An aircraft fuel tank continuous inspection quadruped robot

Abstract

This invention discloses a quadruped robot for continuous inspection of aircraft fuel tanks, comprising a fuselage. Two sides of the fuselage are each equipped with a three-degree-of-freedom (DOF) mechanical leg for supporting the fuselage's movement. A camera arm assembly is movably mounted on the top of the fuselage, and the camera arm assembly is equipped with a camera for capturing images of the interior of the fuel tank. A lidar sensor is fixedly mounted on the top of the fuselage for self-positioning, 3D environment mapping, path planning, and obstacle avoidance. This invention utilizes four three-degree-of-freedom mechanical legs, transitioning from a fully elbow-type to a fully knee-type configuration and back to a fully elbow-type configuration. Driven by linear guides, the three-degree-of-freedom mechanical legs move, allowing the fuselage to complete a full traverse. This enables continuous inspection through inspection holes in the vertically mounted ribs separating the individual fuel tanks within the aircraft fuel tank, thus achieving uninterrupted and automated inspection of the fuel tank.

Description

Technical Field

[0001] This invention relates to the field of quadruped robot technology, specifically a quadruped robot for continuous inspection of aircraft fuel tanks. Background Technology

[0002] In civil aviation aircraft maintenance, troubleshooting and repairing aircraft fuel tank malfunctions has always been a challenging issue. Aircraft fuel tanks are enclosed, thin-walled compartments. Main fuel tanks and central fuel tanks are located inside the wings and in the fuselage midsection, respectively. Each fuel tank is laterally divided into multiple sub-tanks by ribs with openings for maintenance personnel to pass through. Maintenance is conducted within the different sub-tanks, which are lined with stringers on their upper and lower surfaces, resulting in discontinuous internal spaces and uneven surfaces. Operators need to inspect both the inside and outside of the fuel tanks for leaks, corrosion, and loose parts. However, the confined space and complex structure of the fuel tank, with its intersecting stringers, webs, and ribs, severely restricts the space for maintenance work. This makes it difficult for operators to move flexibly and perform detailed inspections and repairs. Furthermore, troubleshooting is time-consuming, and the dark and complex interior can easily disorient operators. Furthermore, due to the sealing requirements of fuel tanks, the presence of residual fuel and volatile fuel vapors inside makes it impossible for maintenance personnel to operate inside the tanks for extended periods. Simultaneously, the maintenance process must ensure the fuel tanks are not contaminated or subjected to secondary damage, and strictly control ignition sources and static electricity to prevent fires or explosions. Therefore, aircraft fuel tank maintenance demands extremely high levels of proficiency, skill, physical strength, and familiarity with maintenance equipment from maintenance personnel. However, manual inspection inside fuel tanks is inefficient, aircraft downtime is long, and the tanks are filled with flammable, explosive, and toxic gases, creating a hazardous working environment that threatens the lives and health of maintenance personnel.

[0003] For example, CN102060057B discloses an aircraft fuel tank inspection robot system and its control method. The system consists of a robot body and a ground monitoring system. The robot body includes a chassis, fuselage, two tracks, a camera support frame, a longitudinal motion drive mechanism, a lateral motion drive mechanism, a lifting drive mechanism, and a scheduling and control system. The ground monitoring system is a portable computer. The aircraft fuel tank inspection robot system provided by this invention can replace maintenance personnel to enter the interior of the fuel tank and can detect internal leaks and corrosion locations. This not only improves the working environment for maintenance personnel, ensures maintenance quality, and increases maintenance efficiency, but also shortens aircraft downtime, thereby reducing airport economic losses.

[0004] CN102729240B discloses an aircraft fuel tank inspection robot based on a continuum structure and its control method. The robot includes a mobile platform, a lifting motion unit, a snake-arm motion unit, a system control unit, and a power module. This robot is a biomimetic robot that can enter the interior of an aircraft fuel tank under human supervision to determine internal leaks and inspect for corrosion. It possesses superior bending performance not found in traditional discrete robots, and can flexibly change its shape according to environmental obstacles. It also exhibits unique adaptability to confined and unstructured working environments. This robot can replace humans in working inside fuel tanks, undoubtedly reducing the workload of maintenance personnel, ensuring personnel safety, improving maintenance efficiency, and reducing fuel tank safety hazards, thus significantly contributing to shortening aircraft downtime and reducing economic losses. Furthermore, the part of the robot that extends into the aircraft fuel tank has almost no electrical equipment, thus providing excellent explosion-proof capabilities.

[0005] The invention also discloses a dynamic walking quadrupedal exploration robot and its control method, disclosed in CN113985864A, belonging to the field of deep space exploration technology. It includes a body, a first moving leg, a second moving leg, a third moving leg, and a fourth moving leg. It employs a quadrupedal robot's diagonal trotting gait, using gait planning based on the system's own state rather than time to improve disturbance adaptability. Attitude adjustment is achieved through speed-level planning of the body. The body is tilted forward and backward through centroid planning to adapt to slopes. A two-dimensional adjustment rate for foot placement is established to achieve speed regulation and anti-interference regulation. Progressive tracking of the planned gait is achieved through dynamic control. This invention significantly improves the stability of the quadrupedal robot's diagonal trotting dynamic walking and possesses excellent speed regulation, slope adaptation, and disturbance adaptation capabilities.

[0006] However, in practical applications, the above technologies are:

[0007] Firstly, CN102060057B can only troubleshoot a single fuel tank, cannot cross the rib opening, cannot perform continuous inspection, and after each fuel tank is inspected, it must be removed from the fuel tank and then entered through the inspection hole of another fuel tank, which is a rather cumbersome process.

[0008] CN102729240B can only inspect a single section or adjacent oil tanks. Due to the limitations of the snake-shaped robotic arm's own structure and gravity, it is still unable to perform uninterrupted and continuous automated inspection of the oil tanks.

[0009] Due to the structural design and spatial limitations of its mobile device, CN113985864A's quadruped robot can only drive its mechanical legs to move within a small range. Its function remains focused on improving the stability of the quadruped robot's movement on uneven ground, without addressing the robot's ability to cross vertically, let alone enabling it to pass through vertical wall openings. Summary of the Invention

[0010] The purpose of this invention is to provide a quadruped robot for continuous inspection of aircraft fuel tanks, so as to solve the problem of the inconvenience of uninterrupted and continuous automated inspection of fuel tanks.

[0011] To achieve the above objectives, the present invention provides the following technical solution: including a fuselage, with three-degree-of-freedom mechanical legs movably mounted on both sides of the fuselage for supporting the movement of the fuselage, a camera arm assembly movably mounted on the top of the fuselage, and a camera for capturing images of the inside of the fuel tank mounted on the camera arm assembly, and a laser radar sensor fixedly mounted on the top of the fuselage for realizing self-positioning, 3D environment mapping, path planning, and obstacle avoidance and crossing functions;

[0012] The three-degree-of-freedom robotic leg includes a first joint that can move left and right at one end of the body, and a second joint that can rotate 180° along a vertical axis is rotatably provided on the surface of the first joint. A thigh that can rotate 180° along a horizontal axis is rotatably provided at the end of the second joint away from the first joint. A third joint that can rotate 180° along a horizontal axis is rotatably provided at the end of the thigh away from the second joint. A lower leg is fixedly connected to the end of the third joint away from the thigh. This allows the body to move inside the fuel tank by the relative rotation between the first joint, the second joint, the thigh, and the third joint, with the lower leg supporting the body inside the fuel tank.

[0013] The camera arm assembly includes a lower camera arm rotatably mounted on the top of the body, and an upper camera arm rotatably mounted on the surface of the lower camera arm away from the body, and a camera is rotatably mounted on the upper camera arm away from the lower camera arm.

[0014] Preferably, a depth camera is fixedly installed at one end of the body for collecting and comparing obstacle information and enabling the body to overcome obstacles. The body is a rectangular structure with a hollow interior and bottom. The interior of the body is equipped with a drive battery for providing power and a control circuit board for issuing control commands.

[0015] Preferably, the bottom of the body is fixedly connected to the first joint of the camera arm, and the end of the lower leg away from the thigh is fixedly provided with a foot end, which has an arc-shaped structure to facilitate the lower leg to move in the fuel tank in coordination with the foot end.

[0016] Preferably, the mechanical leg has four first joints, and the four mechanical leg first joints are divided into two groups, with the two mechanical leg first joints in each group being symmetrically arranged about the vertical axis of the midpoint of the body.

[0017] Preferably, a linear guide rail is fixedly connected to the inner wall of the body corresponding to the first joint position of the mechanical leg. A slider is slidably connected to the surface of the linear guide rail. A connecting block is fixedly connected to the top of the slider. The connecting block movably passes through and extends to the outside of the body. The connecting block is fixedly connected to one end of the mechanical leg corresponding to the body position of the first joint, so that when the linear guide rail drives the slider to move back and forth, it will drive the first joint of the mechanical leg to move back and forth through the connecting block.

[0018] Preferably, each end of the body is fixedly provided with an explosion-proof lamp for providing illumination to the acquisition camera, and the number of explosion-proof lamps is four. The four explosion-proof lamps are respectively arranged on the front, back, left and right sides of the body, and a bottom plate is fixedly connected to the bottom of the body.

[0019] Preferably, both ends of the thigh are hollow structures, and the second and third joints of the mechanical leg are located on the inner walls of both ends of the thigh, so that the hollow structures at both ends of the thigh provide space for the rotation of the second and third joints of the mechanical leg.

[0020] Preferably, a base is fixedly connected to the top of the body corresponding to the lower arm position of the camera arm, and a first joint of the camera arm is rotatably provided on the top of the base. The first joint of the camera arm is fixedly connected to the bottom of the lower arm. A second joint of the camera arm is fixedly connected to one end of the lower arm corresponding to the upper arm position of the camera arm, and the second joint of the camera arm is rotatably connected to one end of the upper arm corresponding to the lower arm position of the camera arm. A third joint of the camera arm is fixedly connected to one end of the upper arm away from the lower arm position of the camera arm, and the acquisition camera is rotatably connected to the end of the third joint away from the upper arm position of the camera arm.

[0021] Preferably, each of the mechanical leg's first joint, second joint, third joint, base, camera arm's first joint, second joint, upper arm, and third joint is equipped with a drive motor. The drive motor in the middle of the first joint drives the second joint to rotate 180°, the motor in the middle of the second joint drives the thigh to rotate 180°, and the motor in the middle of the third joint drives the lower leg to rotate 180°. The output shafts of the drive motors in the second and third joints are parallel to each other. The motor in the middle of the base drives the first joint to rotate 180°, the motor in the middle of the first joint drives the lower arm to rotate 360°, the motor in the middle of the second joint drives the upper arm to rotate 360°, the motor in the middle of the upper arm drives the third joint to rotate 360°, and the motor in the middle of the third joint drives the camera to rotate 180°.

[0022] Preferably, the second joint of the camera arm is perpendicular to the lower and upper arms of the camera arm, respectively, so that the upper and lower arms of the camera arm can remain parallel to each other during movement. The motors in the middle of the first, second, and third joints of the mechanical leg, the middle of the base, and the middle of the third joint of the camera arm are all dual-axis motors.

[0023] Compared with the prior art, the beneficial effects of the present invention are:

[0024] 1. This invention utilizes four three-degree-of-freedom mechanical legs, transitioning from a full elbow type to a full knee type, and then back to a full elbow type. These legs, driven by linear guides, allow the fuselage to complete a full span, enabling continuous inspection through inspection holes on vertically mounted ribs separating the individual fuel tanks. This achieves uninterrupted and automated inspection of the fuel tanks. When inspecting the wing fuel tanks, the fuselage no longer enters the wing area; the camera arm assembly extends through the rib inspection holes to perform the inspection. Simultaneously, electronic marking is achieved through real-time 3D mapping using lidar sensors, preventing the leaving of physical or chemical residues inside the fuel tanks. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the overall structure of a quadruped robot for continuous inspection of aircraft fuel tanks according to the present invention;

[0026] Figure 2 This is a bottom view of the overall structure of a quadruped robot for continuous inspection of aircraft fuel tanks according to the present invention.

[0027] Figure 3 This is a schematic diagram of the three-degree-of-freedom mechanical leg structure of a quadruped robot for continuous inspection of aircraft fuel tanks according to the present invention;

[0028] Figure 4 This is a schematic diagram of the camera arm assembly of a quadruped robot for continuous inspection of aircraft fuel tanks according to the present invention.

[0029] In the diagram: 1. Body; 2. Linear guide rail; 3. Depth camera; 4. Three-DOF robotic leg; 5. Camera arm assembly; 6. Acquisition camera; 7. LiDAR sensor; 8. Explosion-proof light; 9. Lower base plate; 10. Slider; 11. Connecting block; 12. First joint of robotic leg; 13. Second joint of robotic leg; 14. Thigh; 15. Third joint of robotic leg; 16. Lower leg; 17. Foot; 18. Base; 19. First joint of camera arm; 20. Lower arm of camera arm; 21. Second joint of camera arm; 22. Upper arm of camera arm; 23. Third joint of camera arm. Detailed Implementation

[0030] 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. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0031] As a crucial component for aircraft fuel storage, the fuel tank is located in key positions in the wings, fuselage midsection, and tail section. It plays a vital role in aircraft weight balance and significantly impacts safe flight. Fuel tank inspection is a critical part of aircraft maintenance. Maintenance personnel must enter the fuel tank for inspection. Due to the complex internal structure, confined space, darkness, and the presence of flammable, toxic volatile gases and fuel residue, movement is difficult, prolonged internal work is not possible, troubleshooting efficiency is low, and oversights are possible. Fuel tank inspection is challenging, demanding high levels of physical fitness, skill proficiency, and familiarity with the tank's internal structure from maintenance personnel. The harsh environment and potential explosion hazards within the fuel tank pose a threat to the personal safety of maintenance personnel, and prolonged work in this environment can negatively impact their health. Therefore, this invention provides a quadruped robot for continuous aircraft fuel tank inspection, which can significantly improve troubleshooting efficiency, increase the extent of fuel tank inspection, and achieve mechanization of fuel tank inspection.

[0032] Please see Figure 1-4This invention provides a technical solution: It includes a body 1, which is a rectangular structure with a hollow interior and bottom. A lower base plate 9 is fixedly installed on the bottom of the body 1. The interior of the body 1 houses a drive battery for providing power and a control circuit board for issuing control commands. The body 1, together with the lower base plate 9, encloses the drive battery and control circuit board. A depth camera 3 is fixedly installed at one end of the body 1 for collecting and comparing obstacle information, enabling the body 1 to overcome obstacles. The depth camera 3 is located at one end in the walking direction of the body 1, used to measure and calculate obstacles in the walking direction, thus enabling the device to overcome obstacles. Three-degree-of-freedom mechanical legs 4 are movably installed on both sides of the body 1 to support its movement. A camera arm assembly 5 is movably installed on the top of the body 1. Component 5 is equipped with a camera 6 for capturing images of the inside of the fuel tank. The camera 6 has a spherical structure, making it compact and less prone to impact. The top of the fuselage 1 is fixed with a lidar sensor 7 for self-positioning, 3D environment mapping, path planning, and obstacle avoidance. The lidar sensor 7 is located at the rear end of the camera arm component 5 in the corresponding walking direction. The lidar sensor 7 is not affected by the internal structure and materials of the aircraft fuel tank. Combined with SLAM real-time localization and mapping technology, it can realize self-positioning, 3D environment mapping, path planning, obstacle avoidance, and other functions. Using the lidar positioning and mapping function, combined with the special environment inside the aircraft fuel tank, the detected fault points are electronically marked on the working condition map to achieve rapid point-to-point repair.

[0033] The three-degree-of-freedom robotic leg 4 includes a first joint 12 that can move left and right at one end of the body 1, and a second joint 13 that can rotate 180° along a vertical axis is rotatably provided on the surface of the first joint 12. A thigh 14 that can rotate 180° along a horizontal axis is rotatably provided at the end of the second joint 13 away from the first joint 12. A third joint 15 that can rotate 180° along a horizontal axis is rotatably provided at the end of the thigh 14 away from the second joint 13, and the third joint 15 is located away from the thigh 14. A lower leg 16 is fixedly installed at one end of the position so that the lower leg 16 can support the body 1 inside the fuel tank through the relative rotation between the first joint 12, the second joint 13, the thigh 14 and the third joint 15 of the mechanical leg. Both ends of the thigh 14 are hollow structures, and the second joint 13 and the third joint 15 of the mechanical leg are located on the inner wall of both ends of the thigh 14, so that the hollow structure at both ends of the thigh 14 provides space for the rotation of the second joint 13 and the third joint 15 of the mechanical leg.

[0034] The camera arm assembly 5 includes a lower camera arm 20 rotatably mounted on the top of the body 1, and an upper camera arm 22 rotatably mounted on the surface of the lower camera arm 20 away from the body 1. A camera 6 is rotatably mounted on the end of the upper camera arm 22 away from the lower camera arm 20. A base 18 is fixedly mounted on the top of the body 1 corresponding to the position of the lower camera arm 20, and a first camera arm joint 19 is rotatably mounted on the top of the base 18. The first camera arm joint 19 is fixedly mounted on the bottom of the lower camera arm 20. The lower arm 20 of the camera arm is fixedly installed with a second joint 21 at one end corresponding to the upper arm 22 of the camera arm. The second joint 21 is rotatably connected to the upper arm 22 at one end corresponding to the lower arm 20 of the camera arm. The upper arm 22 is fixedly installed with a third joint 23 at one end away from the lower arm 20 of the camera arm. The camera 6 is rotatably connected to the third joint 23 at one end away from the upper arm 22 of the camera arm. The lower arm 20 and the upper arm 22 of the camera arm are cylindrical structures.

[0035] The bottom of the fuselage 1 is fixedly equipped with the first joint 19 of the camera arm. The lower leg 16 is fixedly provided with a foot end 17 at the end away from the thigh 14. The foot end 17 has an arc-shaped structure to facilitate the lower leg 16 to move in the fuel tank. The foot end 17 is wrapped with an elastic material that is corrosion-resistant, slip-resistant, explosion-proof, and anti-static to avoid hard contact between the foot end 17 and the inner surface of the aircraft fuel tank. The biomimetic shape of the foot end 17 with its arc-shaped surface structure is conducive to obstacle crossing and increases the contact surface to make walking more stable.

[0036] The mechanical leg has four first joints 12, which are divided into two groups. Each group of two first joints 12 are symmetrically arranged about the vertical axis of the midpoint of the body 1. A linear guide rail 2 is fixedly installed on the inner wall of the body 1 corresponding to the position of the first joint 12 of the mechanical leg. The linear guide rail 2 is parallel to the central axis of the body 1. A slider 10 is slidably connected to the surface of the linear guide rail 2. A connecting block 11 is fixedly installed on the top of the slider 10. The connecting block 11 is movable through and extends to the outside of the body 1. The connecting block 11 is fixedly installed at one end of the first joint 12 of the mechanical leg corresponding to the position of the body 1, so that when the linear guide rail 2 drives the slider 10 to move back and forth, it will drive the first joint 12 of the mechanical leg to move back and forth through the connecting block 11.

[0037] Each end of the body 1 is fixed with an explosion-proof light 8 for providing illumination to the acquisition camera 6, so as to achieve a better image acquisition effect. There are four explosion-proof lights 8, which are respectively set on the front, back, left and right sides of the body 1.

[0038] Each of the mechanical leg's first joint 12, second joint 13, third joint 15, base 18, camera arm's first joint 19, second joint 21, upper arm 22, and third joint 23 is equipped with a drive motor. The drive motor in the middle of the first joint 12 drives the second joint 13 to rotate 180°. The motor in the middle of the second joint 13 drives the thigh 14 to rotate 180°. The motor in the middle of the third joint 15 drives the lower leg 16 to rotate 180°. The output shaft of the drive motor in the middle of the second joint 13 is parallel to the output shaft of the drive motor in the middle of the third joint 15. The motor in the middle of the base 18 drives the first joint 19 of the camera arm to rotate 180°. The motor in the middle of the second joint 21 of the camera arm is used to drive the lower arm 20 of the camera arm to rotate 360°. The motor in the middle of the upper arm 22 of the camera arm is used to drive the third joint 23 of the camera arm to rotate 360°. The motor in the middle of the third joint 23 of the camera arm is used to drive the acquisition camera 6 to rotate 180°. The second joint 21 of the camera arm is perpendicular to the lower arm 20 and the upper arm 22 of the camera arm, respectively, so that the upper arm 22 and the lower arm 20 can remain parallel to each other during the movement. The motors in the middle of the first joint 12, the second joint 13, the third joint 15 of the mechanical leg, the base 18, and the third joint 23 of the camera arm are all dual-axis motors. All components of this device are coated with anti-corrosion, explosion-proof, and anti-static materials.

[0039] Working principle: In use, the device enters through the inspection hole on the lower cover of the aircraft fuel tank. The lidar sensor 7 scans and maps the inside of the fuel tank. The camera arm assembly 5 drives the acquisition camera 6 to inspect each corner of this section of the fuel tank. If internal leaks, corrosion, or parts falling off are found, they are electronically marked on the constructed 3D map, and the information is transmitted back to facilitate quick point-to-point repair by maintenance personnel. Once all problem points are marked, or if the section of the fuel tank is undamaged, the inspection of this section of the fuel tank is completed, and the inspection of the second section of the fuel tank begins. The device is driven to move to the rib plate separating the first and second fuel tanks. The depth camera 3 at one end of the fuselage 1 detects the location of the inspection hole opening on the rib plate. With the front of the fuselage 1 facing the opening, the camera arm assembly 5 extends, first capturing the... Camera 6 is inserted into the inspection hole to conduct a preliminary inspection of the second oil tank, avoiding any omissions in the inspection of the lower plate area blocked after the machine body enters. After the preliminary inspection is completed, the acquisition camera 6 is retracted, and the camera arm assembly 5 is folded so that it is close to the machine body. The machine body begins to enter the second oil tank, and the four lower legs 16 extend so that the lower base plate 9 is slightly higher than the lower limit of the rib opening. The four linear guides 2 translate the four three-degree-of-freedom mechanical legs 4 to the ends of the respective linear guides 2. The machine body 1 moves forward so that it passes through the rib opening until the front ends of the two linear guides 2 at the front of the machine body 1 exceed the rib being crossed. The second joint 13 and the third joint 15 of the two three-degree-of-freedom mechanical legs 4 at the front end of the machine body 1 drive one of the three-degree-of-freedom mechanical legs at the front end. The three-degree-of-freedom mechanical leg 4 (hereinafter, one of the three-degree-of-freedom mechanical legs 4 on the front end is replaced by leg A, the other three-degree-of-freedom mechanical leg 4 on the front end is replaced by leg B, one of the three-degree-of-freedom mechanical legs 4 on the rear end is replaced by leg C, and the other three-degree-of-freedom mechanical leg 4 on the rear end is replaced by leg B) folds up off the ground. The drive shaft of the drive motor in the middle of the first joint 12 of the mechanical leg drives leg A to rotate 180° counterclockwise, changing leg A from an inward elbow position to an outward knee position, changing from the top of the lower leg 16 being at the back to the top of the lower leg 16 being at the front. After the change, leg A is moved by the linear guide 2 to the front end of the linear guide 2, so that leg A passes through the rib plate opening until the first joint 12 of leg A passes through the rib plate. At this time, the entire leg A passes through the rib plate opening and enters the second oil tank from the first oil tank. The second joint 13 and the third joint 15 of the mechanical leg drive the extension of leg A, completing the crossing of leg A. Legs B, C, and D all cross in the same way. After all four three-degree-of-freedom mechanical legs 4 have passed through the rib openings, the second joint 13 and the third joint 15 of the mechanical leg drive the bending of the three-degree-of-freedom mechanical legs 4, causing the fuselage center of gravity to drop and improving stability. The first joint 12 of the mechanical legs of all four three-degree-of-freedom mechanical legs 4 rotates 180° clockwise, returning from the full knee position to the full elbow position, and the fuselage completes a complete crossing. Subsequent inspections are similar to the inspection process for entering the first fuel tank. When inspecting the top of the wing fuel tank, due to the narrow space at the top, only the acquisition camera 6 needs to be inserted to complete the inspection, and the fuselage does not enter again to avoid unnecessary secondary damage.

[0040] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0041] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. An aircraft fuel tank continuous inspection quadruped robot comprising a fuselage, characterized by: Both sides of the fuselage are equipped with three-degree-of-freedom mechanical legs for supporting the movement of the fuselage. A camera arm assembly is movably mounted on the top of the fuselage, and the camera arm assembly is equipped with a camera for capturing images of the inside of the fuel tank. A laser radar sensor is fixedly mounted on the top of the fuselage for realizing self-positioning, 3D environment mapping, path planning, and obstacle avoidance and crossing functions. The three-degree-of-freedom robotic leg includes a first joint that can move left and right at one end of the body, and a second joint that can rotate 180° along a vertical axis is rotatably provided on the surface of the first joint. A thigh that can rotate 180° along a horizontal axis is rotatably provided at the end of the second joint away from the first joint. A third joint that can rotate 180° along a horizontal axis is rotatably provided at the end of the thigh away from the second joint. A lower leg is fixedly connected to the end of the third joint away from the thigh. This allows the body to move inside the fuel tank by the relative rotation between the first joint, the second joint, the thigh, and the third joint, with the lower leg supporting the body inside the fuel tank. The camera arm assembly includes a lower camera arm rotatably mounted on the top of the body, and an upper camera arm rotatably mounted on the surface of the lower camera arm away from the body, and a camera is rotatably mounted on the upper camera arm away from the lower camera arm. The mechanical leg has four first joints, and the four mechanical leg first joints are divided into two groups. The two mechanical leg first joints in each group are symmetrically arranged about the vertical axis of the midpoint of the body. A linear guide rail is fixedly connected to the inner wall of the body corresponding to the first joint of the mechanical leg. A slider is slidably connected to the surface of the linear guide rail. A connecting block is fixedly connected to the top of the slider. The connecting block moves through and extends to the outside of the body. The connecting block is fixedly connected to one end of the mechanical leg corresponding to the body position of the first joint, so that when the linear guide rail drives the slider to move back and forth, it will drive the first joint of the mechanical leg to move back and forth through the connecting block. Both ends of the thigh are hollow structures, and the second and third joints of the mechanical leg are located on the inner walls of both ends of the thigh, so that the hollow structures at both ends of the thigh provide space for the rotation of the second and third joints of the mechanical leg.

2. The quadruped robot for continuous inspection of aircraft fuel tanks according to claim 1, characterized in that: One end of the body is fixedly equipped with a depth camera for collecting and comparing obstacle information and enabling the body to overcome obstacles. The body is a rectangular structure with a hollow interior and bottom. The interior of the body is equipped with a drive battery for providing power and a control circuit board for issuing control commands.

3. The quadruped robot for continuous inspection of aircraft fuel tanks according to claim 2, characterized in that: The top of the machine body is fixedly connected to the first joint of the camera arm, and the end of the lower leg away from the thigh is fixedly provided with a foot end, which has an arc-shaped structure to facilitate the lower leg to move in the fuel tank in coordination with the foot end.

4. A quadruped robot for continuous inspection of aircraft fuel tanks according to claim 3, characterized in that: Each end of the body is fixedly equipped with an explosion-proof light for providing illumination to the acquisition camera, and there are four explosion-proof lights. The four explosion-proof lights are respectively arranged on the front, back, left and right sides of the body. The bottom of the body is fixedly connected to a bottom plate.

5. A quadruped robot for continuous inspection of aircraft fuel tanks according to claim 4, characterized in that: A base is fixedly connected to the top of the body corresponding to the lower arm of the camera arm, and a first joint of the camera arm is rotatably provided on the top of the base. The first joint of the camera arm is fixedly connected to the bottom of the lower arm of the camera arm. A second joint of the camera arm is fixedly connected to one end of the lower arm corresponding to the upper arm of the camera arm, and the second joint of the camera arm is rotatably connected to one end of the upper arm corresponding to the lower arm of the camera arm. A third joint of the camera arm is fixedly connected to one end of the upper arm away from the lower arm of the camera arm, and the camera is rotatably connected to the end of the third joint of the camera arm away from the upper arm of the camera arm.

6. A quadruped robot for continuous inspection of aircraft fuel tanks according to claim 5, characterized in that: Each of the mechanical leg's first joint, second joint, and third joint, the base, the camera arm's first joint, second joint, upper arm, and third joint is equipped with a drive motor. The drive motor in the middle of the first joint drives the second joint to rotate 180°, the motor in the middle of the second joint drives the thigh to rotate 180°, and the motor in the middle of the third joint drives the lower leg to rotate 180°. The output shafts of the drive motors in the second and third joints are parallel to each other. The motor in the middle of the base drives the first joint to rotate 180°, the motor in the middle of the first joint drives the lower arm to rotate 360°, the motor in the middle of the second joint drives the upper arm to rotate 360°, the motor in the middle of the upper arm drives the third joint to rotate 360°, and the motor in the middle of the third joint drives the camera to rotate 180°.

7. A quadruped robot for continuous inspection of aircraft fuel tanks according to claim 6, characterized in that: The second joint of the camera arm is perpendicular to the lower and upper arms of the camera arm, respectively, so that the upper and lower arms of the camera arm can remain parallel to each other during movement. The motors in the middle of the first, second, and third joints of the mechanical leg, the middle of the base, and the middle of the third joint of the camera arm are all dual-axis motors.

Images