Lightweight, High-strength and Intelligent Inspection Robot for Appearance and Cable Force Detection of Bridge Cables

Abstract

The present invention discloses a light and high-strength intelligent inspection robot for the appearance and cable force detection of bridge stay cables, which includes a main frame, a crawling mechanism, a camera, an end induction sensor, and a cable force sensor mechanism. By setting the cable force sensor mechanism, the cable force sensor can be precisely controlled to closely fit with the stay cable, so as to accurately collect the cable force of the bridge stay cable. A wireless communication is adopted between the cable climbing robot device and the control system to achieve remote control. The appearance diseases of the bridge stay cable are photographed by the camera, and the distance of the cable climbing robot is collected by the distance encoder. The distance is updated in the image in a timely manner, so as to intuitively display the disease defects. After the inspection, it is also convenient for the inspectors to demonstrate and repair the disease appearance in a timely manner through the video image data. Based on the characteristics of high detection efficiency, many detection parameters, strong reliability, low energy consumption, low use and maintenance costs of the cable climbing robot device, it can be adapted to the appearance and cable force detection of the stay cables, cable-supported bridges, and arch bridge cable rods of various cable-stayed bridges in China.

Description

Technical Field

[0001] The present invention relates to the technical field of bridge cable detection, and more specifically, to a lightweight, high-strength and intelligent detection robot for the appearance and cable force detection of bridge cables. Background Art

[0002] With the rapid development of world bridge engineering technology, the span of bridges has been continuously increasing, which has also increased the difficulty and requirements of bridge cable force detection, and the detection distance of the damage diseases of the protective layer on the surface of the cables has increased. The main task of developing a cable-climbing robot is to carry detection equipment and climb along vertical cables and inclined cables on the straight, concave, and convex uneven surfaces of the cables to complete the detection of the appearance and cable force of the cables. Bridge cables are the most important components in cable-stayed bridges, directly bearing the bridge load and controlling the internal force distribution and linearity of the entire bridge deck system. Usually, the cables are prone to vibration under the high stress concentration, corrosion, fatigue, and wind and rain effects in the anchorage area, resulting in changes in the cable force of the cable-stayed bridge. The cable force is an important indicator for evaluating the health status of the cable-stayed bridge. Therefore, it is crucial to detect the cable force and evaluate the status of the cables of the cable-stayed bridge.

[0003] The existing cable force detection mainly has the following deficiencies:

[0004] 1. When a cable force sensor detects the cable force, it needs to be in close contact with the cable to achieve accurate measurement. The closer it is, the more accurate it is. In conventional bridge cable force detection, the sensor is bound to the cable rod. Since different testers have different binding relaxations for the sensor, it will also cause deviations in the data collected by the sensor. And the cable force sensors of some detection robots are fixed to the frame of the robot. However, the diameters of the cables of different bridges are different, resulting in different distances between the cable force sensor and the cable, and even a relatively large distance, making it difficult to achieve accurate measurement of the cable force; and for crawling, the cable force sensor and the cable cannot be in close contact because if they are in close contact, the crawling resistance is large and the cable force sensor will be damaged.

[0005] 2. The conventional bridge cable force test points are relatively high, and it is difficult for the testers to reach the cable force test points by retracting the stairs. If the test height cannot be reached, there will be errors in the conventional cable force test data. The cable force test points are relatively high. In the conventional method, the testers climb too high, and there are relatively large safety hazards in the personnel experiment.

[0006] 3. The existing cable-climbing robots do not have an intelligent obstacle avoidance function. The traditional solution observes obstacles through video images or at a long distance by people; when the robot encounters an obstacle or runs to the top of the cable, it is easy for people to misjudge or the judgment is lagged, and it is impossible to observe the obstacles in front of the cable-climbing robot in a timely and accurate manner. The robot continues to run when it encounters an obstacle, which may cause the cable-climbing robot to collide with the obstacle or the robot's wheels to get stuck, resulting in the potential risk of the equipment falling.

[0007] 4. Existing cable - climbing robots may encounter failures during high - altitude cable detection, such as equipment operation alarms, sudden power outages in the circuit, component failures, etc. When these occur, the mechanical power of the cable - climbing robot will suddenly interrupt, causing the cable - climbing robot to rapidly fall in mid - air. This will result in damage to the robot equipment, and the rapid fall of the equipment will also damage the PE sheath of the bridge cable. If not careful, it will pose a safety hazard to on - site personnel.

[0008] 5. Most existing cable - climbing robots have many mechanical joints, large volume, are heavy, and have poor load - carrying capacity, etc., and are easily restricted by conditions. Summary of the Invention

[0009] In order to overcome the above - mentioned defects of the prior art, the present invention provides a light - weight, high - strength and intelligent detection robot for the appearance and cable force detection of bridge cables.

[0010] To achieve the above object, the present invention provides the following technical solutions:

[0011] A light - weight, high - strength and intelligent detection robot for the appearance and cable force detection of bridge cables, including a main frame, a crawling mechanism, a camera, an end - sensing sensor, and a cable - force sensor mechanism;

[0012] The crawling mechanism includes a driving wheel, a driven wheel, and a driving device. The driving device is in transmission connection with the driving wheel, and both the driving wheel and the driven wheel are rotatably connected to wheel seats arranged inside the main frame;

[0013] A plurality of cameras and end - sensing sensors are installed at the front end of the main frame;

[0014] The cable - force sensor mechanism includes a sliding table, a cable - force sensor, and a screw. The sliding table is installed on the main frame, and a slider groove is fixed on the sliding table. A slider is placed in the slider groove. A stepping motor is installed on the side of the slider groove. One end of the screw is connected to the stepping motor. The screw passes through the side of the slider groove and through the threaded hole of the slider, and the threaded hole matches the screw; An installation bracket is fixed on the slider. A plurality of sliding shafts are installed on the installation bracket. One end of the sliding shaft passes through the hole on the installation bracket and is provided with a nut at the end, and the other end of the sliding shaft is fixedly connected to the cable - force sensor. A spring is sleeved on the sliding shaft. Two object - sensing sensors are fixed on the side of the slider groove; A distance encoder is installed on the main frame, and the distance encoder is connected to the rotating shaft of one of the driven wheels;

[0015] The camera, the end - sensing sensor, the cable - force sensor, the stepping motor, and the distance encoder are all electrically connected to the main controller. The main controller is connected to a first network bridge and is connected to the ground receiving and control platform through the first network bridge.

[0016] The driving device includes a stepping motor and a speed reducer connected to the stepping motor. The output shaft of the speed reducer is in transmission connection with the driving wheel through a belt.

[0017] The main frame includes a middle frame, a left frame, and a right frame. The left and right sides of the middle frame are respectively hinged to the left frame and the right frame. The left frame and the right frame are adjustably connected by a tightener.

[0018] A first bridge box, a main electric control box, an electrical accessory box, and a battery box are installed on the side of the main frame.

[0019] A handle is installed on the top of the main frame.

[0020] It further includes a robot wire winding and unwinding mechanism. The robot wire winding and unwinding mechanism includes a wire winding and unwinding disc and a fixed seat. The wire winding and unwinding disc is rotatably installed on the side of the fixed seat. A pulling rope is wound around the wire winding and unwinding disc. One end of the pulling rope is connected to the main frame. A second bridge is installed on the fixed seat. The second bridge is connected to a mobile power supply for power supply. The first bridge, the second bridge, and the ground receiving and control platform are wirelessly connected.

[0021] The main frame is made of high-strength die-cast alloy aluminum, and Si element, Cu element and Mg element are added to the aluminum.

[0022] The technical effects and advantages of the present invention:

[0023] 1. A cable force sensor mechanism is provided, which can accurately control the cable force sensor to be closely attached to the cable, realizing accurate acquisition of the cable force of the bridge cable. It can realize real-time monitoring of the vibration condition of the bridge in different environments, and identify the vibration fundamental frequency of the stay cable. At the same time, the fundamental frequency is converted into the cable force magnitude by using the vibration method principle. A spring is provided, which can reduce vibration after the cable force sensor moves into place, preventing the cable force sensor from colliding with the cable, and effectively protecting the cable force sensor and the motor slide.

[0024] 2. Wireless communication is adopted between the cable climbing robot device and the control system to realize remote control. The appearance diseases of the bridge cable are photographed through a camera, and the distance of the cable climbing robot is collected through a distance encoder. The distance is updated in the image in a timely manner, realizing an intuitive display of the disease defects. It is also convenient for the inspection personnel to demonstrate and repair the disease appearance in a timely manner through the video image data after the inspection. Multiple groups of sensors are used in cooperation to detect and identify the internal force change of the cable. Whether the internal force of the cable is abnormal is judged, and an effective conclusion is given, providing a precise plan for the later maintenance of the bridge cable. The wireless long-distance communication technology is adopted. Through long-distance bridge transmission, a signal transmitting end is established inside the cable climbing robot, and a signal receiving end is established on the ground receiving and control platform. Through the self-built network bridge, a wireless network transmission signal of more than 1 kilometer for the cable climbing robot is realized. The range covered by this wireless network signal realizes the detection of all large stay cable bridges.

[0025] 3. When the end induction sensor encounters an obstacle, it can control the automatic deceleration and braking function of the stepping motor through the main controller, which can quickly prevent the occurrence of accidental operation of the cable climbing robot.

[0026] 4. Based on the characteristics of high detection efficiency, many detection parameters, strong reliability, low energy consumption, low use and maintenance costs, etc., the cable climbing robot equipment can be adapted to the appearance and cable force detection of various cable-stayed bridges, cable bridges, and arch bridge cable rods in China.

[0027] 5. The cable climbing robot has a distance encoder to collect the walking distance of the robot. Through precise distance capture, the cable force sensor can be accurately stopped at the detection height, thus solving the error problem of test data caused by non-compliance of the test height.

[0028] 6. The cable climbing robot adopts high-strength die-cast alloy aluminum. Adding an appropriate amount of Si element to the aluminum can improve the process fluidity of the alloy, reduce the tendency of hot cracking, and improve the airtightness, corrosion resistance and thermal conductivity of the material; adding an appropriate amount of Cu element can enhance the corrosion resistance, mechanical strength and thermal conductivity of the alloy, improve the process fluidity, creep resistance, fatigue strength and machining performance of the alloy; when Cu exists in the aluminum matrix as a strengthening phase or in the form of granular compounds, the strength and hardness of the alloy can be significantly improved; adding an appropriate amount of Mg element can improve the corrosion resistance and mechanical strength of the alloy, and the tendency of sticking to the mold will also be reduced, improving the machining performance of the alloy. Continuously optimize and adjust the composition of the die-cast alloy material, combine high-vacuum die-casting technology with the regulation of heat treatment process parameters, give full play to the process characteristics of the alloy material, and continuously improve the comprehensive mechanical properties of the die-cast alloy material by means of high-pressure injection and low-speed filling. According to the integrated lightweight design of the material and the structure of the cable climbing robot, use the die-casting process for production and research and development to reduce its production cost, reduce the structural weight, and increase the structural strength. Through lightweight high-strength die-cast aluminum alloy materials, the structure is 2.5 - 3 times lighter than traditional materials, providing a development basis for the research and development path of lightweight high-strength cable climbing robots. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a three-dimensional structure schematic diagram of the present invention;

[0030] Figure 2 It is a structural schematic diagram of the cable force sensor mechanism;

[0031] Figure 3 It is a schematic diagram of the structure of the present invention from another perspective;

[0032] Figure 4 It is a schematic diagram of the structure of the present invention from another perspective;

[0033] Figure 5 It is a schematic diagram of the structure of the present invention from another perspective;

[0034] Figure 6 It is a bottom view structural schematic diagram of the present invention;

[0035] Figure 7 It is a schematic diagram of the partial structure of the cable force sensor mechanism;

[0036] Figure 8 It is a system structure block diagram of the present invention;

[0037] Figure 9 It is a schematic diagram of the structure of the robot's wire winding and unwinding mechanism. Specific implementation manners

[0038] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0039] Such as Figures 1-9 shown, a light - weight and high - strength intelligent inspection robot for the appearance and cable force detection of bridge stay cables includes a main frame 1, a crawling mechanism, a camera 3, an end induction sensor 4, and a cable force sensor mechanism 5;

[0040] The crawling mechanism includes a set of driving wheels 21, three sets of driven wheels 22, and a driving device 23. The driving device 23 is in transmission connection with the driving wheels 21, and both the driving wheels 21 and the driven wheels 22 are rotatably connected to a wheel seat 24 arranged inside the main frame;

[0041] A plurality of cameras 3 and end induction sensors 4 are installed at the front end of the main frame 1;

[0042] The cable force sensor mechanism 5 comprises a slide 51, a cable force sensor 52 and a screw 53. The slide 51 is fixedly mounted on the main frame 1. A slider groove 54 is fixed on the slide 51. A slider 55 is placed in the slider groove. A stepper motor 56 is mounted on the side of the slider groove 54. The stepper motor is connected to one end of the screw 53. The screw 53 passes through the side of the slider groove 54 and the threaded hole of the slider 55, and the threaded hole matches the screw. A mounting bracket 57 is fixed on the slider 55. A plurality of sliding shafts 58 are mounted on the mounting bracket 57. One end of the sliding shaft 58 passes through the hole on the mounting bracket and a nut is provided at the end. The other end of the sliding shaft is fixedly connected to the cable force sensor 52. A spring 59 is sleeved on the sliding shaft. Two object sensing sensors 6 are fixed on the side of the slider groove. A distance encoder 7 is mounted on the main frame 1. The distance encoder 7 is connected to the rotating shaft of one of the driven wheels. The cable force sensor mechanism is provided to accurately control the cable force sensor and the cable to fit closely, so as to realize the accurate collection of the cable force of the bridge cable. It can realize real-time monitoring of bridge vibration conditions in different environments, identify the fundamental frequency of the vibration of the cable, and convert the fundamental frequency into the cable force using the principle of vibration method. A spring is provided to reduce vibration after the cable force sensor moves into place, preventing the cable force sensor from colliding with the cable, and effectively protecting the cable force sensor and the motor slide.

[0043] Preferably, the camera, the end sensing sensor, the cable force sensor, the stepping motor, and the distance encoder are all electrically connected to a main controller, and the main controller is connected to a first network bridge.

[0044] Preferably, the driving device 23 includes a stepping motor 231 and a reducer 232 connected to the stepping motor 231 , and the output shaft of the reducer is transmission-connected to the driving wheel 21 via a belt 233 .

[0045] Preferably, the main frame 1 includes a middle frame 111, a left frame 112, and a right frame 113. The left and right sides of the middle frame 11 are hinged to the left frame 112 and the right frame 113 respectively; the left frame and the right frame are adjustably connected through a rope tightener 114; the rope tightener is a prior art, which can be detachably installed and locked.

[0046] The side of the main frame 1 is equipped with a first network bridge box 8, a main electric control box 9, an electrical accessory box 10, and two battery boxes 11.

[0047] Preferably, a handle 12 is installed on the main frame 1.

[0048] Preferably, a robot wire winding and unwinding mechanism is further included. The robot wire winding and unwinding mechanism includes a wire winding and unwinding reel 131 and a fixed seat 132. The wire winding and unwinding reel 131 is rotatably installed on the side of the fixed seat 132. A pulling rope is wound around the wire winding and unwinding reel. One end of the pulling rope is connected to the main frame. A second network bridge 133 is installed on the fixed seat 132, and the second network bridge is connected to a mobile power source 134 for power supply; the first network bridge, the second network bridge, and the ground receiving and control platform are wirelessly connected. The robot wire winding and unwinding mechanism can recover the robot manually in case of power failure.

[0049] Preferably, the main frame is made of high-strength die-cast alloy aluminum, and Si element, Cu element, and Mg element are added to the aluminum.

[0050] Finally, several points should be noted: First, in the description of this application, it should be noted that unless otherwise specified and limited, the terms "installation", "connection", and "connection" should be understood in a broad sense, which can be mechanical connection or electrical connection, or the communication inside two components, and can be directly connected. "Up", "down", "left", "right", etc. are only used to represent the relative position relationship. When the absolute position of the object being described changes, the relative position relationship may change;

[0051] The above are only the preferred embodiments of the present invention and are not used to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A lightweight, high-strength, intelligent inspection robot for bridge cable appearance and cable force inspection. Features: It includes a main frame, a crawling mechanism, a camera, an end sensing sensor, and a cable force sensor mechanism; The crawling mechanism includes a driving wheel, a driven wheel, and a driving device, wherein the driving device is connected to the driving wheel in a transmission manner, and the driving wheel and the driven wheel are both rotatably connected to a wheel seat provided in the main frame; A plurality of cameras and end sensing sensors are installed at the front end of the main frame; The cable force sensor mechanism includes a slide, a cable force sensor, and a screw. The slide is installed on the main frame, and a slider groove is fixed on the slide. A slider is placed in the slider groove. A stepper motor is installed on the side of the slider groove. The stepper motor is connected to one end of the screw. The screw passes through the side of the slider groove and the threaded hole of the slider, and the threaded hole matches the screw. A mounting bracket is fixed on the slider, and a plurality of sliding shafts are installed on the mounting bracket. One end of the sliding shaft passes through the hole on the mounting bracket and a nut is provided at the end. The other end of the sliding shaft is fixedly connected to the cable force sensor. A spring is sleeved on the sliding shaft. Two object sensing sensors are fixed on the side of the slider groove. A distance encoder is installed on the main frame, and the distance encoder is connected to the rotating shaft of one of the driven wheels. The camera, the end sensing sensor, the cable force sensor, the stepping motor, and the distance encoder are all electrically connected to the main controller, and the main controller is connected to a first network bridge, and a connection is established with a ground receiving and controlling platform through the first network bridge; The driving device includes a stepper motor and a reducer connected to the stepper motor, wherein the output shaft of the reducer is connected to the driving wheel through a belt; The main frame comprises a middle frame, a left frame and a right frame. The left and right sides of the middle frame are respectively hinged to the left frame and the right frame. The left frame and the right frame are adjustably connected through a rope tightener.

2. A lightweight, high-strength, intelligent detection robot for bridge cable appearance and cable force detection according to claim 1, Features: The first network bridge box, the main electric control box, the electrical accessory box and the battery box are installed on the side of the main frame.

3. A lightweight, high-strength, intelligent detection robot for bridge cable appearance and cable force detection according to claim 1, Features: A handle is installed on the main frame.

4. A lightweight, high-strength, intelligent detection robot for bridge cable appearance and cable force detection according to claim 1, Features: It also includes a robot wire-retracting and -releasing mechanism, which includes a wire-retracting and -releasing drum and a fixed seat. The wire-retracting and -releasing drum is rotatably mounted on the side of the fixed seat, a pull rope is wound around the wire-retracting and -releasing drum, one end of the pull rope is connected to the main frame, a second network bridge is installed on the fixed seat, and the second network bridge is connected to a mobile power source for power supply; the first network bridge, the second network bridge, and the ground receiving and control platform are wirelessly connected.

5. A lightweight, high-strength, intelligent detection robot for bridge cable appearance and cable force detection according to claim 1, Features: The main frame is made of high-strength die-casting alloy aluminum material, to which Si, Cu and Mg elements are added.

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