An aircraft fuel tank internal inspection robot and a fuel tank defect inspection method

Abstract

The application discloses an aircraft fuel tank internal detection robot and a fuel tank defect detection method. The detection robot comprises a walking chassis, an adjusting support mechanism, a six-axis mechanical arm and a detection sensor. The detection sensor is connected to the walking chassis through the six-axis mechanical arm and the adjusting support mechanism. The adjusting support mechanism comprises a first translation module, a second translation module and a support mechanism. The six-axis mechanical arm is connected to the first translation module through the second translation module. The support mechanism is connected to the first translation module and can be switched between a retracted state and an expanded state. In the retracted state, the support mechanism is in close contact with the first translation module. In the expanded state, the support mechanism can abut against the bottom of the aircraft fuel tank. In the application, the state switching of the support mechanism enables the support mechanism to enter the fuel tank and abut against the bottom of the fuel tank to provide stable support force for the first translation module which is cantilevered, eliminates the swing of the cantilever, and ensures the stability and precision of the detection operation.

Description

Technical Field

[0001] This invention relates to the field of aircraft fuel tank defect detection technology, and in particular to an aircraft fuel tank internal inspection robot and a fuel tank defect detection method. Background Technology

[0002] In civil aviation aircraft maintenance, detecting leaks and corrosion in aircraft fuel tanks has always been a complex and challenging task. Due to the harsh environment, extremely confined working space, and complex structure inside the fuel tank, manual entry for inspection is not only labor-intensive and inefficient, but also poses safety risks such as flammability, explosiveness, and personnel poisoning. Therefore, there is an urgent need for an automated detection robot that can replace manual entry into the fuel tank.

[0003] In the prior art, patent CN102729240A discloses a biomimetic continuum robot for inspecting aircraft fuel tanks and its control method. This robot mainly consists of a mobile platform, a lifting motion unit, and a snake-arm motion unit driven by ropes and supported by flexible rods. This continuum structure has excellent bending performance, enabling it to flexibly change its shape according to environmental obstacles, and possesses unique adaptability to the confined and unstructured environment inside fuel tanks.

[0004] However, the aforementioned existing technologies have significant drawbacks in practical operation. First, as the snake-arm structure extends deeper into the oil tank, its cantilever length continuously increases. Due to the combined effects of its own weight and the elasticity of the flexible support rod, the end of the robotic arm exhibits noticeable drooping and low-frequency vibration. Second, due to the extremely poor stiffness of the continuous structure, it cannot withstand effective contact force. If it is necessary to carry ultrasonic or eddy current probes for contact flaw detection (which requires applying a certain pressure and maintaining stable contact), the robot will be unable to complete the detection task due to force-induced backward movement or deformation. Finally, the robot is expensive; the arm components are not generic parts, requiring complete customization and complex assembly. Summary of the Invention

[0005] Purpose of the invention: In order to overcome the shortcomings of the existing technology, the present invention provides a low-cost and highly stable robot for inspecting the interior of aircraft fuel tanks and a method for detecting defects in fuel tanks.

[0006] Technical solution: To achieve the above objectives, the present invention provides an aircraft fuel tank internal inspection robot, which includes a walking chassis, an adjustment support mechanism, a six-axis robotic arm, and detection sensors; the detection sensors are connected to the walking chassis through the six-axis robotic arm and the adjustment support mechanism.

[0007] The adjustment support mechanism includes a first translation module, a second translation module, and a support mechanism; the six-axis robotic arm is connected to the first translation module via the second translation module;

[0008] The support mechanism is connected to the first translation module, and the support mechanism can switch between a retracted state and an extended state.

[0009] In the retracted state, the support mechanism is attached to the first translation module to reduce the overall envelope size, so that the adjustment support mechanism can pass through the inlet and outlet of the aircraft fuel tank.

[0010] In the deployed state, the support mechanism can abut against the bottom of the aircraft fuel tank to provide rigid support for the first translation module. At this time, the support force provided by the support mechanism to the first translation module is located at the end of the first translation module.

[0011] The first translation module has a module base, a first translation seat, and a second translation seat. Both the first translation seat and the second translation seat are capable of controllable translational movement relative to the module base. The first translation seat and the second translation seat are located on the upper and lower sides of the module base, respectively. The second translation module is mounted on the first translation seat.

[0012] The support mechanism includes a first rod, a second rod, an intermediate block, and a support block;

[0013] One end of the first rod is rotatably connected to the side of the module base, and the other end is rotatably connected to the middle block. The hinge point between the first rod and the module base is located at the end of the module base, that is, the end away from the walking chassis. One end of the second rod is rotatably connected to the second translation seat, and the other end is coaxially hinged to the first rod and the middle block on the first axis.

[0014] The support block is hinged to the second axis relative to the intermediate block, and the first axis and the second axis are perpendicular to each other.

[0015] In the retracted state, the distance between the second translation seat and the module base is at its maximum. At this time, the relative angle between the first and second rods is also at its maximum, and the distance between the support block and the module base is at its minimum. The entire support mechanism is positioned to rest against the module base. In this state, the second rod is parallel to the module base. Since the hinge point between the first rod and the module base is located on the side of the module base, the end of the first rod is higher than the second rod, forming an obtuse angle between them. This avoids creating a structural dead point, and the reciprocating translation of the second translation seat allows the support mechanism to switch states.

[0016] During the unfolding process, the second translation seat moves towards the end of the module base, causing the first and second rods to rotate. The support block moves away from the module base, which allows the support point to be as close as possible to the end of the module base. The distance between the support block and the module base is adjustable.

[0017] Furthermore, the first translation module also includes a first motor, a second motor, a first drive screw, and a second drive screw; the first drive screw and the second drive screw are both disposed in the module base and are driven to rotate by the first motor and the second motor, respectively; the first drive screw is driven to the first translation base, and the second drive screw is driven to the second translation base.

[0018] Furthermore, the adjustment support mechanism also includes a first rotary drive mechanism and a lifting mechanism; the first rotary drive mechanism is connected to the chassis via the lifting mechanism; the module seat of the first translation module is fixed to the output end of the first rotary drive mechanism, and the first rotary drive mechanism and the lifting mechanism form a "7" shape, with the end of the first rotary drive mechanism facing outward and extending beyond the outline of the chassis in a top-view direction; the first end of the module seat in the first translation module is rotatably mounted on the upper side of the end of the first rotary drive mechanism. The "7" shape structure allows the rotation axis of the first rotary drive mechanism to be located inside the inlet / outlet port after entering the aircraft fuel tank.

[0019] Furthermore, the adjustment support mechanism also includes a second rotation drive mechanism; the second translation module is connected to the first translation seat through the second rotation drive mechanism to drive the second translation module to rotate relative to the first translation seat in the horizontal plane.

[0020] Furthermore, the second translation module is a telescopic translation module; all six motion joints of the six-axis robotic arm are rotary joints, and the six-axis robotic arm can switch between a folded state and a working state during operation. In the folded state, the six-axis robotic arm has the smallest envelope size and the shortest overall length to facilitate passage through the inlet and outlet holes and connecting holes of the oil tank.

[0021] A method for detecting fuel tank defects using an aircraft fuel tank internal inspection robot, as described above, involves the following steps: In the initial state, the six-axis robotic arm is in a folded state with its minimum envelope and is collinear with the first translation module. Both the six-axis robotic arm and the first translation module are located above the walking chassis, and the support mechanism is in an extended state, supporting the top of the walking chassis. At this time, when the walking chassis moves, the six-axis robotic arm and the adjustment support mechanism will not encounter surrounding obstacles. The fuel tank defect detection method includes the following steps:

[0022] Step S11: Control the six-axis robotic arm to be in the folded state of minimum envelope and collinear with the first translation module, the support mechanism to be in the retracted state, and control the first translation module to be suspended outside the walking chassis, and adjust the height of the first translation module so that the height of the six-axis robotic arm is adapted to the height of the inlet and outlet holes.

[0023] Step S12: Move the walking chassis so that the adjustment support mechanism and the six-axis robotic arm enter the intermediate compartment of the fuel tank through the inlet and outlet holes;

[0024] Step S13: Control the second translation seat to translate towards the end of the module seat, drive the support mechanism to switch to the unfolded state until the support block fully contacts the bottom of the oil tank;

[0025] Step S14: Control the adjustment support mechanism to work in coordination with the six-axis robotic arm to drive the detection sensor to collect data.

[0026] Furthermore, the procedures for inspecting the side compartments also include:

[0027] Step S21: Control the six-axis robotic arm to return to the folded state, and make the detection sensor aligned with the target connecting hole by swinging the first translation module, translating the first translation seat in the first translation module, and rotating the second rotation drive mechanism relative to the first translation seat.

[0028] Step S22: Coordinate the translation of the first translation seat and the extension of the second translation module to allow the detection sensor and the six-axis robotic arm to enter the target side compartment;

[0029] Step S23: After the six-axis robotic arm has fully entered the target side compartment, control it to unfold and perform the detection operation.

[0030] In this invention, the inspection robot performs an inspection of one half of the fuel tank at a time. After completing the inspection of one half of the fuel tank, the walking chassis 1 moves to the other half of the fuel tank, so that the six-axis robotic arm 3 and the adjustment support mechanism 2 can enter and exit the fuel tank through the inlet and outlet hole a on the other side to complete the inspection of the other half.

[0031] Before each pose adjustment of the module base, the support mechanism is controlled to raise the support block relative to the bottom of the oil tank by a preset height. After the pose adjustment of the module base is completed, the support mechanism is controlled to re-establish the contact support of the module base. Then, the actual spatial pose of the module base after the re-support is determined and used as a reference pose to control the second translation module and the six-axis robotic arm to perform detection operations.

[0032] Beneficial effects: The aircraft fuel tank internal inspection robot and fuel tank defect detection method of the present invention have the following beneficial effects:

[0033] (1) In this invention, the support mechanism is switched to the retracted state during the entry and exit phase, which ensures that the robot can pass smoothly through the narrow entry and exit hole; during the operation phase, it is switched to the unfolded state, which provides stable support for the first translation module of the suspension by abutting the bottom of the oil tank, eliminating the swaying of the long-distance cantilever and ensuring that the detection sensor can stably perform contact flaw detection operation.

[0034] (2) In the support mechanism, the hinged connection between the first rod, the second rod and the middle block enables the support mechanism to be retracted and unfolded. In the unfolded state, the support block can be as close as possible to the end of the module seat to form a reliable support. The support block can achieve multi-directional rotation through two mutually perpendicular hinge axes, ensuring that the support block can effectively and fully contact the bottom plane or curved surface of the aircraft fuel tank, thereby enhancing the reliability of the support.

[0035] (3) The fuel tank defect detection method uses the logic of first entering the hole, then supporting, and then operating. It uses the support mechanism to establish a stable mechanical fulcrum for the long cantilever structure inside the aircraft fuel tank, eliminating the dynamic shaking caused by the movement of the six-axis robotic arm, and ensuring the constant pressure and stable signal of the detection sensor during contact detection.

[0036] (4) The existing six-axis robotic arm and integrated adjustment support mechanism are used, resulting in low cost. Attached Figure Description

[0037] Figure 1 This is a structural diagram of an aircraft fuel tank;

[0038] Figure 2 This is a first-state structural diagram of the robot for inspecting the inside of an aircraft fuel tank.

[0039] Figure 3 This is a structural diagram of the support mechanism in its retracted state;

[0040] Figure 4 This is a diagram showing the second-state structure of a robot for inspecting the inside of an aircraft fuel tank.

[0041] Figure 5 This is a magnified view of a portion of the supporting mechanism;

[0042] Figure 6 This is a diagram showing the combined structure of the aircraft fuel tank inspection robot and the aircraft fuel tank in the second state.

[0043] Figure 7 This is a diagram of the third-state structure of a robot for inspecting the interior of an aircraft fuel tank.

[0044] Figure 8 This is a diagram showing the combined structure of the aircraft fuel tank inspection robot and the aircraft fuel tank in the third state.

[0045] Figure 9This is a diagram showing the combined structure of the aircraft fuel tank inspection robot and the aircraft fuel tank in the fourth state.

[0046] Figure 10 This is a diagram showing the combined structure of the aircraft fuel tank inspection robot and the aircraft fuel tank in the fifth state.

[0047] Figure 11 This is a diagram showing the combined structure of the aircraft fuel tank inspection robot and the aircraft fuel tank in the sixth state.

[0048] In the diagram: a-Inlet / outlet hole; b-Connecting hole; 1-Walking chassis; 2-Adjustment support mechanism; 21-First translation module; 211-Module base; 212-First motor; 213-Second motor; 214-First translation seat; 215-Second translation seat; 22-Second translation module; 221-Cylinder base; 222-Telescopic rod; 223-Third motor; 23-Support mechanism; 231-First rod; 232-Second rod; 233-Intermediate block; 234-Support block; 24-First rotary drive mechanism; 25-Second rotary drive mechanism; 26-Lifting mechanism; 27-Rotation support mechanism; 3-Six-axis robotic arm; 4-Detection sensor. Detailed Implementation

[0049] The invention will now be further described with reference to the accompanying drawings.

[0050] like Figure 1 The aircraft fuel tank shown has three compartments. The middle compartment has two access ports a at the front and rear, and there are two connecting ports b between adjacent compartments.

[0051] like Figure 2 The shown aircraft fuel tank internal inspection robot includes a walking chassis 1, an adjustment support mechanism 2, a six-axis robotic arm 3, and a detection sensor 4. The detection sensor 4 is connected to the walking chassis 1 via the six-axis robotic arm 3 and the adjustment support mechanism 2. The adjustment support mechanism 2 includes a first translation module 21, a second translation module 22, and a support mechanism 23. The six-axis robotic arm 3 is connected to the first translation module 21 via the second translation module 22. The support mechanism 23 is connected to the first translation module 21 and can switch between a retracted state and an extended state. Figure 3 As shown, in the retracted state, the support mechanism 23 abuts against the first translation module 21 to reduce the overall envelope size, allowing the adjustment support mechanism 2 to pass through the inlet / outlet port a of the aircraft fuel tank; as Figure 4 and Figure 6As shown, in the deployed state, the support mechanism 23 can abut against the bottom of the aircraft fuel tank to provide rigid support for the first translation module 21. At this time, the support force provided by the support mechanism 23 to the first translation module 21 is located at the end of the first translation module 21.

[0052] In this invention, the support mechanism 23 is switched to the retracted state during the entry and exit phase, ensuring that the robot can pass smoothly through the narrow entry and exit hole a; during the operation phase, it is switched to the extended state, and by abutting against the bottom of the oil tank, it provides stable support for the suspended first translation module 21, eliminating the swaying of the long-distance cantilever and ensuring that the detection sensor 4 can stably perform contact flaw detection operations.

[0053] Preferably, the first translation module 21 has a module base 211, a first translation seat 214, and a second translation seat 215, both of which are capable of controllable translational movement relative to the module base 211; the first translation seat 214 and the second translation seat 215 are respectively located on the upper and lower sides of the module base 211; the second translation module 22 is mounted on the first translation seat 214.

[0054] The support mechanism 23 includes a first rod 231, a second rod 232, an intermediate block 233, and a support block 234. One end of the first rod 231 is rotatably connected to the side of the module base 211, and the other end is rotatably connected to the intermediate block 233. The hinge point between the first rod 231 and the module base 211 is located at the end of the module base 211, that is, the end away from the chassis 1. One end of the second rod 232 is rotatably connected to the second translation seat 215, and the other end is coaxially hinged to the first rod 231 and the intermediate block 233 on the first axis c. The support block 234 is hinged relative to the intermediate block 233 on the second axis d. Figure 5 As shown, the first axis c and the second axis d are perpendicular to each other. Thus, during the process of the support block 234 contacting the bottom of the oil tank, it can adaptively adjust the rotation angle around the first axis c and the second axis d respectively until the support block 234 is in full contact with the bottom of the oil tank. This avoids the fact that the bottom of the oil tank has a curvature, which would cause the support block 234 to have insufficient point or line contact with the bottom of the oil tank, resulting in insufficient support and causing the six-axis robotic arm 3 to shake during the detection process.

[0055] In the retracted state, the distance between the second translation seat 215 and the module base 211 is at its maximum. At this time, the relative angle between the first rod 231 and the second rod 232 is at its maximum, and the distance between the support block 234 and the module base 211 is at its minimum. The entire support mechanism 23 is arranged to rest against the module base 211. At this time, the second rod 232 is parallel to the module base 211. Since the hinge point between the first rod 231 and the module base 211 is located on the side of the module base 211, the end of the first rod 231 is higher than the second rod 232. An obtuse angle is formed between the first rod 231 and the second rod 232, which does not form a structural dead point. The reciprocating translation of the second translation seat 215 enables the support mechanism 23 to switch states.

[0056] During the unfolding process, the second translation seat 215 moves to the end of the module seat 211, causing the first rod 231 and the second rod 232 to rotate. The support block 234 moves away from the module seat 211, so that the support point can be as close as possible to the end of the module seat 211. The distance between the support block 234 and the module seat 211 is adjustable.

[0057] In the support mechanism 23, the hinged connection between the first rod 231, the second rod 232 and the intermediate block 233 enables the support mechanism 23 to be retracted and extended. In the extended state, the support block 234 can be as close as possible to the end of the module base 211 to form reliable support. The support block 234 can be rotated in multiple directions through two mutually perpendicular hinge axes, ensuring that the support block 234 can effectively and fully contact the bottom plane or curved surface of the aircraft fuel tank, thereby enhancing the reliability of the support.

[0058] Preferably, the first translation module 21 further includes a first motor 212, a second motor 213, a first drive screw, and a second drive screw; the first drive screw and the second drive screw are both disposed in the module base 211 and are driven to rotate by the first motor 212 and the second motor 213, respectively; the first drive screw is driven to be connected to the first translation seat 214, and the second drive screw is driven to be connected to the second translation seat 215.

[0059] By setting up a dual-screw structure with dual motors driving independently, the first translation seat 214 and the second translation seat 215 can achieve motion decoupling on the same module seat 211, which can accurately and independently adjust the depth posture of the working component and the support height and position of the support mechanism 23.

[0060] Preferably, the adjustment support mechanism 2 further includes a first rotary drive mechanism 24 and a lifting mechanism 26; the first rotary drive mechanism 24 is connected to the chassis 1 via the lifting mechanism 26; the module base 211 of the first translation module 21 is fixed to the output end of the first rotary drive mechanism 24, and the first rotary drive mechanism 24 and the lifting mechanism 26 form a "7" shape, with the end of the first rotary drive mechanism 24 facing outward and extending beyond the outline of the chassis 1 in the top view; the first end of the module base 211 in the first translation module 21 is rotatably mounted on the upper side of the end of the first rotary drive mechanism 24. The "7" shape structure allows the rotation axis of the first rotary drive mechanism 24 to be located inside the inlet / outlet port a after entering the aircraft fuel tank. The lifting mechanism 26 can drive the other parts of the adjustment support mechanism 2 and the entire six-axis robotic arm 3 to perform lifting movements. In this way, the height of the six-axis robotic arm 3 can be adjusted according to the height of the inlet and outlet hole a, so that the six-axis robotic arm 3 can smoothly enter and exit the aircraft fuel tank. Thus, the inspection robot can meet the inspection needs of different models of aircraft fuel tanks.

[0061] By utilizing the “7” shaped layout in conjunction with the lifting mechanism 26, it is ensured that after the adjustment support mechanism 2 enters the oil tank, the rotation of the first rotary drive mechanism 24 is not interfered with by the edge of the inlet / outlet hole a, which greatly improves the robot’s swing flexibility and work coverage in a limited space.

[0062] Preferably, the adjustment support mechanism 2 further includes a second rotation drive mechanism 25; the second translation module 22 is connected to the first translation seat 214 through the second rotation drive mechanism 25 to drive the second translation module 22 to rotate relative to the first translation seat 214 in the horizontal plane.

[0063] By adding a second rotary drive mechanism 25 to the first translation seat 214, the second translation module 22 is given independent pointing adjustment capability, which enables the robot to accurately guide the six-axis robotic arm 3 to align with the connecting hole b of the adjacent compartment without moving the module seat 211.

[0064] Preferably, the second translation module 22 is a telescopic translation module; the second translation module 22 includes a cylinder seat 221 rotatably mounted relative to the first translation base 214, a telescopic rod 222 capable of translating and extending relative to the cylinder seat 221, and a third motor 223 driving the telescopic rod 222 to translate relative to the cylinder seat 221. A six-axis robotic arm 3 is mounted on the end of the telescopic rod 222. The cylinder seat 221 is connected to the first translation base 214 via a rotary support mechanism 27, and a second rotary drive mechanism 25 drives the rotary support mechanism 27 to rotate, causing the cylinder seat 221 to rotate relative to the first translation base 214.

[0065] All six joints of the six-axis robotic arm 3 are rotary joints. The six-axis robotic arm 3 can switch between a folded state and a working state during operation. In the folded state, the six-axis robotic arm 3 has the smallest envelope size and the shortest overall length, facilitating passage through the inlet / outlet port a and the connecting port b of the fuel tank. The six-axis robotic arm 3 is a commercially available lightweight six-axis robotic arm.

[0066] This invention also provides a method for detecting fuel tank defects using an aircraft fuel tank internal inspection robot as described above. Figure 2 As shown, in the initial state, the six-axis robotic arm 3 is in a folded state with its minimum envelope and is collinear with the first translation module 21. Both the six-axis robotic arm 3 and the first translation module 21 are located above the walking chassis 1, and the support mechanism 23 is in an unfolded state, supporting the top of the walking chassis 1. At this time, when the walking chassis 1 moves, the six-axis robotic arm 3 and the adjustment support mechanism 2 will not encounter surrounding obstacles; the fuel tank defect detection method includes the following steps:

[0067] Step S11: Control the six-axis robotic arm 3 to be in the folded state of minimum envelope and collinear with the first translation module 21, the support mechanism 23 to be in the retracted state, and control the first translation module 21 to be suspended outside the walking chassis 1, and adjust the height of the first translation module 21 so that the height of the six-axis robotic arm 3 is adapted to the height of the inlet / outlet hole a.

[0068] Step S12: Move the walking chassis 1 so that the adjustment support mechanism 2 and the six-axis robotic arm 3 enter the intermediate compartment of the fuel tank through the inlet / outlet a;

[0069] Step S13: Control the second translation seat 215 to translate towards the end of the module seat 211, drive the support mechanism 23 to switch to the unfolded state, until the support block 234 fully contacts the bottom of the oil tank, such as Figure 4 and Figure 6 As shown;

[0070] Step S14: As Figure 7 and Figure 8 As shown, the adjustment support mechanism 2 and the six-axis robotic arm 3 work together to drive the detection sensor 4 to collect data.

[0071] The fuel tank defect detection method uses the logic of first entering the hole, then supporting, and then operating. The support mechanism 23 establishes a stable mechanical fulcrum for the long cantilever structure inside the aircraft fuel tank, eliminating the dynamic shaking caused by the movement of the six-axis robotic arm 3, and ensuring the constant pressure and stable signal of the detection sensor 4 during contact detection.

[0072] Preferably, the steps for inspecting the side compartments further include:

[0073] Step S21: Control the six-axis robotic arm 3 to return to the folded state, and through the swinging of the first translation module 21, the translation of the first translation seat 214 in the first translation module 21, and the rotation of the second rotation drive mechanism 25 relative to the first translation seat 214, align the detection sensor 4 with the target connecting hole b. Specifically, through the swinging motion of the first translation seat 214, the translation motion of the first translation seat 214, and the rotation of the second translation module 22 relative to the first translation seat 214, the coordinated movement of these three actions causes the tail of the second translation module 22 to enter the connecting hole b located on the opposite side of the target connecting hole b, and the detection sensor 4 to face the target connecting hole b. Through the swinging motion of the first translation seat 214, the translation motion of the first translation seat 214, and the rotation of the second translation module 22 relative to the first translation seat 214, the coordinated movement of these three actions aligns the detection sensor 4 with the target connecting hole b. Figure 9 As shown.

[0074] Step S22, as follows Figure 10 As shown, the first translation seat 214 is translated and the second translation module 22 is extended in coordination, so that the detection sensor 4 and the six-axis robotic arm 3 enter the target side compartment.

[0075] Step S23: After the six-axis robotic arm 3 has fully entered the target side compartment, control it to deploy and perform the detection operation, such as... Figure 11 As shown.

[0076] In this invention, the inspection robot performs an inspection of one half of the fuel tank at a time. After completing the inspection of one half of the fuel tank, the walking chassis 1 moves to the other half of the fuel tank, so that the six-axis robotic arm 3 and the adjustment support mechanism 2 can enter and exit the fuel tank through the inlet and outlet hole a on the other side to complete the inspection of the other half.

[0077] Through multi-axis linkage and telescopic compensation, cross-compartment transfer is achieved by utilizing the through-hole characteristics of the opposite side connecting hole b, enabling the detection sensor 4 to cover multiple compartments from a single entrance, significantly reducing the relocation frequency of the traveling chassis 1 and improving maintenance efficiency.

[0078] Before each pose adjustment of the module base 211, the support mechanism 23 is controlled to move so that the support block 234 is raised to a preset height relative to the bottom of the oil tank. After the pose adjustment of the module base 211 is completed, the support mechanism 23 is controlled to re-establish the abutment support of the module base 211. Then, the actual spatial pose of the module base 211 after the re-support is determined, and this is used as the reference pose to control the second translation module 22 and the six-axis robotic arm 3 to perform detection operation.

[0079] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A robot for inspecting the interior of an aircraft fuel tank, comprising a walking chassis (1), an adjustment support mechanism (2), a six-axis robotic arm (3), and a detection sensor (4); wherein the detection sensor (4) is connected to the walking chassis (1) via the six-axis robotic arm (3) and the adjustment support mechanism (2); characterized in that: The adjustment support mechanism (2) includes a first translation module (21), a second translation module (22), and a support mechanism (23); the six-axis robotic arm (3) is connected to the first translation module (21) via the second translation module (22); The support mechanism (23) is connected to the first translation module (21), and the support mechanism (23) can switch between a retracted state and an unfolded state; In the retracted state, the support mechanism (23) is attached to the first translation module (21), so that the adjustment support mechanism (2) can pass through the inlet / outlet port (a) of the aircraft fuel tank. In the deployed state, the support mechanism (23) can abut against the bottom of the aircraft fuel tank to provide rigid support for the first translation module (21); The first translation module (21) has a module base (211), a first translation seat (214) and a second translation seat (215); the second translation module (22) is mounted on the first translation seat (214); The support mechanism (23) includes a first rod (231), a second rod (232), an intermediate block (233), and a support block (234); One end of the first rod (231) is rotatably connected to the side of the module base (211), and the other end is rotatably connected to the intermediate block (233); one end of the second rod (232) is rotatably connected to the second translation seat (215), and the other end is coaxially hinged to the first rod (231) and the intermediate block (233) on the first axis; The support block (234) is hinged to the second axis relative to the intermediate block (233), and the first axis and the second axis are perpendicular to each other.

2. The aircraft fuel tank internal inspection robot according to claim 1, characterized in that, The first translation module (21) further includes a first motor (212), a second motor (213), a first drive screw, and a second drive screw; the first drive screw and the second drive screw are both disposed in the module base (211) and are driven to rotate by the first motor (212) and the second motor (213) respectively; the first drive screw is driven to connect with the first translation seat (214), and the second drive screw is driven to connect with the second translation seat (215).

3. The aircraft fuel tank internal inspection robot according to claim 1, characterized in that, The adjustment support mechanism (2) further includes a first rotary drive mechanism (24) and a lifting mechanism (26); the first rotary drive mechanism (24) is connected to the walking chassis (1) through the lifting mechanism (26); the module seat (211) of the first translation module (21) is fixed at the output end of the first rotary drive mechanism (24), and the first rotary drive mechanism (24) and the lifting mechanism (26) form a "7" shaped structure.

4. The aircraft fuel tank internal inspection robot according to claim 1, characterized in that, The adjustment support mechanism (2) further includes a second rotation drive mechanism (25); the second translation module (22) is connected to the first translation seat (214) through the second rotation drive mechanism (25) to drive the second translation module (22) to rotate relative to the first translation seat (214) in the horizontal plane.

5. The aircraft fuel tank internal inspection robot according to claim 1, characterized in that, The second translation module (22) is a telescopic translation module; all six motion joints of the six-axis robotic arm (3) are rotary joints.

6. A method for detecting defects in an aircraft fuel tank using an internal inspection robot as described in any one of claims 1 to 5, characterized in that, The method for detecting defects in fuel tanks includes the following steps: Step S11: Control the support mechanism (23) to be in the retracted state, and control the first translation module (21) to be suspended outside the walking chassis (1), and adjust the height of the first translation module (21) so that the height of the six-axis robotic arm (3) matches the height of the inlet / outlet hole (a); Step S12: Move the walking chassis (1) so that the adjustment support mechanism (2) and the six-axis robotic arm (3) enter the intermediate compartment of the oil tank through the inlet / outlet (a); Step S13: Control the second translation seat (215) to translate to the end of the module seat (211), drive the support mechanism (23) to switch to the unfolded state, until the support block (234) fully contacts the bottom of the oil tank; Step S14: Control the adjustment support mechanism (2) to cooperate with the six-axis robotic arm (3) to drive the detection sensor (4) to collect data.

7. The fuel tank defect detection method according to claim 6, characterized in that, The procedures for inspecting the side compartments also include: Step S21: Control the six-axis robotic arm (3) to return to the folded state, and make the detection sensor (4) aligned with the target connecting hole (b) by swinging the first translation module (21), translating the first translation seat (214) in the first translation module (21), and rotating the second rotation drive mechanism (25) relative to the first translation seat (214). Step S22: Coordinate the translation of the first translation seat (214) and the extension of the second translation module (22) to allow the detection sensor (4) and the six-axis robotic arm (3) to enter the target side compartment; Step S23: After the six-axis robotic arm (3) has fully entered the target side cabin, control it to unfold and perform the detection operation.

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