Railway track surface perception and detection system based on drone

Abstract

The present invention relates to the field of track surface detection technology, and in particular to a railway track surface perception and detection system based on an unmanned aerial vehicle (UAV). The system comprises a fixing rod and a controller fixed to the UAV, wherein the bottom end of the fixing rod is hingedly connected to a mounting rod via a connecting rod, the mounting rod is in a balancing state, the connecting rod is fixedly connected to the mounting rod, the left and right sides of the bottom end of the mounting rod are respectively fixedly connected to a light source and a first high-speed camera via connectors, and the middle position of the mounting rod is fixedly connected to a second high-speed camera. In a fixed-altitude flight state, light emitted by the light source can be reflected by the track surface and captured by the first high-speed camera. The system can suppress large-angle fluctuations of the light source and the high-speed camera on the mounting rod during image acquisition by the UAV, thereby increasing stability and the ability to obtain high-quality images.

Description

Technical Field

[0001] The present invention relates to the technical field of track surface detection, and in particular to a railway track surface sensing and detection system based on an unmanned aerial vehicle (UAV). Background Art

[0002] Rail surface defect detection is one of the core contents of railway infrastructure maintenance. Efficient, accurate and timely detection of rail surface defects is particularly important for the safe operation of trains. Defects mainly include cracks, wear, peeling, etc. Drones are widely used in railway inspection due to their high efficiency and sensitivity.

[0003] Installing a high-speed camera on a drone to capture images and then perform image recognition can detect defects. High-quality images can greatly reduce the need for later denoising. The quality of the image is closely related to the different lighting methods. The appropriate light source angle can make concave or convex defects more obvious, reduce or eliminate reflections and shadows on the surface of the object being inspected, and improve the accuracy of defect detection.

[0004] like Figure 1 As shown, most of the high-angle incident light from the light source 3 is reflected and enters the high-speed camera 4. Most of the field of view of the image sensor is bright. Bright field illumination is mainly used for the detection of scattered and absorbed light defect types, such as depressions 8, including cracks, wear and peeling. In the image, the workpiece surface appears bright, while the defects appear dark.

[0005] The above detection environment needs to maintain the angle between the light source and the high-speed camera to ensure that the light emitted by the light source enters the high-speed camera after being reflected by the track surface. In order to distinguish the forward component during flight, the drone needs to maintain an inclined posture, such as Figure 2 , and the degree of inclination is different at different altitudes, flight speeds or air humidity, such as when passing through a tunnel.

[0006] Therefore, to address the above problems, a railway track surface perception and detection system based on drones is proposed, which can steadily maintain the angle of the light source and high-speed camera after the flight attitude changes, and realize stable track image acquisition. Summary of the Invention

[0007] The purpose of the present invention is to provide a railway track surface perception and detection system based on a drone, which can steadily maintain the angle of the light source and the high-speed camera after the flight attitude changes, thereby achieving stable track image acquisition.

[0008] To achieve the above objectives, the present invention provides the following technical solution: a railway track surface sensing and detection system based on an unmanned aerial vehicle (UAV), comprising a fixing rod and a controller fixed to the UAV, wherein the bottom end of the fixing rod is hingedly connected to a mounting rod via a connecting rod, the mounting rod being in a trim state, the connecting rod being fixedly connected to the mounting rod, the left and right sides of the bottom end of the mounting rod being fixedly connected via connectors to a light source and a first high-speed camera, respectively, and the middle position of the mounting rod being fixedly connected to a second high-speed camera. When the UAV is in a fixed-altitude flight state, light emitted by the light source can be reflected by the track surface and captured by the first high-speed camera.

[0009] Tilt sensors are fixedly connected to both the fixing rod and the mounting rod, and downward-facing laser rangefinders are fixedly connected to both sides of the mounting rod;

[0010] A telescopic rod is connected between the fixed rod and the mounting rod through a hinge. The telescopic rod suppresses the tilt of the mounting rod when the inclination of the drone changes rapidly. After the inclination of the drone is changed, the mounting rod is effectively limited within a range to maintain the stability of the mounting rod during flight.

[0011] The present invention is used to detect tracks distributed in a straight line;

[0012] If the mounting rod is fixed to the drone, the angles of the light source and high-speed camera will also change during flight. Furthermore, because the weight of the mounting rod is mainly distributed at both ends, it will be unstable due to airflow during movement, which will also affect the angles of the light source and high-speed camera.

[0013] If the angle is adjusted directly according to the tilt of the mounting pole, there will be a large hysteresis, causing large angle fluctuations of the mounting pole, and effective image information will be easily lost during flight.

[0014] The present invention can suppress large-angle fluctuations of the light source and high-speed camera on the mounting pole during the image acquisition process of the drone, whether the drone is adjusting its attitude or in a stable flight state, thereby increasing stability and the ability to obtain high-quality images.

[0015] The drone moves along the direction of track laying, and the direction of the mounting pole is also consistent with the direction of track laying. When conducting railway track surface inspections at different altitudes, the tilt posture of the drone's flight will also be different due to different air densities. The railway track surface perception and detection system of the drone of the present invention can relatively stably maintain the angle of the light source and the high-speed camera after the flight posture changes during the drone flight inspection process, thereby achieving stable track surface image acquisition. The first high-speed camera obtains bright field illumination images, and the second high-speed camera obtains direct illumination images. By combining and analyzing the two images, more accurate track surface inspection is obtained. The laser rangefinder is used to obtain the precise altitude of the drone during flight and make timely adjustments.

[0016] The first high-speed camera has a larger light-collecting area than the light source, which increases the angular redundancy for continuous image acquisition when the drone's angle changes.

[0017] The telescopic rod is installed at the edge of the fixed rod and the mounting rod, far away from the rotation point, which can increase the telescopic control distance of the telescopic rod and improve the control accuracy. The outer tube and inner rod are used to suppress the angle fluctuation when the drone's attitude changes. The electric push rod is used to compensate for small angles and maintain the horizontal state of the mounting rod.

[0018] As a preferred embodiment of the railway track surface sensing and detection system based on the drone of the present invention, the telescopic rod includes an outer tube, the inner side of the outer tube is slidably connected to the inner rod, the top end of the inner rod is hinged to the bottom end of the fixed rod, the inner side of the outer tube is slidably connected to the second piston and the third piston, there is a closed gap between the second piston and the third piston, the second piston is limited by the closed gap, the gap is connected to a movable space, the third piston can actively follow the movement of the second piston, the top end of the second piston is fixedly connected to the inner rod, when the drone tilts, the inner rod acts on the second piston in the active state, and the third piston quickly follows to compensate for the space and maintain the limit of the second piston.

[0019] When the reading of the tilt sensor on the fixed rod changes, that is, when the tilt of the drone changes, because the second piston is in an active state, the inner rod directly lifts or pulls the second piston. When the second piston produces a slight displacement, the movable space first compensates for the gap through spatial changes, so that the second piston is in a free state within a shorter stroke, and the fixed rod and the mounting rod are in a soft connection within a certain range, reducing the degree to which the mounting rod follows the tilt of the fixed rod, and the shorter free stroke of the second piston can be continuously restored as the third piston quickly follows the movement, thereby suppressing the tilt of the mounting rod when the inclination of the drone changes rapidly, greatly increasing the stability. After the inclination of the drone is changed, the reading of the tilt sensor on the fixed rod does not change, the third piston no longer follows the movement, and the gap can effectively limit the mounting rod within a smaller free range, thereby maintaining the stability of the mounting rod during flight.

[0020] As a preferred embodiment of the railway track surface sensing and detection system based on a drone of the present invention, a cavity is defined on the inner side of the bottom end of the inner rod, into which a first piston is slidably connected. The first piston divides the cavity into an upper air chamber and a lower air chamber. An air chamber is connected to the upper side of the upper air chamber, and the volume of the air chamber is at least 10 times that of the cavity. The larger volume of the air chamber is intended to reduce fluctuations in pressure changes within the air chamber during movement of the first piston, thereby increasing the sensitivity of the first piston's movement. The lower air chamber is a movable space and is connected to the gap. When the drone tilts, because the diameter of the cavity is much smaller than the inner diameter of the outer cylinder, slight changes in the second piston can sensitively force the first piston to move rapidly, thereby increasing sensitivity to the movement trend of the inner rod. Rapid upward or downward movement of the first piston compensates for the gap. After detecting the direction of the first piston's movement, the third piston begins synchronously following and compensating, and continuously resets the first piston. The inner rod remains in a highly free state until the drone completes attitude adjustment. As the drone changes its tilt, the telescopic rod can sensitively and promptly follow and compensate, maintaining the relative levelness of the mounting rod.

[0021] By connecting the lower air chamber to the gap, the diameter of the cavity is much smaller than the inner diameter of the outer cylinder. As a result, when the second piston moves, the first piston will produce a larger vertical change, thereby increasing the sensitivity of detecting the movement of the second piston, allowing the third piston to follow the movement in time, continuously stabilizing the air pressure in the gap, and allowing the second piston to continue in a free state. This ensures that during the entire tilting process of the drone, the fixing rod and the mounting rod are in a soft connection, maintaining the relative level of the mounting rod.

[0022] As a preferred embodiment of the railway track surface sensing and detection system based on a drone of the present invention, the bottom end of the outer cylinder is fixedly connected to an electric push rod, and the lower movable end of the electric push rod is rotatably connected to the top end of the mounting rod through a hinge.

[0023] When the UAV's flight attitude changes, the friction between the second piston and the inner wall of the outer cylinder will cause the mounting rod to tilt. When the tilt sensor on the mounting rod tilts too much, the electric push rod extends to compensate for the horizontal direction of the mounting rod.

[0024] As a preferred embodiment of the UAV-based railway track surface sensing and detection system of the present invention, the top end of the telescopic rod is slightly inclined toward the connecting rod, thereby increasing the sliding amount of the inner rod when the UAV is tilted and reducing the sliding resistance.

[0025] Because the hinge point of the mounting rod is in the middle of the mounting rod, when the drone moves forward, the left side of the drone tilts upward, and the left side of the mounting rod moves to the upper right, slightly tilting the top of the telescopic rod toward the connecting rod. Compared with other installation angles, a larger telescopic amount can be obtained, the sensitivity of the first piston is increased, and there is smaller telescopic resistance, which reduces the associated tilt of the mounting rod.

[0026] As a preferred embodiment of the UAV-based railway track surface sensing and detection system of the present invention, a first through hole is opened on the inner side of the top end of the outer cylinder, and a limit block is fixedly connected to the top end of the cavity to limit the effective motion range of the inner rod.

[0027] As a preferred embodiment of the railway track surface sensing and detection system based on a drone of the present invention, a first potentiometer is fixedly connected to the inner side of the bottom end of the inner rod, a first slider is fixedly connected to the inner side of one end of the first piston, and the first slider slides on the first potentiometer, thereby continuously obtaining the position of the first slider.

[0028] The movement of the first piston is determined by the movement of the first slider, so that the third piston can make a follow-up movement in time.

[0029] As a preferred embodiment of the UAV-based railway track surface sensing and detection system of the present invention, a second potentiometer is fixedly connected to the inner side of the outer cylinder, a second slider is fixedly connected to the inner side of one end of the second piston, and the second slider slides on the second potentiometer, thereby continuously obtaining the position of the second slider.

[0030] The second potentiometer and the second slider are used to obtain the position of the second piston, so as to facilitate subsequent initialization and restoration to the initial position.

[0031] As a preferred embodiment of the railway track surface sensing and detection system based on a drone of the present invention, the bottom end of the outer cylinder is fixedly connected to a motor, the inner side of the outer cylinder is fixedly connected to a partition, the end of the main shaft of the motor is fixedly connected to a screw, the other end of the screw is rotatably connected to the bottom end of the partition, the outer side of the screw is spirally connected to a slide, the top end of the slide is fixedly connected to a synchronization rod, the top end of the synchronization rod passes through the partition and is fixedly connected to the third piston, and the synchronization rod is slidably connected to the partition.

[0032] The third piston follows the movement through the rotation of the motor. The forward and reverse rotation of the motor will force the slide plate to move up or down through the screw. The slide plate drives the third piston to move up and down and follows the movement of the second piston through the synchronization rod.

[0033] The railway track surface perception and detection method based on drones includes the following steps:

[0034] Step 1: The drone moves along the track's direction of installation. The mounting pole is also aligned with the track's direction of installation. The first high-speed camera obtains a brightfield illumination image, while the second high-speed camera obtains a direct illumination image. By combining and analyzing these two images, a more accurate track surface detection is achieved. The laser rangefinder is used to obtain the drone's precise flight altitude and make timely adjustments.

[0035] Step 2: After the flight environment changes, in order to maintain the flight speed and altitude of the drone, the tilt posture of the drone will change. Because the second piston is in an active state, the inner rod directly lifts or pulls the second piston. The movable space first compensates for the gap through spatial changes, so that the second piston is in a free state within a shorter stroke. The fixed rod and the mounting rod are in a soft connection within a certain range, reducing the degree to which the mounting rod follows the tilt of the fixed rod, and the shorter free stroke of the second piston can be continuously restored as the third piston quickly follows the movement, thereby suppressing the tilt of the mounting rod when the tilt of the drone changes rapidly, greatly increasing stability.

[0036] Step 3: After the drone's inclination is changed, because the third piston no longer makes follow-up movements, the gap can effectively limit the mounting rod within a smaller free range, maintaining the relative stability of the mounting rod during flight.

[0037] Compared with the prior art, the present invention has the following beneficial effects:

[0038] 1. The railway track surface perception and detection system based on a drone can suppress large-angle fluctuations of the light source and high-speed camera on the mounting pole during the drone's image acquisition process, thereby increasing stability and the ability to obtain high-quality images. The drone moves along the track laying direction, and the direction of the mounting pole is also consistent with the track laying direction. When performing railway track surface detection at different altitudes, the drone's flight tilt posture will also be different due to different air densities. The railway track surface perception and detection system for the drone of the present invention can steadily maintain the angles of the light source and high-speed camera after the flight posture changes during the drone flight detection process, thereby achieving stable track image acquisition. The first high-speed camera obtains bright field illuminated images, and the second high-speed camera obtains directly illuminated images. By combining and analyzing the two images, more accurate track surface detection is obtained. The laser rangefinder is used to obtain the precise altitude of the drone during flight and make timely adjustments.

[0039] 2. In the UAV-based railway track surface sensing and detection system, when the reading of the tilt sensor on the fixed rod changes, that is, when the tilt of the UAV changes, because the second piston is in an active state, the inner rod directly lifts or pulls the second piston, and the movable space first compensates for the gap through spatial changes, so that the second piston is in a free state within a shorter stroke, and the fixed rod and the mounting rod are in a soft connection within a certain range, reducing the degree to which the mounting rod follows the tilt of the fixed rod, and the shorter free stroke of the second piston can be continuously restored as the third piston quickly follows the movement, thereby suppressing the tilt of the mounting rod when the UAV's inclination changes rapidly, greatly increasing stability, and after the UAV's inclination is completed, because the third piston no longer follows the movement, the gap can effectively limit the mounting rod within a smaller free range, thereby maintaining the stability of the mounting rod during flight.

[0040] 3. This UAV-based railway track surface sensing and detection system connects the lower air chamber with the gap, and the diameter of the cavity is much smaller than the inner diameter of the outer cylinder. As a result, when the second piston moves, the first piston will produce a larger vertical change, thereby increasing the sensitivity of the detection of the second piston movement, allowing the third piston to follow the movement in time, continuously stabilizing the air pressure in the gap, and keeping the second piston in a free state. This ensures that during the entire tilting process of the UAV, the fixing rod and the mounting rod are in a soft connection, maintaining the relative level of the mounting rod.

[0041] 4. This UAV-based railway track surface perception and detection system has a mounting rod with its hinge point in the middle. When the UAV moves forward, the left side of the UAV tilts upward, and the left side of the mounting rod moves to the upper right, slightly tilting the top of the telescopic rod toward the connecting rod. Compared with other installation angles, this system can achieve a greater telescopic range, increase the sensitivity of the first piston, and have a smaller telescopic resistance, thereby reducing the associated tilt of the mounting rod. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 Schematic diagram of bright field illumination in the prior art.

[0043] Figure 2 This is a structural diagram of the tilting posture of the UAV during flight.

[0044] Figure 3 It is a schematic diagram of the overall appearance structure of the present invention.

[0045] Figure 4 This is a front view structural diagram of the mounting rod of the present invention.

[0046] Figure 5 Schematic diagram of the internal structure of the telescopic rod of the present invention.

[0047] Figure 6 For the present invention Figure 5 Schematic diagram of the structure at point A.

[0048] Figure 7 For the present invention Figure 5 Schematic diagram of the structure at point B.

[0049] Figure 8 This is a schematic diagram of the structure of the fixed rod of the present invention when it follows the tilt of the drone.

[0050] In the figure: 1. UAV; 2. Mounting rod; 3. Light source; 4. First high-speed camera; 5. Track; 6. Telescopic rod; 7. Connecting rod; 8. Depression; 9. Tilt sensor; 10. Fixing rod; 11. Connector; 12. Laser rangefinder; 13. Second high-speed camera; 14. Controller; 61. Outer tube; 62. Inner rod; 63. First through hole; 64. Limit block; 65. Upper air chamber; 66. Gap; 67. Lower air chamber; 68. First piston; 69. First slider; 610. First potentiometer; 611. Second potentiometer; 612. Second piston; 613. Second slider; 614. Partition; 615. Synchronous rod; 616. Screw; 617. Slide plate; 618. Motor; 619. Third piston; 620. Electric push rod; 621. Air chamber. DETAILED DESCRIPTION

[0051] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0052] Example 1, please refer to Figure 3-8 , the present invention provides a technical solution:

[0053] The railway track surface sensing and detection system based on a drone includes a fixing rod 10 and a controller 14 fixed to a drone 1. The bottom end of the fixing rod 10 is hinged to a mounting rod 2 via a connecting rod 7. The mounting rod 2 is in a trim state, and the connecting rod 7 is fixedly connected to the mounting rod 2. The left and right sides of the bottom end of the mounting rod 2 are fixedly connected to a light source 3 and a first high-speed camera 4 via connectors 11, respectively. The middle position of the mounting rod 2 is fixedly connected to a second high-speed camera 13. When flying at a fixed altitude, light emitted by the light source 3 can be reflected by the surface of the track 5 and captured by the first high-speed camera 4.

[0054] The fixed rod 10 and the mounting rod 2 are both fixedly connected with a tilt sensor 9, and both sides of the mounting rod 2 are fixedly connected with a downward laser rangefinder 12;

[0055] A telescopic rod 6 is connected between the fixed rod 10 and the mounting rod 2 by a hinge. The telescopic rod 6 suppresses the tilt of the mounting rod 2 when the inclination of the drone 1 changes rapidly, and effectively limits the mounting rod 2 after the inclination of the drone 1 is changed, thereby maintaining the stability of the mounting rod 2 during flight.

[0056] The present invention can suppress large-angle fluctuations of the light source 3 and the high-speed camera on the mounting pole 2 during image acquisition by the drone 1, thereby increasing stability and the ability to obtain high-quality images.

[0057] The drone 1 moves along the direction of track laying, and the direction of the mounting pole 2 is also consistent with the direction of track laying. When the flight environment changes, when the surface of the railway track 5 is inspected at different altitudes, or when the drone 1 passes through a tunnel, the tilt posture of the drone 1 will also be different due to the change in air density. The railway track surface perception and detection system of the drone of the present invention can steadily maintain the angle of the light source 3 and the high-speed camera after the flight posture changes during the flight inspection process of the drone 1, thereby achieving stable track image acquisition. The first high-speed camera 4 obtains a bright field illuminated image, and the second high-speed camera 13 obtains a directly illuminated image. By combining and analyzing the two images, a more accurate track surface detection is obtained. The laser rangefinder 12 is used to obtain the precise altitude of the drone 1 during flight and make timely adjustments.

[0058] The light-collecting area of ​​the first high-speed camera 4 is larger than the light source 3 emission area, which increases the angle redundancy of the continuous image acquisition when the angle of the drone 1 changes, allowing a smaller angle deviation;

[0059] Specifically, the telescopic rod 6 includes an outer tube 61, the inner side of the outer tube 61 is slidably connected to the inner rod 62, the top of the inner rod 62 is hinged to the bottom end of the fixed rod 10, the inner side of the outer tube 61 is slidably connected to the second piston 612 and the third piston 619, there is a closed gap 66 between the second piston 612 and the third piston 619, the gap 66 is connected to a movable space, the third piston 619 can actively follow the movement of the second piston 612, and the position of the second piston 612 is limited by the closed gap 66, that is, the length of the telescopic rod 6 is limited, the top of the second piston 612 is fixedly connected to the inner rod 62, when the drone 1 tilts, the inner rod 62 acts on the second piston 612 in the active state, and the third piston 619 quickly follows to compensate for the space and maintain the position limit of the second piston 612.

[0060] When and only when the reading of the tilt sensor 9 on the fixed rod 10 changes, that is, when the tilt of the drone 1 changes, because the second piston 612 is in an active state, the inner rod 62 directly lifts or pulls the second piston 612, and the movable space first compensates for the gap 66 through spatial changes, so that the second piston 612 is in a free state within a shorter stroke, and the fixed rod 10 and the mounting rod 2 are in a soft connection within a certain range, reducing the degree to which the mounting rod 2 follows the tilt of the fixed rod 10, and the shorter free stroke of the second piston 612 can be continuously restored as the third piston 619 quickly follows the movement, thereby suppressing the tilt of the mounting rod 2 when the tilt of the drone 1 changes rapidly, greatly increasing the stability, and after the tilt of the drone 1 is completed, because the third piston 619 no longer follows the movement, the gap 66 can effectively limit the mounting rod 2 within a smaller free range, thereby maintaining the stability of the mounting rod 2 during flight.

[0061] Specifically, a cavity is provided on the inner side of the bottom end of the inner rod 62, and a first piston 68 is slidably connected in the cavity. The first piston 68 divides the cavity into an upper air chamber 65 and a lower air chamber 67. In the initial state, the first piston 68 is in the middle position of the cavity. The upper side of the upper air chamber 65 is connected to the air chamber 621, and the volume of the air chamber 621 is more than 10 times the volume of the cavity. The larger volume of the air chamber 621 is to reduce the fluctuation of the pressure change in the air chamber 621 when the first piston 68 moves, and to increase the sensitivity of the movement of the first piston 68. The lower air chamber 67 is a movable space, and the lower air chamber 67 is connected to the gap 66. When the drone 1 tilts, the cavity The diameter is much smaller than the inner diameter of the outer cylinder 61. The slight change of the second piston 612 can sensitively force the first piston 68 to move quickly, realize the reaction in a shorter time, and increase the sensitivity to the movement trend of the inner rod. The first piston 68 makes a rapid up or down movement to compensate for the gap 66. After detecting the movement of the first piston 68, the third piston 619 starts to follow the compensation movement synchronously. The inner rod 62 is always in a highly free state until the drone 1 completes the attitude adjustment. When the drone 1 changes its inclination, the telescopic rod 6 can always sensitively and timely follow the compensation to maintain the relative level of the mounting rod 2.

[0062] For example, when the tilt angle of the drone 1 increases, the inner rod 62 acts on the second piston 612 in a free state and generates an upward lifting force. The slight displacement of the second piston 612 can sensitively force the first piston 68 to move downward quickly. The first piston 68 moves downward quickly to compensate for the gap 66, so that the second piston 612 is always in a free state within a certain range. After detecting the downward movement of the first piston 68, the third piston 619 starts to make a synchronous upward follow-up compensation movement, so that during the attitude adjustment process of the drone 1, the inner rod 62 is always in a free state, effectively reducing the associated follow-up tilt of the mounting rod 2 and suppressing the angle fluctuation of the mounting rod 2.

[0063] By connecting the lower air chamber 67 with the gap 66, the diameter of the cavity is much smaller than the inner diameter of the outer tube 61. As a result, when the second piston 612 moves, a slight change in the second piston 612 will cause the first piston 68 to produce a larger vertical change, thereby increasing the sensitivity of the detection of the movement of the second piston 612, allowing the third piston 619 to follow the movement in time, continuously stabilizing the air pressure in the gap 66, and keeping the second piston 612 in a free state. This ensures that during the entire tilting process of the drone 1, the fixing rod 10 and the mounting rod 2 are in a soft connection, maintaining the relative level of the mounting rod 2.

[0064] Specifically, the bottom end of the outer cylinder 61 is fixedly connected to an electric push rod 620 , and the lower movable end of the electric push rod 620 is rotatably connected to the top end of the mounting rod 2 via a hinge.

[0065] When the flight attitude of the UAV 1 changes, the friction between the second piston 612 and the inner wall of the outer cylinder 61 will cause the mounting rod 2 to tilt. When the tilt sensor 9 on the mounting rod 2 tilts too much, the electric push rod 620 will extend and retract to compensate for the horizontal direction of the mounting rod 2.

[0066] Specifically, the top end of the telescopic rod 6 is slightly tilted toward the connecting rod 7 , thereby increasing the sliding amount of the inner rod 62 and reducing the sliding resistance when the drone 1 tilts.

[0067] Because the hinge point (rotation center) of the mounting rod 2 is in the middle of the mounting rod 2, when the drone 1 moves forward, the left side of the drone 1 tilts upward, and the left side of the mounting rod 2 moves to the upper right, slightly tilting the top of the telescopic rod 6 toward the connecting rod 7. Compared with other installation angles, a larger telescopic range can be obtained, increasing the sensitivity of the first piston 68, and having a smaller telescopic resistance, thereby reducing the associated tilt of the mounting rod 2;

[0068] Specifically, a first through hole 63 is opened on the inner side of the top end of the outer cylinder 61 , and a limit block 64 is fixedly connected to the top end of the cavity to limit the effective movement range of the inner rod 62 .

[0069] Specifically, a first potentiometer 610 is fixedly connected to the inner side of the bottom end of the inner rod 62, and a first slider 69 is fixedly connected to the inner side of one end of the first piston 68. The first slider 69 slides on the first potentiometer 610, thereby continuously obtaining and detecting the position of the first slider 69.

[0070] The movement of the first piston 68 is determined by the movement of the first slider 69 , so that the third piston 619 can make a follow-up movement in time.

[0071] Specifically, the inner side of the outer cylinder 61 is fixedly connected to the second potentiometer 611 , the inner side of one end of the second piston 612 is fixedly connected to the second slider 613 , and the second slider 613 slides on the second potentiometer 611 to continuously obtain the position of the second slider 613 .

[0072] The second potentiometer 611 and the second slider 613 are used to obtain the position of the second piston 612, so as to facilitate subsequent initialization and restoration to the initial position;

[0073] Specifically, the bottom end of the outer cylinder 61 is fixedly connected to the motor 618, the inner side of the outer cylinder 61 is fixedly connected to the partition 614, the end of the main shaft of the motor 618 is fixedly connected to the screw 616, the other end of the screw 616 is rotatably connected to the bottom end of the partition 614, the outer side of the screw 616 is spirally connected to the slide 617, the top of the slide 617 is fixedly connected to the synchronization rod 615, the top of the synchronization rod 615 passes through the partition 614 and is fixedly connected to the third piston 619, and the synchronization rod 615 is slidably connected to the partition 614.

[0074] The third piston 619 achieves following motion through the rotation of the motor 618. The forward and reverse rotation of the motor 618 forces the slide 617 to move up or down through the screw 616. The slide 617 drives the third piston 619 to rise and fall and follow the movement of the second piston 612 through the synchronization rod 615.

[0075] The present invention also discloses a railway track surface sensing and detection method based on a drone, the steps of which are:

[0076] Step 1: The drone 1 moves along the direction of the track, and the direction of the mounting pole 2 is also consistent with the track laying direction. The first high-speed camera 4 obtains an image of bright field illumination, and the second high-speed camera 13 obtains an image of direct illumination. By combining and analyzing the two images, a more accurate track surface detection is obtained. The laser rangefinder 12 is used to obtain the precise altitude of the drone 1 during flight and make timely adjustments.

[0077] Step 2: After the flight environment changes, in order to maintain the flight speed and altitude of the drone 1, the tilt posture of the drone 1 will change. Because the second piston 612 is in an active state, the inner rod 62 directly lifts or pulls the second piston 612. The movable space first compensates for the gap 66 through spatial changes, so that the second piston 612 is in a free state within a shorter stroke. The fixed rod 10 and the mounting rod 2 are in a soft connection within a certain range, reducing the degree to which the mounting rod 2 follows the tilt of the fixed rod 10, and the shorter free stroke of the second piston 612 can be continuously restored as the third piston 619 quickly follows the movement, thereby suppressing the tilt of the mounting rod 2 when the tilt of the drone 1 changes rapidly, greatly increasing the stability.

[0078] Step 3: After the inclination of the drone 1 is changed, since the third piston 619 no longer makes a follow-up motion, the gap 66 can effectively limit the mounting rod 2 within a smaller free range, thereby maintaining the relative stability of the mounting rod 2 during flight.

[0079] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A railway track surface sensing and detection system based on an unmanned aerial vehicle (UAV), comprising a fixing rod (10) fixed to an unmanned aerial vehicle (UAV) and a controller (14), characterized in that: The bottom end of the fixing rod (10) is hingedly connected to the mounting rod (2) via the connecting rod (7). The mounting rod (2) is in a trimming state. The left and right sides of the bottom end of the mounting rod (2) are fixedly connected to a light source (3) and a first high-speed camera (4) via connectors (11), respectively. The middle position of the mounting rod (2) is fixedly connected to a second high-speed camera (13). In a fixed-altitude flight state, light emitted by the light source (3) can be reflected by the surface of the track (5) and captured by the first high-speed camera (4). Tilt sensors (9) are fixedly connected to the fixing rod (10) and the mounting rod (2), and downward laser rangefinders (12) are fixedly connected to both sides of the mounting rod (2); A telescopic rod (6) is rotatably connected between the fixed rod (10) and the mounting rod (2) via a hinge, and the telescopic rod (6) suppresses the inclination of the mounting rod (2) when the inclination of the drone (1) changes rapidly, and effectively limits the mounting rod (2) after the inclination of the drone (1) is changed, thereby maintaining the stability of the mounting rod (2) during flight. The telescopic rod (6) includes an outer tube (61), the inner side of the outer tube (61) is slidably connected to the inner rod (62), the top end of the inner rod (62) is hinged to the bottom end of the fixed rod (10), the inner side of the outer tube (61) is slidably connected to the second piston (612) and the third piston (619), a closed gap (66) is present between the second piston (612) and the third piston (619), and the second piston (612) is limited within a range by the closed gap (66), and the top end of the second piston (612) is fixedly connected to the inner rod (62); A cavity is provided on the inner side of the bottom end of the inner rod (62), and a first piston (68) is slidably connected to the cavity. The first piston (68) divides the cavity into an upper air chamber (65) and a lower air chamber (67). The upper side of the upper air chamber (65) is connected to an air room (621). The volume of the air room (621) is more than 10 times the volume of the cavity. The lower air chamber (67) is a movable space. The lower air chamber (67) is connected to the gap (66). When the UAV (1) tilts, because the diameter of the cavity is smaller than the inner diameter of the outer cylinder (61), the second piston (612) can sensitively force the first piston (68) to move quickly, thereby increasing the sensitivity to the movement trend of the inner rod (62).

2. The UAV-based railway track surface sensing and detection system according to claim 1, characterized in that: The gap (66) is connected to a movable space, and the third piston (619) can follow the movement of the second piston (612) in time. When the UAV (1) tilts, the inner rod (62) acts on the second piston (612) in the movable state, and the third piston (619) will follow in time to compensate for the space and maintain the limit of the second piston (612).

3. The UAV-based railway track surface sensing and detection system according to claim 2, characterized in that: The bottom end of the outer cylinder (61) is fixedly connected to an electric push rod (620), and the lower movable end of the electric push rod (620) is rotatably connected to the top end of the mounting rod (2) via a hinge.

4. The UAV-based railway track surface sensing and detection system according to any one of claims 1 to 3, characterized in that: The top end of the telescopic rod (6) is tilted toward the connecting rod (7), thereby increasing the sliding amount of the inner rod (62) and reducing the sliding resistance when the drone (1) is tilted.

5. The UAV-based railway track surface sensing and detection system according to claim 1, characterized in that: A first through hole (63) is provided on the inner side of the top end of the outer cylinder (61), and a limit block (64) is fixedly connected to the top end of the cavity to limit the effective motion range of the inner rod (62).

6. The UAV-based railway track surface sensing and detection system according to claim 1, characterized in that: A first potentiometer (610) is fixedly connected to the inner side of the bottom end of the inner rod (62), and a first slider (69) is fixedly connected to the inner side of one end of the first piston (68). The first slider (69) slides on the first potentiometer (610), thereby continuously obtaining the movement direction of the first slider (69).

7. The UAV-based railway track surface sensing and detection system according to claim 1, characterized in that: A second potentiometer (611) is fixedly connected to the inner side of the outer cylinder (61), and a second slider (613) is fixedly connected to the inner side of one end of the second piston (612). The second slider (613) slides on the second potentiometer (611), thereby continuously obtaining the position of the second slider (613).

8. The UAV-based railway track surface sensing and detection system according to claim 1, characterized in that: The bottom end of the outer cylinder (61) is fixedly connected to a motor (618), the inner side of the outer cylinder (61) is fixedly connected to a partition (614), the end of the main shaft of the motor (618) is fixedly connected to a screw (616), the other end of the screw (616) is rotatably connected to the bottom end of the partition (614), the outer side of the screw (616) is spirally connected to a slide (617), the top end of the slide (617) is fixedly connected to a synchronization rod (615), the top end of the synchronization rod (615) passes through the partition (614) and is fixedly connected to the third piston (619), and the synchronization rod (615) is slidably connected to the partition (614).

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