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CN-121979241-A - Bridge bottom inspection control method for autonomous flight without navigation and unmanned aerial vehicle control equipment

CN121979241ACN 121979241 ACN121979241 ACN 121979241ACN-121979241-A

Abstract

The invention discloses a navigation-free autonomous flying bridge bottom inspection control method and unmanned aerial vehicle-mounted control equipment, which respond to the acquisition of three-dimensional point cloud data of a bridge to be inspected, and selecting a bridge bottom inspection path through three-dimensional point cloud data planning, wherein the starting point of the bridge bottom inspection path is required to start from the outside of the bridge. Generating a bridge bottom inspection route based on the bridge bottom inspection route and executing inspection, wherein the inspection comprises bridge bottom navigation-free flight control, autonomous obstacle avoidance, top-simulated flight and inspection navigation point image acquisition. After the unmanned aerial vehicle flies out of the bridge, when the electric quantity of the unmanned aerial vehicle is too low or the unmanned aerial vehicle is triggered to return, the return route of the unmanned aerial vehicle is automatically called to execute the return task during return. The method can be operated on the light-weight embedded equipment with high efficiency, so that the unmanned aerial vehicle can realize real-time perception and real-time flight control of the bridge in the flight process, a more efficient and safe bridge bottom inspection flight control solution is provided, and the development of the unmanned aerial vehicle in the field of bridge inspection is promoted.

Inventors

  • LIU XIANGZHEN
  • XIANG MEIYUAN
  • LIU JIAQI
  • CHAI JINGYUN
  • ZHANG WENLONG

Assignees

  • 西安因诺航空科技有限公司

Dates

Publication Date
20260505
Application Date
20260121

Claims (10)

  1. 1. The bridge bottom inspection control method without navigation autonomous flight is characterized by being integrated in unmanned aerial vehicle-mounted control equipment and comprising the following steps, Step 1, responding to obtaining three-dimensional point cloud data of a bridge to be inspected; step 2, planning and selecting a bridge bottom inspection path through the three-dimensional point cloud data, wherein the starting point of the bridge bottom inspection path is required to start from the outside of the bridge; Step 3, generating a bridge bottom inspection route based on the bridge bottom inspection route and executing inspection, wherein the inspection comprises bridge bottom navigation-free flight control, autonomous obstacle avoidance, top-simulated flight and inspection navigation image acquisition; Step 4, after the unmanned aerial vehicle flies outside the bridge, the unmanned aerial vehicle is triggered to return to the voyage by manual work or the electric quantity of the unmanned aerial vehicle is too low; step 5, automatically calling a return route of the unmanned aerial vehicle to execute a return task during return; when the inspection is executed, an IMU inertial sensor built in the laser radar in the unmanned aerial vehicle control equipment is fused into laser inertial SLAM autonomous flight control so as to cope with the drift phenomenon after disconnection without satellite navigation.
  2. 2. The method for controlling bridge bottom inspection of navigation-free autonomous flight of claim 1, wherein in the step 1, a Xinjiang M350 unmanned aerial vehicle is matched with a Xinjiang Buddha's line L2 cradle head to record point clouds, then a Xinjiang intelligent graph is used for reconstructing three-dimensional point clouds from the result of the point clouds recording to obtain a three-dimensional point cloud model, and three-dimensional point cloud data are obtained according to the three-dimensional point cloud model.
  3. 3. The method for controlling bridge bottom inspection of navigation-free autonomous flight of claim 2, wherein when the bridge bottom inspection path is planned through three-dimensional point cloud data in the step 2, shooting point location intervals are not needed to be considered, geographic information system software is used for opening and reconstructing the three-dimensional point cloud data, and a required bridge bottom inspection path is selected from the three-dimensional point cloud data according to the set inspection distance.
  4. 4. The method for controlling the bridge bottom inspection of the unmanned aerial vehicle, which is characterized in that in the step 3, the bridge bottom inspection route is generated based on the inspection route, the length of the inspection route is calculated based on the bridge bottom inspection route, then the interval between the photographing waypoints is calculated by acquiring the field angle and the overlapping rate of a cloud platform camera arranged below the unmanned aerial vehicle body, and the interval between the photographing waypoints is utilized from the starting point to the ending point of the bridge bottom inspection route, and a plurality of inspection waypoints are generated one by one along the direction vector of the inspection route to form the bridge bottom inspection route.
  5. 5. The method for controlling the bottom inspection of the bridge in the autonomous fly without navigation according to claim 4, wherein the controlling the fly without navigation in the step 3 further comprises the following steps: Step 3.1.1, endowing a height value for the patrol waypoint, and calculating the target displacement between the patrol waypoint and the current unmanned aerial vehicle by taking the patrol waypoint as a target waypoint; step 3.1.2, calculating the residual distance from the current unmanned aerial vehicle to the target waypoint based on the target displacement; Step 3.1.3, judging whether the unmanned aerial vehicle is in a deceleration zone or an acceleration zone by utilizing the deceleration distance and the residual distance of the current speed of the unmanned aerial vehicle; Step 3.1.4, correcting the current speed according to the acceleration of the deceleration section and the acceleration section respectively so as to keep the current speed to fly at a constant speed; And 3.1.5, decomposing the corrected current speed into three speed components in the axial direction, and transmitting the three speed components to the virtual tele-bar to execute the flight of the unmanned aerial vehicle.
  6. 6. The method for controlling the bottom inspection of the bridge without navigation and autonomous flight of claim 5, further comprising the steps of: Step 3.2.1, acquiring radar point cloud data around the unmanned aerial vehicle through the laser radar; Step 3.2.2, filtering the radar point cloud data to remove all existing noise points; step 3.2.3, calculating the included angle between each point in the filtered radar point cloud data and the direction vector, and selecting points with included angles within a specific angle range to form an obstacle data set; Step 3.2.4, calculating Euclidean distances between each point of the obstacle data set and the center point of the laser radar, and taking the minimum value of the distances as the nearest distance of the obstacle in the specific direction; And 3.2.5, sequentially calculating the nearest distances of the obstacles in all directions, and feeding back in time to perform flight control.
  7. 7. The method for controlling the bottom inspection of the bridge, which is free of navigation and autonomous flight, according to claim 6, wherein in the step 3, the top flying behavior is simulated, the distance from the first navigation point of the unmanned aerial vehicle entering the bottom of the bridge to the bottom of the bridge is recorded as a reference distance, the distance from the unmanned aerial vehicle to the bottom of the bridge at a certain moment in the inspection process is recorded as a top distance, when the reference distance is larger than the top distance, the compensating height of the unmanned aerial vehicle needs to be far away from the bottom of the bridge, otherwise, the compensating height needs to be close to the bottom of the bridge, and finally the compensating height is added into the vertical components of the three speed components in the step 3.1.5.
  8. 8. The method for controlling the bridge bottom inspection of the autonomous flying without navigation according to claim 7, wherein the image of the inspection waypoint in the step 3 is acquired, the unmanned aerial vehicle calls a pan-tilt camera control interface of the unmanned aerial vehicle through a PSDK interface to trigger photographing after reaching each inspection waypoint, and the unmanned aerial vehicle sequentially moves to the next inspection waypoint after photographing is completed until all the inspection waypoints are photographed.
  9. 9. The method for controlling bridge bottom inspection of autonomous flying without navigation according to claim 8, wherein the laser inertial SLAM autonomous flying is characterized in that the relative motion quantity of an IMU between two scans of a laser radar is calculated, prior information of unmanned aerial vehicle attitude estimation is obtained through a Kalman filter, the unmanned aerial vehicle linear velocity is converted into an IMU coordinate system, a residual error is calculated through unmanned aerial vehicle linear velocity displacement and IMU prior estimation relative distance difference, and then the residual error and Kalman gain are substituted into a posterior state, and the motion trail of the unmanned aerial vehicle is obtained through superposition of the relative motion information.
  10. 10. The unmanned aerial vehicle-mounted control equipment for the bridge bottom inspection of the unmanned aerial vehicle without navigation autonomous flight is characterized by being arranged on the top of the unmanned aerial vehicle and comprising a laser radar, an edge calculation module and a coaxial line, wherein an inertial sensor IMU is integrated in the laser radar, the laser radar is used for sensing the distance from the bridge bottom and the surrounding environment in real time, the edge calculation module provides calculation force support for a bridge bottom inspection control method without navigation autonomous flight, the coaxial line is used for connecting the unmanned aerial vehicle-mounted control equipment to supply power to the unmanned aerial vehicle-mounted control equipment and can also be connected with the edge calculation module to realize communication between the edge calculation module and the unmanned aerial vehicle, and a cradle head camera is arranged below a body of the unmanned aerial vehicle and calls a cradle head camera control interface of the unmanned aerial vehicle through a PSDK interface to realize control.

Description

Bridge bottom inspection control method for autonomous flight without navigation and unmanned aerial vehicle control equipment Technical Field The invention belongs to the technical field of unmanned aerial vehicle application, and particularly relates to a bridge bottom inspection control method for autonomous flight without navigation and unmanned aerial vehicle-mounted control equipment. Background With the continuous promotion of the construction of the infrastructure of China, the number and the scale of various bridges are continuously increased. The bridge is used as an important transportation junction, and the safety condition of the bridge is directly related to the smoothness of transportation and the life and property safety of people. The bridge is used as an infrastructure which needs high importance, so that safe and reliable operation of the bridge is ensured, and comprehensive, timely and efficient inspection of the bridge is required to achieve the aim. According to statistics, the number of the existing bridges in China is millions, and the number of the bridges newly increased each year is considerable. In these bridges, the bridge bottom is often a high incidence of safety hazards due to its special location and complex structure. The bridge bottom structure is exposed in natural environment for a long time, is influenced by various factors such as wind and rain erosion, vehicle collision, ship impact and the like, and is easy to cause problems such as cracks, flaking, rust and the like. Once these problems are not timely discovered and addressed, serious safety accidents, such as bridge collapse, etc., may be initiated. Traditional bridge bottom inspection mainly relies on the manual work to carry out, and inspection personnel need to be close to the bridge bottom with the help of equipment such as ship, hanging flower basket to inspect. But this approach is not only inefficient, but also presents a significant safety risk. Meanwhile, the accuracy of manual inspection is difficult to guarantee due to complex bridge bottom environment. However, with the continuous advancement of infrastructure construction, the number and scale of bridges continue to increase, which puts tremendous strain on inspection and maintenance of bridges. In addition, some bridges are located in remote areas or places with inconvenient traffic, and the difficulty and cost of manual inspection are higher. The rapid development of unmanned aerial vehicle technology brings new opportunities for bridge bottom inspection. As the unmanned aerial vehicle has the advantages of flexibility, low cost, high efficiency and the like, the unmanned aerial vehicle can quickly reach the bottom of the bridge for inspection. At present, although some unmanned aerial vehicles are applied to bridge inspection, most of the unmanned aerial vehicles rely on satellite navigation systems for flight control. However, due to the complex environment of the bridge bottom and large signal interference, the satellite navigation system often cannot work normally at the bridge bottom, which brings great challenges to the autonomous flight control of the unmanned aerial vehicle. Therefore, there is a need for a bridge bottom inspection control method that enables an unmanned airborne control device to achieve autonomous flight in an environment without satellite navigation signals. Disclosure of Invention The summary of the application is provided to introduce a selection of concepts in a simplified form that are further described below in the detailed description. The summary of the application is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter. Aiming at the problems and the defects existing in the prior art, the invention aims to provide a navigation-free autonomous flying bridge bottom inspection control method and unmanned aerial vehicle control equipment, which realize autonomous flying control and accurate inspection of an unmanned aerial vehicle in a bridge bottom environment without satellite navigation signals by taking the unmanned aerial vehicle control equipment as a core, taking an unmanned aerial vehicle body as a carrier, taking an unmanned aerial vehicle laser radar and a tripod head camera as main sensors, and provide powerful technical support for safety management of a bridge. To solve the problems set forth in the background art. In order to achieve the above purpose, the present invention provides the following technical solutions: As a first aspect of the present application, the present application discloses a method for controlling a bridge bottom patrol of a non-navigational autonomous flight, the method being integrated in an unmanned aerial vehicle control device, comprising the steps of, Step 1, responding to obtaining three-dimensional point cloud data of a bridge to be inspected; step 2, planning