Adaptive telescopic detection device for tunnel detection and obstacle avoidance method thereof

Abstract

The application relates to a self-adaptive telescopic detection device for tunnel detection and an obstacle avoidance method thereof. The detection device comprises a walking main body, a mechanical arm and a detection assembly connected in sequence. The detection assembly comprises a detection device, an outer frame, a bearing plate and elastic shock absorbers. The outer frame has opposite first and second surfaces. The detection device is arranged inside the outer frame and has a detection direction towards the first surface. The first surface is provided with a walking wheel. The bearing plate is arranged outside the second surface. The elastic shock absorbers are connected between the bearing plate and the second surface. The side surface of the bearing plate away from the second surface is hingedly connected to the end of the mechanical arm. When the tunnel lining surface has construction joint dislocation, local repair unevenness and different cross-section curvature changes and the like, the walking posture of the detection assembly can be self-adaptively adjusted based on the elastic shock absorbers and the hinged structure between the mechanical arm and the bearing plate. Therefore, the relative position with the lining surface can be kept stable, so that the data acquisition quality is improved.

Description

Technical Field

[0001] This application relates to the field of tunnel inspection equipment technology, and in particular to an adaptive telescopic inspection device for tunnel inspection and its obstacle avoidance method. Background Technology

[0002] During long-term use, tunnel linings are prone to internal voids and other defects due to geological stress, groundwater erosion, and other factors, requiring regular inspection. Currently, inspection devices with extendable robotic arms are commonly used to inspect tunnel linings.

[0003] However, in existing detection devices, the end detection components mostly use rigid connections or simple movable structures to connect the robotic arm. When there are construction joint misalignments, uneven local repairs, and different cross-sectional curvatures on the tunnel lining surface, the detection components cannot automatically adjust their posture with the undulations of the lining surface, resulting in large fluctuations in bonding pressure and affecting the accuracy of the detection. Summary of the Invention

[0004] Therefore, it is necessary to provide an adaptive telescopic detection device for tunnel detection and its obstacle avoidance method to address the above-mentioned technical problems.

[0005] An adaptive telescopic detection device for tunnel inspection includes a walking body, a robotic arm, and a detection component. One end of the robotic arm is connected to the walking body, and the detection component is connected to the other end of the robotic arm. The detection component includes a detection device, an outer frame, a support plate, and elastic shock absorbers. The outer frame has a first surface and a second surface facing each other. The detection device is disposed inside the outer frame and its detection direction is towards the first surface. A walking wheel is disposed on the first surface. The support plate is disposed on the outer side of the second surface. Multiple elastic shock absorbers are connected between the support plate and the second surface. The side of the support plate facing away from the second surface is hinged to the end of the robotic arm.

[0006] When the tunnel lining surface has issues such as misaligned construction joints, uneven local repairs, and variations in curvature of different sections, the aforementioned detection device can adaptively adjust the walking posture of the detection component based on the hinge structure between the robotic arm and the bearing plate, as well as the setting of elastic shock absorbers. The hinge structure provides the degree of freedom for angle changes, and the elastic shock absorbers can provide normal floating and absorb vibration while maintaining contact between the walking wheels and the lining surface. This ensures the stability of the relative position between the detection component and the lining surface under the aforementioned conditions, thereby improving the quality of data acquisition.

[0007] In some embodiments, the elastic shock absorber includes a guide shaft, a shock absorber spring, and a linear bearing. One end of the guide shaft is fixed to the second surface, and the other end is housed in the linear bearing. The linear bearing is fixed to the side surface of the support plate facing the second surface. The shock absorber spring is sleeved on the guide shaft, and its two ends abut against the second surface and the support plate, respectively.

[0008] In some embodiments, the resilient damper further includes a damping bushing nested between the linear bearing and the guide shaft, and the damping bushing is fixed to the linear bearing.

[0009] In some embodiments, an attitude adjustment component is also provided at the end of the robotic arm. The attitude adjustment component includes a first telescopic drive member and a connector. The connector is fixedly sleeved on the robotic arm. One end of the first telescopic drive member is hinged to the connector, and the other end is hinged to the side surface of the support plate opposite to the second surface.

[0010] In some embodiments, the robotic arm includes a first arm, a second arm, and a third arm, all configured as hollow columnar structures. The second arm is at least partially nested within the first arm, and the third arm is at least partially nested within the second arm. The robotic arm also includes a second telescopic drive and a linkage mechanism. The end of the second telescopic drive is fixed within the first arm, and the drive end of the second telescopic drive is connected to the second arm. The linkage mechanism is connected between the second arm and the third arm and is used to cause the third arm to telescopically extend and retract synchronously when the second telescopic drive drives the second arm to extend and retract.

[0011] In some embodiments, the linkage mechanism includes: a first linkage unit comprising a first movable pulley and a first rope that cooperate with each other, the first movable pulley being fixed to the end of the second arm, one end of the first rope being fixed to a first anchor point on the inner side of the first arm, and the other end of the first rope being fixed to a second anchor point on the end of the third arm; and a second linkage unit comprising a second movable pulley and a second rope that cooperate with each other, the second movable pulley being fixed to the inner side of the second arm, one end of the second rope being fixed to a third anchor point on the end of the third arm, and the other end of the second rope being fixed to a fourth anchor point on the inner side of the first arm.

[0012] In some embodiments, the robotic arm further includes a stroke amplification assembly, which includes a third movable pulley and a third cable that cooperate with each other. The third movable pulley is fixed to the drive end of the second telescopic drive member, one end of the third cable is fixed to the fifth anchor point at the end of the first arm, and the other end of the third cable is fixed to the sixth anchor point at the end of the second arm.

[0013] In some embodiments, one end of the robotic arm is connected to the rotating base of the walking body. The rotating base includes a base and a rotating seat disposed on the base. The end of the robotic arm is hinged to the rotating seat, and a third telescopic drive is connected between the robotic arm and the rotating seat. The rotating seat is configured as a worm gear structure, and the walking body is provided with a worm drive that meshes with the rotating seat.

[0014] In some embodiments, the system further includes a controller and a first obstacle avoidance sensor and a second obstacle avoidance sensor electrically connected to the controller. The first obstacle avoidance sensor includes a depth camera, and the second obstacle avoidance sensor includes a lidar. The controller is disposed on the walking body, the first obstacle avoidance sensor is disposed on the third surface of the outer frame, which is the front end surface of the outer frame when it moves with the walking body, and the second obstacle avoidance sensor is disposed on two opposite fourth surfaces of the outer frame, with the opposite direction of the two fourth surfaces perpendicular to the direction of movement of the outer frame with the walking body.

[0015] An obstacle avoidance method for an adaptive telescopic detection device for tunnel inspection is provided. The detection device includes a robotic arm and a LiDAR and a depth camera mounted on the robotic arm. The method includes: transforming the coordinate systems of the LiDAR and depth camera to the coordinate system of the robotic arm's end effector, and aligning the sampling data of the LiDAR and depth camera in the time dimension; generating a first two-dimensional grid map based on the LiDAR sampling data, and projecting a second two-dimensional grid map based on the depth camera sampling data; fusing the first and second two-dimensional grid maps, merging the occupancy states of the same grid cells in both maps, and generating a comprehensive occupancy grid map; constructing an artificial potential field based on the comprehensive occupancy grid map, and determining the resultant force on the end effector of the robotic arm based on the artificial potential field to control the robotic arm to perform obstacle avoidance movements; the artificial potential field includes an attractive field generated by the target point on the end effector of the robotic arm, a repulsive field generated by the obstacle on the end effector of the robotic arm, and a limiting potential field used to constrain the range of motion of the robotic arm joints. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the overall structure of the detection device in some embodiments of this application.

[0017] Figure 2 This is a partial schematic diagram of the detection device at the detection component.

[0018] Figure 3 for Figure 2 A schematic diagram of the structure shown from another perspective.

[0019] Figure 4 This is a partial schematic diagram of the detection component at the elastic damper.

[0020] Figure 5 This is a schematic diagram of the first obstacle avoidance sensor at the detection component.

[0021] Figure 6 This is a partial cross-sectional view of the robotic arm of the detection device.

[0022] Figure 7 This is a transient dynamics analysis cloud diagram of the robotic arm of the detection device in some embodiments of this application.

[0023] Figure 8 The first-order mode shape contour map of the robotic arm of the detection device.

[0024] Figure 9 The second-order mode shape contour map of the robotic arm of the detection device.

[0025] Figure 10 The third-order mode shape cloud diagram of the robotic arm of the detection device.

[0026] Figure 11 The fourth-order mode shape cloud diagram of the robotic arm of the detection device.

[0027] Figure 12 The fifth-order mode shape cloud diagram of the robotic arm of the detection device.

[0028] Figure 13 The image shows the sixth-order modal vibration mode cloud diagram of the robotic arm of the detection device.

[0029] Figure label:

[0030] 1. Robotic arm; 11. First arm; 111. First anchor point; 112. Fourth anchor point; 113. Fifth anchor point; 12. Second arm; 121. Sixth anchor point; 13. Third arm; 131. Second anchor point; 132. Third anchor point; 14. Second telescopic drive component; 15. First linkage unit; 151. First movable pulley; 152. First rope; 16. Second linkage unit; 161. Second movable pulley; 162. Second rope; 17. Stroke amplification component; 171. Third movable pulley; 172. Third rope; 18. Through-hole;

[0031] 2. Detection components; 21. Outer frame; 211. Opening; 21a. First surface; 21b. Second surface; 21c. Third surface; 22. Elastic shock absorber; 221. Guide optical axis; 222. Shock-absorbing spring; 223. Linear bearing; 23. Bearing plate; 24. Wheels; 25. Detection device;

[0032] 3. Rotary base; 31. Rotary seat; 32. Third telescopic drive component;

[0033] 4. Attitude adjustment component; 41. Connector; 42. First telescopic drive component;

[0034] 5. First obstacle avoidance sensor. Detailed Implementation

[0035] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0036] In the description of this application, it should be understood that if terms such as "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" appear, these terms indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and 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, and therefore should not be construed as a limitation of this application.

[0037] Furthermore, where the terms "first" and "second" appear, these terms are 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 with "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, where the term "multiple" appears, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0038] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; 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; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0039] In this application, unless otherwise expressly specified and limited, the use of descriptions such as "above" or "below" the second feature indicates that the first and second features are in direct contact or indirect contact via an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. Similarly, "below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0040] It should be noted that if an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. If an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. If so, the terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used in this application are for illustrative purposes only and do not represent the only possible implementation.

[0041] In some embodiments, please refer to Figure 1 and Figure 2 This application provides an adaptive telescopic detection device for tunnel inspection, including a traveling body (not shown in the drawings), a robotic arm 1, and a detection component 2. One end of the robotic arm 1 is connected to the traveling body, and the detection component 2 is connected to the other end of the robotic arm 1. The traveling body is used to move the entire detection device along the tunnel to continuously inspect the lining in different areas along the tunnel's extension direction. The traveling body can be a vehicle adapted to the tunnel space. The robotic arm 1 is used to extend and retract to drive the detection component 2 to the corresponding detection position. For example, for the lining at different heights in the tunnel, the extension and retraction of the telescopic arm can drive the detection component 2 to the corresponding height. The detection component 2 moves with the traveling body to scan and inspect the lining.

[0042] The detection component 2 includes a detection device 25, an outer frame 21, a support plate 23, and elastic shock absorbers 22. The outer frame 21 is generally designed as a rectangular box structure with opposing first surfaces 21a and second surfaces 21b. The first surface 21a faces the lining to be detected. The detection device 25 is located inside the outer frame 21 with its detection direction facing the first surface 21a. Wheels 24 (which can be universal wheels) are provided on the first surface 21a to allow the detection component 2 to move along the lining surface. The support plate 23 is located outside the second surface 21b and spaced apart from it. Multiple elastic shock absorbers 22 are connected between the support plate 23 and the second surface 21b. The side of the support plate 23 facing away from the second surface 21b is hinged to the end of the robotic arm 1; this hinge can be achieved using a universal joint.

[0043] In use, the robotic arm 1 drives the detection component 2 to the corresponding position on the lining. With the first surface 21a of the outer frame 21 facing the lining, the traveling wheels 24 on the first surface 21a contact the lining surface. At this time, the robotic arm 1 applies force to the outer frame 21 through the bearing plate 23 and the elastic shock absorber 22, ensuring stable contact between the traveling wheels 24 and the lining surface. Driven by the traveling body, the detection component 2 can move along the lining surface to perform scanning detection.

[0044] Based on this, when there are issues such as misaligned construction joints, uneven local repairs, and variations in curvature of different sections on the tunnel lining surface, the walking posture of the detection component 2 can be adaptively adjusted based on the hinge structure between the robotic arm 1 and the bearing plate 23 and the setting of the elastic shock absorber 22. The hinge structure can provide the degree of freedom for angle changes, and the elastic shock absorber 22 can provide normal (i.e., the direction perpendicular to the lining surface) floating and absorb vibration while keeping the walking wheel 24 in contact with the lining surface. Thus, the relative position of the detection component 2 and the lining surface can be kept stable under the above conditions, thereby improving the quality of data acquisition.

[0045] Optionally, the side of the support plate 23 facing away from the second surface 21b is hinged to the end of the robotic arm 1 via a universal joint. The universal joint includes mutually orthogonal pitch and yaw rotation axes, providing the detection assembly 2 with two passive rotational degrees of freedom, pitch and yaw, enabling the detection assembly 2 to automatically adjust its attitude according to changes in the curvature of the tunnel cross section. The center of the universal joint is located on the vertical line of the center of gravity of the outer frame 21 and the detection device 25 as a whole, reducing the influence of gravitational eccentricity on free rotation.

[0046] Optionally, the detection device 25 described above can be a ground penetrating radar (GPR). See also... Figure 3The ground-penetrating radar is embedded in the outer frame 21. The first surface 21a of the outer frame 21 is set at the opening 211 corresponding to the ground-penetrating radar, which is used to allow the ground-penetrating radar to emit electromagnetic waves to the lining.

[0047] In some embodiments, please refer to Figure 4 Multiple elastic shock absorbers 22 can be provided between the support plate 23 and the second surface 21b of the outer frame 21. For example, four elastic shock absorbers 22 can be provided, located at the four corners of the second surface 21b of the outer frame 21. The elastic shock absorber 22 includes a guide shaft 221, a shock absorber spring 222, and a linear bearing 223.

[0048] The guide optical shaft 221 has a diameter of 20mm. One end is fixed to the second surface 21b via an end face flange, and the other end is housed in a linear bearing 223. The linear bearing 223 is fixed to the side of the support plate 23 facing the second surface 21b via the end face flange. The linear bearing 223 has a cylindrical structure with an inner diameter that matches the diameter of the guide optical shaft 221, and an effective guiding length of 80mm, used to overcome lateral bending moments. A shock-absorbing spring 222 is sleeved on the guide optical shaft 221, with one end abutting against the second surface 21b and the other end abutting against the side of the support plate 23 facing the second surface 21b, providing normal elastic floating stroke for the outer frame 21 and the detection device 25 as a whole.

[0049] Optionally, the elastic damper 22 also includes a damping bushing (not shown in the attached figure), which is nested between the linear bearing 223 and the guide optical shaft 221, and is fixed to the linear bearing 223. The damping bushing is made of a polymer damping material, which can absorb high-frequency vibration energy under dynamic detection conditions and suppress resonance of the spring-mass system.

[0050] In some embodiments, please refer to Figure 2 The detection device also includes an attitude adjustment component 4 disposed at the end of the robotic arm 1. The attitude adjustment component 4 includes a first telescopic drive component 42 and a connecting component 41. The connecting component 41 can be a clamp structure and fixedly sleeved on the robotic arm 1; the first telescopic drive component 42 can be an electric push rod, one end of which is hinged to the connecting component 41 and the other end of which is hinged to the side surface of the bearing plate 23 opposite to the second surface 21b.

[0051] The aforementioned hinge can be achieved through a universal joint (e.g., a cross universal joint) to relieve torsional internal stress in multi-axis motion, transform the spatially constrained system into a statically determinate mechanism, and prevent the push rod from bearing bending moment.

[0052] Based on the above-mentioned attitude adjustment component 4, during normal scanning operations, it can compensate for the long cantilever gravity deflection of the robotic arm 1 and the vehicle body sway error, thereby improving the accuracy of the relative position of the detection component 2 and the tunnel lining. When obstacle avoidance is required, the attitude adjustment component 4 can drive the detection component 2 to adjust its attitude by driving the bearing plate 23, such as deflection or lifting, to achieve obstacle avoidance.

[0053] In some embodiments, please refer to Figure 1 One end of the robotic arm 1 is connected to the rotating base 3 of the walking body, meaning the robotic arm 1 is connected to the walking body via the rotating base 3. The rotating base 3 includes a base (not shown in the attached drawings) and a rotating seat 31. The base is located on the walking body, and the rotating seat 31 is located on the base and can rotate relative to the base. The rotating seat 31 is configured with a worm gear structure, and the walking body is equipped with a worm drive component (not shown in the attached drawings) that meshes with the rotating seat 31. The self-locking characteristic of the worm gear prevents instability and overturning in the event of a power outage or malfunction.

[0054] For example, the bottom of the rotary seat 31 is constructed as a worm gear structure; or, the rotary seat 31 includes a main body and a worm gear connected by bolts, with the worm drive meshing with the worm gear.

[0055] The end of the robotic arm 1 is hinged to the top of the rotary base 31, and a third telescopic drive member 32 is connected between the robotic arm 1 and the rotary base 31. The third telescopic drive member 32 is disposed on the rotary base 31, and the driving end of the third telescopic drive member 32 is hinged to a position near the end of the robotic arm 1; the third telescopic drive member 32 is used to adjust the overall pitch angle of the robotic arm 1, specifically, it can drive the robotic arm 1 to pitch and swing within the range of -30° to +70°.

[0056] Furthermore, the rotary seat 31 can be configured as a trapezoidal structure, wider at the bottom and narrower at the top. This widened bottom increases the bending section modulus, reduces stress concentration, and lowers the center of gravity, improving lateral stability; while the narrowed top allows space for the robotic arm 1 to move at large elevation angles.

[0057] In some examples, a scissor lift mechanism can also be installed between the aforementioned rotating base 3 and the traveling body, i.e., the rotating base 3 is mounted on the scissor lift mechanism, and the scissor lift mechanism is mounted on the traveling body. The scissor lift mechanism can work in conjunction with the extension and retraction of the robotic arm 1 to meet the detection requirements at different heights of the tunnel lining, and can relatively reduce the extension length requirement of the robotic arm 1. At the same time, the scissor lift mechanism can be used to lower the overall height of the detection device when retracting, meeting the height limits when passing through certain scenarios; and then raise it to the reference working height when working.

[0058] In some embodiments, please refer to Figure 5The detection device also includes a controller (not shown in the figure) and a first obstacle avoidance sensor 5 and a second obstacle avoidance sensor (not shown in the figure) electrically connected to the controller. The first obstacle avoidance sensor 5 includes a depth camera, and the second obstacle avoidance sensor includes a lidar.

[0059] The controller is located on the walking body and is also electrically connected to corresponding components to control the movement of the corresponding components or receive data from the corresponding components. For example, the controller can also be electrically connected to the aforementioned detection device 25 and the corresponding telescopic drive component. The first obstacle avoidance sensor 5 is located on the third surface 21c of the outer frame 21, which is the front end surface of the outer frame 21 when it moves with the walking body. The second obstacle avoidance sensors are respectively located on two opposite fourth surfaces of the outer frame 21, with the opposite direction of the two fourth surfaces perpendicular to the direction of movement of the outer frame 21 with the walking body.

[0060] Based on this, the first obstacle avoidance sensor 5 and the second obstacle avoidance sensor can detect the environment around the detection component 2, identify obstacles, and transmit the information to the controller so that the controller can control the movement of the robotic arm 1 and other components of the detection device to achieve obstacle avoidance.

[0061] Furthermore, the lidar can be a 360° all-around scanning radar based on the Time of Flight (ToF) principle, with its scanning plane parallel to the travel plane of the detection component 2 (i.e., the lining surface). The sampling frequency is 20Hz, and the detection range is 15m. It is used for: detecting obstacles such as lighting fixtures, fans, and cable trays on the tunnel wall 5-10m in advance; establishing a safety protection zone with a radius of 2m around the end of the robotic arm 1; and providing self-interference early warning by scanning the links of the robotic arm 1 in real time.

[0062] The depth camera can be a binocular structured light depth camera, with its optical axis tilted downwards at 30° relative to the travel plane, and the center of its field of view aligned with the area in front of the travel path of the detection component 2. The sampling frequency is 30Hz, and the output is dense 3D point cloud data. Its function is to compensate for low-lying obstacles and abnormal terrain features that cannot be detected by lidar, including gravel, bulges, and surface peeling and pitting.

[0063] The first obstacle avoidance sensor 5 and the second obstacle avoidance sensor complement each other in four dimensions: detection range, with the lidar covering medium to long distances (1m~15m) and the depth camera covering short distances (0.3m~5m); data dimension, with the lidar providing two-dimensional information and the depth camera providing three-dimensional elevation; field of view, with the lidar performing a 360° full-circle scan and the depth camera focusing on the area in front; and environmental adaptability, with the lidar unaffected by lighting conditions and the depth camera offering higher accuracy in close-range recognition.

[0064] In some embodiments, please refer to Figure 1 and Figure 6The robotic arm 1 includes multiple arm segments, specifically a first arm 11, a second arm 12, and a third arm 13, all of which are hollow columnar structures. The second arm 12 is at least partially nested within the first arm 11, and the third arm 13 is at least partially nested within the second arm 12. The first arm 11, the second arm 12, and the third arm 13 can extend and retract relative to each other to achieve overall extension and retraction of the robotic arm 1.

[0065] All boom sections are made of high-strength aluminum alloy with a non-equilateral rectangular cross-section where the height is greater than the width. The primary stress directions are vertical gravity and dynamic loads, with relatively small lateral forces. Therefore, increasing the height and decreasing the width allows for weight reduction while maintaining bending stiffness, while also reducing wind resistance and lateral flutter by decreasing the width of the windward face. The dimensions of robotic arm 1 are as follows: First arm 11: 2400mm in length, 120mm wide × 160mm high, 6mm thick; Second arm 12: 2100mm in length, 80mm wide × 120mm high, 5mm thick; Third arm 13: 2000mm in length, 60mm wide × 90mm high, 5mm thick. Sliding supports are achieved between boom sections using self-lubricating polymer guide sliders made of modified MC nylon or heavy-duty polyurethane to compensate for machining and assembly errors. Dustproof and waterproof sealing strips are installed at the boom section joints to adapt to the dusty and humid environment of tunnels. Each boom segment is equipped with a mechanical limit stop and a travel switch to prevent overtravel.

[0066] Furthermore, the robotic arm 1 also includes a second telescopic drive component 14 (e.g., a servo electric cylinder) and a linkage mechanism. The second telescopic drive component 14 is fixed to the end of the first arm 11, and its drive end is connected to the second arm 12. The linkage mechanism is connected between the second arm 12 and the third arm 13, and is used to synchronously extend and retract the third arm 13 when the second telescopic drive component 14 drives the second arm 12 to extend and retract. Based on the second telescopic drive component 14 and the linkage mechanism, multi-stage extension and retraction of the robotic arm 1 can be achieved using a single power source.

[0067] In some embodiments, such as Figure 6 As shown, the linkage mechanism includes a first linkage unit 15 and a second linkage unit 16.

[0068] The first linkage unit 15 includes a first movable pulley 151 and a first rope 152 that cooperate with each other. The first movable pulley 151 is fixed to the end inside the second arm 12. One end of the first rope 152 is fixed to the first anchor point 111 on the inner side of the first arm 11. The other end of the first rope 152 passes through the corresponding through hole on the second arm 12 and around the first movable pulley 151 before being fixed to the second anchor point 131 at the end outside the third arm 13.

[0069] The second linkage unit 16 includes a second movable pulley 161 and a second rope 162 that cooperate with each other. The second movable pulley 161 is fixed to the inner side of the second arm 12. One end of the second rope 162 is fixed to the third anchor point 132 at the outer end of the third arm 13. The other end of the second rope 162 passes around the second movable pulley 161 and through the corresponding through hole on the second arm 12, and is fixed to the fourth anchor point 112 on the inner side of the first arm 11.

[0070] Based on this, when the second telescopic drive 14 directly drives the second arm 12 to extend, the second movable pulley 161 of the second linkage unit 16 moves with the second arm 12, thereby driving the second rope 162. The second rope 162 drives the third arm 13 to extend synchronously through the third anchor point 132. Furthermore, based on the stroke amplification characteristic of the movable pulley mechanism, the extension length of the third arm 13 driven by the third anchor point 132 is twice the extension length of the second arm 12, thus achieving multi-stage extension. When the second telescopic drive 14 directly drives the second arm 12 to retract, the first movable pulley 151 of the first linkage unit 15 moves with the second arm 12, thereby driving the first rope 152. The first rope 152 drives the third arm 13 to retract synchronously through the second anchor point 131. Furthermore, based on the stroke amplification characteristic of the movable pulley mechanism, the retraction length of the third arm 13 driven by the second anchor point 131 is twice the retraction length of the second arm 12, thus achieving multi-stage retraction.

[0071] Furthermore, Figure 6 This is merely an illustrative representation of the principle structure of the aforementioned linkage unit within the robotic arm 1 and does not represent the actual structural design. In actual implementation, considering the balance of forces, a first linkage unit 15 can be respectively arranged on opposite sides of the robotic arm 1 in one direction, and a second linkage unit 16 can be respectively arranged on opposite sides of the robotic arm 1 in another direction. Furthermore, the first linkage unit 15 and the second linkage unit 16 are offset from the aforementioned guide sliders arranged between the arm segments.

[0072] In some embodiments, such as Figure 6 As shown, the ends of the second arm 12 and the third arm 13 are provided with through openings 18 to avoid the second telescopic drive member 14 and to provide space for the installation of the second telescopic drive member 14. Specifically, when the robotic arm 1 is not extended, the second telescopic drive member 14 extends at least partially into the interior of the third arm 13 through the through openings 18 at the ends of the second arm 12 and the third arm 13.

[0073] Based on this, the robotic arm 1 also includes a stroke amplification component 17, which includes a third movable pulley 171 and a third rope 172 that cooperate with each other. The third movable pulley 171 is fixed to the drive end of the second telescopic drive member 14, one end of the third rope 172 is fixed to the fifth anchor point 113 at the end of the first arm 11 inside, and the other end of the third rope 172 is fixed to the sixth anchor point 121 at the end of the second arm 12.

[0074] When the second telescopic drive member 14 extends, it drives the third movable pulley 171. The third movable pulley 171 drives the second arm 12 through the third rope 172 and the sixth anchor point 121. At this time, based on the stroke amplification characteristic of the movable pulley mechanism, the movement stroke of the second arm 12 is twice the movement stroke of the third movable pulley 171 and the drive end of the second telescopic drive member 14, thereby amplifying the extension and retraction of the second telescopic drive member 14 on the robotic arm 1.

[0075] For example, based on the tunnel dimensions, if the highest point of the detection area requires the robotic arm 1 to extend 4m, this includes the second arm 12 extending 2m relative to the first arm 11, and the third arm 13 extending 2m relative to the second arm 12. Therefore, a second telescopic drive component 14 with a maximum extension of not less than 2m is typically required. In this case, the maximum extension and length of the second telescopic drive component 14 are relatively large, which is not conducive to installation; at the same time, as the extension increases, the reliability of the second telescopic drive component 14 also decreases. Therefore, by setting the aforementioned stroke amplification component 17, the extension of the second telescopic drive component 14 is amplified on the robotic arm 1 through the movable pulley structure, ensuring that the maximum extension of the second telescopic drive component 14 is not less than 1m, thus meeting the above requirements. This allows for a reduction in the size of the second telescopic drive component 14, facilitating installation and improving reliability.

[0076] Furthermore, in conjunction with the aforementioned scissor lift mechanism, since the scissor lift mechanism also has a certain stroke, the strokes of the robotic arm 1 and the scissor lift mechanism are superimposed, so that the detection range of the detection component 2 covers an area within 5m of the walking body.

[0077] In some embodiments, the inner wall of the first arm 11 is provided with a cable isolation channel. The second arm 12 and the third arm 13, located inside the first arm 11, are installed together against one side of the first arm 11, leaving a 20mm~25mm wide physical isolation space on the other side for setting up a micro-engineering cable chain. The cables of the detection device 25 and obstacle avoidance sensors are placed in the aforementioned micro-engineering cable chain to achieve physical isolation from the pulley structure of the linkage unit, and to protect the cables from exceeding the minimum bending radius to prevent motion interference.

[0078] In some embodiments, a static calibration is performed on the robotic arm 1, that is, a theoretical calibration is performed on key components under the extreme working posture of the robotic arm 1 in its fully extended horizontal state. The maximum bending moment M at the root of the first arm 11 is calculated according to the cantilever beam model. max And check the bending normal stress σ max ≤ [σ] (allowable bending normal stress) and end deflection of robotic arm 1. The critical buckling pressure of the third telescopic drive component 32 is checked according to Euler's formula, and the stability safety factor [n] is used. k The range satisfies 2~4. The shear stress and hole wall extrusion stress of the hinge pin between the robotic arm 1 and the rotary seat 31 are checked according to the double shear model. The tensile strength of the high-strength bolts between the rotary seat 31 and the base is checked according to the torque distribution principle under the ultimate overturning moment.

[0079] A 3D digital prototype of the entire machine was built and imported into the ANSYS Workbench platform for multi-condition simulation analysis. Static analysis was performed on the horizontal full extension limit condition, and the results are as follows: Figures 7 to 13 As shown. The results indicate that the maximum equivalent stress of the key components is much lower than the allowable stress of aluminum alloy (specifically 6061-T6) and steel (specifically Q355B). Modal analysis extracted the first six natural frequencies. The frequencies of the first three and above (i.e., the fourth to sixth orders) are all higher than 8Hz, effectively avoiding the 1~3Hz low-frequency excitation range commonly found in the chassis suspension system of the walking body (e.g., heavy truck vehicle platform). Transient dynamic analysis simulated the impact caused by the walking body encountering uneven road surfaces. The maximum transient displacement at the end of the robotic arm 1 was 207mm, and the maximum stress was still lower than the yield limit of the material. The structure maintained elastic deformation and had sufficient impact toughness and safety redundancy. Harmonic response analysis identified the root of the slewing seat 31 as the most dangerous section. In actual manufacturing, the welds in this area can be inspected and high-strength bolts can be used to resist fatigue under long-term alternating loads.

[0080] In some embodiments, this application also provides an obstacle avoidance method for an adaptive telescopic detection device for tunnel detection, applied to the detection device of the above embodiments, based on the lidar and depth camera of the detection device, the obstacle avoidance method includes:

[0081] S101: Transform the coordinate system of the LiDAR and depth camera to the end-effector coordinate system of the robotic arm 1, and align the sampling data of the LiDAR and depth camera in the time dimension.

[0082] Specifically, the homogeneous transformation matrix of the coordinate systems of the LiDAR and depth camera relative to the end-effector coordinate system of the robotic arm 1 is solved using the hand-eye calibration method. Based on this homogeneous transformation matrix, the coordinate systems of the LiDAR and depth camera are transformed to the end-effector coordinate system of the robotic arm 1, achieving spatial alignment. According to the sampling frequencies of the LiDAR and depth camera, the sampling time of the LiDAR with a lower sampling frequency (20Hz) is used as a reference, and linear interpolation is performed on the sampling data of the depth camera with a higher sampling frequency (30Hz), thereby achieving temporal alignment of the sampling data of the LiDAR and depth camera.

[0083] S102: Generate a first two-dimensional grid pattern based on the sampling data of the lidar, and project a second two-dimensional grid pattern based on the sampling data of the depth camera.

[0084] First, the sampling data from the LiDAR and depth camera are denoised and filtered. The LiDAR point cloud undergoes statistical filtering for denoising and pass-through filtering, with the pass-through filtering range being 0~5m in the X-axis direction, -3m~3m in the Y-axis direction, and -1m~2m in the Z-axis direction. The depth camera point cloud undergoes pass-through filtering (range 0.5m~3m in front), elevation filtering (within ±100mm of the bottom surface of the detection device 25 as the reference, with the bottom surface facing the lining), and voxel downsampling. Then, based on the denoised and filtered sampling data, a first two-dimensional grid map and a second two-dimensional grid map are generated. The second two-dimensional grid map is formed by converting the three-dimensional elevation data of the depth camera into two-dimensional raster data through orthogonal projection.

[0085] S103: Merge the first two-dimensional grid diagram with the second two-dimensional grid diagram (the maximum value fusion method can be used), merge the occupancy status of the same grid cell in the first two-dimensional grid diagram and the second two-dimensional grid diagram, and generate a comprehensive occupancy grid diagram.

[0086] S104: Construct an artificial potential field based on the comprehensive occupancy grid map, determine the resultant force on the end of the robotic arm 1 according to the artificial potential field, and control the robotic arm 1 to perform obstacle avoidance motion; the artificial potential field includes the gravitational field generated by the target point on the end of the robotic arm 1, the repulsive field generated by the obstacle on the end of the robotic arm 1, and the limiting potential field used to constrain the range of motion of the joints of the robotic arm 1.

[0087] In addressing the shortcomings of traditional artificial potential field methods in obstacle avoidance of robotic arm 1, such as being prone to getting trapped in local optima and failing to consider collisions of robotic arm 1 components and joint limit constraints, this embodiment proposes: introducing a relative distance factor between the end of robotic arm 1 and the target point in the repulsive force field function to avoid local optima; adding end-of-arm posture constraint terms and joint limit constraint terms to the potential field function; and optimizing the solution method of force in Cartesian space to joint space.

[0088] Gravitational field function: In the formula, Let q be the gravitational potential field, and q be the current pose of the end effector of robotic arm 1. The gravitational field gain coefficient is... Let ρ be the target pose, and ρ be the generalized distance between the current pose of the robotic arm 1's end effector and the target pose. A repulsive field is generated when an obstacle enters the safety threshold ρ0. The repulsive field function is: In the formula, For repulsive potential field, The repulsive field gain coefficient is... Location of the obstacle. The distance between the current pose of the end effector of robotic arm 1 and the obstacle. The total resultant force at the end effector of robotic arm 1 is the vector sum of the gravitational force and all repulsive forces.

[0089] The Cartesian space forces are mapped to joint space generalized forces using the Jacobian matrix transpose method: The target motion command for each joint is calculated, where, The resultant force at the end of robotic arm 1 in Cartesian space. This is the transpose of the Jacobian matrix. This refers to the generalized torque in the joint space.

[0090] Based on the above, the obstacle avoidance logic in a typical scenario is as follows: When the depth camera detects a pothole obstacle ahead, the repulsive force moves upward along the Z-axis and backward along the X-axis (forward direction), preferentially driving the first telescopic drive member 42 at the end of the robotic arm 1 to lift the detection component 2; if necessary (e.g., when the pothole is deep), the third telescopic drive member 32 is simultaneously driven to lift the robotic arm 1, and the second telescopic drive member 14 is driven to retract the robotic arm 1 a certain distance. When the lidar detects a lateral obstacle, the repulsive force moves horizontally along the Y-axis, driving the worm gear drive member to rotate the robotic arm 1 and the detection component 2 away from the obstacle, while simultaneously coordinating with the telescopic adjustment of the robotic arm 1.

[0091] 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.

[0092] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. An adaptive telescopic detection device for tunnel inspection, characterized in that, It includes a walking body, a robotic arm, and a detection component. One end of the robotic arm is connected to the walking body, and the detection component is connected to the other end of the robotic arm. The detection component includes a detection device, an outer frame, a support plate, and an elastic shock absorber. The outer frame has a first surface and a second surface opposite to each other. The detection device is disposed inside the outer frame and its detection direction is towards the first surface. A walking wheel is disposed on the first surface. The support plate is disposed on the outside of the second surface. A plurality of elastic shock absorbers are connected between the support plate and the second surface. The side of the support plate facing away from the second surface is hinged to the end of the robotic arm.

2. The adaptive telescopic detection device for tunnel inspection according to claim 1, characterized in that, The elastic shock absorber includes a guide optical shaft, a shock absorber spring, and a linear bearing. One end of the guide optical shaft is fixed to the second surface, and the other end is accommodated in the linear bearing. The linear bearing is fixed to the side of the support plate facing the second surface. The shock absorber spring is sleeved on the guide optical shaft, and its two ends abut against the second surface and the support plate, respectively.

3. The adaptive telescopic detection device for tunnel inspection according to claim 2, characterized in that, The elastic shock absorber also includes a damping bushing, which is nested between the linear bearing and the guide optical axis, and the damping bushing is fixed to the linear bearing.

4. The adaptive telescopic detection device for tunnel inspection according to any one of claims 1 to 3, characterized in that, It also includes an attitude adjustment component disposed at the end of the robotic arm. The attitude adjustment component includes a first telescopic drive member and a connecting member. The connecting member is fixedly sleeved on the robotic arm. One end of the first telescopic drive member is hinged to the connecting member, and the other end is hinged to the side surface of the support plate opposite to the second surface.

5. The adaptive telescopic detection device for tunnel inspection according to claim 1, characterized in that, The robotic arm includes a first arm, a second arm, and a third arm, all of which are hollow columnar structures. The second arm is at least partially nested within the first arm, and the third arm is at least partially nested within the second arm. The robotic arm also includes a second telescopic drive and a linkage mechanism. The second telescopic drive is fixed to the end of the first arm, and the drive end of the second telescopic drive is connected to the second arm. The linkage mechanism is connected between the second arm and the third arm, and is used to make the third arm extend and retract synchronously when the second telescopic drive drives the second arm to extend and retract.

6. The adaptive telescopic detection device for tunnel inspection according to claim 5, characterized in that, The linkage mechanism includes: The first linkage unit includes a first movable pulley and a first rope that cooperate with each other. The first movable pulley is fixed to the end of the second arm. One end of the first rope is fixed to a first anchor point on the inner side of the first arm. The other end of the first rope is fixed to a second anchor point at the end of the third arm. The second linkage unit includes a second movable pulley and a second rope that cooperate with each other. The second movable pulley is fixed to the inner side of the second arm, one end of the second rope is fixed to the third anchor point at the end of the third arm, and the other end of the second rope is fixed to the fourth anchor point on the inner side of the first arm.

7. The adaptive telescopic detection device for tunnel inspection according to claim 5 or 6, characterized in that, The robotic arm also includes a stroke amplification component, which includes a third movable pulley and a third rope that cooperate with each other. The third movable pulley is fixed to the drive end of the second telescopic drive member, one end of the third rope is fixed to the fifth anchor point at the end of the first arm, and the other end of the third rope is fixed to the sixth anchor point at the end of the second arm.

8. The adaptive telescopic detection device for tunnel inspection according to any one of claims 1 to 3, characterized in that, One end of the robotic arm is connected to the rotating base of the walking body. The rotating base includes a base and a rotating seat disposed on the base. The end of the robotic arm is hinged to the rotary seat, and a third telescopic drive is connected between the robotic arm and the rotary seat. The rotary seat is configured as a worm gear structure, and the walking body is provided with a worm drive that meshes with the rotary seat.

9. The adaptive telescopic detection device for tunnel inspection according to any one of claims 1 to 3, characterized in that, It also includes a controller and a first obstacle avoidance sensor and a second obstacle avoidance sensor that are electrically connected to the controller, the first obstacle avoidance sensor including a depth camera and the second obstacle avoidance sensor including a lidar; The controller is disposed on the walking body, the first obstacle avoidance sensor is disposed on the third surface of the outer frame, the third surface being the front end surface of the outer frame when it moves with the walking body, and the second obstacle avoidance sensor is disposed on two opposite fourth surfaces of the outer frame, the opposite direction of the two fourth surfaces being perpendicular to the direction of movement of the outer frame with the walking body.

10. An obstacle avoidance method for an adaptive telescopic detection device for tunnel inspection, applied to the detection device according to any one of claims 1 to 9, characterized in that, The detection device includes a robotic arm and a lidar and depth camera mounted on the robotic arm. The obstacle avoidance method includes: The coordinate systems of the lidar and the depth camera are transformed to the coordinate system of the end effector of the robotic arm, and the sampling data of the lidar and the depth camera are aligned in the time dimension. A first two-dimensional grid pattern is generated based on the sampling data of the lidar, and a second two-dimensional grid pattern is generated by projection based on the sampling data of the depth camera. The first two-dimensional grid diagram and the second two-dimensional grid diagram are merged, and the occupancy status of the same grid cell in the first two-dimensional grid diagram and the second two-dimensional grid diagram are combined to generate a comprehensive occupancy grid diagram. An artificial potential field is constructed based on the comprehensive occupancy grid map. The resultant force on the end effector of the robotic arm is determined according to the artificial potential field to control the robotic arm to perform obstacle avoidance motion. The artificial potential field includes the gravitational field generated by the target point on the end effector of the robotic arm, the repulsive field generated by the obstacle on the end effector of the robotic arm, and the limiting potential field used to constrain the range of motion of the robotic arm joints.

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