radial telescopic arms 2 can be folded parallel to the central rod 1, making it convenient for single-person carrying and transportation.

[0034] The ultrasonic detection unit includes multiple ultrasonic sensors 3 located at the ends of each telescopic arm 2, which have high sensitivity, narrow beam angle (e.g., 10°-15°) and high transmission and reception efficiency (operating frequency adapted to 500kHz-1MHz).

[0035] In one implementation, the telescopic arms 2 are arranged in six groups at equal intervals along the circumference of the central rod 1, and the included angle between the ultrasonic sensors 3 at the ends of adjacent telescopic arms 2 is 60 degrees.

[0036] In another implementation, the telescopic arms 2 are arranged in eight groups at equal intervals along the circumference of the central rod 1, and the included angle between the ultrasonic sensors 3 at the ends of adjacent telescopic arms 2 is 45 degrees.

[0037] Furthermore, each ultrasonic sensor 3 is connected to the end of the telescopic arm 2 via a ball joint structure, which allows for an angle adjustment of ±15°.

[0038] With the above setup, the ultrasonic sensors 3 are positioned at the end of the telescopic robotic arm, forming a circular array of multiple ultrasonic sensors 3 on the same plane around the end of the arm. By adjusting the ball joint structure at the end of the telescopic arm 2, it can be ensured that the ultrasonic sensors 3 conform to the curvature of the pile hole sidewall. Furthermore, by adjusting the beam angle direction of each ultrasonic sensor 3, the overlap width of the beam angle edges of adjacent ultrasonic sensors 3 is not less than 10% of the beam width (e.g., when the beam angle is 10°, the overlap width is not less than 1°), ensuring complete 360-degree scanning coverage of the pile hole sidewall, avoiding detection blind spots, and improving the integrity and accuracy of imaging. After installation, the angles of the ultrasonic sensors 3 are calibrated using a laser calibrator to ensure that the angle deviation between two adjacent ultrasonic sensors 3 does not exceed ±0.5 degrees.

[0039] By employing the above technical solution, the distance between the ultrasonic sensor 3 and the sidewall of the pile hole can be flexibly adjusted using a telescopic umbrella-shaped robotic arm. This allows the ultrasonic sensor 3 to be positioned close to the sidewall of pile holes with different diameters, significantly reducing the propagation distance of ultrasonic waves in turbid mud and minimizing the attenuation effect of the mud on the ultrasonic waves. This results in clearer and stronger echo signals, significantly improving the clarity and resolution of the imaging. Furthermore, this structure not only facilitates rapid adjustment of the overall size of the robotic arm according to the pile hole size but also features a folding storage function. Its small size and light weight make it easy to carry and deploy on-site, reducing preparation time and labor intensity for inspection operations and improving inspection efficiency. In addition, the ring-array arrangement of the ultrasonic probes ensures complete coverage of the scanning area, eliminating blind spots and enabling accurate detection of all parts of the pile hole sidewall, thus improving the integrity and reliability of the imaging.

[0040] Furthermore, the present invention also provides a pile hole detection system based on ultrasonic imaging. The system includes the above-mentioned pile hole detection device based on ultrasonic imaging, and also includes a central axis setting component, a lifting drive device, a position information acquisition unit, a three-dimensional coordinate correction unit, and a data processing terminal.

[0041] The central axis setting assembly includes a bracket 4, a traction rope 5, and a centering lead block 6. (Combined) Figure 1 , Figure 3 and Figure 5 The support 4 is erected above the pile hole 100. The support 4 includes two crossbars arranged radially along the pile hole 100 in a cross shape. A wire hole 400 is provided at the center of the crossbars. One end of the traction rope 5 is connected to the centering lead block 6, and the other end passes through the central through hole 200 of the central rod 1 and the wire hole 400 of the support 4, and is fixed to the output end of the lifting drive device 7. In this embodiment, the lifting drive device 7 is a winch with a built-in meter counting function. The winch can be set above the support 4 or fixed to the ground. The traction rope 5 is fixed to the drum of the winch. Starting the winch can drive the robotic arm to move along the scanning center axis, so that the robotic arm drives the ultrasonic sensor 3 to reciprocate along the center axis to scan and collect signals.

[0042] In this embodiment, the support 4 is an adjustable-height metal support set above the pile hole 100. The length of the support crossbar is not less than 1.5 times the diameter of the pile hole 100, and the material is Q235 steel. The traction rope 5 is a high-strength nylon traction rope with a diameter of 2-3mm and a breaking strength of not less than 500N. The centering lead block 6 is made of cast iron, and its weight is determined according to the depth of the pile hole (5-8kg for a pile hole depth of 5-10m; 8-12kg for a depth of 10-20m), ensuring that the traction rope 5 is completely taut under the weight of the centering lead block 6 and is not affected by the flow of mud slurry. When calibrating the central axis, a laser line projector (accuracy ±0.05mm / m) can be used as a measuring tool to adjust the position of the support 4 so that the projection of the threaded hole 400 coincides with the center point of the edge of the pile opening 101, ensuring that the hanging traction rope 5 is located at the center of the pile opening 101, forming a scanning central axis perpendicular to the pile bottom.

[0043] The location information acquisition unit is used to acquire the distance information of the ultrasonic sensor 3 relative to the central axis.

[0044] The three-dimensional coordinate correction unit is used to dynamically correct the three-dimensional coordinates of the ultrasonic scan to ensure coordinate accuracy.

[0045] In this embodiment, the position information acquisition unit is a position sensor 12 installed on the robotic arm; the three-dimensional coordinate correction unit includes a magnetic north pole sensor 13 installed on the robotic arm to determine the orientation angle of the robotic arm, and a gyroscope 14 for real-time monitoring of the attitude changes (such as tilting and rotation) of the robotic arm.

[0046] like Figure 2 and 4 As shown, a mounting box 11 is provided at the bottom of the central rod 1, and the main control board 15, position sensor 12, magnetic north pole sensor 13, and gyroscope 14 are all fixed inside the mounting box 11. The position sensor 12, magnetic north pole sensor 13, and gyroscope 14 are all electrically connected to the main control board 15. Each sensor and the main control board are provided with a waterproof sealing shell (not shown in the figure) to ensure that each unit can work normally in the mud. The data collected by each sensor is sent to the data processing terminal (not shown in the figure) through the main control board 15. The data processing terminal stores the data in real time and processes the data through a specific algorithm to finally form an image.

[0047] In this embodiment, the position sensor 12 is a laser displacement sensor with an accuracy of ±1 mm, which can collect the distance information of the ultrasonic sensor 3 relative to the central axis in real time; the lifting drive device 7 has a built-in meter counting function, which can determine the descent height of the robotic arm, and together with the position sensor 12, it can realize the position measurement of the ultrasonic sensor. The magnetic north pole sensor 13 is a digital magnetoresistive sensor HMC5883L with an accuracy of ±0.1°; the gyroscope 14 is a MEMS gyroscope MPU6050 with a sampling rate of 100Hz and an attitude accuracy of ±0.5°; the sealing shell is a waterproof sealing shell with a waterproof rating of IP68 to prevent mud from entering and affecting performance.

[0048] By adopting the above technical solution, the verticality of the central axis and the center positioning accuracy are ensured by the calibration of the bracket 4 and the centering lead block 6. In conjunction with the dynamic correction of the three-dimensional coordinates by the magnetic north pole sensor 13 and the gyroscope 14, the measurement accuracy of position and attitude is further improved. The signal can be accurately mapped to the specific position of the pile hole sidewall, which improves the accuracy of imaging and positioning accuracy, and provides more reliable data for pile hole quality inspection.

[0049] In this embodiment, the data processing terminal (not shown in the figure) is connected to the main control board 15 via a waterproof data cable. The data processing terminal performs real-time data storage and integration of the echo signal collected by the ultrasonic sensor 3, the distance information of the ultrasonic sensor 3 relative to the central axis collected by the position sensor 12, the azimuth angle of the robotic arm collected by the magnetic north pole sensor 13, and the posture of the robotic arm collected by the gyroscope 14. Using a specific algorithm, based on parameters such as signal strength and propagation time, and combined with the corrected coordinates, an image of the pile hole sidewall is generated. In this way, the received ultrasonic signal can be accurately converted into intuitive image information, clearly showing the condition of the pile hole sidewall.

[0050] A pile hole detection method based on ultrasonic imaging, applied to the aforementioned pile hole detection system based on ultrasonic imaging, includes the following steps: Step 1: Adjust the position of the support to ensure that the traction rope is located in the center of the pile hole, forming a scanning center axis perpendicular to the bottom of the pile, and ensure that the robotic arm moves along the center axis; Step 2: Based on the diameter of the pile hole, drive the telescopic arm to extend using the mechanical arm drive device, so that the ultrasonic sensor installed at the end of the telescopic arm is close to the side wall of the pile hole. Step 3: Start the lifting drive device to pull the robotic arm to move along the central axis, so that the robotic arm drives the ultrasonic sensor to perform reciprocating scanning along the central axis; at the same time, the position sensor collects the distance information of the ultrasonic sensor relative to the central axis, the magnetic north pole sensor collects the azimuth information of the robotic arm, and the gyroscope collects the tilt angle information of the robotic arm. Step 4: Transmit the collected echo signal from the ultrasonic sensor, the position information of the ultrasonic sensor relative to the central axis, the azimuth information of the robotic arm, and the tilt angle information of the robotic arm to the data processing terminal. Step 5: The data processing terminal stores the data in real time and processes it using a specific algorithm to finally create an image.

[0051] Furthermore, the data processing terminal stores the data in real time and processes the data using a specific algorithm to ultimately create an image, including the following steps: Step 1: Coordinate correction. Based on the tilt angle output by the gyroscope, attitude compensation is performed on the distance measured by the position sensor. Combined with the azimuth angle of the magnetic north pole sensor, the relative position of the ultrasonic sensor is converted into absolute three-dimensional coordinates with the central axis of the pile hole as the origin and due north as the reference. Step 2: Distance calculation. Based on the propagation speed of ultrasonic waves in mud and the propagation time of the echo signal (the time difference from transmission to reception), calculate the straight-line distance between the ultrasonic sensor and the reflection point on the side wall of the pile hole. Step 3: Image generation. The absolute three-dimensional coordinates of the reflection point are correlated with the echo signal intensity. A voxel reconstruction algorithm is used to generate a three-dimensional image of the pile hole sidewall. The image is then subjected to grayscale enhancement processing (such as histogram equalization) to improve the image contrast and make defects such as cracks, diameter expansion, and diameter contraction of the pile hole sidewall more clearly visible.

[0052] Furthermore, the method for attitude compensation of the distance measured by the position sensor based on the tilt angle output by the gyroscope is to calculate and correct the actual horizontal distance using trigonometric functions based on the tilt angle. In the absolute three-dimensional coordinate system, the X-axis represents the east-west direction, the Y-axis represents the north-south direction, and the Z-axis represents the depth direction of the pile hole. The propagation speed of the ultrasonic wave in the mud can be obtained through previous experimental measurements, and is generally 1450-1550 m / s.

[0053] Preferably, the distance between the ultrasonic sensor and the sidewall is controlled at 5-10cm.

[0054] Preferably, the robotic arm drives the ultrasonic probe to perform reciprocating scanning along the central axis at a speed of 5-10 cm / s.

[0055] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Variations, modifications and substitutions made by those skilled in the art to the above embodiments within the scope of the present invention are still covered by the protection scope of the present invention.

Claims

1. An ultrasonic imaging-based pile hole detection device, characterized by: The utility model relates to a pile hole detection device and a pile hole detection method, and belongs to the field of pile hole detection. The utility model discloses a telescopic mechanical arm assembly, including center pole (1) and the multiple sets of telescopic arms (2) of setting in the center pole (1) radial distribution, The utility model discloses an ultrasonic detection unit, including the ultrasonic sensor (3) of setting in each set of telescopic arms (2) end, The utility model discloses a mechanical arm driving device for driving the multiple sets of telescopic arms telescopic.

2. The ultrasonic imaging based pile hole detection apparatus according to claim 1, characterized in that: The utility model discloses the telescopic arm (2) including first skeleton (21) and second skeleton (22), One end of the first skeleton (21) is hinged to the lower part of the center pole (1), and the other end is fixedly connected to the ultrasonic sensor (3), The center pole (1) is slidably sleeved with a middle ring (10), one end of the second skeleton (22) is hinged to the middle part of the first skeleton (21), and the other end is fixed to the middle ring (10).

3. An ultrasonic imaging based pile hole detection apparatus according to claim 2, characterized in that: The utility model discloses the mechanical arm driving device is electric push rod (8), and the electric push rod (8) includes push rod motor (81) and push rod (82), and the push rod motor (81) is fixed with the center pole (1), and the push rod (82) is fixed with the middle ring (10), and the electric push rod (8) drives the middle ring (10) reciprocating sliding on the center pole (1), so that the telescopic arm (2) telescopic.

4. The ultrasonic imaging based pile hole detection apparatus according to claim 1, characterized in that: The utility model discloses the telescopic arm (2) sets up six sets or eight sets, and is along the equidistant distribution of center pole (1) circumference.

5. The ultrasonic imaging based pile hole detection apparatus according to claim 1, characterized in that: The utility model discloses the ultrasonic sensor (3) with telescopic arm (2) spherical hinge connection.

6. An ultrasonic imaging based pile hole detection system characterized by: The utility model discloses a pile hole detection device and a pile hole detection method, and belongs to the field of pile hole detection. The utility model discloses a center shaft setting assembly, including support (4), traction rope (5) and centering lead block (6), the support (4) is erected above the pile hole (100), and the support (4) is hinged to the lower part of the center pole (1), and the other end is fixed with the output end of the lifting driving device (7) through the center pole (1), and the lifting driving device (7) drives the pile hole detection device reciprocating motion in the pile hole (100) along the center shaft perpendicular to the pile bottom, The utility model discloses a position information acquisition unit, including the position sensor (12) for gathering the distance information of ultrasonic sensor (3) relative to the center shaft, The utility model discloses a three-dimensional coordinate correction unit, including the magnetic north pole sensor (13) for determining the azimuth angle of the mechanical arm, and the gyroscope (14) for monitoring the attitude change of the mechanical arm, The utility model discloses a data processing terminal, and the data collected by the system is processed and imaged.

7. The pile hole detection method based on ultrasonic imaging, applied to the pile hole detection system based on ultrasonic imaging of claim 6, characterized in that: The utility model discloses a pile hole detection device and a pile hole detection method, and belongs to the field of pile hole detection. Step one: adjust the position of the support to ensure that the traction rope is located at the center of the pile hole, form a scanning center shaft perpendicular to the pile bottom, and ensure that the mechanical arm moves along the center shaft. Step two: according to the diameter of the pile hole, drive the telescopic arm to extend through the mechanical arm driving device, so that the ultrasonic sensor installed at the end of the telescopic arm is close to the sidewall of the pile hole. Step three: start the lifting driving device, pull the mechanical arm to move along the center shaft, so that the mechanical arm drives the ultrasonic sensor to reciprocating scan along the center shaft; at the same time, the position sensor collects the distance information of the ultrasonic sensor relative to the center shaft, the magnetic north pole sensor collects the azimuth angle information of the mechanical arm, and the gyroscope collects the inclination angle information of the mechanical arm. Step four: the collected echo signals of the ultrasonic sensor, the position information of the ultrasonic sensor relative to the central axis, the azimuth information of the mechanical arm, and the tilt angle information of the mechanical arm are transmitted to the data processing terminal; Step five: the data processing terminal stores the data in real time, processes the data through a specific algorithm, and finally images.

8. The pile hole detection method based on ultrasonic imaging according to claim 7, characterized in that: The data processing terminal stores the data in real time, processes the data through a specific algorithm, and finally images, including the following steps: Step one: coordinate correction, according to the tilt angle output by the gyroscope, the attitude of the distance measured by the position sensor is compensated; combined with the azimuth of the magnetic north sensor, the relative position of the ultrasonic sensor is converted into absolute three-dimensional coordinates with the pile hole central axis as the origin and the north direction as the reference; Step two: distance calculation, according to the propagation speed of ultrasonic waves in mud liquid and the propagation time of echo signals, the straight line distance between the ultrasonic sensor and the reflection point on the pile hole side wall is calculated; Step three: image generation, the absolute three-dimensional coordinates of the reflection point are associated with the echo signal intensity, the voxel reconstruction algorithm is used to generate the three-dimensional image of the pile hole side wall, and the image is processed by gray scale enhancement to improve the contrast of the image.

9. The pile hole detection method based on ultrasonic imaging according to claim 8, characterized in that: The method for compensating the distance measured by the position sensor according to the tilt angle output by the gyroscope is to correct the actual horizontal distance by trigonometric function according to the tilt angle; In the absolute three-dimensional coordinates, X axis: east-west direction, Y axis: south-north direction, Z axis: pile hole depth direction; The propagation speed of ultrasonic waves in mud liquid can be measured by preliminary experiment.

10. The pile hole detection method based on ultrasonic imaging according to any one of claims 7-9, characterized in that: The distance between the ultrasonic sensor and the pile hole side wall is controlled within 5-10 cm; The mechanical arm drives the ultrasonic sensor to reciprocate along the central axis direction at a speed of 5-10 cm / s.

Images