Rail top walking mechanism and method for single-rail eddy current detection robot

Abstract

The invention discloses a rail top walking mechanism and method for a monorail eddy current detection robot. The rail top walking mechanism comprises a frame, a magnetic attraction unit, a main control unit, a walking supporting unit, an eddy current sensing unit and a flywheel stabilizing unit, wherein the walking supporting unit, the eddy current sensing unit and the flywheel stabilizing unit are electrically connected with the main control unit; the magnetic attraction unit comprises front and rear magnetic attraction units at the front and rear ends of the frame, the walking supporting unit comprises driving walking and driven supporting mechanisms at the front and rear ends of the frame, and the flywheel stabilizing unit is used for outputting righting torque when the robot inclines. A traditional mechanical clamping structure is abandoned, the equivalent gravity center is lowered through magnetic attraction, the flywheel stabilizes and actively righting to form a dual-stable system, walking stability and track trafficability are both considered, the lift-off distance of the eddy current sensor is kept constant, the accuracy of detection signals is improved, the structure is compact and light, and the device is suitable for complex single-track detection scenes.

Description

Technical Field

[0001] This invention relates to the field of nondestructive testing technology, specifically to a track-top walking mechanism and method for a single-track eddy current testing robot. Background Technology

[0002] As the core infrastructure of railway transportation, rail surface and near-surface damage directly threatens train operation safety. With the development of rail transit towards high speed and heavy load, rail damage detection is gradually upgrading from manual inspection to automated and intelligent equipment. Eddy current testing has become the mainstream technology for online detection of rail surface cracks, peeling, and edge thickening due to its advantages such as sensitivity to surface and near-surface defects, no need for coupling agent, and fast detection speed.

[0003] Eddy current testing is highly sensitive to changes in the lift-off distance between the sensor and the track surface. Even slight fluctuations in distance can significantly alter the amplitude of the detection signal, directly reducing the accuracy of defect identification. Therefore, stringent requirements are placed on the walking stability of inspection robots equipped with eddy current sensors. Currently, track inspection robots are mainly divided into two categories: dual-rail robots and single-rail robots. Dual-rail robots straddle two rails and have better stability, but they are complex in structure, heavy, and have poor versatility. Single-rail robots walk along a single rail and have advantages such as compact structure, light weight, portability, and easy deployment, making them more suitable for complex tracks and rapid on-site inspection needs.

[0004] Existing monorail inspection robots generally employ a two-sided clamping walking mechanism. Clamping wheels apply elastic clamping force to the sides of the rail head, the lower jaw of the rail head, and the rail web area, enabling the robot to grip the rail and prevent overturning or derailment. While this mechanism improves operational stability, it has insurmountable drawbacks: rail joints, turnouts, and other sections contain obstacles such as rail gaps, fishplates, and bolts, and the clamping mechanism's operating area happens to be precisely where these obstacles are concentrated. When the robot passes through these areas, it is highly susceptible to jamming, derailment, or severe shaking, resulting in poor maneuverability. Furthermore, the complex mechanical clamping structure cannot fundamentally suppress the body vibration caused by track irregularities, making it difficult to guarantee the stable lift-off distance required for eddy current detection.

[0005] Some improved monorail walking mechanisms have optimized adaptability through methods such as widening clamping and elastic clamping, but they still do not deviate from the design concept of side clamping and cannot avoid obstacles in the joint area. The contradiction between stability and passability remains unresolved. At present, the monorail eddy current inspection robot industry generally faces the technical challenge of balancing walking stability and obstacle passability. It cannot meet the requirements of eddy current inspection for smooth walking, nor can it adapt to the continuous inspection needs of complex working conditions such as rail joints and turnouts, thus restricting the engineering application of monorail eddy current inspection robots.

[0006] Based on the above situation, there is an urgent need to develop a single-track eddy current detection robot walking mechanism and control method that does not require mechanical clamping and can simultaneously ensure walking stability and obstacle clearance, so as to solve the core defects of the existing technology. Summary of the Invention

[0007] To address the shortcomings of existing technologies, this invention provides a track-top walking mechanism and method for a single-track eddy current detection robot.

[0008] This invention discloses a track-top walking mechanism for a single-track eddy current detection robot, including a frame, a magnetic adsorption unit, a main control unit, and a walking support unit, an eddy current sensing unit, and a flywheel stabilization unit electrically connected to the main control unit. The magnetic adsorption unit includes a front magnetic adsorption unit and a rear magnetic adsorption unit disposed at the front and rear ends of the bottom of the frame, which are used to make the robot adhere to the top surface of the track by magnetic adsorption force to reduce the equivalent center of gravity. The walking support unit includes an active walking mechanism and a driven support mechanism disposed at the front and rear ends of the frame, which are used to support the frame and drive the robot to walk along the rail. The eddy current sensing unit is disposed at the bottom of the frame and located between the active walking mechanism and the driven support mechanism, and is used to detect damage to the top surface of the rail. The flywheel stabilization unit is mounted on the frame and is used to actively output a righting torque to maintain walking stability when the robot tilts.

[0009] As a further improvement of the present invention, the active walking mechanism, the driven support mechanism, the front magnetic attraction unit, and the rear magnetic attraction unit are all left-right symmetrical structures centered on the rail axis.

[0010] As a further improvement of the present invention, the active walking mechanism includes a first active wheel bearing and a second active wheel bearing coaxially disposed at both ends of the active wheel axial direction. The active wheel is rotatably mounted on the bottom of the frame through the two active wheel bearings and is connected to the drive mechanism for transmission. The driven support mechanism includes a first driven wheel bearing and a second driven wheel bearing coaxially disposed at both ends of the driven wheel axial direction. The driven wheel is rotatably mounted on the bottom of the vehicle frame through the two driven wheel bearings and is connected to the mileage measuring mechanism. The drive mechanism and the mileage measurement mechanism are electrically connected to the main control unit. The wheel axes of the drive wheel and the driven wheel are parallel to each other and perpendicular to the robot's walking direction. The treads of both wheels are in rolling contact with the top surface of the rail and the upper area of ​​the gauge angle, jointly supporting the frame suspended above the rail top.

[0011] As a further improvement of the present invention, both the driving wheel and the driven wheel adopt a circular arc tread structure that is adapted to the rail top profile of the rail.

[0012] As a further improvement of the present invention, both the front magnetic attraction unit and the rear magnetic attraction unit include a magnetic attraction bracket, a magnetic magnet, a first auxiliary wheel and a second auxiliary wheel; The magnetic bracket is fixedly installed at the bottom of the vehicle frame, and the magnetic magnet is installed at the lower part of the magnetic bracket to provide magnetic attraction to the top of the rail; The first auxiliary wheel and the second auxiliary wheel are rotatably mounted on the left and right sides of the magnetic support bracket, and are symmetrically arranged on the transverse sides of the magnetic magnet. The tread surfaces of both wheels are in rolling contact with the top surface of the rail and the upper area of ​​the gauge angle, which is used to support the frame to maintain a constant lifting gap between the magnetic magnet and the top of the rail, and form an alternating support cooperation with the wheels of the active travel mechanism and the driven support mechanism to cross the rail gap.

[0013] As a further improvement of the present invention, when the wheel of the active walking mechanism or the driven support mechanism enters the rail gap, the first auxiliary wheel and the second auxiliary wheel of the magnetic attraction unit on the corresponding side are still supported on the rail surface. When the first or second auxiliary wheel of the front magnetic attraction unit or the rear magnetic attraction unit enters the rail gap, at least one of the wheels of the active walking mechanism and the driven support mechanism remains supported on the rail surface, so that the robot always has at least two sets of wheels in contact with the rail surface, in order to maintain the design gap between the magnetic magnet and the top of the rail and avoid the magnetic magnet from being attracted to the top of the rail and causing jamming.

[0014] As a further improvement of the present invention, the minimum magnetic attraction force F required by the magnetic magnets of the front magnetic attraction unit and the rear magnetic attraction unit is... mag satisfy: F mag ≥ m1g(1+L / Δx) / 2; In the formula, m1 is the total mass of the robot, g is the acceleration due to gravity, L is the vertical distance from the robot's actual center of gravity to the magnetic attraction surface, Δx is the designed lift-off distance between the magnet and the top surface of the track, and the actual magnetic attraction force of the magnetic magnet at Δx is greater than F. mag 1.1 to 1.3 times that.

[0015] As a further improvement of the present invention, the eddy current sensing unit includes an array eddy current sensor fixture, an array eddy current sensor main module, and a plurality of eddy current sensors electrically connected to the array eddy current sensor main module, wherein the array eddy current sensor main module is electrically connected to the main control unit. The bottom of the array eddy current sensor fixture has a contoured structure that matches the gauge angle on both sides of the rail and the top surface of the rail to ensure that the sensor fits the rail surface contour; the surface of the array eddy current sensor fixture has several mounting holes, and multiple eddy current sensors are respectively installed in the corresponding mounting holes; the array eddy current sensor main module is installed on the side of the array eddy current sensor fixture.

[0016] As a further improvement of the present invention, the flywheel stabilization unit includes a flywheel motor and a flywheel that is drivenly connected to its output shaft. The flywheel motor is mounted on the vehicle frame and is electrically connected to the main control unit. The main control unit has a built-in attitude sensor to detect changes in the robot's attitude in real time, and controls the flywheel motor to adjust the speed of the flywheel according to the attitude signal, so that the flywheel generates a righting torque opposite to the overturning torque; the axis of the flywheel is set perpendicular to the direction of the robot's movement.

[0017] This invention discloses a track-top walking control method for a single-track eddy current detection robot, which is applied to the aforementioned track-top walking mechanism and includes: Step S1: Place the robot on the top of the rail. Use the magnetic attraction force of the front and rear magnetic units to make the robot adhere to the surface of the rail top and keep the robot initially stable. Step S2: Activate the flywheel stabilization unit to make the flywheel of the flywheel stabilization unit rotate and reach a stable speed; Step S3: Start the drive mechanism and drive the robot to walk along the rail through the active walking mechanism. At the same time, the eddy current sensor unit detects the damage on the top surface of the rail in real time. Step S4: During the walking process, the attitude sensor built into the main control unit detects the robot's attitude changes in real time. When the robot is detected to be tilting, the speed of the flywheel motor of the flywheel stabilization unit is adjusted according to the attitude change signal, so that the flywheel generates a reaction torque to counteract the overturning torque and maintain the stability of the robot's walking. Step S5: When a stop command is received, first control the drive mechanism to stop working so that the robot stops walking along the rail. Then, manually assist the robot to keep it stable and control the flywheel motor to drive the flywheel to decelerate and stop until the robot comes to a complete stop.

[0018] Compared with the prior art, the beneficial effects of the present invention are as follows: This invention abandons the mechanical clamping structure of existing monorail eddy current inspection robots, and adopts a technical solution that combines a magnetic adsorption unit and a flywheel stabilization unit, fundamentally solving the core contradiction of the difficulty in balancing stability and maneuverability in traditional technologies. By having the wheels of the magnetic adsorption unit and the walking support unit act on the unobstructed continuous area above the rail top surface and the gauge angle, it completely avoids areas with concentrated obstacles such as rail joints, rail gaps, and turnouts, eliminating the problems of jamming and derailment that are common in clamping structures, and significantly improving the robot's maneuverability in complex track environments. At the same time, the absence of mechanical clamping simplifies the overall structure, achieves lightweight equipment, and reduces deployment and maintenance costs.

[0019] This invention establishes a dual stabilization system combining magnetic passive stabilization and flywheel active stabilization. The magnetic adsorption unit uses magnetic force to keep the robot in contact with the rail top and lower its equivalent center of gravity, providing basic anti-tipping and anti-shaking capabilities for movement. The flywheel stabilization unit relies on the real-time attitude perception of the main control unit. When the robot tilts due to environmental disturbances such as wind loads or track irregularities, it dynamically adjusts the flywheel speed to output a reaction torque to counteract the overturning torque, achieving real-time correction of the walking posture. This dual stabilization system ensures the robot's smooth movement on the rail top, effectively maintaining a constant lift-off distance between the array eddy current sensor and the rail top surface. It completely solves the problem of detection signal fluctuations caused by attitude jitter in traditional technologies, significantly improving the stability and accuracy of eddy current detection signals and ensuring the reliability of rail surface damage assessment.

[0020] This invention further enhances the operational continuity and practical value of the equipment through optimized design and efficient collaboration of its various functional modules. The auxiliary wheels of the magnetic suction unit and the wheels of the walking support unit form an alternating support mechanism that crosses the rail gap, ensuring that at least two sets of wheels are always in contact with the rail surface. This maintains the designed gap between the magnetic magnet and the rail top, preventing magnet jamming and ensuring continuous robot movement. The arc-shaped contoured tread structure of the driving and driven wheels optimizes the wheel-rail contact stress distribution and provides lateral guidance to help the robot move stably along the rail axis, reducing the risk of derailment during long-distance inspections. Simultaneously, the driven wheels are reused as metering wheels and eddy current sensor contoured clamps to conform to the rail surface, achieving functional integration and structural compactness. This makes the equipment easy to operate and highly adaptable, widely applicable to rail inspection on various monorail lines, improving the automation and intelligence level of rail transit rail inspection and providing reliable technical support for traffic safety. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the working operation of the track-top walking mechanism for a monorail eddy current detection robot disclosed in one embodiment of the present invention. Figure 2 This is a schematic diagram of the track-top walking mechanism for a monorail eddy current detection robot disclosed in one embodiment of the present invention. Figure 3 This is a schematic diagram of the driving wheel and driven wheel of the track-top walking mechanism for a monorail eddy current detection robot disclosed in an embodiment of the present invention. Figure 4 This is a schematic diagram of the flywheel stabilizing unit of the track-top walking mechanism for a monorail eddy current detection robot, as disclosed in an embodiment of the present invention. Figure 5 This is a flowchart of a track-top walking control method for a single-track eddy current detection robot, as disclosed in one embodiment of the present invention.

[0022] In the picture: 1. Rail; 2. Chassis; 3. Rear magnetic unit; 31. First rear auxiliary wheel; 32. Rear magnetic magnet; 33. Second rear auxiliary wheel; 34. Rear magnetic bracket; 4. Driven support mechanism; 41. Odometer transmission gear; 42. Odometer; 43. First driven wheel bearing; 44. Driven wheel; 45. Second driven wheel bearing; 5. Eddy current sensing unit; 6. Flywheel stabilization unit; 61. Flywheel motor; 62. Flywheel; 7. Drive mechanism; 71. Drive motor; 72. Motor bracket; 73. First synchronous pulley; 74. Synchronous belt; 75. Second synchronous pulley; 8. Active walking mechanism; 81. First drive wheel bearing; 82. Drive wheel; 83. Second drive wheel bearing; 9. Front magnetic unit; 91. First front auxiliary wheel; 92. Front magnetic bracket; 93. Front magnetic magnet; 94. Second front auxiliary wheel; 10. Main control unit. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, 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, 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.

[0024] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for 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 the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0025] In the description of this invention, it should also 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 or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0026] The present invention will now be described in further detail with reference to the accompanying drawings: like Figure 1-2As shown, a rail-top walking mechanism for a single-rail eddy current detection robot according to the present invention includes a frame 2, a magnetic adsorption unit, a main control unit 10, a walking support unit, an eddy current sensing unit 5, and a flywheel stabilizing unit 6. The main control unit 10 is mounted on the frame 2. The walking support unit, eddy current sensing unit 5, and flywheel stabilizing unit 6 are electrically connected to the main control unit 10. The magnetic adsorption unit includes a front magnetic adsorption unit 9 and a rear magnetic adsorption unit 3 located at the front and rear ends of the bottom of the frame 2, used to make the robot adhere to the rail top surface through magnetic adsorption force to reduce the equivalent center of gravity. The walking support unit includes an active walking mechanism 8 and a driven support mechanism 4 located at the front and rear ends of the frame 2, used to support the frame 2 and drive the robot to walk along the rail 1. The eddy current sensing unit 5 is located at the bottom of the frame 2 and between the active walking mechanism 8 and the driven support mechanism 4, used to detect damage to the rail top surface of the rail 1. The flywheel stabilizing unit 6 is located on the frame 2, used to actively output a corrective torque to maintain walking stability when the robot tilts.

[0027] Specifically: like Figure 2-3 As shown, in the above embodiment, preferably, the active walking mechanism 8 includes a first active wheel bearing 81 and a second active wheel bearing 83 coaxially disposed at both ends of the active wheel 82. The active wheel 82 is rotatably mounted on the bottom of the frame 2 through the first active wheel bearing 81 and the second active wheel bearing 83, and is connected to the drive mechanism 7. The driven support mechanism 4 includes a first driven wheel bearing 43 and a second driven wheel bearing 45 coaxially disposed at both ends of the driven wheel 44. The driven wheel 44 is rotatably mounted on the bottom of the frame 2 through the first driven wheel bearing 43 and the second driven wheel bearing 45, and is connected to the mileage measuring mechanism. In this embodiment, the drive mechanism 7 and the mileage measuring mechanism are electrically connected to the main control unit 10. The wheel axes of the active wheel 82 and the driven wheel 44 are parallel to each other and both are perpendicular to the robot's walking direction. The tread surfaces of both wheels are in rolling contact with the top surface of the rail 1 and the upper area of ​​the gauge angle, jointly supporting the frame 2 suspended above the rail top.

[0028] In the above embodiments, preferably, both the driving wheel 82 and the driven wheel 44 adopt a circular arc tread structure that matches the rail top profile of the rail 1. In this embodiment, this configuration firstly allows the circular arc treads of the driving wheel 82 and the driven wheel 44 to form good geometric complementarity with the circular arc surface of the rail top, increasing the wheel-rail contact area and making the contact stress distribution more uniform; secondly, the circular arc tread structure can constrain the robot's walking direction through the lateral limiting effect of the circular arc surface—when the robot tends to deviate laterally, the geometry of the wheel-rail contact area will naturally generate a lateral component force pointing towards the center line of the track, guiding the robot to automatically return to the correct position, thereby ensuring that the robot always moves stably along the axial direction of the rail 1 during long-distance detection, reducing the risk of derailment and dependence on the correction mechanism.

[0029] In the above embodiments, preferably, both the driving wheel 82 and the driven wheel 44 are made of metal. On the one hand, metal wheels have good wear resistance and load-bearing capacity, and can adapt to the working conditions of rolling on the rail 1 for a long time. On the other hand, since the eddy current sensing unit 5 is sensitive to the change in the lift-off distance of the metal conductor, the use of metal wheels can ensure that when the wheel-rail contact conditions change (such as passing through rail gaps or uneven sections), the driving wheel 82 and the driven wheel 44 always maintain stable contact with the surface of the rail 1, thereby maintaining the relative lift-off distance between the array eddy current sensor 5 and the top surface of the rail basically constant, and avoiding fluctuations in the detection signal caused by wheel deformation or wear.

[0030] In the above embodiment, preferably, the drive mechanism 7 includes a drive motor 71, a motor bracket 72, a first synchronous pulley 73, a synchronous belt 74, and a second synchronous pulley 75. The drive motor 71 is fixed to the frame 2 through the motor bracket 72. The output shaft of the drive motor 71 is connected to the first synchronous pulley 73. The synchronous belt 74 connects the first synchronous pulley 73 and the second synchronous pulley 75. The second synchronous pulley 75 is connected to the drive wheel 82 to provide power to the drive wheel 82. The robot adopts a front-wheel drive form.

[0031] In the above embodiment, preferably, the odometer transmission gear 41 and the odometer 42, and the driven wheel 44 are mounted on the frame 2 via a first driven wheel bearing 43 and a second driven wheel bearing 45. The odometer 42 is connected to the driven wheel 44 via the odometer transmission gear 41 to provide mileage measurement along the track. In this embodiment, the axle of the driven wheel 44 located on one side of the first driven wheel bearing 43 passes through the outside of the bearing and is coaxially fixed to the odometer transmission gear 41; the odometer transmission gear 41 meshes with the odometer 42 gear mounted on the frame 2. This not only allows for real-time recording of the robot's position and feedback of speed information during movement, but also reuses the driven wheel 44 as a meter-counting wheel, achieving a compact and space-saving design goal.

[0032] like Figure 2As shown, in the above embodiment, preferably, the front magnetic attraction unit 9 includes a first front auxiliary wheel 91, a front magnetic attraction bracket 92, a front magnetic attraction magnet 93, and a second front auxiliary wheel 94; 3, the rear magnetic attraction unit 3 includes a first rear auxiliary wheel 31, a rear magnetic attraction magnet 32, a second rear auxiliary wheel 33, and a rear magnetic attraction bracket 34; wherein, the front magnetic attraction bracket 92 and the rear magnetic attraction bracket 34 are respectively fixedly installed on the bottom of the frame 2, and are respectively located on the outside of the active walking mechanism 8 and the driven support mechanism 4, and the front magnetic attraction magnet 93 and the rear magnetic attraction magnet 32 ​​are installed on the front magnetic attraction bracket 92 and the rear magnetic attraction bracket 94. The lower part of the bracket 34 is used to provide magnetic attraction to the top of the rail. The first front auxiliary wheel 91 and the second front auxiliary wheel 94 are rotatably mounted on the left and right sides of the front magnetic bracket 92, and are symmetrically arranged on the lateral sides of the front magnetic magnet 93. The tread surfaces of both wheels are in rolling contact with the top surface of the rail 1 and the upper area of ​​the gauge angle. The first rear auxiliary wheel 31 and the second rear auxiliary wheel 33 are rotatably mounted on the left and right sides of the rear magnetic bracket 34, and are symmetrically arranged on the lateral sides of the rear magnetic magnet 32. The tread surfaces of both wheels are in rolling contact with the top surface of the rail 1 and the upper area of ​​the gauge angle. In this embodiment, the first rear auxiliary wheel 31 and the second rear auxiliary wheel 33 are arranged in the same cross-section as the rear magnetic magnet 32, and the first front auxiliary wheel 91 and the second front auxiliary wheel 94 are arranged in the same cross-section as the front magnetic magnet 93.

[0033] In the above embodiment, preferably, within the same magnetic unit, along the longitudinal direction of rail 1, the horizontal distance between the center of the two auxiliary wheels and the center of the magnetic magnet is 30 mm; along the transverse direction of rail 1, the center distance between the two auxiliary wheels is 30 mm, and when the tread surfaces of the two auxiliary wheels contact the upper part of the gauge angle, the gap between the magnetic magnet and the rail top is 2 mm. The driven wheel 44 in the driven support mechanism 4, the driving wheel 82 in the active walking mechanism 8, and the aforementioned first front auxiliary wheel 91, second front auxiliary wheel 94, first rear auxiliary wheel 31, and second rear auxiliary wheel 33 all act on the rail top surface and the upper region of the gauge angle of rail 1, ensuring that each wheel can avoid rail gap obstacles by utilizing the continuous support surface at the upper part of the gauge angle when passing through the rail 1 joint, thus achieving stable rolling.

[0034] In this embodiment, the auxiliary wheel and the front and rear support wheels form an alternating support relationship across the rail gap: when the driving wheel 82 or the driven wheel 44 enters the rail gap area of ​​the rail 1 joint, the auxiliary wheels (first rear auxiliary wheel 31, second rear auxiliary wheel 33 or first front auxiliary wheel 91, second front auxiliary wheel 94) located in the same cross-section are still reliably supported on the top surface of the rail and the upper part of the gauge angle, maintaining the height of the frame 2 unchanged, thereby avoiding the rear magnetic magnet 32 ​​and the front magnetic magnet 93 from being attracted to the surface of the rail 1 due to the reduced lift distance and getting stuck; when the auxiliary wheel of the front magnetic unit 9 or the rear magnetic unit 3 enters the rail gap, at least one of the driven wheel 44 and the driving wheel 82 is still supported on the rail surface. Through this alternating support, the robot always has at least two wheels simultaneously supported in the continuous area of ​​the rail surface, ensuring that the designed lift distance Δx between the rear magnetic magnet 32 ​​and the front magnetic magnet 93 and the top surface of the rail remains constant, while ensuring that the relative position of the eddy current sensing unit 5 and the rail surface is not disturbed by the rail gap, ensuring the stability and accuracy of the eddy current detection signal.

[0035] In this embodiment, the minimum magnetic attraction force F required for the magnetic magnets of the front magnetic attraction unit 9 and the rear magnetic attraction unit 3 is... mag satisfy: F mag ≥ m1g(1+L / Δx) / 2; In the formula, m1 is the total mass of the robot, g is the gravitational acceleration, L is the vertical distance from the actual center of gravity of the robot to the magnetic adsorption surface, Δx is the designed lift-off distance between the magnet and the top surface of the track (the designed lift-off distance is 2mm in this embodiment), and the actual magnetic attraction force of the magnetic magnet at Δx is greater than 1.1 to 1.3 times that of Fmag to provide sufficient safety margin and ensure that the robot can be stably adsorbed under various track conditions.

[0036] In the above embodiments, preferably, the eddy current sensing unit 5 includes an array eddy current sensor fixture, an array eddy current sensor main module, and multiple eddy current sensors electrically connected to the array eddy current sensor main module. The array eddy current sensor main module is electrically connected to the main control unit. The bottom of the array eddy current sensor fixture has a contoured structure that matches the gauge angle on both sides of the rail 1 and the top surface of the rail to ensure that the sensor fits the rail surface contour. The surface of the array eddy current sensor fixture has several mounting holes, and the multiple eddy current sensors are respectively installed in the corresponding mounting holes and perpendicular to the surface of the rail 1. The array eddy current sensor main module is installed on the side of the array eddy current sensor fixture.

[0037] like Figure 1 , Figure 4As shown, in the above embodiment, preferably, the flywheel stabilization unit 6 includes a flywheel motor 61 and a flywheel 62 connected to its output shaft. The flywheel motor 61 is mounted on the frame 2 and electrically connected to the main control unit 10. The main control unit 10 has a built-in attitude sensor for real-time detection of robot attitude changes and controls the flywheel motor 61 to adjust the speed of the flywheel 62 based on the attitude signal, causing the flywheel 62 to generate a righting torque opposite to the overturning torque. The axis of the flywheel 62 is perpendicular to the robot's direction of movement. Specifically, when lateral tilting of the robot is detected, the main control unit 10 controls the flywheel motor 61 to adjust the speed of the flywheel 62, causing the flywheel 62 to generate a reaction torque. This torque works together with the driving wheel 82 and the driven wheel 44 to achieve dynamic righting. According to the torque balance principle, the maximum reaction torque generated by the flywheel 62 is approximately 0.16 N·m, which can counteract the overturning torque caused by environmental wind loads, track irregularities, etc., ensuring stable robot operation. In this embodiment, the flywheel motor 61 is a brushless DC motor with a rated power of 50W and a speed adjustment range of 0~3000 rpm; the flywheel 62 is made of high-density metal material with a moment of inertia of 0.005 kg·m² and a designed maximum speed of 3000 rpm. The attitude sensor is a gyroscope, used to detect the robot's angular velocity changes in real time and calculate the attitude tilt angle.

[0038] In the above embodiments, preferably, the active walking mechanism 8, the driven support mechanism 4, the front magnetic attraction unit 9, and the rear magnetic attraction unit 3 are all symmetrical structures centered on the rail axis. Simultaneously, by arranging heavier components (such as magnetic magnets, drive motors 71, flywheels 62, etc.) close to the rail 1, the overall center of gravity is located in the robot's central plane and at a low height. Based on this, combined with the attraction between the rear magnetic attraction unit 3 and the front magnetic attraction unit 9, the robot's equivalent center of gravity is further aligned with the top surface of the rail. With this low center of gravity design, when the robot experiences slight posture disturbances (such as gusts of wind or minor track irregularities), the restoring torque naturally generated by gravity (i.e., the torque by which gravity attempts to pull the robot back to its equilibrium position when the center of gravity deviates from the support point) has a small amplitude and can be ignored. Therefore, the balancing torque required by the flywheel 62 in the flywheel stabilization unit 6 is mainly used to counteract the overturning torque generated by external disturbances (i.e., the torque that may cause the robot to tip over), rather than to counteract the restoring torque of gravity. This balancing torque can be expressed as: M = F·I; In the formula, F is the equivalent disturbance force (such as the resultant force of external disturbances like wind load and centrifugal force applied to the robot's center of mass); I is the equivalent disturbance arm (i.e., the vertical distance from the line of action of the disturbance force to the robot's overturning axis); and M is the torque required to be provided by the flywheel 62. The attitude sensor built into the main control unit 10 detects the robot's attitude in real time and adjusts the speed of the flywheel 62 by controlling the flywheel motor 61 to dynamically generate this torque and maintain the robot's balance.

[0039] like Figure 5 As shown, the present invention also discloses a track-top walking control method for a single-track eddy current detection robot, which applies the above-mentioned track-top walking mechanism and includes: Step S1: Place the robot on the top of the rail 1. Use the magnetic attraction force of the front magnetic unit 9 and the rear magnetic unit 3 to make the robot adhere to the surface of the rail top. Combined with manual assistance, keep the robot initially stable. Step S2: Activate the flywheel stabilization unit 6 to make the flywheel 62 of the flywheel stabilization unit 6 rotate and reach a stable speed, and at the same time stop manual assistance; Step S3: Start the drive mechanism 7 and drive the robot to walk along the rail 1 through the active walking mechanism 8. At the same time, the eddy current sensing unit 5 detects the damage on the top surface of the rail in real time. Step S4: During the walking process, the attitude sensor built into the main control unit 10 detects the robot's attitude changes in real time. When the robot is detected to be tilting, the speed of the flywheel motor 61 of the flywheel stabilization unit 6 is adjusted according to the attitude change signal, so that the flywheel 62 generates a reaction torque to counteract the overturning torque and maintain the stability of the robot's walking. Step S5: When a stop command is received, first control the drive mechanism 7 to stop working, so that the robot stops walking along the rail 1. Then, manually assist the robot to keep it stable. The main control unit 10 controls the flywheel motor 61 to drive the flywheel 62 to decelerate and stop until the robot comes to a complete stop.

[0040] Advantages of this invention: This invention abandons the mechanical clamping structure of existing monorail eddy current detection robots and adopts a technical solution that combines a magnetic adsorption unit and a flywheel stabilizing unit 6, fundamentally solving the core contradiction of the difficulty in balancing stability and maneuverability in traditional technologies. By applying the wheels of the magnetic adsorption unit and the walking support unit to the unobstructed continuous area above the top surface and gauge angle of the rail 1, it completely avoids areas with concentrated obstacles such as rail joints, rail gaps, and turnouts, eliminating the problems of jamming and derailment caused by clamping structures, and significantly improving the robot's maneuverability in complex track environments. At the same time, the absence of mechanical clamping simplifies the overall structure, achieves lightweight equipment, and reduces deployment and maintenance costs.

[0041] This invention establishes a dual stabilization system combining magnetic passive stabilization and flywheel active stabilization. The magnetic adsorption unit uses magnetic force to keep the robot in contact with the rail top and lower its equivalent center of gravity, providing basic anti-tipping and anti-shaking capabilities for movement. The flywheel stabilization unit 6, relying on the real-time attitude perception of the main control unit 10, dynamically adjusts the flywheel speed to output a reaction torque to counteract the overturning torque when the robot tilts due to environmental disturbances such as wind loads or track irregularities, achieving real-time correction of the walking posture. This dual stabilization system ensures the robot's smooth movement on the rail top, effectively maintaining a constant lift-off distance between the array eddy current sensor and the rail top surface. It completely solves the problem of detection signal fluctuation caused by attitude jitter in traditional technologies, significantly improving the stability and accuracy of eddy current detection signals and ensuring the reliability of rail surface damage assessment.

[0042] This invention further enhances the operational continuity and practical value of the equipment through optimized design and efficient collaboration of its various functional modules. The auxiliary wheel of the magnetic suction unit and the wheel of the walking support unit form an alternating support mechanism that crosses the rail gap, ensuring that at least two sets of wheels are always in contact with the rail surface. This maintains the designed gap between the magnetic magnet and the rail top, preventing magnet jamming and ensuring continuous robot movement. The arc-shaped contoured tread structure of the active wheel 82 and the driven wheel 44 optimizes the wheel-rail contact stress distribution and provides lateral guidance to help the robot move stably along the rail axis, reducing the risk of derailment during long-distance inspections. Simultaneously, the driven wheel 44 is reused as a metering wheel and an eddy current sensor contoured clamp for rail surface contact, achieving functional integration and structural compactness. This makes the equipment easy to operate and highly adaptable, widely applicable to rail inspection on various monorail lines, improving the automation and intelligence level of rail transit rail inspection and providing reliable technical support for train safety.

[0043] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. 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 track-top traveling mechanism for a single-track eddy current detection robot, characterized in that, It includes a frame, a magnetic adsorption unit, a main control unit, and a walking support unit, an eddy current sensing unit, and a flywheel stabilization unit that are electrically connected to the main control unit; The magnetic adsorption unit includes a front magnetic adsorption unit and a rear magnetic adsorption unit disposed at the front and rear ends of the bottom of the frame, which are used to make the robot adhere to the top surface of the track by magnetic adsorption force to reduce the equivalent center of gravity. The walking support unit includes an active walking mechanism and a driven support mechanism disposed at the front and rear ends of the frame, which are used to support the frame and drive the robot to walk along the rail. The eddy current sensing unit is disposed at the bottom of the frame and located between the active walking mechanism and the driven support mechanism, and is used to detect damage to the top surface of the rail. The flywheel stabilization unit is mounted on the frame and is used to actively output a righting torque to maintain walking stability when the robot tilts.

2. The track-top traveling mechanism according to claim 1, characterized in that, The active walking mechanism, the driven support mechanism, the front magnetic attraction unit, and the rear magnetic attraction unit are all left-right symmetrical structures centered on the rail axis.

3. The track-top traveling mechanism according to claim 1, characterized in that, The active walking mechanism includes a first active wheel bearing and a second active wheel bearing coaxially disposed at both ends of the active wheel axial direction. The active wheel is rotatably mounted on the bottom of the frame through the two active wheel bearings and is connected to the drive mechanism for transmission. The driven support mechanism includes a first driven wheel bearing and a second driven wheel bearing coaxially disposed at both ends of the driven wheel axial direction. The driven wheel is rotatably mounted on the bottom of the vehicle frame through the two driven wheel bearings and is connected to the mileage measuring mechanism. The drive mechanism and the mileage measurement mechanism are electrically connected to the main control unit. The wheel axes of the drive wheel and the driven wheel are parallel to each other and perpendicular to the robot's walking direction. The treads of both wheels are in rolling contact with the top surface of the rail and the upper area of ​​the gauge angle, jointly supporting the frame suspended above the rail top.

4. The track-top traveling mechanism according to claim 3, characterized in that, Both the driving wheel and the driven wheel adopt a circular arc tread structure that matches the rail top profile of the rail.

5. The track-top traveling mechanism according to claim 1, characterized in that, Both the front magnetic attraction unit and the rear magnetic attraction unit include a magnetic attraction bracket, a magnetic attraction magnet, a first auxiliary wheel, and a second auxiliary wheel; The magnetic bracket is fixedly installed at the bottom of the vehicle frame, and the magnetic magnet is installed at the lower part of the magnetic bracket to provide magnetic attraction to the top of the rail; The first auxiliary wheel and the second auxiliary wheel are rotatably mounted on the left and right sides of the magnetic support bracket, and are symmetrically arranged on the transverse sides of the magnetic magnet. The tread surfaces of both wheels are in rolling contact with the top surface of the rail and the upper area of ​​the gauge angle, which is used to support the frame to maintain a constant lifting gap between the magnetic magnet and the top of the rail, and form an alternating support cooperation with the wheels of the active travel mechanism and the driven support mechanism to cross the rail gap.

6. The track-top traveling mechanism according to claim 5, characterized in that, When the wheel of the active walking mechanism or the driven support mechanism enters the rail gap, the first auxiliary wheel and the second auxiliary wheel of the magnetic attraction unit on the corresponding side are still supported on the rail surface. When the first or second auxiliary wheel of the front magnetic attraction unit or the rear magnetic attraction unit enters the rail gap, at least one of the wheels of the active walking mechanism and the driven support mechanism remains supported on the rail surface, so that the robot always has at least two sets of wheels in contact with the rail surface, in order to maintain the design gap between the magnetic magnet and the top of the rail and avoid the magnetic magnet from being attracted to the top of the rail and causing jamming.

7. The track-top traveling mechanism according to claim 5, characterized in that, The minimum magnetic force F required by the magnetic magnets of the front and rear magnetic attraction units. mag satisfy: F mag ≥ m1g(1+L / Δx) / 2; In the formula, m1 is the total mass of the robot, g is the acceleration due to gravity, L is the vertical distance from the robot's actual center of gravity to the magnetic attraction surface, Δx is the designed lift-off distance between the magnet and the top surface of the track, and the actual magnetic attraction force of the magnetic magnet at Δx is greater than F. mag 1.1 to 1.3 times that.

8. The track-top traveling mechanism according to claim 1, characterized in that, The eddy current sensing unit includes an array eddy current sensor fixture, an array eddy current sensor main module, and multiple eddy current sensors electrically connected to the array eddy current sensor main module. The array eddy current sensor main module is electrically connected to the main control unit. The bottom of the array eddy current sensor fixture has a contoured structure that matches the gauge angle on both sides of the rail and the top surface of the rail to ensure that the sensor fits the rail surface contour; the surface of the array eddy current sensor fixture has several mounting holes, and multiple eddy current sensors are respectively installed in the corresponding mounting holes; the array eddy current sensor main module is installed on the side of the array eddy current sensor fixture.

9. The track-top traveling mechanism according to claim 1, characterized in that, The flywheel stabilization unit includes a flywheel motor and a flywheel that is drivenly connected to its output shaft. The flywheel motor is mounted on the vehicle frame and is electrically connected to the main control unit. The main control unit has a built-in attitude sensor to detect changes in the robot's attitude in real time, and controls the flywheel motor to adjust the speed of the flywheel according to the attitude signal, so that the flywheel generates a righting torque opposite to the overturning torque; the axis of the flywheel is set perpendicular to the direction of the robot's movement.

10. A method for controlling the track-top movement of a single-track eddy current detection robot, applied to the track-top movement mechanism according to any one of claims 1-9, characterized in that, include: Step S1: Place the robot on the top of the rail. Use the magnetic attraction force of the front and rear magnetic units to make the robot adhere to the surface of the rail top and keep the robot initially stable. Step S2: Activate the flywheel stabilization unit to make the flywheel of the flywheel stabilization unit rotate and reach a stable speed; Step S3: Start the drive mechanism and drive the robot to walk along the rail through the active walking mechanism. At the same time, the eddy current sensor unit detects the damage on the top surface of the rail in real time. Step S4: During the walking process, the attitude sensor built into the main control unit detects the robot's attitude changes in real time. When the robot is detected to be tilting, the speed of the flywheel motor of the flywheel stabilization unit is adjusted according to the attitude change signal, so that the flywheel generates a reaction torque to counteract the overturning torque and maintain the stability of the robot's walking. Step S5: When a stop command is received, first control the drive mechanism to stop working so that the robot stops walking along the rail. Then, manually assist the robot to keep it stable and control the flywheel motor to drive the flywheel to decelerate and stop until the robot comes to a complete stop.

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