A mobile drone inspection system for large bridges based on ship-machine collaboration

Abstract

The present invention discloses a mobile unmanned aerial vehicle inspection system and scheme for large bridges based on ship-machine collaboration. The mobile ship-machine collaborative operation system consists of a tethered unmanned aerial vehicle and an unmanned boat that carries a power source and supplies power to it through a cable. The tethered unmanned aerial vehicle determines the relative position information with the unmanned boat and the bottom of the bridge with the help of a laser module, and obtains its own precise position in combination with the position of the unmanned boat. The inspection scheme includes remotely controlling the unmanned boat to record the position at the bottom of the bridge span, controlling the unmanned aerial vehicle to take off to scan the bottom structure of the bridge and record flight parameters, associating the position of the unmanned aerial vehicle with the unmanned boat to form a route, the unmanned aerial vehicle collects data and then lands, and the unmanned boat moves to the next bridge span to repeat the operation until all bridge spans are inspected and a laser point cloud three-dimensional model is generated. The present invention effectively solves many drawbacks of existing bridge inspection methods, improves inspection efficiency, accuracy and safety, and provides a strong guarantee for bridge maintenance.

Description

Technical Field

[0001] This article deals with a mobile UAV inspection system for large bridges based on ship-machine collaboration. Background Art

[0002] With the continuous development of bridge construction, the number of large bridges is increasing, and the importance of bridge inspection is becoming more and more prominent. However, due to the special geographical environment of some large bridges, such as some large bridges across lakes, most of them are built on the water, and the water part is long, which brings many difficulties to the inspection work.

[0003] The current manual inspection method has limitations. It can only observe a limited range of the bridge deck and the upper part of the bridge side. The concrete and steel structure under the bridge cannot be observed, and there are safety risks in the inspection on the highway bridge. The conventional drone inspection mode also faces many problems when applied to such special bridges, such as the short range and endurance of multi-rotor drones, low operational feasibility, accuracy, and safety, high cost and difficult installation of automatic airports; fixed-wing drones are fast and fly at high altitudes, which are not suitable for crossing the bottom of the bridge. Therefore, a new inspection system is urgently needed to solve these problems. Summary of the invention

[0004] The purpose of the present invention is to provide a mobile UAV inspection system for large bridges based on ship-machine collaboration, so as to solve the problems existing in existing bridge inspections, such as limited inspection range, low safety, low efficiency, high cost, and the inadaptability of conventional UAV inspections to special geographical environments.

[0005] A mobile UAV inspection system for large bridges based on ship-machine collaboration, including a mobile ship-machine collaborative operation system, a ground workstation and a remote control system;

[0006] The movable ship-machine cooperative operation system comprises a tethered UAV and an unmanned ship, wherein the tethered UAV is connected to the unmanned ship via a cable, and the unmanned ship carries a power source and provides energy to the UAV in real time;

[0007] When the tethered drone is located in the lower surface area of ​​the bridge, or the tethered drone cannot obtain its own position information through satellite signals, the tethered drone uses a laser module to determine the relative position of the tethered drone and the unmanned boat, as well as the relative height information of the tethered drone and the bottom of the measured bridge; and then obtains the position information of the tethered drone through the position information of the unmanned boat itself.

[0008] Furthermore, the unmanned ship is provided with a UAV take-off and landing platform, a mooring box, a ship-borne camera, an environmental sensor and a communication device.

[0009] In order to improve the stability of the overall system information communication, a communication device is installed on the unmanned ship. The signal transmission direction undertaken by the communication device includes information transmission between the unmanned ship and the UAV, information transmission between the unmanned ship and the ground workstation, and information transmission between the unmanned ship and the remote control system. The unmanned ship and the UAV communicate via 1.4G / 2.4G networking, the unmanned ship and the ground workstation communicate via 1.4G / 2.4G networking, and the unmanned ship and the remote control system communicate via 4G / 5G.

[0010] Furthermore, the laser module is a laser SLAM module. The tethered drone uses the laser SLAM module to scan the three-dimensional structure of the bottom of the bridge and locate its own relative position, and through multiple recordings, a laser point cloud three-dimensional model of the bottom structure of the bridge is obtained at the same time.

[0011] In order to improve the convenience of overall system operation, during the test process or emergency operation, onshore personnel can switch the drone to the emergency remote control channel through the remote control and manually take over the operation of the tethered drone.

[0012] A mobile drone inspection scheme for large bridges based on ship-machine collaboration includes the following steps:

[0013] S1. The operator on the shore remotely controls the unmanned boat to the bottom of a certain bridge span and uses the system platform to record the position coordinates of the unmanned boat, which are obtained through the positioning system of the unmanned boat;

[0014] S2. With the assistance of the surveillance camera on the unmanned boat, the drone is remotely controlled to take off to a suitable data collection position at the bottom of the bridge. During takeoff, the drone scans the three-dimensional structure of the bottom of the bridge with the help of the laser SLAM sensor. At the same time, the system platform records the flight trajectory, altitude, and gimbal angle parameters of the drone.

[0015] S3. When the UAV reaches the preset data collection position, the system platform records the reference coordinate position of the UAV at this time, and associates this waypoint with the previously recorded position coordinates of the unmanned ship to form a preliminary route;

[0016] S4. After the drone completes data collection, it lands on the unmanned boat, and then the unmanned boat moves to the bottom of the next bridge span and repeats the above steps until the waypoint marking work of all bridge spans is completed. During the whole process, the waypoint data is uploaded to the cloud platform in real time for storage and backup, and a laser point cloud 3D model of the bottom structure of the bridge is generated at the same time, providing basic data for subsequent inspections and analysis.

[0017] Beneficial effects:

[0018] 1. The present invention adopts a ship-machine collaboration mode, using the unmanned ship as a mobile energy supply station and positioning reference point for the tethered UAV, which greatly prolongs the inspection operation time of the UAV, improves the inspection efficiency, and can complete the comprehensive inspection task of large bridges in a relatively short time.

[0019] 2. The laser module enables precise positioning of the drone in areas with poor satellite signals, ensuring the accuracy and completeness of the inspection data and providing a reliable basis for the safety assessment of the bridge structure. No personnel are required to work on the road to avoid affecting daily operations (no restrictions or suspension of operations). The unmanned boat and the drone are automatically sailing on the water, and no human intervention is required during the entire operation. The drone is protected by a mooring line, is small in size, highly intelligent (with laser automatic obstacle avoidance function), and has stable and reliable navigation, which not only ensures the safety of the operation, but also does not affect the bridge structure and surface shipping.

[0020] 3. Use smart devices to replace manual labor to achieve automatic inspection. The combination of drones and unmanned boats is like an automatic hangar that can move by itself. Operators only need to remotely operate or monitor through the ground station on the shore, or remotely assist in command at the command center. The drone is tethered to the unmanned boat and powered by its large-capacity power supply. The flight time is almost unlimited and can operate continuously for several hours. One ship, one machine, one platform, and two remote control personnel can complete the detailed inspection data collection of the entire bridge (including the lower part and the bottom) within a week. If combined two-way operations are added, the full inspection time can be shortened to about 3 days.

[0021] 4. The generated 3D laser point cloud model of the bottom structure of the bridge is convenient for long-term storage and comparative analysis, which helps to timely discover minor changes and potential defects in the bridge structure, realize preventive maintenance of the bridge, and extend the service life of the bridge. In addition to the basic inspection function, it can be upgraded and iterated through the centralized cloud management platform, and the collected inspection photo data can be automatically uploaded. After training with AI module data, it can automatically identify bridge image defects and generate inspection reports with one click to realize intelligent inspection. The combination of drones and unmanned boats can also conduct a full-scale 3D scan of the bridge to build a spatial 3D model, which is convenient for comprehensive intelligent management of 3D visualization, and can assist in monitoring the environment, water quality and surface shipping safety, expanding the scope of application. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic diagram of a large bridge mobile UAV inspection system based on ship-machine collaboration for measurement under a large bridge;

[0023] Figure 2 This is a schematic diagram of an unmanned ship;

[0024] 1. UAV lifting platform 2. Mooring box 3. Shipborne equipment. DETAILED DESCRIPTION

[0025] In order to deepen the understanding of the present invention, the present invention will be further described in detail below with reference to embodiments and drawings. The embodiments are only used to explain the present invention and do not constitute a limitation on the protection scope of the present invention.

[0026] Embodiment 1:

[0027] A mobile UAV inspection system for large bridges based on ship-machine collaboration, the system includes the following two parts:

[0028] 1. Intelligent mobile operation system

[0029] The core of this system is an intelligent mobile operation system consisting of a tethered drone and an unmanned ship. The tethered drone adopts a special cage design, equipped with a laser SLAM sensor, a special tethered box and a precision landing module. Its size is 610mm in diameter, with unlimited endurance (connected to the unmanned ship through a tethered cable and powered by the unmanned ship power supply). The payload is a 4K camera, and the positioning relies on laser radar SLAM. It adopts remote control mode, with one link connected to the shore ground station via 2.4G, and the other link connected to the cloud platform via a 5G module.

[0030] The hull size of the unmanned boat is expected to be 2.3mx 1m x 1.2m (length x width x height, height including antenna), the take-off and landing platform size is 1m x 1.5m (length x width), a QR code for precise take-off and landing is sprayed on the top, the load capacity is >100kg, the marine power supply and power system is >2kw, and dual-duct propulsion is adopted. The ship-borne surveillance camera has 4K image quality, a gimbal, a battery life of >8h, a maximum speed of 3m / s, and is equipped with environmental sensors such as wind, rainfall, temperature, and humidity. The wave resistance level is micro-waves, and the positioning module adopts Beidou + RTK dual antenna positioning. The communication modules include 1.4G / 2.4G point-to-multipoint communication, 4G / 5G mobile communication, WiFi (router) AP, and 950M emergency radio (remote control). The control distance varies under different modules (1.4G / 2.4G module >30km; 4G / 5G module has no control distance limit; 950M emergency module >10km). The control module is a PX4 controller + ship-borne computing power module (TX4), which has a laser automatic obstacle avoidance function and is equipped with a solar backup battery panel.

[0031] 2. Supporting Facilities

[0032] The peripheral supporting ground station, the remote control software system located in the command center, as well as the 1.4G / 2.4G networking communication equipment and the telecommunications 4G / 5G communication network, together form a closed-loop system that can perform intelligent inspection operations.

[0033] The specific implementation modes of the present invention are described in detail below with reference to the accompanying drawings.

[0034] In actual operation, the unmanned boat and tethered drone system are first started to ensure the normal operation of each device and stable communication connection. The operator on the shore controls the unmanned boat to sail to the bottom of the designated bridge span through the remote control. The positioning system of the unmanned boat obtains its own position coordinates in real time and transmits them to the ground workstation and system platform for recording. Then, the operator remotely controls the drone to take off from the take-off and landing platform of the unmanned boat. During the take-off process, the drone's laser SLAM sensor begins to scan the three-dimensional structure of the bridge bottom, and the system platform records the drone's flight trajectory, altitude, gimbal angle and other parameters.

[0035] When the drone reaches the preset data collection location, the system platform associates this location with the location of the unmanned ship to form a preliminary route. During the data collection process, the drone transmits the collected data to the unmanned ship through a communication device, and then the unmanned ship transmits the data to the ground workstation and cloud platform for storage and backup. After completing the data collection of a bridge span, the drone lands on the unmanned ship, and the unmanned ship moves to the bottom of the next bridge span, repeating the above steps until the inspection of all bridge spans is completed.

[0036] During the entire process, if special circumstances occur (such as drone failure, environmental abnormalities, etc.), onshore personnel can switch the drone to the emergency remote control channel through the remote control and manually take over the tethered drone operation to ensure the safety and reliability of the inspection operation.

[0037] The deployment implementation modes include the following:

[0038] 1. Waypoint marking scheme: The operator on the shore remotely controls the unmanned boat to the bottom of a certain bridge span, and records the coordinates of the unmanned boat position through the system platform; then, through the monitoring camera on the unmanned boat to assist in monitoring, remotely control the drone to take off to the appropriate data collection position at the bottom of the bridge. During this process, the drone uses the laser SLAM module to scan the three-dimensional structure of the bottom of the bridge and position itself. The system platform records the reference coordinate position, gimbal angle and other parameters of the drone at this time, and the system platform connects these waypoints to form an automatic route. Then, the drone lands on the unmanned boat. In sequence mode, the unmanned boat travels to the next bridge span and repeats the above process until all the waypoints of the unmanned boat and the route parameters of the drone are recorded on the system platform. The laser point cloud data recorded during the drone marking process is imported into the platform, and the laser point cloud three-dimensional model of the bottom structure of the bridge can be obtained at the same time, which can be used as the data base for the expansion of future system functions.

[0039] 2. Operation plan: The unmanned boat carrying the drone is first at the starting point in the water. The operator operates on the shore and remotely sends the unmanned boat operation waypoint parameters to the unmanned boat through the platform. After receiving the waypoint parameters, the unmanned boat automatically drives to the bridge span of the first operation point and moors. After the platform system monitors that the unmanned boat is in place, it automatically sends the corresponding route to the drone. The drone automatically takes off and performs automatic route flight and data collection operations according to the obtained route. After completion, it automatically returns to the starting point of the route, searches for the take-off and landing platform QR code with an optical camera, and automatically and accurately lands on the take-off and landing platform on the unmanned boat. The unmanned boat then drives to the mooring point under the next bridge span, and then repeats the above process until all inspection plans for that time are completed.

[0040] 3. Test emergency response plan: The drone is equipped with a 950M emergency remote control channel. During the test process or emergency operation, the shore personnel can switch the remote control to manual remote control mode, take over the drone remotely, and operate the drone with the assistance of the surveillance camera on the unmanned ship.

[0041] 4. Solution for water level changes: Since the lake water level is constantly changing, in the laser SLAM mode, the reference coordinates are based on the bridge structure as a relative reference system. Therefore, water level changes will not have much impact on the drone waypoints. The corresponding solution is to use the bottom of the bridge as the reference point for the drone's height value.

[0042] Through the above specific implementation methods, the mobile UAV inspection system and solution for large bridges based on ship-machine collaboration of the present invention can effectively realize efficient, accurate and safe inspection operations of large bridges, and provide strong technical support for the maintenance and management of bridges.

[0043] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A mobile drone inspection system for large bridges based on ship-machine collaboration, characterized in that: It includes a mobile ship-machine collaborative operation system, a ground workstation and a remote control system; The movable ship-machine cooperative operation system comprises a tethered UAV and an unmanned ship, wherein the tethered UAV is connected to the unmanned ship via a cable, and the unmanned ship carries a power source and provides energy to the UAV in real time; When the tethered drone is located in the lower surface area of ​​the bridge, or the tethered drone cannot obtain its own position information through satellite signals, the tethered drone uses a laser module to determine the relative position of the tethered drone and the unmanned boat, as well as the relative height information of the tethered drone and the bottom of the measured bridge; and then obtains the position information of the tethered drone through the position information of the unmanned boat itself.

2. According to claim 1, a large-scale bridge mobile drone inspection system based on ship-machine collaboration is characterized in that: The unmanned ship is provided with a UAV take-off and landing platform, a mooring box, a ship-borne camera, an environmental sensor and a communication device.

3. A mobile drone inspection system for large bridges based on ship-machine collaboration according to claim 1 or 2, characterized in that: The unmanned ship is provided with a communication device, and the signal transmission directions undertaken by the communication device include information transmission between the unmanned ship and the unmanned aerial vehicle, information transmission between the unmanned ship and the ground workstation, and information transmission between the unmanned ship and the remote control system.

4. The large-scale bridge mobile drone inspection system based on ship-machine collaboration according to claim 3 is characterized in that: The unmanned ship and the drone communicate via 1.4G / 2.4G networking, the unmanned ship and the ground workstation communicate via 1.4G / 2.4G networking, and the unmanned ship and the remote control system communicate via 4G / 5G.

5. The large-scale bridge mobile drone inspection system based on ship-machine collaboration according to claim 1 is characterized in that: The laser module is a laser SLAM module. The tethered drone uses the laser SLAM module to scan the three-dimensional structure of the bottom of the bridge and locate its own relative position, and through multiple records, simultaneously obtains a laser point cloud three-dimensional model of the bottom structure of the bridge.

6. The large-scale bridge mobile drone inspection system based on ship-machine collaboration according to claim 1 is characterized in that: During the test process or in an emergency operation, onshore personnel can use the remote control to switch the drone to the emergency remote control channel and manually take over the operation of the tethered drone.

7. A mobile drone inspection solution for large bridges based on ship-machine collaboration, characterized in that: The following steps are involved: S1. The operator on the shore remotely controls the unmanned boat to the bottom of a certain bridge span and uses the system platform to record the position coordinates of the unmanned boat, which are obtained through the positioning system of the unmanned boat; S2. With the assistance of the surveillance camera on the unmanned boat, the drone is remotely controlled to take off to a suitable data collection position at the bottom of the bridge. During takeoff, the drone scans the three-dimensional structure of the bottom of the bridge with the help of the laser SLAM sensor. At the same time, the system platform records the flight trajectory, altitude, and gimbal angle parameters of the drone. S3. When the UAV reaches the preset data collection position, the system platform records the reference coordinate position of the UAV at this time, and associates this waypoint with the previously recorded position coordinates of the unmanned ship to form a preliminary route; S4. After the drone completes data collection, it lands on the unmanned boat, and then the unmanned boat moves to the bottom of the next bridge span and repeats the above steps until the waypoint marking work of all bridge spans is completed. During the whole process, the waypoint data is uploaded to the cloud platform in real time for storage and backup, and a laser point cloud 3D model of the bottom structure of the bridge is generated at the same time, providing basic data for subsequent inspections and analysis.

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