An antenna array adaptive leveling device for road disease ground penetrating radar

Abstract

The present application relates to a kind of antenna array adaptive leveling device for road disease ground penetrating radar, including support beam, inertial stabilization platform, antenna array, for compensating the auxiliary attitude correction mechanism of long time attitude tilt of antenna array, upper mounting plate, lower mounting plate, including series first-stage damping air spring, second-stage damping air spring and the third-stage damping air spring of coaxial arrangement in second-stage damping air spring inside damping spring group, for the participation timing of controlling third-stage damping air spring floating limiting mechanism and for providing limiting and adjustable damping magneto-rheological damping unit.The present application can efficiently isolate the high-frequency tiny vibration of road surface, while ensuring the long-term horizontal stability of antenna array adaptive leveling device.

Description

Technical Field

[0001] This invention relates to the field of road ground-penetrating radar auxiliary equipment technology, and in particular to an antenna array adaptive leveling device for road damage ground-penetrating radar. Background Technology

[0002] Ground-penetrating radar (GPR) is a highly efficient non-destructive testing device widely used in fields such as detecting road subsurface defects, asphalt layer thickness measurement, and locating underground pipelines. Taking the ultra-wideband 3D imaging GPR system as an example, it can achieve high-resolution detection from the ground surface to several meters underground by using array antennas of different frequencies. In actual detection operations, the antenna array is usually in contact with the road surface through a support beam and support wheel assembly, and is moved by a detection vehicle or hand-pushed frame.

[0003] However, road surfaces are not ideal planes and have various forms of vibration sources. The most common is road texture noise, which is caused by micro-vibrations of asphalt pavement aggregate (frequency 20-200Hz). The second is tire-road coupled vibration, which is generated by the interaction between tire treads and the road surface, resulting in high-frequency components (frequency 100-1000Hz). Finally, there is the impact of cement pavement joints, which is caused by pulse vibrations (frequency 50-500Hz) from road expansion joints and cracks. These high-frequency, minute vibrations are characterized by small amplitude (typically 0.1-2 mm), high frequency, concentrated energy, and strong randomness. When the antenna array travels over uneven road surfaces with the vehicle frame, the vibrations are directly transmitted to the antenna array through the support wheels and bracket crossbeams, causing the antenna array to tilt and shake instantaneously. The height of the lower end of the antenna array from the ground changes instantaneously, which can easily disrupt the ideal geometric relationship between electromagnetic wave transmission and reception. The vibration signal is coupled into the radar data, causing a decrease in the data signal-to-noise ratio and making shallow defects, such as voids and loose bodies, difficult to identify. In addition, when the detection vehicle travels over potholes or the road surface itself tilts due to the influence of the roadbed, the antenna array will tilt with the vehicle frame, causing the electromagnetic wave transmission angle to shift and the data to be distorted.

[0004] In existing technologies, most solutions for antenna array vibration are passive vibration reduction. Passive vibration reduction uses elastic elements such as rubber pads and ordinary springs to isolate vibration. Such solutions are simple in structure, but their isolation effect on high-frequency vibration is limited. If the stiffness of the elastic element is too low, the low-frequency stability is poor, and the antenna array is easily affected by vehicle acceleration and deceleration, turning, and the tilt of the road surface, causing it to drift. If the stiffness is too high, the high-frequency isolation is insufficient, and it is difficult to effectively suppress small vibrations of the road surface. Moreover, it is difficult to ensure that the antenna array is in a horizontal state for a long time due to the tilt of the road surface. As a result, the antenna array always detects the defects at a certain tilt angle, which can easily lead to data distortion and difficulty in identification.

[0005] Therefore, there is an urgent need for an adaptive leveling device that can efficiently isolate high-frequency micro-vibrations on the road surface while ensuring the long-term horizontal stability of the antenna array, in order to solve the technical problem of vibration affecting data quality in the existing technology. Summary of the Invention

[0006] In view of the above problems, the present invention provides an adaptive leveling device for an antenna array of a ground-penetrating radar for road defects, so as to solve the problems mentioned in the background art.

[0007] The specific technical solution is as follows: An adaptive leveling device for an antenna array of ground-penetrating radar for road defects includes: The support beam is used to connect to the probe vehicle or hand-operated frame. An inertial stabilization platform is located below the support beam; The antenna array is positioned below the inertial stabilization platform; An auxiliary attitude correction mechanism is connected between the support beam and the inertial stabilization platform. It includes four sets of electric push rods. The upper end of each set of electric push rods is connected to the support beam through a spherical bearing, and the lower end of each electric push rod is connected to the inertial stabilization platform through a universal joint. It is used to compensate for the long-term attitude tilt of the antenna array. The upper mounting plate is connected to the lower end of the inertial stabilization platform; The lower mounting plate is connected to the upper end of the antenna array; A vibration damping spring assembly is disposed between the upper mounting plate and the lower mounting plate, including a primary vibration damping air spring, a secondary vibration damping air spring connected in series, and a tertiary vibration damping air spring coaxially disposed inside the secondary vibration damping air spring; A floating limit mechanism is installed between the three-stage damping air spring and the upper mounting plate to control the engagement timing of the three-stage damping air spring. A magnetorheological damping unit is disposed between the upper mounting plate and the lower mounting plate to provide limiting and adjustable damping.

[0008] Furthermore, the upper flange of the secondary damping air spring is connected to the lower end face of the upper mounting plate, the lower flange of the secondary damping air spring is connected to the upper flange of the primary damping air spring, the lower flange of the primary damping air spring is connected to the upper end face of the lower mounting plate, the lower flange of the tertiary damping air spring is connected to the inner side of the lower flange of the secondary damping air spring, and a pressure-bearing boss that cooperates with the floating limiting mechanism is vertically and coaxially arranged on the upper flange of the tertiary damping air spring.

[0009] Furthermore, the floating limiting mechanism includes a limiting cylinder coaxially arranged with the pressure-bearing boss. The upper end of the limiting cylinder is connected to the inner side of the upper flange of the secondary damping air spring. A limiting slide cavity is coaxially arranged inside the limiting cylinder. A first limiting slider and a second limiting slider are symmetrically adapted inside the limiting slide cavity. The pressure-bearing boss includes a floating slider disposed between the first limiting slider and the second limiting slider, and a floating rod for connecting with the floating slider and the upper flange of the tertiary damping air spring.

[0010] Furthermore, buffer pads are provided on the end faces of the first and second limiting sliders that are close to each other to absorb contact impact.

[0011] Furthermore, the limiting slide cavity is provided with a plurality of guide posts parallel to its axial direction, and the plurality of guide posts are evenly spaced around the axis of the limiting slide cavity; the first limiting slider, the second limiting slider and the floating slider are respectively provided with sliding holes adapted to the guide posts.

[0012] Furthermore, the upper end of the secondary damping air spring is also provided with a gap adjustment mechanism for adjusting the distance between the first and second limiting sliders, thereby adjusting the engagement timing of the tertiary damping air spring. The gap adjustment mechanism includes a first double-threaded screw arranged parallel to the axial direction of the limiting cylinder and a first drive motor for driving the first double-threaded screw to rotate. The threads at the upper and lower ends of the first double-threaded screw have opposite directions and the same pitch. A first ball nut block and a second ball nut block are respectively fitted on the left-hand and right-hand threads of the first double-threaded screw. The side of the limiting cylinder is also provided with a through-hole strip opening along its axial direction. A first adjusting rod is provided on the side of the first ball nut block, and the other end of the first adjusting rod is connected to the first limiting slider through the strip opening. A second adjusting rod is provided on the side of the second ball nut block, and the other end of the second adjusting rod is connected to the second limiting slider through the strip opening.

[0013] Furthermore, the magnetorheological damping unit is a circular magnetorheological damper, which is coaxially sleeved on the outside of the vibration damping spring assembly. The upper and lower ends of the circular magnetorheological damper are respectively connected to the upper mounting plate and the lower mounting plate. An excitation coil is provided inside the circular magnetorheological damper, and the control unit adjusts the excitation current according to the vibration acceleration to change the damping coefficient.

[0014] Furthermore, it also includes an inertial mass tuning unit, which is disposed on the lower mounting plate and is used to absorb vibration energy in a specific frequency band.

[0015] Furthermore, the inertial mass tuning unit includes an annular mass block and several elastic support plates; the lower end of the elastic support plate is disposed on the lower mounting plate, and its upper end is connected to the annular mass block, so that the annular mass block is suspended above the lower mounting plate, and the natural frequency of the annular mass block is set to the main frequency band of road vibration.

[0016] Furthermore, at least four of each of the upper mounting plate, lower mounting plate, vibration damping spring assembly, magnetorheological damping unit, and inertial mass tuning unit are provided. Several upper mounting plates are arranged at equal intervals along the circumferential direction of the lower end face of the inertial stabilization platform, and several lower mounting plates are arranged at equal intervals along the circumferential direction of the upper end face of the antenna array. The number of vibration damping spring assembly, magnetorheological damping unit, and inertial mass tuning unit is the same as the number of upper mounting plates and lower mounting plates and is arranged in a one-to-one correspondence.

[0017] Compared with the prior art, the present invention has the following beneficial effects: (1) The present invention provides an adaptive leveling device for an antenna array of a ground-penetrating radar for road defects. By setting up a series-parallel damping spring group consisting of a primary damping air spring, a secondary damping air spring, and a tertiary damping air spring, and combining it with a floating limit mechanism, the amplitude of stiffness is adaptively adjusted. Among them, the primary damping air spring has the lowest stiffness, the secondary damping air spring has the second lowest stiffness, and the tertiary damping air spring has the highest stiffness. The three series-parallel connections form a wideband vibration isolation path. When high-frequency micro-vibrations occur, the tertiary damping air spring does not participate in the load-bearing, and the system exhibits low and medium stiffness, effectively isolating high-frequency vibrations. When a large impact occurs, the tertiary damping air spring participates in the parallel load-bearing, and the system stiffness jumps, effectively limiting excessive displacement and protecting the antenna array structure, thus achieving a balance between micro-vibration isolation and large impact stable support.

[0018] (2) The present invention provides an adaptive leveling device for an antenna array of a ground-penetrating radar for road defects. By setting an auxiliary attitude correction mechanism between the support beam and the inertial stabilization platform, the inertial measurement unit detects the pitch angle and roll angle of the inertial stabilization platform relative to the horizontal plane of the ground in real time. When the deviation exceeds the set threshold and the duration exceeds the set time, each electric push rod will produce a small extension and retraction, pushing the inertial stabilization platform to slowly return to the correct position, so that the inertial stabilization platform remains horizontal for a long time, and the antenna array remains horizontal for a long time, thus ensuring the detection quality.

[0019] (3) The present invention provides an adaptive leveling device for an antenna array of a ground-penetrating radar for road defects. By setting a two-stage vibration damping mechanism and connecting the mechanism in parallel with the vibration damping spring group, when the support beam vibrates downward, the two-stage vibration damping mechanism will generate an upward magnetic force increment on the antenna array, which is opposite in direction and equal in magnitude to the downward elastic force increment generated by the compression of the vibration damping spring group; the same applies when vibrating upward. The spacing between the upper and lower magnetic rings can be adjusted by the magnetic force adjustment mechanism to match the negative stiffness with the positive stiffness, so that the dynamic stiffness of the system approaches zero within a small displacement range. At this time, external vibration is difficult to be transmitted to the antenna array through elastic force, thus ensuring the stability of the antenna array. Attached Figure Description

[0020] Figure 1 This is a front view schematic diagram of the present invention.

[0021] Figure 2 This is a schematic diagram of the left side of the present invention.

[0022] Figure 3 This is a schematic diagram of the joint bearing structure of the present invention.

[0023] Figure 4 This is a schematic diagram showing the relative positions of the vibration damping spring assembly, the magnetorheological damping unit, and the inertial mass tuning unit of the present invention.

[0024] Figure 5 This is a schematic diagram of the relative positions of the vibration damping spring assembly, magnetorheological damping unit, and inertial mass tuning unit of the present invention from another angle.

[0025] Figure 6 This is a schematic diagram of the vibration damping spring assembly structure of the present invention.

[0026] Figure 7 This is a schematic diagram of the floating limit mechanism of the present invention.

[0027] Figure 8 This is a front view schematic diagram of Embodiment 2 of the present invention.

[0028] Figure 9 This is a schematic diagram of the two-stage vibration reduction mechanism of the present invention.

[0029] Figure 10 This is a schematic diagram of the upper magnetic ring structure of the present invention.

[0030] Figure 11 This is a schematic diagram of the lower magnetic ring structure of the present invention.

[0031] Figure 12 This is a schematic diagram of the intermediate magnetic ring structure of the present invention.

[0032] Figure 13 This is a schematic diagram of the guide bracket structure of the present invention.

[0033] In the diagram: 1. Support beam; 2. Inertial stabilization platform; 3. Antenna array; 4. Auxiliary attitude correction mechanism; 41. Electric push rod; 42. Joint bearing; 43. Universal hinge; 5. Upper mounting plate; 6. Lower mounting plate; 7. Vibration damping spring assembly; 71. Primary vibration damping air spring; 72. Secondary vibration damping air spring; 73. Tertiary vibration damping air spring; 74. Floating limit mechanism; 741. Limiting cylinder; 742. Limiting slide cavity; 743. First limiting slider; 744. Second limiting slider; 745. Floating slider; 746. Floating rod; 747. Buffer pad; 748. Strip opening; 749. Guide post; 75. Gap adjustment mechanism; 751. First double-threaded lead screw; 75 2. First ball bearing nut block; 753. Second ball bearing nut block; 756. First drive motor; 8. Magnetorheological damping unit; 91. Annular mass block; 92. Elastic support plate; 10. Front-mounted road surface sensing sensor; 11. Secondary vibration damping mechanism; 111. Upper magnetic ring; 112. Lower magnetic ring; 113. Middle magnetic ring; 1141. Annular support seat; 1142. First guide rod; 1143. Guide hole; 1144. Guide slide; 115. Second guide rod; 1161. Second double-threaded screw; 1162. Third ball bearing nut block; 1163. Fourth ball bearing nut block; 1164. Third adjusting rod; 1165. Fourth adjusting rod; 1166. Second drive motor. Detailed Implementation

[0034] The present application will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, only the parts relevant to the invention are shown in the accompanying drawings.

[0035] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0036] Example 1 This invention discloses an adaptive leveling device for antenna array 3 of ground-penetrating radar for road defects, with reference to... Figure 1 and Figure 2 As shown, it includes a support beam 1, an inertial stabilization platform 2, an antenna array 3, an auxiliary attitude correction mechanism 4, an upper mounting plate 5, a lower mounting plate 6, a vibration damping spring assembly 7, a floating limit mechanism 74, a magnetorheological damping unit 8, an inertial mass tuning unit, and a control unit.

[0037] The support beam 1 is used to connect with the probe vehicle or hand-pushed frame, serving as the load-bearing foundation for the entire device.

[0038] refer to Figure 1The inertial stabilization platform 2 is located below the support beam 1 and is a rectangular rigid plate with a large mass, used to increase the system inertia and improve stability.

[0039] refer to Figure 1 The antenna array 3 is located below the inertial stabilization platform 2 and serves as the transceiver antenna unit for the ground-penetrating radar.

[0040] refer to Figure 1 , Figure 2 and Figure 3 The auxiliary attitude correction mechanism 4 is connected between the support beam 1 and the inertial stabilization platform 2, and is used to compensate for the long-term attitude tilt of the antenna array 3 caused by the change in road surface tilt due to geological defects. The auxiliary attitude correction mechanism 4 includes four sets of electric push rods 41. The upper end of each set of electric push rods 41 is connected to the support beam 1 through a joint bearing 42, and the lower end of the electric push rod 41 is connected to the inertial stabilization platform 2 through a universal joint 43. The inertial measurement unit (IMU) monitors the pitch and roll angles of the inertial stabilization platform 2 relative to the horizontal plane in real time. Based on the attitude deviation detected by the IMU, the control unit determines that the attitude is tilted when the deviation exceeds a set threshold (e.g., 1-5°) and the duration exceeds a set time (e.g., 1 second). The controller calculates the corrective torque to be applied and outputs a command to each electric push rod 41. The electric push rod 41 generates a slight extension and retraction, pushing the inertial stabilization platform 2 to slowly return to the correct position. The electric push rod 41 is driven to make fine adjustments at a relatively slow speed, so that the inertial stabilization platform 2 remains horizontal for a long time, and the antenna array 3 remains horizontal for a long time. Since the adjustment speed is much lower than the road vibration frequency, the action of this mechanism will not be coupled with high-frequency vibration, avoiding the introduction of additional disturbances.

[0041] refer to Figure 1 The upper mounting plate 5 is connected to the lower end of the inertial stabilization platform 2.

[0042] refer to Figure 1 The lower mounting plate 6 is connected to the upper end of the antenna array 3 and corresponds vertically to the upper mounting plate 5.

[0043] refer to Figure 4 and Figure 6The damping spring assembly 7 is disposed between the upper mounting plate 5 and the lower mounting plate 6 to provide positive stiffness support and vibration isolation. The damping spring assembly 7 includes a primary damping air spring 71, a secondary damping air spring 72 connected in series, and a tertiary damping air spring 73 coaxially disposed inside the secondary damping air spring 72. The specific connection relationship is as follows: the upper flange of the secondary damping air spring 72 is connected to the lower end face of the upper mounting plate 5, the lower flange of the secondary damping air spring 72 is connected to the upper flange of the primary damping air spring 71, the lower flange of the primary damping air spring 71 is connected to the upper end face of the lower mounting plate 6, the lower flange of the tertiary damping air spring 73 is connected to the inner side of the lower flange of the secondary damping air spring 72, and a pressure-bearing boss that cooperates with the floating limit mechanism 74 is vertically and coaxially disposed on the upper flange of the tertiary damping air spring 73. The design principle of this series structure is as follows: the first-stage damping air spring 71 has the lowest stiffness and is responsible for isolating high-frequency micro-vibrations; the second-stage damping air spring 72 has moderate stiffness and is responsible for mid-frequency vibrations; and the third-stage damping air spring 73 has the highest stiffness and is responsible for large-amplitude impacts. Through a three-stage series and parallel connection, broadband vibration isolation is achieved. A high-pressure air tank and an air pump for replenishing gas into the high-pressure air tank are also installed on the support beam 1. The high-pressure air tank is equipped with a first air inlet pipe connected to the first-stage damping air spring 71, a second air inlet pipe connected to the second-stage damping air spring 72, and a third air inlet pipe connected to the third-stage damping air spring 73. Solenoid valves are installed on the first, second, and third air inlet pipes. Furthermore, pressure relief valves and air pressure sensors are installed inside the first-stage, second-stage, and third-stage damping air springs 71 and 72, respectively.

[0044] refer to Figure 6 and Figure 7A floating limiting mechanism 74 is disposed between the three-stage damping air spring 73 and the upper mounting plate 5 to control the engagement timing of the three-stage damping air spring 73 and achieve adaptive stiffness amplitude. Its specific structure is as follows: the floating limiting mechanism 74 includes a limiting cylinder 741 coaxially disposed with the pressure-bearing boss. The upper end of the limiting cylinder 741 is connected to the inner side of the upper flange of the two-stage damping air spring 72. A limiting sliding cavity 742 is coaxially disposed inside the limiting cylinder 741. A first limiting slider 743 and a second limiting slider 744 are symmetrically fitted inside the limiting sliding cavity 742. The pressure-bearing boss includes a floating slider 745 disposed between the first limiting slider 743 and the second limiting slider 744, and a floating rod 746 for connecting with the floating slider 745 and the upper flange of the three-stage damping air spring 73. Both the first limiting slider 743 and the second limiting slider 744 have buffer pads 747 on their adjacent end faces to absorb contact impacts and prevent secondary vibrations from rigid impacts. The limiting slide cavity 742 also has several guide posts 749 arranged parallel to its axial direction inside, with the guide posts 749 evenly spaced around the axis of the limiting slide cavity 742. The first limiting slider 743, the second limiting slider 744, and the floating slider 745 are each provided with sliding holes adapted to the guide posts 749, ensuring smooth and non-deflecting movement of the first limiting slider 743, the second limiting slider 744, and the floating slider 745. Initially, the floating slider 745 is located in the middle position between the first limiting slider 743 and the second limiting slider 744, without contacting either of them, and there is an equal gap between the upper and lower parts. When a high-frequency micro-vibration occurs (amplitude less than the gap), the three-stage damping air spring 73 drives the floating slider 745 to slide freely up and down in the limiting slide cavity 742 through the floating rod 746, without contacting the upper and lower limiting sliders. At this time, the three-stage damping air spring 73 does not participate in the load-bearing, and the system stiffness is determined by the series connection of the first-stage damping air spring 71 and the second-stage damping air spring 72, exhibiting low stiffness and achieving high-frequency vibration isolation. When a large-amplitude vibration occurs (amplitude exceeding the gap), the floating slider 745 touches the first limiting slider 743 or the second limiting slider 744, hindering the continued movement of the floating slider 745, causing the three-stage damping air spring 73 to be compressed or stretched. At this time, the three-stage damping air spring 73 participates in the parallel load-bearing, the system stiffness jumps, exhibiting high stiffness, preventing excessive displacement, and ensuring the stability of the antenna array 3.

[0045] Furthermore, as one implementation method, refer to Figure 6 , Figure 7The upper part of the secondary damping air spring 72 is also provided with a gap adjustment mechanism 75 for adjusting the distance between the first limiting slider 743 and the second limiting slider 744, so as to adjust the engagement time of the tertiary damping air spring 73 to adapt to different road conditions and loads; the gap adjustment mechanism 75 includes a first double-threaded screw 751 arranged parallel to the axial direction of the limiting cylinder 741 and a first drive motor 756 for driving the first double-threaded screw 751 to rotate; the threads at the upper and lower ends of the first double-threaded screw 751 have opposite directions and the same pitch. The left-hand and right-hand threads of the lead screw 751 are respectively fitted with a first ball nut block 752 and a second ball nut block 753; the side of the limiting cylinder 741 is also provided with a through-hole strip opening 748 along its axial direction; the side of the first ball nut block 752 is provided with a first adjusting rod, the other end of the first adjusting rod is connected to the first limiting slider 743 through the strip opening 748; the side of the second ball nut block 753 is provided with a second adjusting rod, the other end of the second adjusting rod is connected to the second limiting slider 744 through the strip opening 748. The first drive motor 756 is mounted on the inertial stabilization platform 2; the lower end of the first double-threaded lead screw 751 is connected to the lower end of the side of the limiting cylinder 741 through a first bearing and a first bearing seat; the upper end of the first double-threaded lead screw 751 is connected to the upper flange of the secondary vibration damping air spring 72 through a sealed bearing. When the first drive motor 756 drives the first double threaded screw 751 to rotate around the shaft, the first ball nut block 752 and the second ball nut block 753 move synchronously towards or away from each other. Through the first adjusting rod and the second adjusting rod, the first limiting slider 743 and the second limiting slider 744 move closer or further away from each other, thereby changing the size of the gap between them. If the gap is reduced, the three-stage vibration damping air spring 73 can participate in the load more easily. If the gap is increased, the three-stage vibration damping air spring 73 will find it more difficult to participate in the load, thus realizing the adjustability of the amplitude threshold.

[0046] refer to Figure 4 and Figure 5The magnetorheological damping unit 8 is disposed between the upper mounting plate 5 and the lower mounting plate 6, and is used to provide limiting and adjustable damping. The magnetorheological damping unit 8 is a ring-shaped magnetorheological damper, which is coaxially sleeved on the outside of the vibration damping spring assembly 7. The upper and lower ends of the ring-shaped magnetorheological damper are respectively connected to the upper mounting plate 5 and the lower mounting plate 6. The ring-shaped magnetorheological damper has an excitation coil inside, and the control unit adjusts the excitation current according to the vibration acceleration to change the damping coefficient. The control unit collects the vertical acceleration signal of the inertial measurement unit (IMU) in real time, identifies the dominant frequency of the current vibration through short-time Fourier transform, and adjusts the damping current according to the vibration frequency: for high-frequency vibration (>100Hz): low damping to avoid energy transfer; for medium-frequency vibration (20-100Hz): moderate damping to quickly dissipate energy; for low-frequency resonance (<20Hz): high damping to suppress resonance peak.

[0047] refer to Figure 4 The inertial mass tuning unit is mounted on the lower mounting plate 6 and is used to absorb vibration energy in a specific frequency band. The inertial mass tuning unit includes a ring-shaped mass block 91 and several elastic support plates 92. The lower end of each elastic support plate 92 is mounted on the lower mounting plate 6, and its upper end is connected to the ring-shaped mass block 91, causing the ring-shaped mass block 91 to suspend above the lower mounting plate 6. The natural frequency of the ring-shaped mass block 91 is set to the main frequency band of road vibration. By designing the mass of the ring-shaped mass block 91 and the stiffness of the elastic support plates 92, its natural frequency is set to the main frequency band of road vibration, for example, 80-120Hz. When vibration is transmitted in this frequency band, the ring-shaped mass block 91 resonates, absorbing vibration energy, which is dissipated through the hysteresis effect of the elastic support plates 92, thus acting as a mechanical filter.

[0048] Furthermore, as a specific implementation, at least four of each of the upper mounting plate 5, lower mounting plate 6, vibration damping spring group 7, magnetorheological damping unit 8, and inertial mass tuning unit are provided. A plurality of the upper mounting plates 5 are arranged at equal intervals along the circumferential direction of the lower end face of the inertial stabilization platform 2, and a plurality of the lower mounting plates 6 are arranged at equal intervals along the circumferential direction of the upper end face of the antenna array 3. The number of vibration damping spring group 7, magnetorheological damping unit 8, and inertial mass tuning unit is the same as the number of upper mounting plates 5 and lower mounting plates 6, and they are arranged in a one-to-one correspondence. This multi-point support structure can effectively suppress the pitch and roll motion of the antenna array 3, ensuring that it always remains horizontal.

[0049] The control unit includes a sensor group, an embedded AI controller, and an actuator drive circuit for deep learning prediction and adaptive adjustment. The sensor group includes an inertial measurement unit mounted on the upper mounting plate 5 and the lower mounting plate 6 for measuring vibration acceleration and angular velocity; a displacement sensor mounted on the upper end of the lower mounting plate 6 for measuring the distance between the upper and lower mounting plates 5 and 6; and a front-mounted road surface perception sensor 10 and a speed sensor mounted on the support beam 1. The front-mounted road surface perception sensor 10 uses a high-resolution industrial camera or LiDAR to acquire images or point cloud data of the road surface ahead. The front-mounted road surface perception sensor 10 acquires road surface images or point cloud data within a range of 0.5-5 meters ahead at a frequency of 30-60Hz, and inputs the data to the embedded AI controller after noise reduction and coordinate transformation. The embedded AI controller runs an offline-trained CNN-LSTM deep learning model. This model takes road surface features, IMU time-series data, and vehicle speed as input and outputs the sequence of road surface undulations that the antenna array 3 will experience within the next 0.1 seconds and the corresponding optimal suspension parameters, ensuring that the suspension parameters reach their optimal state at the prediction time, thus achieving feedforward predictive control.

[0050] The control unit predicts future road surface undulations and optimal suspension parameters based on the data collected by the sensor group using a deep learning model, and drives the damping spring group 7, magnetorheological damping unit 8, and intermittent adjustment mechanism to perform adjustments in advance.

[0051] The embedded AI controller runs a CNN-LSTM deep learning model. This model takes as input images collected by the front-end road perception sensor 10 and time-series data collected by the inertial measurement unit, and outputs the optimal suspension parameters for the next 0.1-0.15 seconds. These suspension parameters include the air pressure of the primary damping air spring 71, the secondary damping air spring 72, and the tertiary damping air spring 73, as well as the magnetorheological damping current and the target clearance of the clearance adjustment mechanism 75. The embedded AI controller uses an embedded platform with a GPU (such as NVIDIA Jetson Orin NX) to run a lightweight deep learning model. The embedded AI controller communicates with each sensor and actuator via a CAN bus, connects to the radar host via Ethernet, and is equipped with a synchronization pulse interface to receive the TTL synchronization signal from the radar host.

[0052] The control unit is equipped with a synchronization pulse interface, which is connected to the radar host to synchronously store the predicted value, adjustment amount and sensor data with the radar data, so as to facilitate later traceability and data correction.

[0053] The displacement sensor is a laser displacement sensor or a magnetostrictive displacement sensor, used to measure the relative vertical displacement between the upper mounting plate 5 and the lower mounting plate 6.

[0054] A speed sensor connects to GPS or the vehicle's CAN bus to obtain real-time speed data.

[0055] The actuator drive circuit includes a push rod driver for driving the electric push rod 41, a solenoid valve driver for regulating air pressure, a first motor driver for operating the first drive motor 756, and a current regulator for operating the magnetorheological damping unit 8.

[0056] Example 2 This invention discloses an adaptive leveling device for an antenna array 3 of a ground-penetrating radar for road defects, based on embodiment 1 and with reference to... Figure 8 and Figure 9 It also includes a secondary vibration damping mechanism 11, which includes: The upper magnetic ring 111 and the lower magnetic ring 112 are connected to the upper mounting plate 5 through a guide bracket and a magnetic force adjustment mechanism; The intermediate magnetic ring 113 is connected to the lower mounting plate 6 via the second guide rod 115; The upper magnetic ring 111, the lower magnetic ring 112 and the middle magnetic ring 113 are coaxially arranged and are all axially magnetized permanent magnet rings. The middle magnetic ring 113 is attracted to the upper magnetic ring 111 and the lower magnetic ring 112 respectively. The magnetic force adjustment mechanism includes a second double-threaded lead screw 1161, a third ball nut block 1162, a fourth ball nut block 1163, and a second drive motor 1166, which are used to synchronously adjust the distance between the upper magnetic ring 111 and the lower magnetic ring 112 to change the magnitude of the attraction force on the middle magnetic ring 113.

[0057] The upper magnetic ring 111 has its N pole facing down, the lower magnetic ring 112 has its S pole facing up, and the middle magnetic ring 113 has its S pole facing up and its N pole facing down. In the initial equilibrium state, the middle magnetic ring 113 is located in the middle position between the upper magnetic ring 111 and the lower magnetic ring 112, and is subjected to an attractive force of equal magnitude and opposite direction, with a net force of zero.

[0058] The secondary vibration damping mechanism 11 is used to provide magnetic negative stiffness to achieve quasi-zero stiffness vibration isolation. The secondary vibration damping mechanism 11 is connected in parallel with the vibration damping spring group 7 and is coaxially arranged on the outer periphery of the magnetorheological damping unit 8.

[0059] refer to Figure 9 , Figure 10 , Figure 11 , Figure 12 and Figure 13The guide bracket includes an annular support base 1141 coaxially disposed below the lower magnetic ring 112. A plurality of first guide rods 1142 are arranged sequentially at equal intervals along the circumference of the upper end surface of the annular support base 1141. The upper end of the first guide rods 1142 is connected to the upper mounting plate 5. Each first guide rod 1142 is respectively fitted with two guide cylinders 1144 connected to the outside of the upper magnetic ring 111 and the lower magnetic ring 112 to ensure that the upper magnetic ring 111 and the lower magnetic ring 112 can slide smoothly along the first guide rods 1142. A plurality of guide holes 1143 for the second guide rods 115 to pass through are also provided vertically along the circumference of the annular support base 1141.

[0060] refer to Figure 9 The second double-threaded screw 1161 has opposite thread directions and the same pitch at its upper and lower ends. The third ball nut block 1162 and the fourth ball nut block 1163 respectively engage with the left-hand and right-hand threads of the second double-threaded screw 1161, and are connected to the upper magnetic ring 111 and the lower magnetic ring 112 respectively via the third adjusting rod 1164 and the fourth adjusting rod 1165. The second drive motor 1166 is mounted on the inertial stabilization platform 2 and is used to drive the second double-threaded screw 1161 to rotate around its axis. The lower end of the second double-threaded screw 1161 is connected to the side of the annular support 1141 via a second bearing and a second bearing seat, and the upper end of the second double-threaded screw 1161 is connected to the lower end face of the inertial stabilization platform 2 via a third bearing and a third bearing seat. When the second drive motor 1166 drives the second double threaded screw 1161 to rotate, the third ball nut block 1162 and the fourth ball nut move synchronously towards or away from each other, causing the upper magnetic ring 111 and the lower magnetic ring 112 to move closer or further away from each other. When the gap decreases, the magnetic force increases and the absolute value of the negative stiffness increases. When the gap increases, the magnetic force weakens. By adjusting the gap, the negative stiffness of the magnetic force can be matched with the positive stiffness of the current damping spring group 7.

[0061] When the support beam 1 vibrates downwards, the antenna array 3, the lower mounting plate 6, and the intermediate magnetic ring 113 remain stationary due to inertia. The primary damping air spring 71 and the secondary damping air spring 72 in the damping spring assembly 7 are compressed, generating a downward force acting on the antenna array 3. Meanwhile, the upper magnetic ring 111 and the lower magnetic ring 112 move downwards relative to the intermediate magnetic ring 113. The attraction of the upper magnetic ring 111 to the intermediate magnetic ring 113 increases, while the attraction of the lower magnetic ring 112 to the intermediate magnetic ring 113 decreases. This results in an upward magnetic attraction between the intermediate magnetic ring 113 and the antenna array 3. This upward magnetic attraction increases to counteract the downward force of the antenna array 3. Similarly, when the support beam 1 vibrates downwards... During the upward vibration, the antenna array 3, the lower mounting plate 6, and the intermediate magnetic ring 113 are stationary due to inertia. The primary damping air spring 71 and the secondary damping air spring 72 in the damping spring assembly 7 are stretched, generating an upward elastic force acting on the antenna array 3. Meanwhile, the upper magnetic ring 111 and the lower magnetic ring 112 move upward relative to the intermediate magnetic ring 113. The attraction of the upper magnetic ring 111 to the intermediate magnetic ring 113 decreases, while the attraction of the lower magnetic ring 112 to the intermediate magnetic ring 113 increases. This causes the intermediate magnetic ring 113 and the antenna array 3 to generate a downward magnetic attraction force. The increase in the downward magnetic attraction force counteracts the upward elastic force of the antenna array 3, making the net force change on the antenna array 3 zero. Through this mechanism, the force change generated by the secondary vibration damping mechanism 11 is equal in magnitude and opposite in direction to the change of the vibration damping spring group 7, so that the total stiffness of the system approaches zero within a small displacement range, achieving quasi-zero stiffness vibration isolation. At this time, external vibration is difficult to be transmitted to the antenna array 3 through elastic force, and the antenna array 3 and the support beam 1 are dynamically decoupled, reducing the impact of the vibration of the support beam 1 on the antenna array 3, so that the antenna array 3 maintains a stable motion state.

[0062] The actuator drive circuit also includes a second motor driver for operating the second drive motor 1166.

[0063] Working principle: Before detection, the air source is activated to inflate each air spring to the preset pressure. The control unit adjusts the distance between the upper magnetic ring 111 and the lower magnetic ring 112 to the corresponding value through the second drive motor 1166 according to the current antenna weight and the inflation pressure of each air spring, so that the negative stiffness matches the positive stiffness of the spring and the system is in a balanced state. While the vehicle is moving, the front-mounted road perception sensor 10 (using a camera) collects road images, the IMU collects triaxial acceleration and angular velocity, the displacement sensor collects relative displacement, and the speed is obtained from GPS. All data are aligned by timestamp. The deep learning model adopts a CNN-LSTM structure. The CNN extracts features such as road surface texture, cracks, and potholes from the image; the LSTM processes temporal IMU data to capture vibration history patterns. The model takes the current moment and the data from the past second as input and outputs the road surface undulation sequence and optimal suspension parameters for the next 0.1 seconds, including the distance between the first limit slider 743 and the second limit slider 744, the air pressure of the first-stage damping air spring 71, the air pressure of the second-stage damping air spring 72, the air pressure of the third-stage damping air spring 73, the damping current, and the distance between the upper magnetic ring 111 and the lower magnetic ring 112. The model is trained offline using a large amount of real road surface data and inferred online. Based on the prediction results, the controller sends instructions to the first motor driver, solenoid valve driver, current regulator, and second motor driver 0.1 seconds in advance. The first drive motor 756 drives the first double threaded screw 751 to adjust the clearance, and the corresponding solenoid valve and pressure relief valve adjust the pressure of each air spring. The current regulator sets the damping current, and the second drive motor 1166 drives the second double threaded screw 1161 to adjust the magnetic force. After the adjustment is completed, the suspension system is in the optimal state at the predicted time. When encountering high-frequency micro-vibrations (amplitude <0.5mm), the three-stage damping air spring 73 does not participate, and the system stiffness is determined by the series connection of the two-stage damping air spring 72 and the first-stage damping air spring 71. At the same time, the two-stage damping mechanism 11 generates a change in opposite force, making the total stiffness approach zero. The dynamic force on the antenna array 3 is almost zero, and the antenna array 3 maintains its original motion state and is not affected by vibration. When encountering a large impact (amplitude > 0.5 mm), the three-stage damping air spring 73 participates in bearing the load, increasing the system stiffness. The magnetorheological damping unit 8 adjusts the damping according to the vibration intensity, and the inertial mass tuning unit absorbs the main frequency energy, thus dissipating the vibration together.

[0064] Meanwhile, the auxiliary attitude correction mechanism 4 slowly adjusts the level of the inertial stabilization platform 2 and the antenna array 3 according to the attitude tilt detected by the IMU, ensuring that the antenna array 3 remains level for a long time.

[0065] All predicted values, adjustment values, sensor data, and radar synchronization pulses are bound to a storage medium and written to a storage medium for later traceability and data correction.

[0066] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0067] The embodiments described above are merely illustrative of implementation methods of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention. Therefore, the scope of protection of this patent should be determined by the appended claims.

Claims

1. An adaptive leveling device for an antenna array used in ground-penetrating radar for road defects, characterized in that, include: The support beam (1) is used to connect to the probe vehicle or the pusher frame; An inertial stabilization platform (2) is located below the support beam (1); Antenna array (3) is located below inertial stabilization platform (2); An auxiliary attitude correction mechanism (4) is connected between the support beam (1) and the inertial stabilization platform (2). It includes four sets of electric push rods (41). The upper end of each set of electric push rods (41) is connected to the support beam (1) through a joint bearing (42), and the lower end of the electric push rods (41) is connected to the inertial stabilization platform (2) through a universal joint (43). It is used to compensate for the long-term attitude tilt of the antenna array (3). The upper mounting plate (5) is connected to the lower end of the inertial stabilization platform (2); The lower mounting plate (6) is connected to the upper end of the antenna array (3); The damping spring assembly (7) is disposed between the upper mounting plate (5) and the lower mounting plate (6), including a first-stage damping air spring (71) and a second-stage damping air spring (72) connected in series, and a third-stage damping air spring (73) coaxially disposed inside the second-stage damping air spring (72). A floating limit mechanism (74) is provided between the three-stage damping air spring (73) and the upper mounting plate (5) to control the engagement timing of the three-stage damping air spring (73); A magnetorheological damping unit (8) is disposed between the upper mounting plate (5) and the lower mounting plate (6) to provide limiting and adjustable damping.

2. The adaptive leveling device for an antenna array of a ground-penetrating radar for road defects according to claim 1, characterized in that, The upper flange of the secondary damping air spring (72) is connected to the lower end face of the upper mounting plate (5), the lower flange of the secondary damping air spring (72) is connected to the upper flange of the primary damping air spring (71), the lower flange of the primary damping air spring (71) is connected to the upper end face of the lower mounting plate (6), the lower flange of the tertiary damping air spring (73) is connected to the inner side of the lower flange of the secondary damping air spring (72), and a pressure-bearing boss that cooperates with the floating limit mechanism (74) is vertically and coaxially arranged on the upper flange of the tertiary damping air spring (73).

3. The adaptive leveling device for an antenna array of ground-penetrating radar for road defects according to claim 2, characterized in that, The floating limiting mechanism (74) includes a limiting cylinder (741) coaxially arranged with the pressure-bearing boss. The upper end of the limiting cylinder (741) is connected to the inner side of the upper flange of the secondary damping air spring (72). A limiting slide cavity (742) is coaxially arranged inside the limiting cylinder (741). A first limiting slider (743) and a second limiting slider (744) are symmetrically adapted inside the limiting slide cavity (742). The pressure-bearing boss includes a floating slider (745) disposed between the first limiting slider (743) and the second limiting slider (744) and a floating rod (746) for connecting with the floating slider (745) and the upper flange of the tertiary damping air spring (73).

4. The adaptive leveling device for an antenna array of a ground-penetrating radar for road defects according to claim 3, characterized in that, Both the first limiting slider (743) and the second limiting slider (744) have buffer pads (747) on their respective end faces that are close to each other, which are used to absorb contact impact.

5. The adaptive leveling device for an antenna array of a ground-penetrating radar for road defects according to claim 3, characterized in that, The limiting slide cavity (742) is further provided with a plurality of guide posts (749) parallel to its axial direction. The plurality of guide posts (749) are evenly spaced around the axis of the limiting slide cavity (742). The first limiting slider (743), the second limiting slider (744) and the floating slider (745) are respectively provided with sliding holes adapted to the guide posts (749).

6. The adaptive leveling device for an antenna array of a ground-penetrating radar for road defects according to claim 3, characterized in that, The upper part of the secondary damping air spring (72) is also provided with a gap adjustment mechanism (75) for adjusting the distance between the first limiting slider (743) and the second limiting slider (744), so as to adjust the engagement time of the tertiary damping air spring (73); the gap adjustment mechanism (75) includes a first double-threaded screw (751) arranged parallel to the axial direction of the limiting cylinder (741) and a first drive motor (756) for driving the first double-threaded screw (751) to rotate; the threads at the upper and lower ends of the first double-threaded screw (751) have opposite directions and the same pitch, and the first double-threaded screw (751) is... The left-hand thread and the right-hand thread of 51) are respectively equipped with a first ball nut block (752) and a second ball nut block (753); the side of the limiting cylinder (741) is also provided with a through strip opening (748) along its axial direction; the side of the first ball nut block (752) is provided with a first adjusting rod, the other end of the first adjusting rod is connected to the first limiting slider (743) through the strip opening (748); the side of the second ball nut block (753) is provided with a second adjusting rod, the other end of the second adjusting rod is connected to the second limiting slider (744) through the strip opening (748).

7. The adaptive leveling device for an antenna array of a ground-penetrating radar for road defects according to claim 1, characterized in that, The magnetorheological damping unit (8) is a circular magnetorheological damper. The circular magnetorheological damper is coaxially sleeved on the outside of the vibration damping spring group (7). The upper and lower ends of the circular magnetorheological damper are respectively connected to the upper mounting plate (5) and the lower mounting plate (6). The circular magnetorheological damper is equipped with an excitation coil. The control unit adjusts the excitation current according to the vibration acceleration to change the damping coefficient.

8. An adaptive leveling device for an antenna array of a ground-penetrating radar for road defects according to any one of claims 1-7, characterized in that, It also includes an inertial mass tuning unit, which is mounted on the lower mounting plate (6) and is used to absorb vibration energy in a specific frequency band.

9. The adaptive leveling device for an antenna array of a ground-penetrating radar for road defects according to claim 8, characterized in that, The inertial mass tuning unit includes an annular mass block (91) and several elastic support plates (92); the lower end of the elastic support plate (92) is located on the lower mounting plate (6), and its upper end is connected to the annular mass block (91), so that the annular mass block (91) is suspended above the lower mounting plate (6), and the natural frequency of the annular mass block (91) is set to the main frequency band of road vibration.

10. The adaptive leveling device for an antenna array of a ground-penetrating radar for road defects according to claim 9, characterized in that, At least four of each of the upper mounting plate (5), lower mounting plate (6), vibration damping spring group (7), magnetorheological damping unit (8), and inertial mass tuning unit are provided. Several of the upper mounting plates (5) are arranged at equal intervals along the lower end face of the inertial stabilization platform (2), and several of the lower mounting plates (6) are arranged at equal intervals along the upper end face of the antenna array (3). The number of vibration damping spring group (7), magnetorheological damping unit (8), and inertial mass tuning unit is the same as the number of upper mounting plate (5) and lower mounting plate (6) and they are arranged in a one-to-one correspondence.

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