Railway track surface sensing detection system based on unmanned aerial vehicle

Abstract

The invention relates to the technical field of track surface detection, in particular to a railway track surface sensing detection system based on an unmanned aerial vehicle, which comprises a fixed rod and a controller fixed on the unmanned aerial vehicle, the bottom end of the fixed rod is hinged with a mounting rod through a connecting rod, the mounting rod is in a balancing state, and the connecting rod is fixedly connected with the mounting rod. A light source and a first high-speed camera are fixedly connected to the left side and the right side of the bottom end of the mounting rod through connectors respectively, a second high-speed camera is fixedly connected to the middle position of the mounting rod, and light emitted by the light source can be captured by the first high-speed camera after being reflected by the surface of a track in a fixed-height flight state; in the image acquisition process of the unmanned aerial vehicle, large-angle fluctuation of the light source and the high-speed camera on the mounting rod can be inhibited, the stability is improved, and the capability of obtaining high-quality images is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of track surface detection, and specifically to an unmanned aerial vehicle-based railway track surface perception and detection system. Background Art

[0002] The detection of rail surface defects is one of the core contents of railway infrastructure maintenance. It is particularly important to efficiently, accurately, and timely detect rail surface defects for the safe operation of trains. The defects mainly include cracks, wear, spalling, etc. Unmanned aerial vehicles are widely used in railway detection due to their advantages of high efficiency and sensitivity.

[0003] Installing a high-speed camera on an unmanned aerial vehicle to collect images and then performing image recognition can detect defects. High-quality images can greatly reduce the post-processing of denoising. The quality of the images is closely related to different light source illumination methods. An appropriate light source angle can make the defects of depressions or protrusions more obvious, reduce or eliminate the reflections and shadows on the surface of the object to be detected, and improve the accuracy of defect detection.

[0004] As Figure 1 shown, most of the high-angle incident light of the light source 3 is reflected and then 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 defect types that scatter and absorb light, such as the depression 8, including cracks, wear, and spalling. In the image, the surface of the workpiece 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. When the unmanned aerial vehicle is flying, it needs to maintain an inclined attitude to separate the forward component. As Figure 2 shown, and at different altitudes, flight speeds, or air humidities, such as when passing through a tunnel, the degree of inclination is also different.

[0006] Therefore, in view of the above problems, an unmanned aerial vehicle-based railway track surface perception and detection system is proposed, which can stably maintain the angle between the light source and the high-speed camera after the flight attitude changes, and realize the acquisition of stable track images. Summary of the Invention

[0007] The purpose of the present invention is to provide an unmanned aerial vehicle-based railway track surface perception and detection system, which can stably maintain the angle between the light source and the high-speed camera after the flight attitude changes, and realize the acquisition of stable track images.

[0008] To achieve the above object, the present invention provides the following technical solutions: A railway track surface perception and detection system based on a drone, including a fixed rod and a controller fixed on the drone. The bottom end of the fixed rod is hinged with an installation rod through a connecting rod. The installation rod is in a balanced state. The connecting rod is fixedly connected with the installation rod. The left and right sides of the bottom end of the installation rod are respectively fixedly connected with a light source and a first high-speed camera through connectors. A second high-speed camera is fixedly connected to the middle position of the installation rod. In the fixed-height flight state, the light emitted by the light source can be captured by the first high-speed camera after being reflected by the track surface; Inclination sensors are fixedly connected to both the fixed rod and the installation rod, and downward laser rangefinders are fixedly connected to both sides of the installation rod; A telescopic rod is rotatably connected between the fixed rod and the installation rod through a hinge. The telescopic rod suppresses the inclination of the installation rod when the inclination of the drone changes rapidly, and after the inclination of the drone is changed, effectively limits the installation rod within a range to maintain the stability of the installation rod during flight.

[0009] The present invention is used to detect tracks distributed in a straight line; If the installation rod is fixedly connected to the drone, when the drone flies, the angles of the light source and the high-speed camera will also change. And because the weight of the installation rod is mainly distributed at both ends, during the movement, it will also be in an unstable state under the interference of air flow, which will also affect the angles of the light source and the high-speed camera; If the angle adjustment is directly based on the inclination state of the installation rod, there will be a large lag, resulting in a large angle fluctuation of the installation rod. During the flight, it is easy to lose effective image information.

[0010] The present invention can suppress large-angle fluctuations of the light source and the high-speed camera on the installation rod during the process of image acquisition by the drone, whether the drone is adjusting its attitude or in a stable flight state, increasing the stability and the ability to obtain high-quality images; The drone moves forward along the laying direction of the track, and the direction of the installation rod is also the same as the laying direction of the track. When detecting the railway track surface at different altitudes, due to different air densities, the inclination attitude of the drone flight will also be different. The railway track surface perception and detection system of the drone in the present invention can relatively stably maintain the angles of the light source and the high-speed camera after the flight attitude changes during the flight detection process of the drone, realizing stable acquisition of the track surface image. The first high-speed camera obtains an image with bright-field illumination, and the second high-speed camera obtains an image with direct illumination. Through the combined analysis of the two images, more accurate track surface detection is obtained. The laser rangefinder is used to obtain the accurate height of the drone during flight and make timely adjustments.

[0011] The light-gathering area of the first high-speed camera is larger than the light-emitting area of the light source, increasing the angular redundancy for continuous image acquisition when the angle of the unmanned aerial vehicle (UAV) changes. The telescopic rod is installed at the edge of the fixed rod and the mounting rod, far from the rotation point, which can increase the telescopic control distance of the telescopic rod and improve the control accuracy. The outer cylinder and the inner rod are used to suppress the angular fluctuation when the UAV changes its attitude, and the electric push rod is used for small-angle compensation to maintain the horizontal state of the mounting rod.

[0012] Preferably, for the railway track surface perception and detection system based on UAV of the present invention, the telescopic rod includes an outer cylinder, and an inner rod is slidably connected to the inner side of the outer cylinder. The top end of the inner rod is hinged to the bottom end of the fixed rod. A second piston and a third piston are slidably connected to the inner side of the outer cylinder. There is a sealed gap between the second piston and the third piston, and the second piston is limited by the closed gap. The gap communicates with a movable space, and 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 UAV tilts, the inner rod acts on the second piston in the movable state, and the third piston quickly follows for space compensation and maintains the limitation of the second piston.

[0013] When the reading of the tilt sensor on the fixed rod changes, that is, when the UAV tilts, since the second piston is in a movable state, the inner rod directly pulls or lifts the second piston. When the second piston generates a slight displacement, the movable space first compensates the gap through the space change, so that the second piston is in a free state within a short stroke. The fixed rod and the mounting rod are in a soft connection within a certain range, reducing the degree of tilting of the mounting rod following the fixed rod. And the short free stroke of the second piston can be continuously restored as the third piston quickly follows the movement. Thus, when the tilt angle of the UAV changes rapidly, the tilting of the mounting rod is suppressed, greatly increasing the stability. After the tilt angle of the UAV is changed, the reading of the tilt sensor on the fixed rod does not change, and the third piston no longer makes a following movement. The gap can effectively limit the mounting rod within a small free range and maintain the stability of the mounting rod during flight.

[0014] 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.

[0015] 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.

[0016] 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.

[0017] 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.

[0018] 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.

[0019] 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.

[0020] Preferably, for the UAV-based railway track surface perception and detection system of the present invention, a first through hole is provided inside the top end of the outer cylinder, and a limiting block is fixedly connected to the top end of the cavity for restricting the effective movement range of the inner rod.

[0021] Preferably, for the UAV-based railway track surface perception and detection system of the present invention, a first potentiometer is fixedly connected to the inner side of the bottom end of the inner rod, and a first slider is fixedly connected to the inner side of one end of the first piston. The first slider slides on the first potentiometer, thereby continuously obtaining the position of the first slider.

[0022] The movement of the first piston is judged by the movement of the first slider, so that the third piston can make a following movement in time.

[0023] Preferably, for the UAV-based railway track surface perception and detection system of the present invention, a second potentiometer is fixedly connected to the inner side of the outer cylinder, and a second slider is fixedly connected to the inner side of one end of the second piston. The second slider slides on the second potentiometer, thereby continuously obtaining the position of the second slider.

[0024] The second potentiometer and the second slider are used to obtain the position of the second piston, which is convenient for subsequent initialization to return to the initial position.

[0025] Preferably, for the UAV-based railway track surface perception and detection system of the present invention, a motor is fixedly connected to the bottom end of the outer cylinder, a partition is fixedly connected to the inner side of the outer cylinder, the end of the main shaft of the motor is fixedly connected to a screw rod, the other end of the screw rod is rotatably connected to the bottom end of the partition, a slide plate is spirally connected to the outside of the screw rod, a synchronous rod is fixedly connected to the top end of the slide plate, the top end of the synchronous rod passes through the partition and is fixedly connected to the third piston, and the synchronous rod is slidably connected to the partition.

[0026] The third piston realizes the following 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 rod, and the slide plate drives the third piston to lift and follow the movement of the second piston through the synchronous rod.

[0027] The UAV-based railway track surface perception and detection method is characterized in the following steps: Step 1: The UAV moves forward along the laying direction of the track. The direction of the mounting rod is also the same as the laying direction of the track. The first high-speed camera obtains an image with bright-field illumination, and the second high-speed camera obtains an image with direct illumination. By combining and analyzing the two images, more accurate detection of the track surface is obtained. The laser rangefinder is used to obtain the accurate height during the flight of the UAV and make timely adjustments.

[0028] Step 2: After the flight environment changes, in order to maintain the flight speed and altitude of the drone, the tilt attitude of the drone during flight will change. Since 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 the space change, so that the second piston is in a free state within a short stroke. The fixed rod and the mounting rod are in a soft connection within a certain range, reducing the degree of inclination of the mounting rod following the fixed rod. Moreover, the short free stroke of the second piston can be continuously restored as the third piston follows quickly, so as to suppress the inclination of the mounting rod when the inclination of the drone changes rapidly, greatly increasing the stability.

[0029] Step 3: After the inclination of the drone is completed, since the third piston no longer makes a following movement, the gap can effectively limit the mounting rod within a small free range, maintaining the relative stability of the mounting rod during flight.

[0030] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. The railway track surface perception and detection system based on the drone can suppress the large-angle fluctuations of the light source and the high-speed camera on the mounting rod during the image acquisition process of the drone, increasing the stability and the ability to obtain high-quality images. The drone advances along the laying direction of the track, and the direction of the mounting rod is also the same as the laying direction of the track. When detecting the railway track surface at different altitudes, due to the different air densities, the tilt attitude of the drone during flight will also be different. The railway track surface perception and detection system of the drone in the present invention can stably maintain the angles of the light source and the high-speed camera after the flight attitude changes during the flight detection process of the drone, realizing the acquisition of stable track images. The first high-speed camera obtains images with bright field illumination, and the second high-speed camera obtains directly illuminated images. By combining and analyzing the two images, more accurate track surface detection can be obtained. The laser rangefinder is used to obtain the accurate altitude of the drone during flight and make timely adjustments.

[0031] 2. When the reading of the tilt sensor on the fixed rod changes, that is, when the drone has an inclination change, since 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 the space change, so that the second piston is in a free state within a short stroke. The fixed rod and the mounting rod are in a soft connection within a certain range, reducing the degree of inclination of the mounting rod following the fixed rod. Moreover, the short free stroke of the second piston can be continuously restored as the third piston follows quickly, so as to suppress the inclination of the mounting rod when the inclination of the drone changes rapidly, greatly increasing the stability. After the inclination of the drone is completed, since the third piston no longer makes a following movement, the gap can effectively limit the mounting rod within a small free range, maintaining the stability of the mounting rod during flight.

[0032] 3. The UAV-based railway track surface perception and detection system makes the lower air chamber communicate with the gap, and the diameter of the cavity is much smaller than the inner diameter of the outer cylinder. When the second piston moves, a large vertical change will be generated in the first piston, thereby increasing the sensitivity of detecting the movement of the second piston, enabling the third piston to make a following movement in a timely manner, continuously stabilizing the air pressure in the gap, and continuously maintaining the free state of the second piston. Ensure that during the entire tilting process of the UAV, the fixed rod and the mounting rod are in a soft connection, maintaining the relative level of the mounting rod.

[0033] 4. In the UAV-based railway track surface perception and detection system, since the hinge point of the mounting rod is at the middle position of the mounting rod, when the UAV moves forward and the left side of the UAV tilts upward, the left side of the mounting rod will move right upward, slightly tilting the top of the telescopic rod toward the connecting rod. Compared with other mounting angles, a larger telescopic amount can be obtained, increasing the sensitivity of the first piston and having a smaller telescopic resistance, reducing the associated tilt of the mounting rod. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 It is a schematic diagram of bright-field illumination in the prior art.

[0035] Figure 2 It is a schematic structural diagram of the tilting attitude during UAV flight.

[0036] Figure 3 It is a schematic diagram of the overall external structure of the present invention.

[0037] Figure 4 It is a front-view structural diagram of the mounting rod of the present invention.

[0038] Figure 5 It is a schematic internal structure diagram of the telescopic rod of the present invention.

[0039] Figure 6 For the present invention Figure 5 Schematic diagram of the structure at location A.

[0040] Figure 7 For the present invention Figure 5 Schematic diagram of the structure at location B.

[0041] Figure 8 It is a schematic structural diagram of the fixed rod following the tilt of the UAV of the present invention.

[0042] In the figure: 1, unmanned aerial vehicle; 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 cylinder; 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 board; 615, synchronizing rod; 616, screw rod; 617, slide plate; 618, motor; 619, third piston; 620, electric push rod; 621, air chamber. Specific embodiments

[0043] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts shall fall within the protection scope of the present invention.

[0044] Example 1, please refer to Figure 3-8 , the present invention provides a technical solution: A railway track surface perception and detection system based on an unmanned aerial vehicle includes a fixing rod 10 and a controller 14 fixed on the unmanned aerial vehicle 1. The bottom end of the fixing rod 10 is hinged with a mounting rod 2 through a connecting rod 7. The mounting rod 2 is in a balanced state. 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 respectively fixedly connected with a light source 3 and a first high-speed camera 4 through a connector 11. A second high-speed camera 13 is fixedly connected to the middle position of the mounting rod 2. In the fixed-height flight state, the light emitted by the light source 3 can be captured by the first high-speed camera 4 after being reflected by the surface of the track 5; Tilt sensors 9 are fixedly connected to both 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 fixing rod 10 and the mounting rod 2 through a hinge. The telescopic rod 6 suppresses the tilt of the mounting rod 2 when the tilt angle of the unmanned aerial vehicle 1 changes rapidly, and effectively limits the mounting rod 2 after the tilt angle of the unmanned aerial vehicle 1 is changed, maintaining the stability of the mounting rod 2 during flight.

[0045] The present invention can suppress large-angle fluctuations of the light source 3 and the high-speed camera on the mounting rod 2 during the image acquisition process of the unmanned aerial vehicle 1, increase stability, and increase the ability to obtain high-quality images; The drone 1 moves forward along the laying direction of the track, and the direction of the mounting rod 2 is also the same as the laying direction of the track. When the flight environment changes, when performing surface detection of the railway track 5 at different altitudes, or when the drone 1 passes through a tunnel, due to the change in air density, the tilt attitude of the drone 1 during flight will also be different. In the railway track surface perception detection system of the drone in the present invention, during the flight detection process of the drone 1, after the flight attitude changes, the angles of the light source 3 and the high-speed camera can be stably maintained, and stable track images can be obtained. The first high-speed camera 4 obtains images under bright-field illumination, and the second high-speed camera 13 obtains images under direct illumination. By combining and analyzing the two types of images, more accurate track surface detection can be obtained. The laser rangefinder 12 is used to obtain the accurate height of the drone 1 during flight and make timely adjustments.

[0046] The light-gathering area of the first high-speed camera 4 is larger than the emitting area of the light source 3. When the angle of the drone 1 changes, the angular redundancy for continuous image acquisition is increased, allowing for a small angular deviation. Specifically, the telescopic rod 6 includes an outer cylinder 61. An inner rod 62 is slidably connected to the inner side of the outer cylinder 61. The top end of the inner rod 62 is hinged to the bottom end of the fixed rod 10. A second piston 612 and a third piston 619 are slidably connected to the inner side of the outer cylinder 61. There is a sealed gap 66 between the second piston 612 and the third piston 619. The gap 66 communicates with a movable space. The third piston 619 can actively follow the movement of the second piston 612. By means of the closed gap 66, the second piston 612 is limited, that is, the length of the telescopic rod 6 is limited. The top end of the second piston 612 is fixedly connected to the inner rod 62. When the drone 1 has a tilt change, through the action of the inner rod 62 on the second piston 612 in the active state, the third piston 619 quickly follows for space compensation and maintains the limitation of the second piston 612.

[0047] When and only when the reading of the tilt sensor 9 on the fixed rod 10 changes, that is, when the drone 1 has a tilt change, because the second piston 612 is in an active state, the inner rod 62 directly pulls or lifts the second piston 612. The movable space first compensates the gap 66 through space change, so that the second piston 612 is in a free state within a short stroke. The fixed rod 10 and the mounting rod 2 are in a soft connection within a certain range, reducing the degree of tilt of the mounting rod 2 following the fixed rod 10. And the short free stroke of the second piston 612 can be continuously restored as the third piston 619 quickly follows the movement. Thus, when the tilt angle of the drone 1 changes rapidly, the tilt of the mounting rod 2 is suppressed, greatly increasing the stability. After the tilt angle of the drone 1 is changed, because the third piston 619 no longer follows the movement, the gap 66 can effectively limit the mounting rod 2 within a small free range, maintaining the stability of the mounting rod 2 during flight.

[0048] 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.

[0049] 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.

[0050] 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.

[0051] 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.

[0052] When the flight attitude of the drone 1 changes, due to factors such as the frictional force between the second piston 612 and the inner wall of the outer cylinder 61, it will have an associated tilting effect on the mounting rod 2. When the tilt sensor 9 of the electric push rod 620 on the mounting rod 2 tilts within an excessive range, the electric push rod 620 expands and contracts to compensate for the horizontal direction of the mounting rod 2.

[0053] Specifically, the top end of the telescopic rod 6 tilts slightly towards the connecting rod 7, increasing the sliding amount of the inner rod 62 when the drone 1 tilts and reducing the sliding resistance.

[0054] Since the hinge point (rotation center) of the mounting rod 2 is at the middle position of the mounting rod 2, when the drone 1 moves forward and the left side of the drone 1 tilts upward, the left side of the mounting rod 2 will move right upward. Tilting the top end of the telescopic rod 6 slightly towards the connecting rod 7 can obtain a larger telescopic amount compared to other mounting angles, increase the sensitivity of the first piston 68, and have a smaller telescopic resistance, reducing the associated tilt of the mounting rod 2.

[0055] Specifically, a first through hole 63 is provided on the inner side of the top end of the outer cylinder 61, and a limiting block 64 is fixedly connected to the top end of the cavity for restricting the effective movement range of the inner rod 62.

[0056] 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 to continuously obtain and detect the position of the first slider 69.

[0057] The movement of the first piston 68 is judged by the movement of the first slider 69, so that the third piston 619 can make a following movement in a timely manner.

[0058] Specifically, 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 to continuously obtain the position of the second slider 613.

[0059] The second potentiometer 611 and the second slider 613 are used to obtain the position of the second piston 612, which is convenient for subsequent initialization to return to the initial position. Specifically, a motor 618 is fixedly connected to the bottom end of the outer cylinder 61, a partition 614 is fixedly connected to the inner side of the outer cylinder 61, the end of the main shaft of the motor 618 is fixedly connected to a screw rod 616, the other end of the screw rod 616 is rotatably connected to the bottom end of the partition 614, a slide plate 617 is helically connected to the outside of the screw rod 616, the top end of the slide plate 617 is fixedly connected to a synchronous rod 615, the top end of the synchronous rod 615 passes through the partition 614 and is fixedly connected to the third piston 619, and the synchronous rod 615 is slidably connected to the partition 614.

[0060] The third piston 619 realizes a following motion through the rotation of the motor 618. The forward and reverse rotation of the motor 618 will force the slide plate 617 to move up or down through the screw rod 616. The slide plate 617 drives the third piston 619 to lift and follow the movement of the second piston 612 through the synchronous rod 615.

[0061] The present invention also discloses a method for detecting the surface of a railway track based on an unmanned aerial vehicle, and the steps are as follows: Step 1: The unmanned aerial vehicle 1 moves forward along the laying direction of the track. The direction of the mounting rod 2 is also the same as the laying direction of the track. The first high-speed camera 4 obtains an image under bright-field illumination, and the second high-speed camera 13 obtains an image under direct illumination. By combining and analyzing the two images, a more accurate detection of the track surface is obtained. The laser rangefinder 12 is used to obtain the accurate height of the unmanned aerial vehicle 1 during flight and make timely adjustments.

[0062] Step 2: After the flight environment changes, in order to maintain the flight speed and height of the unmanned aerial vehicle 1, the tilt attitude of the unmanned aerial vehicle 1 during flight will change. Since the second piston 612 is in an active state, the inner rod 62 directly lifts or pulls the second piston 612. The available space first compensates for the gap 66 through the space change, so that the second piston 612 is in a free state within a short stroke. The fixed rod 10 and the mounting rod 2 are in a soft connection within a certain range, reducing the degree of inclination of the mounting rod 2 following the fixed rod 10. Moreover, the short free stroke of the second piston 612 can be continuously restored as the third piston 619 quickly follows the movement. Thus, when the inclination of the unmanned aerial vehicle 1 changes rapidly, the inclination of the mounting rod 2 is suppressed, greatly increasing the stability.

[0063] Step 3: After the inclination of the unmanned aerial vehicle 1 is changed, since the third piston 619 no longer makes a following motion, the gap 66 can effectively limit the mounting rod 2 within a small free range, maintaining the relative stability of the mounting rod 2 during flight.

[0064] Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. An unmanned aerial vehicle-based railway track surface perception and detection system, comprising a fixed rod (10) and a controller (14) fixed on the unmanned aerial vehicle (1), characterized in that: The bottom end of the fixed rod (10) is hinged with an installation rod (2) through a connecting rod (7). The installation rod (2) is in a balanced state. The left and right sides of the bottom end of the installation rod (2) are fixedly connected with a light source (3) and a first high-speed camera (4) respectively through connectors (11). A second high-speed camera (13) is fixedly connected to the middle position of the installation rod (2). In the state of flying at a fixed height, the light emitted by the light source (3) can be captured by the first high-speed camera (4) after being reflected by the surface of the track (5). Inclination sensors (9) are fixedly connected to both the fixed rod (10) and the installation rod (2). Laser rangefinders (12) are fixedly connected downward on both sides of the installation rod (2). A telescopic rod (6) is rotatably connected between the fixed rod (10) and the installation rod (2) through a hinge. The telescopic rod (6) inhibits the inclination of the installation rod (2) when the inclination of the drone (1) changes rapidly, and effectively limits the installation rod (2) after the inclination of the drone (1) is changed, maintaining the stability of the installation rod (2) during flight.

2. The railway track surface perception and detection system based on an unmanned aerial vehicle according to claim 1, wherein: The telescopic rod (6) includes an outer cylinder (61). An inner rod (62) is slidably connected to the inner side of the outer cylinder (61). The top end of the inner rod (62) is hinged to the bottom end of the fixed rod (10). A second piston (612) and a third piston (619) are slidably connected to the inner side of the outer cylinder (61). There is a sealed gap (66) between the second piston (612) and the third piston (619). The second piston (612) is limited within a certain range through the closed gap (66). The gap (66) communicates with a movable space. The third piston (619) can follow the movement of the second piston (612) in a timely manner. The top end of the second piston (612) is fixedly connected to the inner rod (62). When the inclination of the drone (1) changes, the inner rod (62) acts on the second piston (612) in a movable state, and the third piston (619) will follow in a timely manner for space compensation and maintain the limitation of the second piston (612).

3. The rail track surface perception and detection system based on an unmanned aerial vehicle according to claim 2, wherein: A cavity is formed inside the bottom end of the inner rod (62). A first piston (68) is slidably connected inside the cavity. The first piston (68) divides the cavity into an upper air chamber (65) and a lower air chamber (67). The upper air chamber (65) communicates with an air chamber (621) on its upper side. The volume of the air chamber (621) is more than 10 times that of the cavity. The lower air chamber (67) is a movable space, and the lower air chamber (67) communicates with a gap (66). When the drone (1) tilts, since 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, increasing the sensitivity to the movement trend of the inner rod (62). When the first piston (68) moves up or down quickly, it compensates for the gap (66). After detecting the movement direction of the first piston (68), the third piston (619) starts to perform a synchronous follow-up compensation movement to reset the first piston (68), so that the inner rod (62) is always in a freely movable height range until the drone (1) completes the attitude adjustment. During the process of the drone (1) changing its tilt, the telescopic rod (6) can always sensitively and timely perform follow-up compensation to maintain the horizontal position of the mounting rod (2).

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

5. The drone-based railway track surface perception and detection system according to any one of claims 1-3, characterized in that: The top end of the telescopic rod (6) inclines towards the connecting rod (7), increasing the sliding amount of the inner rod (62) when the drone (1) tilts and reducing the sliding resistance.

6. The railway track surface perception and detection system based on an unmanned aerial vehicle according to claim 3, wherein: A first through hole (63) is formed inside the top end of the outer cylinder (61). A limiting block (64) is fixedly connected to the top end of the cavity, which is used to limit the effective movement range of the inner rod (62).

7. The railway track surface perception and detection system based on an unmanned aerial vehicle according to claim 3, characterized in that: A first potentiometer (610) is fixedly connected to the inner side of the bottom end of the inner rod (62). 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), so as to continuously obtain the movement direction of the first slider (69).

8. The railway track surface perception and detection system based on an unmanned aerial vehicle according to claim 3, wherein: A second potentiometer (611) is fixedly connected to the inner side of the outer cylinder (61). 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), so as to continuously obtain the position of the second slider (613).

9. The rail track surface perception and detection system based on an unmanned aerial vehicle according to claim 3, characterized in that: A motor (618) is fixedly connected to the bottom end of the outer cylinder (61). A partition plate (614) is fixedly connected to the inner side of the outer cylinder (61). The end of the main shaft of the motor (618) is fixedly connected with a screw rod (616). The other end of the screw rod (616) is rotatably connected to the bottom end of the partition plate (614). A slide plate (617) is helically connected to the outer side of the screw rod (616). The top end of the slide plate (617) is fixedly connected with a synchronous rod (615). The top end of the synchronous rod (615) passes through the partition plate (614) and is fixedly connected with the third piston (619). The synchronous rod (615) is slidably connected to the partition plate (614).

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