Contact type bridge detection aerial robot, control method and related equipment

Abstract

The application provides a contact type bridge detection aerial robot, a control method and related equipment, and relates to the technical field of bridge detection aerial robots.The contact type bridge detection aerial robot comprises a first mechanical arm provided with an elastic driving joint.The elastic driving joint comprises a rudder, a fixing frame, an input end support and an output end support.The rudder is fixedly installed on the fixing frame and is connected with the input end support.The output end support is rotationally connected with the input end support and is provided with an elastic component between the input end support.The elastic component is used to provide a reset elastic force for the output end support when the output end support rotates relative to the input end support.The contact type bridge detection aerial robot can carry detection equipment in contact with a bridge body and detect the bridge through contact, effectively avoids damage or loss of control of the aerial robot caused by contact collision, and greatly improves the stability of the aerial robot during flight and contact detection.

Description

Technical Field

[0001] This invention relates to the field of aerial robot technology for bridge inspection, and more specifically, to a contact-type aerial robot for bridge inspection, its control method, and related equipment. Background Technology

[0002] Bridge inspection is crucial for assessing the structural safety of bridges, eliminating potential safety hazards, ensuring safe and smooth traffic flow, and reducing the occurrence of disasters and accidents. The scope of inspection generally includes the bridge deck, the bridge bottom, and the piers. However, due to the complex terrain of some bridges, such as cross-sea bridges and mountain bridges, the inspection of the bridge bottom and piers is quite challenging.

[0003] In response, existing technologies propose using aerial robots to replace manual inspection of bridges. However, most existing drone bridge inspection technologies do not carry inspection equipment that requires contact with the bridge structure, such as rebound hammers, ultrasonic non-metallic internal defect detectors, and crack observation instruments, to avoid damage or loss of control of the aerial robots due to contact collisions. This limits their analysis to non-contact methods (such as observing the bridge and taking photos). This method often only detects surface defects of the bridge and cannot detect internal defects, resulting in incomplete inspection items and significant limitations.

[0004] There is currently no effective technical solution to the above problems. Summary of the Invention

[0005] The purpose of this invention is to provide a contact-type aerial robot for bridge inspection, a control method, and related equipment. This robot can carry inspection equipment that contacts the bridge structure and inspect the bridge through contact. It also effectively avoids damage or loss of control of the aerial robot due to contact collisions, greatly improving the stability of the aerial robot during flight and contact inspection.

[0006] In a first aspect, the present invention provides a contact-type aerial robot for bridge inspection, comprising an aircraft and a first robotic arm, wherein the first robotic arm is disposed at the bottom of the aircraft and is used to contact the bridge to inspect the bridge; The first robotic arm includes an elastic drive joint, which includes a servo motor, a fixed frame, an input end bracket, and an output end bracket. The servo motor is fixedly mounted on the fixed frame and connected to the input end bracket, and is used to drive the input end bracket to rotate. The output bracket is rotatably connected to the input bracket and an elastic component is provided between them. The elastic component is used to provide a restoring force to the output bracket when the output bracket rotates relative to the input bracket.

[0007] The aerial robot for bridge inspection provided by this invention provides a buffering capability to the first robotic arm by setting an elastic drive joint on the robotic arm, so that the aerial robot can effectively resist external impact during contact operations and achieve the effect of stable flight and stable contact.

[0008] Furthermore, the elastic component includes a first linear compression spring and a second linear compression spring arranged coaxially; The output end bracket and the input end bracket are provided with a fixing part that protrudes radially along the rotational connection, and the fixing part divides the input end bracket into a left cavity and a right cavity; The first linear compression spring is installed in the left cavity, with one end of the first linear compression spring connected to the input end bracket and the other end connected to the fixing part; The second linear compression spring is installed in the right cavity, with one end of the second linear compression spring connected to the input end bracket and the other end connected to the fixing part.

[0009] It can achieve both driver-to-load compliance and load-to-driver buffering performance, ensuring structural strength while being compact and lightweight.

[0010] Furthermore, it includes two of the first robotic arms and also includes a second robotic arm; The first robotic arm also includes a swing arm, which is connected to the output end bracket; The second robotic arm is mounted on top of the aircraft and is used to contact the bridge to inspect it.

[0011] Using two first robotic arms together can greatly increase the collaborative working space of the aerial robot during inspection operations, enabling flexible contact inspection operations at the top and front of the aerial robot.

[0012] Secondly, the present invention provides a control method for the aforementioned contact-type bridge inspection aerial robot, comprising the following steps: S1. Based on the established dynamic model, obtain the total centroid position vector when the robotic arm group moves to a specified posture; the robotic arm group includes two of the first robotic arms; S2. Calculate the gravitational torque generated by the robotic arm assembly on the aircraft based on the total centroid position vector; S3. When the robotic arm assembly has no external load, control the servo motor according to the following steps S31-S32: S31. Calculate the first swing angle of the swing arm under the action of the spring group based on the gravitational torque; the spring group includes the first linear compression spring and the second linear compression spring; S32. Using the first swing angle as compensation, control the torque of the servo motor; S4. When the robotic arm assembly has an external load, control the servo motor according to the following steps S41-S43: S41. Calculate the equivalent external torque generated by the robotic arm assembly on the aircraft based on the preset expected contact force; S42. Calculate the second swing angle generated by the swing arm under the action of the spring group based on the gravitational torque and the equivalent external torque; S43. Using the second swing angle as compensation, control the torque of the servo motor.

[0013] Furthermore, the specific steps in step S31 include: S311. Calculate the first swing angle according to the following formula: ; ; in, For the first swing angle, This refers to the stiffness coefficient of a single linear compression spring in the selected spring group. The distance from the center of the end face of a single linear compression spring in the spring assembly near the fixed part to the center of the swing arm. Let be the radius of a single linear compression spring in the spring assembly. The gravitational torque, Let be the total centroid position vector. The total mass of the robotic arm assembly is... This is the acceleration due to gravity.

[0014] Furthermore, the specific steps in step S41 include: S411. Calculate the equivalent external torque according to the following formula: ; ; in, The equivalent external torque is... The preset desired contact force, The relative position of the contact point in the local coordinate system of the robotic arm assembly. Let be the transformation matrix between the local coordinate system of the robotic arm assembly and the local coordinate system of the elastic drive joint. Let x be the x-coordinate of the contact point in the local coordinate system of the robotic arm assembly. Let y be the y-coordinate of the contact point in the local coordinate system of the robotic arm assembly. Let z be the z-coordinate of the contact point in the local coordinate system of the robotic arm assembly.

[0015] Furthermore, the specific steps in step S42 include: S421. Calculate the second swing angle according to the following formula: ; in, This is the second swing angle.

[0016] Thirdly, the present invention provides a control device for the aforementioned contact-type bridge inspection aerial robot, comprising: The first acquisition module is used to acquire the total centroid position vector of the robotic arm group when it moves to a specified posture based on the established dynamic model; the robotic arm group includes two first robotic arms. The calculation module is used to calculate the gravitational torque generated by the robotic arm assembly on the aircraft based on the total center of mass position vector; The first control module is used to control the servo motor according to the following steps S31-S32 when the robotic arm assembly has no external load: S31. Calculate the first swing angle of the swing arm under the action of the spring group based on the gravitational torque; the spring group includes the first linear compression spring and the second linear compression spring; S32. Using the first swing angle as compensation, control the torque of the servo motor; The second control module is used to control the servo motor according to the following steps S41-S43 when the robotic arm assembly has an external load: S41. Calculate the equivalent external torque generated by the robotic arm assembly on the aircraft based on the preset expected contact force; S42. Calculate the second swing angle generated by the swing arm under the action of the spring group based on the gravitational torque and the equivalent external torque; S43. Using the second swing angle as compensation, control the torque of the servo motor.

[0017] The control device provided by this invention breaks through the traditional non-contact detection method, can detect internal defects in bridges, effectively expands the scope of detection, and greatly reduces the limitations in use.

[0018] Fourthly, the present invention provides an electronic device including a processor and a memory, the memory storing computer-readable instructions, which, when executed by the processor, perform the steps of the control method provided in the first aspect above.

[0019] Fifthly, the present invention provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, performs the steps of the control method provided in the first aspect above.

[0020] As can be seen from the above, the contact-type aerial bridge inspection robot provided by the present invention uses two first robotic arms to carry and operate inspection equipment that contacts the bridge body to inspect the bridge in a contact manner. This allows for the acquisition of internal bridge data and the implementation of inspections for more items, which is beneficial to ensuring bridge safety. At the same time, the first robotic arms are also equipped with elastic drive joints, which give the first robotic arms buffer performance and greatly increase their compliance. On the one hand, this effectively avoids damage or loss of control of the aerial robot caused by external impacts during contact operations, thereby improving the stability and operational safety of the aerial robot. On the other hand, it ensures that the inspection equipment can make stable contact with the bridge body, which is beneficial to obtaining accurate inspection data.

[0021] Other features and advantages of the invention will be set forth in the following description, and will be apparent in part from the description, or may be learned by practicing embodiments of the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures particularly pointed out in the written description and the accompanying drawings. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the structure of a contact-type aerial robot for bridge inspection provided in an embodiment of the present invention.

[0023] Figure 2 This is a schematic diagram of a contact-type aerial bridge inspection robot performing bridge inspection operations, as provided in an embodiment of the present invention.

[0024] Figure 3 for Figure 1 A schematic diagram of a local structure labeled a.

[0025] Figure 4 for Figure 1 A schematic diagram of a partial structure, labeled b.

[0026] Figure 5 This is an exploded view of the elastically driven joint in an embodiment of the present invention.

[0027] Figure 6 This is a side view of the elastically driven joint in an embodiment of the present invention.

[0028] Figure 7 A flowchart of a control method provided in an embodiment of the present invention.

[0029] Figure 8This is a schematic diagram of a control device provided in an embodiment of the present invention.

[0030] Figure 9 This is a schematic diagram of the structure of an electronic device provided in an embodiment of the present invention.

[0031] Label Explanation: 100. Aircraft; 200. First robotic arm; 210. Servo motor; 220. Mounting frame; 230. Input end bracket; 231. Left cavity; 232. Right cavity; 240. Output end bracket; 241. Fixing part; 251. First linear compression spring; 252. Second linear compression spring; 260. Swing arm; 270. Universal ball joint; 271. Suction cup; 272. Detection equipment; 280. Hall position sensor; 290. Magnet; 300. Second robotic arm; 400. First acquisition module; 500. Calculation module; 600. First control module; 700. Second control module; 13. Electronic equipment; 1301. Processor; 1302. Memory; 1303. Communication bus. Detailed Implementation

[0032] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0033] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0034] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection, an electrical connection, or a connection that allows for communication; 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. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0035] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0036] The following disclosure provides many different embodiments or examples for implementing various structures of the invention. To simplify the disclosure, specific examples of components and arrangements are described below. These are merely examples and are not intended to limit the invention. Furthermore, reference numerals and / or letters may be repeated in different examples; such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed. In addition, examples of various specific processes and materials are provided in this invention, but those skilled in the art will recognize the application of other processes and / or the use of other materials.

[0037] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0038] It should be noted that similar reference numerals and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of the stated features. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified. Also, in the description of this invention, the terms "first," "second," etc., are used only for distinguishing descriptions and should not be construed as indicating or implying relative importance.

[0039] Reference Appendix Figure 1 Appendix Figure 2 Appendix Figure 3 Appendix Figure 5 and attached Figure 6 The contact bridge inspection aerial robot includes an aircraft 100 and a first robotic arm 200. The first robotic arm 200 is located at the bottom of the aircraft 100 and is used to contact the bridge to inspect it. The first robotic arm 200 includes an elastic drive joint, which includes a servo motor 210, a fixed frame 220, an input end bracket 230 and an output end bracket 240. The servo motor 210 is fixedly mounted on the fixed frame 220 and connected to the input end bracket 230. The servo motor 210 is used to drive the input end bracket 230 to rotate. The output bracket 240 is rotatably connected to the input bracket 230 and an elastic component is provided between the output bracket 240 and the input bracket 230. The elastic component is used to provide a reset force for the output bracket 240 when the output bracket 240 rotates relative to the input bracket 230.

[0040] In this embodiment, the first robotic arm 200 is mainly used to inspect the vertical and inclined structures of the bridge (e.g., the location of the piers). In actual application, it is inspected by carrying inspection equipment 272, such as a rebound hammer or a non-metallic ultrasonic detector, in contact with the bridge surface. The first robotic arm 200 generally increases its degrees of freedom by setting multiple motion joints (e.g., setting a shoulder joint to enable shoulder swing and shoulder pitch, setting an elbow joint to enable elbow pitch, setting a wrist joint to enable wrist rotation, etc., but not limited to these) so that the inspection equipment 272 can better fit the bridge surface, thereby helping to ensure the accuracy of the inspection data.

[0041] Furthermore, since the inspection equipment 272 needs to be in direct and close contact with the bridge and apply a certain positive pressure during the inspection operation, high requirements are placed on the compliance and safety of the first robotic arm 200. Reasonable design plays an important role in the efficiency of the inspection operation and the reliability of the inspection data. For the first robotic arm 200, the driving force needs to be transmitted to the first robotic arm 200 in a gentler way to avoid the inspection equipment 272 from impacting and colliding with the bridge, which would cause damage to the inspection equipment 272 and the bridge. At the same time, when the inspection equipment 272 contacts the bridge, the reaction force of the contact force (hereinafter referred to as the external force) also needs to be transmitted to the aircraft 100 in a gentler way to avoid the aircraft 100 from losing balance.

[0042] In this embodiment, an elastic drive joint is provided in the first robotic arm 200. The elastic drive joint constitutes the motion joint of the first robotic arm. When the servo motor 210 outputs driving force, the driving force is transmitted to the elastic component through the input end bracket 230. The elastic component uses its own elasticity to convert the driving force into elastic force and then gradually transmits it to the output end bracket 240. The elastic component absorbs the impact generated by the output of the servo motor 210, realizing the smooth output of the drive servo to the load, thereby avoiding damage to the detection device 272 and the bridge. When the output end bracket 240 is subjected to external force, the external force is transmitted to the elastic component through the output end bracket 240. The elastic component uses its own elasticity to convert the external force into elastic force and then gradually transmits it to the input end bracket 230. The elastic component absorbs the impact generated by the external force input, realizing the buffering effect of the load on the drive servo, thereby avoiding damage to the servo motor 210 and imbalance of the aircraft 100.

[0043] This structure breaks through the traditional non-contact inspection method, enabling the detection of internal defects in bridges, effectively expanding the scope of inspection, greatly reducing the limitations of use, and facilitating the replacement of manual labor in the inspection of bridges in complex terrain. It reduces the difficulty of work for workers and labor costs, and effectively ensures bridge safety.

[0044] In some embodiments, reference is made to the appendix. Figure 5 and attached Figure 6 The elastic component includes a first linear compression spring 251 and a second linear compression spring 252 arranged coaxially. A fixing part 241 protruding radially along the rotational connection between the output end bracket 240 and the input end bracket 230 is provided at the rotational connection point. The fixing part 241 divides the input end bracket 230 into a left cavity 231 and a right cavity 232. The first linear compression spring 251 is installed in the left cavity 231. One end of the first linear compression spring 251 is connected to the input end bracket 230 and the other end is connected to the fixing part 241. The second linear compression spring 252 is installed in the right cavity 232. One end of the second linear compression spring 252 is connected to the input end bracket 230 and the other end is connected to the fixing part 241.

[0045] In this embodiment, the linear compression springs (i.e., the first linear compression spring 251 and the second linear compression spring 252) in the spring assembly (including the first linear compression spring 251 and the second linear compression spring 252) are installed between the output end bracket 240 and the input end bracket 230 in a compressed state (i.e., a pre-compression installation method is adopted). Therefore, the elastic force generated by the linear compression spring is always a pressure action rather than a tension action.

[0046] In practical applications, when the servo motor 210 outputs driving force to drive the input end bracket 230 to rotate clockwise, the output end bracket 240 remains stationary due to inertia. The first linear compression spring 251 is compressed and the second linear compression spring 252 is released. The linear compression springs transmit torque to the fixed part 241 in the form of elastic force, thereby driving the output end bracket 240 to rotate clockwise, and vice versa. Similarly, when an external force drives the output end bracket 240 to drive the fixed part 241 to rotate counterclockwise, the input end bracket 230 remains stationary due to inertia. The first linear compression spring 251 is released and the second linear compression spring 252 is compressed. The linear compression springs transmit torque to the input end bracket 230 in the form of elastic force, and vice versa. This demonstrates good driving and load-carrying capabilities, achieving both compliance from the driver to the load and buffering performance from the load to the driver. While ensuring structural strength, it also features a compact and lightweight structure.

[0047] It should be noted that the stiffness of the linear compression spring determines the overall compliance of the elastic drive joint, which plays an important role in the stable movement of the first robotic arm 200.

[0048] In some embodiments, the overall stiffness of the elastically driven joint is calculated according to the following formula: ; in, To elastically drive the overall stiffness of the joint, This represents the stiffness coefficient of a single linear compression spring in the selected spring group. This is the distance from the center of the end face of a single linear compression spring near the fixed part in the spring assembly to the center of the swing arm. Let be the radius of a single linear compression spring in the spring assembly. The relative deflection angle between the input and output brackets (limited by the structure of the input and output brackets). There are minimum and maximum values. When the input support and output support rotate relative to each other to their limit positions, Reaching the maximum value is When the input bracket and the output bracket do not rotate relative to each other, The minimum value is 0, from which we can calculate The maximum and minimum values ​​are used to obtain the stiffness range of the elastically driven joint. However, since the overall stiffness of the elastically driven joint differs from the actual stiffness... The stiffness is related to the value, so the elastically driven joint exhibits different levels of compliance in real time when the input and output supports move relative to each other, but this is acceptable as long as it is within the required stiffness range.

[0049] In some embodiments, reference is made to the appendix. Figure 1The contact bridge inspection aerial robot includes two first robotic arms 200 and also includes a second robotic arm 300. The first robotic arm 200 also includes a swing arm 260, which is connected to the output end bracket 240; The second robotic arm 300 is mounted on top of the aircraft 100 and is used to contact the bridge to inspect it.

[0050] In this embodiment, two first robotic arms 200 are set up so that they can be controlled independently to complete the detection work, or they can mimic the coordinated work of human hands. For some detection items, the detection device 272 includes a receiver and a transmitter. In this case, two first robotic arms 200 are required to carry the receiver and transmitter respectively in order to complete the detection work of the detection item.

[0051] Furthermore, since the rotor is located above the first robotic arm 200, it is difficult for the first robotic arm 200 to pass over the rotor to perform inspection work on the bottom of the bridge. Therefore, in this embodiment, a second robotic arm 300 is set on the top of the aircraft 100. The second robotic arm 300 has two degrees of freedom and can realize upward lifting and downward retraction movements, thereby meeting the requirements for inspection work on the bottom structure of the bridge. The use of the two first robotic arms 200 together can greatly increase the collaborative working space of the aerial robot during inspection work, realize a flexible contact inspection operation mode of the top and front of the aerial robot, and further improve the cooperation and environmental adaptability of the aerial robot in the process of bridge inspection work.

[0052] In some embodiments, reference is made to the appendix. Figure 4 The first robotic arm 200 also includes a pressure sensor, a universal ball joint 270, a suction cup 271 mounted on the universal ball joint 270, and a detection device 272. The universal ball joint 270 is mounted at the end of the swing arm 260 and is used to change the orientation of the suction cup 271 so that the suction cup 271 is adsorbed onto the bridge surface, thereby making the detection device 272 fit against the bridge surface. The pressure sensor is used to measure the actual contact force between the first robotic arm 200 and the bridge surface.

[0053] In this embodiment, the universal ball joint 270 can further increase the degree of freedom of the first robotic arm 200, thereby improving the fit between the detection device 272 and the bridge contact surface. The suction cup 271 is used to adhere to the bridge surface, thereby assisting the positioning of the first robotic arm 200 and helping the detection device 272 and the bridge to maintain a stable contact with constant pressure.

[0054] In some embodiments, reference is made to the appendix. Figure 5 and attached Figure 6The elastic drive joint also includes a Hall position sensor 280 and a magnet 290. The magnet 290 is mounted on the input end bracket 230 and is coaxially arranged with the output shaft of the servo motor 210. The magnet 290 can rotate together with the output shaft of the servo motor 210. The Hall position sensor 280 is fixedly mounted on the output end bracket 240.

[0055] When an external load is applied to the output bracket 240, the magnet 290 and the Hall position sensor 280 rotate relative to each other, and the Hall position sensor 280 can thus measure the swing angle of the swing arm.

[0056] Please refer to Figure 7 , Figure 7 This is a flowchart of the control method. This control method, used for the contact bridge inspection aerial robot in the above embodiments, includes the following steps: S1. Based on the established dynamic model, obtain the total centroid position vector when the robotic arm group moves to the specified posture; the robotic arm group includes two first robotic arms; S2. Calculate the gravitational torque generated by the robotic arm assembly on the aircraft based on the total center of mass position vector; S3. When the robotic arm assembly has no external load, control the servo motor according to the following steps S31-S32: S31. Calculate the first swing angle of the swing arm under the action of the spring group based on the gravitational torque; the spring group includes a first linear compression spring and a second linear compression spring. S32. Using the first swing angle as compensation, control the torque of the servo motor; S4. When the robotic arm assembly has an external load, control the servo motor according to the following steps S41-S43: S41. Calculate the equivalent external torque generated by the robotic arm assembly on the aircraft based on the preset expected contact force; S42. Calculate the second swing angle of the swing arm under the action of the spring group based on the gravitational torque and the equivalent external torque; S43. Use the second swing angle as compensation to control the torque of the servo motor.

[0057] In this embodiment, the dynamic model includes three reference coordinate systems, namely the Earth fixed inertial coordinate system. Local coordinate system of aircraft fuselage Local coordinate system of robotic arm assembly Among them, the local coordinate system of the aircraft fuselage The origin of the coordinate system is The point coincides with the center of mass of the aircraft, and the local coordinate system of the robotic arm assembly. Including the local coordinate system of the left arm (i.e., one of the first robotic arms) and the local coordinate system of the right arm (i.e., another first robotic arm), left arm local coordinate system The origin of the coordinate system is Point, local coordinate system of the right arm The origin of the coordinate system is point.

[0058] Assuming the total center of mass of the robotic arm assembly is at... Point 1 indicates that the center of mass of the left arm is 10 ... The point represents the center of mass of the right arm. The point represents the movement of the first robotic arm. The position of the point will change; in practical applications, when the position of the total center of mass of the robotic arm group changes, the pressure sensor detects the slow change in the contact force. At this time, the system drives the servo motor to adjust the rotation angle of the elastic drive joint to compensate for the shift in attitude position, thereby maintaining a constant contact force. Considering that the first robotic arm is in contact with the environment when it is working, the influence of the inertial term and the centrifugal term on the first robotic arm is much smaller than the influence of gravity or external torque. Moreover, the movement process of the elastic drive joint is relatively slow, so the influence of the inertial term and the centrifugal term can be ignored.

[0059] In step S1, the position vector of the total centroid is obtained according to the following formula: ; in, The total centroid position vector (i.e., in the local coordinate system of the aircraft fuselage). Click (vector of a point) The position vector of the center of mass of the left arm (i.e., in the local coordinate system of the aircraft fuselage). Click (vector of a point) For the mass of the left arm, The position vector of the center of mass of the right arm (i.e., in the local coordinate system of the aircraft fuselage). Click (vector of a point) For the mass of the right arm, This represents the total mass of the robotic arm assembly.

[0060] It should be noted that the position vector of the center of mass of the left arm can be obtained through... and The coordinate transformation matrix and the current pose are used to solve for the coordinate transformation matrix. Similarly, the centroid position vector of the right arm can be obtained through... and The coordinate transformation matrix and the current pose are used to solve for the coordinate transformation matrix. The solution process is common knowledge and will not be described in detail here.

[0061] In step S2, the gravitational torque is calculated according to the following formula: ; in, For gravitational torque, The position vector of the total centroid. The total mass of the robotic arm assembly. This is the acceleration due to gravity.

[0062] In step S3, since the first robotic arm is set as a cantilever below the aircraft, the joints of the first robotic arm rotate during the flight of the aircraft, which causes the center of gravity of the first robotic arm to change, thus affecting the stability of the aircraft during flight. Therefore, when the robotic arm assembly has no external load (i.e. it is not in contact with the bridge and is not subject to external force), it is necessary to compensate for the gravitational torque generated by the change in the center of gravity of the first robotic arm on the aircraft in order to control the attitude of the aircraft and ensure stable flight of the aircraft.

[0063] Specifically, the specific steps in step S31 include: S311. Calculate the first swing angle according to the following formula: ; in, For the first swing angle, This represents the stiffness coefficient of a single linear compression spring in the selected spring group. This is the distance from the center of the end face of a single linear compression spring near the fixed part to the center of the swing arm in the spring assembly. Let be the radius of a single linear compression spring in the spring assembly.

[0064] It should be noted that in step S32, the corresponding first torque can be calculated based on the first swing angle (the specific calculation process is common knowledge and will not be repeated here). The torque of the servo motor is controlled based on the first torque to ensure the stability of the first robotic arm's attitude, thereby ensuring the stable flight of the aircraft. In practical applications, the torque output of the servo motor can be increased in advance to compensate for the gravitational torque, thereby offsetting the influence of the gravitational torque during the movement of the first robotic arm. Then, the torque output of the servo motor can be gradually reduced until it meets the calculation result.

[0065] In some embodiments, a Hall position sensor can be placed on the elastic drive joint to observe the swing angle of the swing arm caused by the deformation of the linear compression spring. After obtaining the first swing angle, it can be directly based on Calculate the rotation angle of the servo motor This allows for stabilizing the posture of the first robotic arm by controlling the rotation angle of the servo motor, eliminating the need to calculate torque based on the swing angle and effectively reducing computational load.

[0066] In step S4, when the robotic arm assembly is under an external load (i.e., is in contact with the bridge and subjected to external force), in order to avoid excessive contact force between the detection equipment and the bridge surface, which could damage the detection equipment and the bridge, it is necessary to control the contact force output by the first robotic arm. Since forces are mutual, and for the aircraft, the bridge surface will also exert an equivalent reaction force (i.e., external force) on the aircraft. Under the action of the external force, the center of mass of the first robotic arm will also change, thereby introducing a gravitational torque, which will lead to errors in the control of the contact force. Therefore, in order to improve the control accuracy of the contact force, it is also necessary to compensate for the gravitational torque to ensure that the contact force between the detection equipment and the bridge surface meets the requirements.

[0067] Specifically, the specific steps in step S41 include: S411. Calculate the equivalent external torque according to the following formula: ; ; in, For equivalent external torque, The preset desired contact force, The relative position of the contact point in the local coordinate system of the robotic arm assembly. Let be the transformation matrix between the local coordinate system of the robotic arm assembly and the local coordinate system of the elastically driven joint. Let x be the x-coordinate of the contact point in the local coordinate system of the robotic arm assembly. Let y be the y-coordinate of the contact point in the local coordinate system of the robotic arm assembly. Let z be the z-coordinate of the contact point in the local coordinate system of the robotic arm assembly.

[0068] Furthermore, the specific steps in step S42 include: S421. Calculate the second swing angle according to the following formula: ; in, This is the second swing angle.

[0069] It should be noted that in step S43, the corresponding second torque can be calculated based on the second swing angle. The torque of the servo motor is then controlled based on the second torque to ensure that the first robotic arm stably drives the detection device to contact the bridge with the expected contact force. In practical applications, the torque output of the servo motor can be increased in advance to compensate for the gravitational torque and thus counteract the influence of the gravitational torque during the movement of the first robotic arm. After that, the torque output of the servo motor is gradually reduced until it meets the calculation result.

[0070] In some embodiments, a Hall position sensor can be placed on the elastic drive joint to observe the swing angle of the swing arm caused by the deformation of the linear compression spring. After obtaining the second swing angle, it can be directly based on Calculate the rotation angle of the servo motor This allows the detection equipment to achieve stable contact with the bridge by controlling the rotation angle of the servo motor, eliminating the need to calculate torque by swinging the angle and effectively reducing the computational load.

[0071] In some embodiments, the preset desired contact force can be a threshold range. The maximum and minimum rotation angles of the servo motor can be calculated based on the maximum and minimum values ​​of the threshold range, or the maximum and minimum output torques of the servo motor can be calculated. By controlling the rotation angle of the servo motor to be between the maximum and minimum rotation angles, or controlling the output torque of the servo motor to be between the maximum and minimum output torques, the contact force between the detection equipment and the bridge surface can be guaranteed to meet the requirements.

[0072] Please refer to Figure 8 , Figure 8 This is a control device in some embodiments of the present invention, used for the contact-type bridge inspection aerial robot in the above embodiments. The control device is integrated into the back-end control equipment in the form of a computer program, including: The first acquisition module 400 is used to acquire the total centroid position vector of the robotic arm group when it moves to a specified posture based on the established dynamic model; the robotic arm group includes two first robotic arms. The calculation module 500 is used to calculate the gravitational torque generated by the robotic arm assembly on the aircraft based on the total center of mass position vector; The first control module 600 is used to control the servo motor according to the following steps S31-S32 when the robotic arm assembly has no external load: S31. Calculate the first swing angle of the swing arm under the action of the spring group based on the gravitational torque; the spring group includes a first linear compression spring and a second linear compression spring. S32. Using the first swing angle as compensation, control the torque of the servo motor; The second control module 700 is used to control the servo motor according to the following steps S41-S43 when the robotic arm assembly has an external load: S41. Calculate the equivalent external torque generated by the robotic arm assembly on the aircraft based on the preset expected contact force; S42. Calculate the second swing angle of the swing arm under the action of the spring group based on the gravitational torque and the equivalent external torque; S43. Use the second swing angle as compensation to control the torque of the servo motor.

[0073] In some embodiments, the first control module 600 performs the following when calculating the first swing angle of the swing arm under the action of the spring assembly based on the gravitational torque: S311. Calculate the first swing angle according to the following formula: ; ; in, For the first swing angle, This represents the stiffness coefficient of a single linear compression spring in the selected spring group. This is the distance from the center of the end face of a single linear compression spring near the fixed part to the center of the swing arm in the spring assembly. Let be the radius of a single linear compression spring in the spring assembly. For gravitational torque, The position vector of the total centroid. The total mass of the robotic arm assembly. This is the acceleration due to gravity.

[0074] In some embodiments, the second control module 700 performs the following when calculating the equivalent external torque generated by the robotic arm assembly on the aircraft based on a preset desired contact force: S411. Calculate the equivalent external torque according to the following formula: ; ; in, For equivalent external torque, The preset desired contact force, The relative position of the contact point in the local coordinate system of the robotic arm assembly. Let be the transformation matrix between the local coordinate system of the robotic arm assembly and the local coordinate system of the elastically driven joint. Let x be the x-coordinate of the contact point in the local coordinate system of the robotic arm assembly. Let y be the y-coordinate of the contact point in the local coordinate system of the robotic arm assembly. Let z be the z-coordinate of the contact point in the local coordinate system of the robotic arm assembly.

[0075] In some embodiments, the second control module 700 performs the following when calculating the second swing angle generated by the swing arm under the action of the spring assembly based on the gravitational torque and the equivalent external torque: S421. Calculate the second swing angle according to the following formula: ; in, This is the second swing angle.

[0076] Please refer to Figure 9 , Figure 9This is a schematic diagram of the structure of an electronic device provided in an embodiment of the present invention. The present invention provides an electronic device 13, including: a processor 1301 and a memory 1302. The processor 1301 and the memory 1302 are interconnected and communicate with each other via a communication bus 1303 and / or other forms of connection mechanisms (not shown). The memory 1302 stores computer-readable instructions executable by the processor 1301. When the electronic device is running, the processor 1301 executes the computer-readable instructions to execute the control method in any optional implementation of the above embodiments, thereby achieving the following functions: based on an established dynamic model, obtaining the total center of mass position vector of the robotic arm group when it moves to a specified posture; the robotic arm group includes two first robotic arms; based on the total center of mass position... The vector is set, and the gravitational torque generated by the robotic arm assembly on the aircraft is calculated. When the robotic arm assembly has no external load, the servo motor is controlled according to the following steps S31-S32: S31. Calculate the first swing angle generated by the swing arm under the action of the spring assembly based on the gravitational torque; the spring assembly includes a first linear compression spring and a second linear compression spring; S32. Use the first swing angle as compensation to control the torque of the servo motor. When the robotic arm assembly has an external load, the servo motor is controlled according to the following steps S41-S43: S41. Calculate the equivalent external torque generated by the robotic arm assembly on the aircraft based on the preset desired contact force; S42. Calculate the second swing angle generated by the swing arm under the action of the spring assembly based on the gravitational torque and the equivalent external torque; S43. Use the second swing angle as compensation to control the torque of the servo motor.

[0077] This invention provides a computer-readable storage medium storing a computer program. When the computer program is executed by a processor, it executes the control method in any optional implementation of the above embodiments to achieve the following functions: Based on an established dynamic model, obtaining the total center of mass position vector of the robotic arm assembly when it moves to a specified posture; the robotic arm assembly includes two first robotic arms; calculating the gravitational torque generated by the robotic arm assembly on the aircraft based on the total center of mass position vector; when the robotic arm assembly has no external load, controlling the servo motor according to the following steps S31-S32: S31. Calculate the gravitational torque based on the gravitational torque... Calculate the first swing angle generated by the swing arm under the action of the spring assembly; the spring assembly includes a first linear compression spring and a second linear compression spring; S32. Use the first swing angle as compensation to control the torque of the servo motor; when the robotic arm assembly has an external load, control the servo motor according to the following steps S41-S43: S41. Calculate the equivalent external torque generated by the robotic arm assembly on the aircraft according to the preset desired contact force; S42. Calculate the second swing angle generated by the swing arm under the action of the spring assembly according to the gravitational torque and the equivalent external torque; S43. Use the second swing angle as compensation to control the torque of the servo motor.

[0078] The computer-readable storage medium can be implemented by any type of volatile or non-volatile storage device or a combination thereof, such as Static Random Access Memory (SRAM), Electrically Erasable Programmable Read-Only Memory (EEPROM), Erasable Programmable Read Only Memory (EPROM), Programmable Red-Only Memory (PROM), Read-Only Memory (ROM), magnetic storage, flash memory, magnetic disk, or optical disk.

[0079] In the embodiments provided by this invention, it should be understood that the disclosed apparatus and method can be implemented in other ways. The apparatus embodiments described above are merely illustrative. For example, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. Furthermore, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Additionally, the displayed or discussed mutual couplings, direct couplings, or communication connections may be through some communication interfaces; indirect couplings or communication connections between devices or units may be electrical, mechanical, or other forms.

[0080] Furthermore, the units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0081] Furthermore, the functional modules in the various embodiments of the present invention can be integrated together to form an independent part, or each module can exist independently, or two or more modules can be integrated to form an independent part.

[0082] In this document, relational terms such as first and second are used only to distinguish one entity or operation from another entity or operation, without necessarily requiring or implying any such actual relationship or order between these entities or operations.

[0083] The use of terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., refers to specific features, structures, materials, or characteristics described in connection with the described embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0084] The above description is merely an embodiment of the present invention and is not intended to limit the scope of protection of the present invention. For those skilled in the art, the present invention can have various modifications and variations. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A control method for an aerial robot used for contact bridge inspection, characterized in that, The contact bridge inspection aerial robot includes an aircraft (100) and a first robotic arm (200), the first robotic arm (200) being disposed at the bottom of the aircraft (100) and used to contact the bridge to inspect the bridge; The first robotic arm (200) includes an elastic drive joint, which includes a servo motor (210), a fixed frame (220), an input end bracket (230), and an output end bracket (240). The servo motor (210) is fixedly mounted on the fixed frame (220) and connected to the input end bracket (230). The servo motor (210) is used to drive the input end bracket (230) to rotate. The output bracket (240) is rotatably connected to the input bracket (230) and an elastic component is provided between the output bracket (230) and the input bracket (230). The elastic component is used to provide a restoring force for the output bracket (240) when the output bracket (240) rotates relative to the input bracket (230). The elastic component includes a first linear compression spring (251) and a second linear compression spring (252) arranged coaxially. The output end bracket (240) and the input end bracket (230) are provided with a fixing part (241) that protrudes radially along the rotational connection. The fixing part (241) divides the input end bracket (230) into a left cavity (231) and a right cavity (232). The first linear compression spring (251) is installed in the left cavity (231), one end of the first linear compression spring (251) is connected to the input end bracket (230) and the other end is connected to the fixing part (241); The second linear compression spring (252) is installed in the right cavity (232), one end of the second linear compression spring (252) is connected to the input end bracket (230) and the other end is connected to the fixing part (241); The contact bridge inspection aerial robot also includes two of the first robotic arms (200) and a second robotic arm (300). The first robotic arm (200) also includes a swing arm (260), which is connected to the output end bracket (240); The second robotic arm (300) is mounted on top of the aircraft (100) and is used to contact the bridge to inspect it; The control method for the aerial robot used for contact bridge inspection includes the following steps: S1. Based on the established dynamic model, obtain the total centroid position vector when the robotic arm group moves to a specified posture; the robotic arm group includes two of the first robotic arms; S2. Calculate the gravitational torque generated by the robotic arm assembly on the aircraft based on the total centroid position vector; S3. When the robotic arm assembly has no external load, control the servo motor according to the following steps S31-S32: S31. Calculate the first swing angle of the swing arm under the action of the spring group based on the gravitational torque; the spring group includes the first linear compression spring and the second linear compression spring; S32. Using the first swing angle as compensation, control the torque of the servo motor; S4. When the robotic arm assembly has an external load, control the servo motor according to the following steps S41-S43: S41. Calculate the equivalent external torque generated by the robotic arm assembly on the aircraft based on the preset expected contact force; S42. Calculate the second swing angle generated by the swing arm under the action of the spring group based on the gravitational torque and the equivalent external torque; S43. Using the second swing angle as compensation, control the torque of the servo motor.

2. The control method for an aerial robot used for contact bridge inspection according to claim 1, characterized in that, The specific steps in step S31 include: S311. Calculate the first swing angle according to the following formula: ； ； in, For the first swing angle, This refers to the stiffness coefficient of a single linear compression spring in the selected spring group. The distance from the center of the end face of a single linear compression spring in the spring assembly near the fixed part to the center of the swing arm. Let be the radius of a single linear compression spring in the spring assembly. The gravitational torque, Let be the total centroid position vector. The total mass of the robotic arm assembly is... This is the acceleration due to gravity.

3. The control method for an aerial robot used for contact bridge inspection according to claim 2, characterized in that, The specific steps in step S41 include: S411. Calculate the equivalent external torque according to the following formula: ； ； in, The equivalent external torque is... The preset desired contact force, The relative position of the contact point in the local coordinate system of the robotic arm assembly. Let be the transformation matrix between the local coordinate system of the robotic arm assembly and the local coordinate system of the elastic drive joint. Let x be the x-coordinate of the contact point in the local coordinate system of the robotic arm assembly. Let y be the y-coordinate of the contact point in the local coordinate system of the robotic arm assembly. Let z be the z-coordinate of the contact point in the local coordinate system of the robotic arm assembly.

4. The control method for an aerial robot for contact bridge inspection according to claim 3, characterized in that, The specific steps in step S42 include: S421. Calculate the second swing angle according to the following formula: ； in, This is the second swing angle.

5. A control device for an aerial robot used for contact bridge inspection, characterized in that, The contact bridge inspection aerial robot includes an aircraft (100) and a first robotic arm (200), the first robotic arm (200) being disposed at the bottom of the aircraft (100) and used to contact the bridge to inspect the bridge; The first robotic arm (200) includes an elastic drive joint, which includes a servo motor (210), a fixed frame (220), an input end bracket (230), and an output end bracket (240). The servo motor (210) is fixedly mounted on the fixed frame (220) and connected to the input end bracket (230). The servo motor (210) is used to drive the input end bracket (230) to rotate. The output bracket (240) is rotatably connected to the input bracket (230) and an elastic component is provided between the output bracket (230) and the input bracket (230). The elastic component is used to provide a restoring force for the output bracket (240) when the output bracket (240) rotates relative to the input bracket (230). The elastic component includes a first linear compression spring (251) and a second linear compression spring (252) arranged coaxially. The output end bracket (240) and the input end bracket (230) are provided with a fixing part (241) that protrudes radially along the rotational connection. The fixing part (241) divides the input end bracket (230) into a left cavity (231) and a right cavity (232). The first linear compression spring (251) is installed in the left cavity (231), one end of the first linear compression spring (251) is connected to the input end bracket (230) and the other end is connected to the fixing part (241); The second linear compression spring (252) is installed in the right cavity (232), one end of the second linear compression spring (252) is connected to the input end bracket (230) and the other end is connected to the fixing part (241); The contact bridge inspection aerial robot also includes two of the first robotic arms (200) and a second robotic arm (300). The first robotic arm (200) also includes a swing arm (260), which is connected to the output end bracket (240); The second robotic arm (300) is mounted on top of the aircraft (100) and is used to contact the bridge to inspect it; The control device for the aerial robot used for contact bridge inspection includes: The first acquisition module is used to acquire the total centroid position vector of the robotic arm group when it moves to a specified posture based on the established dynamic model; the robotic arm group includes two first robotic arms. The calculation module is used to calculate the gravitational torque generated by the robotic arm assembly on the aircraft based on the total center of mass position vector; The first control module is used to control the servo motor according to the following steps S31-S32 when the robotic arm assembly has no external load: S31. Calculate the first swing angle of the swing arm under the action of the spring group based on the gravitational torque; the spring group includes the first linear compression spring and the second linear compression spring; S32. Using the first swing angle as compensation, control the torque of the servo motor; The second control module is used to control the servo motor according to the following steps S41-S43 when the robotic arm assembly has an external load: S41. Calculate the equivalent external torque generated by the robotic arm assembly on the aircraft based on the preset expected contact force; S42. Calculate the second swing angle generated by the swing arm under the action of the spring group based on the gravitational torque and the equivalent external torque; S43. Using the second swing angle as compensation, control the torque of the servo motor.

6. An electronic device, characterized in that, It includes a processor and a memory, the memory storing computer-readable instructions, which, when executed by the processor, perform the steps of the control method for an aerial robot for contact bridge inspection as described in any one of claims 1-4.

7. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it performs the steps in the control method for an aerial robot for contact bridge inspection as described in any one of claims 1-4.

Images