Unmanned aerial vehicle surveying and mapping information acquisition method and system

Abstract

The invention relates to the technical field of unmanned aerial vehicle surveying and mapping control, in particular to an unmanned aerial vehicle surveying and mapping information acquisition method and system. According to the technical scheme, the task data and the flight acceleration of the surveying and mapping task executed by the unmanned aerial vehicle are obtained, the flight acceleration represents the flight state of the unmanned aerial vehicle, and course monitoring and course adjustment can be performed on the unmanned aerial vehicle according to the obtained flight acceleration, so that the unmanned aerial vehicle is located on the target path of the surveying and mapping task as much as possible; the influence of yaw on surveying and mapping precision is reduced; meanwhile, when the unmanned aerial vehicle is disturbed by airflow and yaws in the target path, determining that the task data obtained in the yawing state is abnormal data; correcting the abnormal data according to the flight acceleration in the yaw state to obtain corrected task data; the surveying and mapping information of the surveying and mapping task is obtained according to the corrected task data and the task data obtained in the non-yaw state, and the technical scheme improves the accuracy of the obtained surveying and mapping information.

Description

Technical Field

[0001] The present invention relates to the technical field of unmanned aerial vehicle (UAV) surveying and mapping control, and in particular to a method and system for collecting UAV surveying and mapping information. Background Art

[0002] Drone mapping refers to the process of aerial measurement and data collection by drones through various sensor devices carried by drones. Drones can efficiently and accurately obtain surface image information and geospatial data from the air. These data can be used to generate maps, digital models, conduct environmental monitoring, resource management, urban planning, etc., providing more accurate, efficient and secure spatial data solutions for various industries and application scenarios.

[0003] Drone mapping has the advantages of convenience, speed and low cost, but the stability of drones is easily affected by air disturbances, which can cause the drone to be unstable or even deviate from its route. When the drone is in a place where the GPS (Global Positioning System) signal is weak, the drone’s position cannot be accurately located. Under the influence of air disturbances, the collected ground position and height information will be inaccurate, which will affect the accuracy of drawing topographic maps. Summary of the invention

[0004] In order to solve the technical problem of how to accurately obtain surveying and mapping information under airflow disturbance, the purpose of the present invention is to provide a method and system for collecting surveying and mapping information by unmanned aerial vehicles, which reduces the influence of airflow disturbance factors on the performance of surveying and mapping tasks by unmanned aerial vehicles, and makes the obtained surveying and mapping information more accurate. The technical solutions adopted are as follows: In a first aspect, an embodiment of the present invention provides a method for collecting surveying and mapping information by an unmanned aerial vehicle, the method comprising: Obtaining the mission data and flight acceleration of the UAV performing the surveying and mapping mission, wherein the mission data includes the longitude position, latitude position and corresponding altitude measurement height of the UAV; The UAV is monitored and adjusted in heading according to the acquired flight acceleration, so that the UAV is on the target path of the surveying and mapping mission; When the UAV is disturbed by airflow and deviates from the target path, it is determined that the mission data obtained in the deviated state is abnormal data; Correct the abnormal data according to the flight acceleration in the yaw state to obtain the corrected mission data; The surveying and mapping information of the surveying and mapping task is obtained based on the corrected task data and the task data obtained when the task is not in the yaw state.

[0005] In an optional embodiment, the heading monitoring and heading adjustment of the UAV is performed according to the acquired flight acceleration, including: Determine whether the drone is in a yaw state based on the monitored flight acceleration and the preset accelerator range; When the UAV is in a yaw state, the correction angle of the UAV and the current flight energy of the current control cycle are obtained according to the historical flight energy of the UAV in the previous control cycle and the flight acceleration of the yaw state; The UAV is steered according to the correction angle and current flight energy until it reaches the target path.

[0006] In an optional embodiment, the correction angle of the drone and the current flight energy of the current control cycle are obtained according to the historical flight energy of the drone in the previous control cycle and the flight acceleration of the yaw state, including: The flight acceleration in the yaw state is orthogonally decomposed on the orthographic projection plane of the UAV to obtain a first acceleration of the UAV on the target path and a second acceleration perpendicular to the target path; Obtaining an energy correction value of a yaw state according to the flight acceleration, the first acceleration and the second acceleration of the UAV in a heading state; The current flight energy is obtained by correcting the historical flight energy according to the energy correction value; The correction angle is obtained according to the tangent angle between the first acceleration and the second acceleration.

[0007] In an optional embodiment, the abnormal data is corrected according to the flight acceleration in the yaw state to obtain the corrected mission data, including: Determining a flight deviation state of the UAV according to the flight acceleration in the yaw state, wherein the flight deviation state includes flight lag or flight advance on the target path; Correct the longitude and latitude positions in the acquired abnormal data according to the flight accelerations of different flight deviation states to obtain the mission longitude and latitude of the UAV on the target path; According to the flight acceleration in the yaw state, the offset distance and offset angle of the UAV in the vertical ground direction are determined; Correct the initial measurement value in the acquired abnormal data according to the offset distance and the offset angle to obtain the altitude measurement height of the UAV on the target path; The mission longitude, mission latitude and corresponding altitude measurement height are determined as the mission data for completion correction.

[0008] In an optional embodiment, the longitude position and latitude position in the acquired abnormal data are corrected according to the flight acceleration of different flight deviation states to obtain the mission longitude and mission latitude of the UAV on the target path, including: When the flight offset state is flight advance, the advance offset of the UAV is obtained according to the flight acceleration, cycle duration and flight speed of the adjacent monitoring cycles; According to the correction result of the longitude position and the latitude position in the abnormal data by the advance offset, the first mission longitude and the first mission latitude of the UAV are obtained; When the flight offset state is flight hysteresis, the hysteresis offset of the UAV is obtained according to the flight acceleration, cycle duration and flight speed of adjacent monitoring cycles; According to the correction result of the longitude position and the latitude position in the abnormal data by the hysteresis offset, the second mission longitude and the second mission latitude of the UAV are obtained.

[0009] In an optional embodiment, after obtaining the lead offset or the hysteresis offset of the drone, the method further includes: According to the formula Get offset confidence , is the amount of acceleration data obtained in the flight deviation state, is the i-th flight acceleration in the flight offset state, is the i+1th flight acceleration in the flight deviation state, is the normalization function; The lead offset or the hysteresis offset is updated according to the offset credibility to obtain the actual offset of the flight offset state.

[0010] In an optional embodiment, determining the offset distance and offset angle of the UAV in a direction vertical to the ground according to the flight acceleration in the yaw state includes: According to the flight acceleration of the UAV on the target path in the yaw state, the path deviation of the UAV is obtained; According to the flight acceleration of the UAV in the vertical direction in the yaw state, the vertical offset of the UAV is obtained; According to the path offset and vertical offset, the offset distance of the UAV is obtained; The offset angle of the drone is obtained based on the sine angle of the vertical offset and the path offset.

[0011] In an optional embodiment, obtaining the offset distance of the drone according to the path offset and the vertical offset includes: According to the formula , get the offset distance ,in, is the path offset, is the vertical offset, is the first credibility of the path offset, is the second reliability of the vertical offset.

[0012] In an optional embodiment, correcting the initial measurement value in the acquired abnormal data according to the offset distance and the offset angle to obtain the altitude measurement height of the UAV on the target path includes: According to the offset distance and the offset angle, a first vertical offset of laser emission and a second vertical offset of laser reception are obtained when the UAV performs ground ranging; An altitude measurement height is obtained according to the initial measurement value, the first vertical offset and the second vertical offset.

[0013] In a second aspect, an embodiment of the present invention further provides a UAV surveying and mapping information collection system, the system comprising: A data collection terminal is used to obtain the mission data and flight acceleration of the UAV performing the surveying and mapping mission, wherein the mission data includes the longitude position, latitude position and corresponding altitude measurement height of the UAV; A control terminal is connected to the data acquisition terminal. The control terminal is used to monitor and adjust the heading of the UAV according to the acquired flight acceleration so that the UAV is on the target path of the surveying and mapping task; A data processing terminal is connected to the data acquisition terminal. The data processing terminal is used to determine that the mission data acquired in the yaw state is abnormal data when the UAV is disturbed by airflow and deviates from the target path; The data processing terminal is also used to correct abnormal data according to the flight acceleration in the yaw state to obtain corrected mission data; The data processing terminal is also used to obtain surveying and mapping information of the surveying and mapping task based on the task data that has been corrected and the task data that is obtained when not in a yaw state.

[0014] The present invention has the following beneficial effects: The technical solution of the present invention obtains the mission data and flight acceleration of the UAV performing the surveying and mapping mission. The flight acceleration characterizes the flight state of the UAV. The UAV can be monitored and adjusted in heading according to the obtained flight acceleration, so that the UAV is as close to the target path of the surveying and mapping mission as possible, thereby reducing the influence of yaw on the surveying and mapping accuracy. At the same time, when the UAV is disturbed by airflow and deviates from the target path, the mission data obtained in the yaw state is determined to be abnormal data. The abnormal data is corrected according to the flight acceleration in the yaw state to obtain the corrected mission data. The surveying and mapping information of the surveying and mapping mission is obtained according to the corrected mission data and the mission data obtained when the UAV is not in the yaw state. Since the abnormal data is corrected, the influence of airflow disturbance on the surveying and mapping accuracy is further reduced, so that the UAV can comprehensively collect data in the area where the surveying and mapping mission is located, so that the obtained surveying and mapping information is accurate and reliable, thereby improving the accuracy of the surveying and mapping information. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solutions and advantages in the embodiments of the present invention or the prior art, the drawings required for use in the embodiments or the prior art descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0016] Figure 1 A flowchart of a method for collecting UAV surveying and mapping information provided by one embodiment of the present invention; Figure 2 A first schematic diagram of a UAV implementing heading adjustment provided by an embodiment of the present invention; Figure 3 A second schematic diagram of a UAV implementing heading adjustment provided by an embodiment of the present invention; Figure 4 A schematic diagram of a flight deviation state as flight hysteresis provided by an embodiment of the present invention; Figure 5 A schematic diagram of a flight deviation state of flight advance provided by an embodiment of the present invention; Figure 6 A schematic diagram of initial measurement value correction provided by an embodiment of the present invention; Figure 7 A schematic structural diagram of an unmanned aerial vehicle surveying and mapping information collection system provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0017] In order to further explain the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the following is a detailed description of the specific implementation method, structure, features and effects of a method and system for collecting information from unmanned aerial vehicle surveying and mapping proposed by the present invention in combination with the accompanying drawings and preferred embodiments. In the following description, different "one embodiment" or "another embodiment" does not necessarily refer to the same embodiment. In addition, specific features, structures or characteristics in one or more embodiments may be combined in any suitable form.

[0018] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

[0019] The specific scheme of the UAV surveying and mapping information collection method and system provided by the present invention is described in detail below with reference to the accompanying drawings.

[0020] See also Figure 1 , which shows a flow chart of a method for collecting UAV surveying and mapping information provided by an embodiment of the present invention, the method specifically includes: S11. Obtaining mission data and flight acceleration of the UAV performing a surveying and mapping mission, wherein the mission data includes the longitude position, latitude position and corresponding altitude measurement height of the UAV.

[0021] Specifically, mapping tasks refer to tasks that use drones to obtain geographic data for the purpose of creating maps or conducting geographic information analysis. Mapping tasks can be used as a reference in areas such as land planning, environmental monitoring, or urban construction. The data collected by drones during mapping tasks include longitude position, latitude position, and altitude. These data help determine the geographic location and altitude of the drone during flight. The longitude position and latitude position can represent the geographic location of the drone on the surface of the earth, while the altitude measurement indicates the vertical distance of the drone relative to sea level.

[0022] Acquiring mission data can be achieved through the drone's built-in global positioning system (or GPS) and altimeter. The GPS module provides accurate longitude and latitude positions, while the altimeter measures the altitude of the drone to obtain the altitude measurement height. This information is transmitted to the ground control center in real time through the drone's data transmission system. Flight acceleration is obtained through the accelerometer (or acceleration sensor) on the drone. The accelerometer can monitor the acceleration changes of the drone along each axis during flight in real time, which is crucial for analyzing the flight stability of the drone and performing precise tasks. Acceleration data helps monitor the motion status of the drone, ensuring the accuracy of its flight path and the successful execution of the mapping mission.

[0023] It is understandable that the use of drone mapping technology to draw topographic maps is mainly based on the measured altitude of each ground location. Therefore, a lidar sensor can also be installed on the drone to obtain the measured altitude by emitting lasers to the ground and receiving the laser signals reflected from the ground, and obtain the flight direction data of the drone based on the gyroscope on the drone. Since it is necessary to analyze the situation of the drone encountering strong winds based on the acceleration changes during the drone's navigation, it is also necessary to install an accelerometer on the drone to monitor the acceleration of the drone in the horizontal and vertical directions respectively. The monitoring frequency of the acceleration sensor is 100Hz. According to the time required for a laser to be emitted and received once, the ground height data is collected every 10s to obtain the measured altitude.

[0024] S12. Monitor and adjust the heading of the UAV according to the acquired flight acceleration, so that the UAV is on the target path of the surveying and mapping task.

[0025] Specifically, when a drone performs surveying and mapping tasks, flight acceleration data is crucial for heading monitoring and adjustment. Flight acceleration is measured in real time by the accelerometer on the drone, which provides the acceleration of the drone in the front, back, left, right, and up and down directions. The acceleration data can be used to calculate the instantaneous speed and direction of movement of the drone, and then deduce the degree of deviation of its actual heading from the target path.

[0026] Heading monitoring involves converting flight acceleration into the UAV's velocity information and calculating the UAV's heading angle in combination with its current position and the predetermined path of the mapping mission. If the actual heading of the UAV is found to deviate from the target path, the UAV's control system will detect this deviation and make corresponding heading adjustments. The adjustment process involves changing the UAV's flight attitude or direction, such as by adjusting the speed or direction of the blades to correct the heading deviation. This adjustment helps the UAV correct its flight trajectory to ensure that it flies along the target path. In order to maintain the accuracy of the heading, the UAV needs to make continuous dynamic corrections. The flight control system monitors the acceleration data in real time and continuously adjusts the heading according to the actual flight status. This dynamic adjustment mechanism enables the UAV to continuously correct its heading during flight to ensure the accurate execution of the mapping mission.

[0027] Exemplarily, step S12 includes sub-steps S12-1 to S12-3, which are specifically described as follows: S12-1. Determine whether the drone is in a yaw state based on the monitored flight acceleration and the preset accelerator interval. The accelerator interval can be set based on the surveying accuracy of the surveying task, or it can be set based on the adjustment requirements of the drone's flight attitude. When the flight acceleration is in the accelerator interval, it means that the drone is flying normally, and it is determined that the drone is not yawed, and the drone is controlled to continue to perform the surveying task; on the contrary, when the flight acceleration is not in the accelerator interval, it means that the drone is greatly affected by the airflow disturbance, and it is determined that the drone is in a yaw state.

[0028] When the drone performs mapping tasks normally, its flight acceleration will be maintained within a small range to ensure the accuracy of the ground data collected by the lidar sensor. When the drone encounters airflow disturbances under strong winds, the flight acceleration of the drone will increase or decrease in a short period of time, making the flight acceleration of the drone differ greatly from the flight acceleration under normal circumstances. Therefore, the box plot can be used to determine the normal range of horizontal and vertical acceleration of the drone during the process of collecting ground data. and When the acceleration of the drone exceeds this range, it is considered that the drone is affected by airflow disturbance and is determined to be in a yaw state.

[0029] S12-2, when the UAV is in a yaw state, the correction angle of the UAV and the current flight energy of the current control cycle are obtained according to the historical flight energy of the UAV in the previous control cycle and the flight acceleration of the yaw state. The correction angle is the flight adjustment angle of the UAV from the yaw state to the heading state. The heading state is the state of the UAV normally mapping on the target path of the mapping task. The calculation model can be set based on the data processing requirements, the historical flight energy and flight acceleration are input into the calculation model, and the correction angle and current flight energy are obtained based on the output results of the calculation model.

[0030] In practical applications, training and verification based on the computational model will consume a lot of time and energy. Based on this, in a specific implementation, sub-step S12-2 includes: In the first step, the flight acceleration in the yaw state is orthogonally decomposed on the orthographic projection plane of the drone (i.e., the horizontal direction of the ground) to obtain the first acceleration of the drone on the target path and the second acceleration perpendicular to the target path. Figure 2 and Figure 3 In the figure, D1 is the direction of the drone in the forward heading state, D2 is the direction of the airflow disturbance, and D3 is the direction in which the drone implements heading correction. It can be seen that in order to maintain the forward heading state, the flight power after adjustment in the forward heading state should be the difference between the original flight power and the wind force of the airflow disturbance in the original flight direction. If the wind is against the flight direction of the drone, the wind force is negative. In the direction perpendicular to the original flight direction, the adjusted flight power should just be able to offset the wind force of the airflow disturbance in that direction (here the right side of the original flight direction is defined as the positive direction of the vertical direction).

[0031] The power of the drone can be measured by its acceleration in the forward heading state. Indicates that, since the drone needs to keep flying at a constant speed in the normal flight state, the average acceleration in the normal flight state is 0, that is, . The acceleration in the yaw state Decomposed into acceleration along the original flight direction ; Acceleration perpendicular to the original flight direction Then the wind force of the airflow disturbance in these two directions can be expressed as: in, It indicates the change in the acceleration of the drone caused by the airflow disturbance in the original flight direction. It represents the change in the acceleration of the drone caused by the airflow disturbance in the direction perpendicular to the original flight direction. Indicates the value of abnormal acceleration in the original flight direction, Indicates the value of abnormal acceleration perpendicular to the original flight direction. Indicates the acceleration of the drone in normal state, that is It is the flight acceleration in the normal heading state.

[0032] Then, the drone's own acceleration in two directions should be adjusted to: in, It indicates the flight acceleration of the drone in the original flight direction after the acceleration of the drone itself is adjusted. It indicates the flight acceleration of the drone in a direction perpendicular to the original flight direction after its own acceleration is adjusted, that is, the second acceleration.

[0033] The second step is to obtain the energy correction value of the yaw state according to the flight acceleration, the first acceleration and the second acceleration of the UAV in the normal flight state. The energy correction value can be determined based on a preset corresponding relationship table or based on a calculation model. For example, by the formula Get the energy correction value k, is the flight acceleration in the normal flight state, for , for ; In the formula Indicates the total acceleration of the drone itself after adjustment.

[0034] The third step is to obtain the current flight energy based on the correction result of the historical flight energy by the energy correction value. The current flight energy can be obtained based on the product of the energy correction value and the historical flight energy, that is, ,in, is the current flight energy, k is the energy correction value, 0 is the historical flight energy.

[0035] The fourth step is to obtain the correction angle according to the tangent angle between the first acceleration and the second acceleration. The correction angle is set as , you can get the adjusted flight direction of the drone: , It represents the angle between the adjusted flight direction and the original flight direction.

[0036] S12-3. Correct the course of the drone according to the correction angle and current flight energy until the drone flies to the target path. The correction angle is the angular difference between the actual course of the drone and the target path. The drone calculates the required adjustment amount based on this angle; the battery power and motor output power of the drone can be determined by the current flight energy. According to the correction angle, the drone controller will issue an adjustment command to correct the course by changing the flight attitude and power output. Through continuous monitoring and adjustment, the drone will eventually fly accurately to the target path.

[0037] Based on the above method, the heading of the drone can be corrected as much as possible to keep it on the target path. However, due to the uncertainty of airflow disturbance during the flight of the drone, strong airflow disturbance will still cause the drone to deviate. When the drone deviates, step S13 is entered.

[0038] S13. When the UAV is disturbed by airflow and deviates from the target path, it is determined that the mission data obtained in the deviated state is abnormal data.

[0039] Specifically, the yaw state is the state in which the actual flight direction of the drone deviates from the target path. In the yaw state, the sensor data of the drone may be abnormally affected. For example, the measurements of longitude, latitude and altitude may fluctuate inaccurately. The abnormal performance of these data is usually due to flight instability caused by airflow disturbances, which makes the sensor unable to accurately capture the true position and altitude of the drone. In this case, the acquired mission data is regarded as abnormal data. This is because these data cannot accurately reflect the true state of the drone, thereby affecting the accuracy of the surveying and mapping results. In order to deal with this problem, it is usually necessary to process these abnormal data through data correction or filtering technology. For example, combining historical data and expected flight trajectories, algorithms can be used to filter out data fluctuations caused by airflow disturbances, thereby improving the reliability of the data.

[0040] S14. Correct the abnormal data according to the flight acceleration in the yaw state to obtain corrected mission data.

[0041] Specifically, under normal circumstances, the flight acceleration of the drone should be kept within a small range during the process of collecting altitude measurements. However, when the drone encounters airflow disturbances, the acceleration of the drone will increase or decrease significantly. Therefore, the impact of the drone encountering airflow disturbances can be analyzed based on the changes in the flight acceleration of the drone. According to the real-time monitoring of the flight acceleration changes, the flight deviation of the drone during the flight adjustment process is analyzed, and the real position information of the drone is obtained, and the collected ground position and altitude data are corrected.

[0042] It is understandable that the UAV power adjustment process requires a certain amount of time. When the UAV power is not balanced with the airflow disturbance, the UAV will still be affected by the airflow disturbance and deviate from the route. Therefore, it is necessary to obtain the real-time position of the UAV at each monitoring moment based on the deviation distance relative to the original flight position during the UAV power adjustment process. The original flight position is the position of the UAV at the last acceleration monitoring moment. When the GPS signal of the UAV is good before this, the position of the UAV is obtained according to the GPS positioning information at the last acceleration monitoring moment; if the UAV continues to be in a position where the GPS signal is weak or there is no signal, the UAV position is calculated based on the change in the flight direction of the UAV monitored by the gyroscope, and the acceleration and deceleration process of the UAV during the flight monitored by the accelerometer. Similarly, the correction coefficient of the abnormal data can be determined based on the flight acceleration in the yaw state, and the abnormal data is corrected by the correction coefficient to obtain the corrected mission data.

[0043] Exemplarily, step S14 includes sub-steps S14-1 to S14-5, which are specifically described as follows: S14-1. Determine the flight deviation state of the UAV according to the flight acceleration in the yaw state, wherein the flight deviation state includes flight hysteresis or flight advance on the target path. Flight hysteresis refers to the lag of the actual flight position of the UAV relative to the target position of the target path, which usually occurs when the flight acceleration of the UAV is insufficient. Please refer to Figure 4 When the wind direction is against the flight direction of the drone, the speed of the drone will gradually decrease under the influence of airflow disturbance, and it may even move backwards. Therefore, the power of the drone itself should gradually increase in this direction, that is, the drone performs a deceleration motion with decreasing acceleration in this direction.

[0044] On the other hand, flight ahead means that the actual flight position of the UAV is ahead of the target path, that is, the UAV exceeds the expected target position on the target path. Figure 5 When the wind direction is along the flight direction of the drone, the drone will be blown to a farther position under the influence of air flow disturbance, so the drone's own power in this direction should gradually decrease, that is, the drone performs an accelerated motion with decreasing acceleration in this direction.

[0045] S14-2, correct the longitude position and latitude position in the acquired abnormal data according to the flight acceleration of different flight offset states to obtain the mission longitude and mission latitude of the UAV on the target path. Under different flight offset states, it is necessary to implement corresponding corrections to the abnormal data, the mission longitude is the longitude after the correction is implemented to the longitude position in the abnormal data, and the mission latitude is the latitude after the correction is implemented to the latitude position in the abnormal data. The flight acceleration can determine the offset of the UAV on the target path, and then implement corresponding corrections to the longitude position and latitude position. Further, sub-step S14-2 includes implementation in the following manner.

[0046] The first step is to obtain the UAV's advance offset based on the flight acceleration, cycle duration and flight speed of the adjacent monitoring cycles when the flight offset state is flight advance. The advance offset is the advance distance between the UAV's current flight position and the target position on the target path. Since the heading correction adjustment will be performed each time there is an abnormality in the monitored acceleration, the offset of the UAV in the time interval between the two monitored flight accelerations is calculated to obtain the advance offset. In the time interval between the two flight acceleration monitoring, the offset of the UAV relative to the original position in the direction of the target path is: in, is the advance offset, which represents the offset of the UAV relative to the original flight position in the original flight direction; is the flight speed, which represents the flight speed of the UAV before it is affected by the airflow disturbance; is the cycle duration, which characterizes the flight acceleration monitoring time interval of the UAV; Indicates the flight acceleration along the target path at the previous monitoring moment; Indicates the flight acceleration along the target path at the next monitoring moment.

[0047] The second step is to obtain the first mission longitude and latitude of the UAV based on the correction result of the longitude and latitude in the abnormal data by the advance offset. The target path is known. After the advance offset is obtained, the longitude and latitude during the flight advance can be corrected based on the advance offset to obtain the first mission longitude and latitude. The first mission longitude and latitude are the longitude and latitude of the UAV at the expected target position.

[0048] The third step is to obtain the hysteresis offset of the drone based on the flight acceleration, cycle duration and flight speed of the adjacent monitoring cycles when the flight offset state is flight hysteresis. Similarly, the calculation process is the same as when the wind direction is along the flight direction of the drone. The hysteresis offset can be obtained based on the flight acceleration, cycle duration and flight speed. .

[0049] The fourth step is to obtain the second mission longitude and latitude of the drone based on the correction result of the longitude and latitude in the abnormal data by the hysteresis offset. Similarly, the second mission longitude and the second mission latitude are the longitude and latitude of the drone at the expected target position when the drone is in flight hysteresis.

[0050] In practical applications, since the change range of flight acceleration reflects the stability change characteristics of the drone, although the lead offset and hysteresis offset can be obtained based on the above method, too large a change range may cause insufficient accuracy of the calculation. Based on this, in a specific implementation, after obtaining the lead offset or hysteresis offset of the drone, the method further includes: According to the formula Get offset confidence , The amount of acceleration data obtained in the flight deviation state, the unit is the number of flight acceleration data; is the i-th flight acceleration in the flight offset state, i is a natural number, is the i+1th flight acceleration in the flight deviation state, is a normalized function; the advance offset or hysteresis offset is updated according to the offset credibility to obtain the actual offset of the flight offset state. It can be understood that when the drone collects ground data, the more the acceleration of the drone shows a decreasing trend during flight, the more stable the drone is before collecting data, that is, the offset data obtained should be more accurate; if the flight acceleration of the drone fluctuates greatly or shows an increasing trend during this process, it means that the stability of the drone is poor during this process, and the offset credibility obtained is low. Therefore, according to the acceleration change trend of the drone, the credibility of the offset can be calculated. The offset credibility characterizes the credibility of the corresponding advance offset or hysteresis offset obtained when the drone is in a flight advance or flight hysteresis flight offset state. It can be represented by a percentage, and the product of the offset credibility and the initial advance offset or initial hysteresis offset is obtained to obtain the updated advance offset or hysteresis offset.

[0051] So far, the deviation correction of the drone in the horizontal direction of the ground has been completed. However, in the actual flight process, the drone also has deviations in the vertical direction of the target path. The following will explain the deviation correction of the drone perpendicular to the target path.

[0052] S14-3. Determine the offset distance and offset angle of the UAV in the vertical ground direction according to the flight acceleration in the yaw state. When the UAV is in the yaw state, the monitored flight acceleration can be orthogonally decomposed in the horizontal direction of the ground and the vertical direction of the ground to obtain the flight acceleration in the vertical direction of the ground. The offset distance and offset angle are obtained based on the flight acceleration in the vertical direction of the ground. The offset distance is the deviation between the UAV's position in the vertical direction of the ground and the expected target position on the target path. The offset angle is the angle between the direction of the offset distance and the vertical direction. The specific implementation of sub-step S14-3 will be described in detail below. Specifically including: The first step is to obtain the path offset of the drone based on the flight acceleration of the drone on the target path in the yaw state. The path offset is the offset of the drone on the target path, which can be a lead offset or a hysteresis offset, and represents the offset of the drone in the horizontal direction of the ground.

[0053] The second step is to obtain the vertical offset of the drone based on the vertical acceleration of the drone in the yaw state. Since the drone has no speed and acceleration in the vertical direction of the original flight direction under normal circumstances, if the drone is displaced in this direction, it is the offset in this direction. The offset of the drone in this direction can be calculated based on the average acceleration of the drone during the time interval of monitoring acceleration: in, is the vertical offset, which indicates the offset of the UAV in the vertical direction of the original flight direction during the current acceleration monitoring time interval; It indicates the flight acceleration of the UAV in the vertical direction of the original flight direction at the next monitoring moment. It indicates the flight acceleration of the UAV in the vertical direction of the original flight direction at the previous monitoring moment. Indicates the time interval between adjacent flight acceleration monitoring.

[0054] The third step is to obtain the offset distance of the drone based on the path offset and vertical offset. The offset distance can be calculated based on the Pythagorean theorem. The offset distance is the distance between the target position and the position of the drone in the vertical direction of the ground, which is equivalent to solving the hypotenuse defined by the Pythagorean theorem. The path offset and vertical offset are the right angle sides respectively.

[0055] In order to further improve the accuracy of offset distance calculation, according to the formula , get the offset distance ,in, is the path offset, is the vertical offset, is the first credibility of the path offset, The first credibility and the second credibility can also be determined based on the calculation method of the above-mentioned offset credibility, which will not be described in detail here.

[0056] The fourth step is to obtain the offset angle of the drone based on the sine angle of the vertical offset and the path offset. The offset angle is recorded as , , is the vertical offset, is the path offset; path offset Lead offset or hysteresis offset .

[0057] S14-4, correcting the initial measurement value in the acquired abnormal data according to the offset distance and the offset angle to obtain the altitude measurement height of the UAV on the target path. The initial measurement value can be the altitude of the UAV measured by an altimeter or the measurement result of laser ranging. A calculation model can be constructed to implement the correction of the initial measurement value to obtain an accurate altitude measurement height.

[0058] Under normal circumstances, when performing surveying and mapping tasks, drones basically maintain the same altitude to measure ground height. If strong winds have a vertical component, the instability of the wind will also cause large fluctuations in the drone, resulting in inaccurate measured height data. Therefore, it is necessary to correct the ground height data affected by strong winds according to the impact of strong winds. The basic principle is to first calculate the vertical offset of the drone on the ground after the strong wind, and then calculate the vertical offset of the drone on the ground at the time of the laser radar after the strong wind. And the vertical offset of the ground when receiving the laser radar , if the drone deviates upward, the offset is positive; if the drone deviates downward, the offset is negative; finally, the accurate altitude measurement height is calculated. The specific explanation is as follows: The first step is to obtain the first vertical offset of laser emission and the second vertical offset of laser reception when the UAV performs ground ranging according to the offset distance and offset angle. Figure 6 , The first vertical offset is the altitude of the drone set in the surveying task. Characterizes the vertical deviation of the drone from the ground when the laser is emitted, the second vertical offset It characterizes the height deviation of the UAV in the vertical direction on the ground when the laser is received. The first vertical offset and the second vertical offset can be obtained by performing trigonometric analysis based on the corresponding offset distance and offset angle.

[0059] The altitude measurement height is obtained based on the initial measurement value, the first vertical offset and the second vertical offset. From the time the laser signal is emitted to the time the signal is received, the distance the intermediate laser signal travels is used to calculate the ground height data that should be measured at this location at a normal drone altitude: in, Indicates the ground height data that should be measured at this location at a normal drone altitude. Indicates the total distance traveled by the laser during the measurement process. is the first vertical offset, is the second vertical offset, is the speed of laser propagation, Indicates the time interval between emitting a laser signal and receiving the reflected laser signal.

[0060] Then calculate the measured ground altitude based on the original set altitude of the drone flight: in, Complete the corrected altitude measurement, Indicates the original altitude at which the drone is set to fly. Indicates the ground height data that should be measured at this location at a normal drone altitude. This allows accurate measurement of all altitudes of the drone in a yaw state.

[0061] At this point, the deviation correction of the drone in the vertical direction on the ground has been completed.

[0062] S14-5, determining the mission longitude, mission latitude and corresponding altitude measurement height as the mission data for completing the correction. In order to implement accurate abnormal data correction, the embodiment of the present invention performs data analysis and processing from two dimensions: horizontal direction and vertical direction of the ground. The obtained mission longitude, mission latitude and corresponding altitude measurement height have good accuracy.

[0063] S15. Obtaining surveying and mapping information of the surveying and mapping task according to the corrected task data and the task data acquired when the task is not in the yaw state.

[0064] Specifically, the task longitude and latitude are the corrections and longitude positions and latitude positions. Each longitude position and latitude position is matched with the corresponding altitude measurement height to obtain the surveying and mapping information of the surveying and mapping task. It can be understood that the surveying and mapping information represents the accurate task data in the surveying and mapping task, and the surveying and mapping information can be used to implement land planning, environmental monitoring or urban construction. For example, a digital elevation model (DEM) is used to draw a topographic map of the information collection area.

[0065] Based on the same technical concept as the acquisition method, the embodiment of the present invention also provides a UAV surveying and mapping information acquisition system, please refer to Figure 7 , Figure 7 The system includes a data acquisition terminal 701, a control terminal 702 and a data processing terminal 703.

[0066] The data acquisition terminal is used to obtain the mission data and flight acceleration of the UAV performing the surveying and mapping mission, wherein the mission data includes the longitude position, latitude position and corresponding altitude measurement height of the UAV; The control terminal is connected to the data acquisition terminal, and the control terminal is used to monitor and adjust the heading of the UAV according to the acquired flight acceleration, so that the UAV is on the target path of the surveying and mapping task; The data processing terminal is connected to the data acquisition terminal, and the data processing terminal is used to determine that the mission data acquired in the yaw state is abnormal data when the UAV is disturbed by airflow and deviates from the target path; The data processing terminal is also used to correct abnormal data according to the flight acceleration in the yaw state to obtain corrected mission data; The data processing terminal is also used to obtain surveying and mapping information of the surveying and mapping task based on the task data that has been corrected and the task data that is obtained when not in a yaw state.

[0067] The technical solution provided in the embodiments of the present invention has at least the following technical effects or advantages: By acquiring the mission data and flight acceleration of the UAV performing the surveying and mapping mission, the flight acceleration characterizes the flight state of the UAV. The UAV can be monitored and adjusted in heading according to the acquired flight acceleration, so that the UAV is as close to the target path of the surveying and mapping mission as possible, reducing the influence of yaw on the surveying and mapping accuracy. At the same time, when the UAV is disturbed by airflow and deviates from the target path, the mission data acquired in the yaw state is determined to be abnormal data. The abnormal data is corrected according to the flight acceleration in the yaw state to obtain the corrected mission data. The surveying and mapping information of the surveying and mapping mission is obtained according to the corrected mission data and the mission data acquired when the UAV is not in the yaw state. Due to the correction of the abnormal data, the influence of airflow disturbance on the surveying and mapping accuracy is further reduced, so that the UAV can comprehensively collect data in the area where the surveying and mapping mission is located, so that the obtained surveying and mapping information is accurate and reliable, thereby improving the accuracy of the surveying and mapping information.

[0068] It should be noted that the sequence of the above embodiments of the present invention is only for description and does not represent the advantages and disadvantages of the embodiments. The processes depicted in the accompanying drawings do not necessarily require the specific order or continuous order shown to achieve the desired results. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0069] The various embodiments in this specification are described in a progressive manner, and the same or similar parts between the various embodiments can be referenced to each other, and each embodiment focuses on the differences from other embodiments.

Claims

1. A method for collecting surveying and mapping information by an unmanned aerial vehicle, characterized in that: The method comprises: Obtaining mission data and flight acceleration of the UAV performing a surveying and mapping mission, wherein the mission data includes the longitude position, latitude position and corresponding altitude measurement height of the UAV; Performing heading monitoring and heading adjustment on the UAV according to the acquired flight acceleration, so that the UAV is on the target path of the surveying and mapping task; When the UAV is disturbed by airflow and deviates from the target path, determining that the mission data acquired in the deviated state is abnormal data; Correcting the abnormal data according to the flight acceleration in the yaw state to obtain corrected mission data; Obtaining surveying and mapping information of the surveying and mapping task according to the corrected task data and the task data acquired when the task is not in the yaw state; The step of correcting the abnormal data according to the flight acceleration in the yaw state to obtain corrected mission data includes: Determining a flight deviation state of the UAV according to the flight acceleration in the yaw state, wherein the flight deviation state includes flight hysteresis or flight advance on the target path; Correcting the longitude and latitude positions in the acquired abnormal data according to the flight accelerations of different flight deviation states to obtain the mission longitude and latitude of the UAV on the target path; Determining the offset distance and offset angle of the UAV in a direction vertical to the ground according to the flight acceleration in the yaw state; Correcting the initial measurement value in the acquired abnormal data according to the offset distance and the offset angle to obtain the altitude measurement height of the UAV on the target path; The mission longitude, the mission latitude and the corresponding altitude measurement height are determined as the mission data for completing the correction.

2. The method for collecting UAV surveying and mapping information according to claim 1, characterized in that: The UAV is subjected to heading monitoring and heading adjustment according to the acquired flight acceleration, including: Determining whether the drone is in a yaw state according to the monitored flight acceleration and a preset accelerator interval; When the UAV is in the yaw state, the correction angle of the UAV and the current flight energy of the current control cycle are obtained according to the historical flight energy of the UAV in the previous control cycle and the flight acceleration of the yaw state; The UAV is steered according to the correction angle and the current flight energy until the UAV flies to the target path.

3. The method for collecting UAV surveying and mapping information according to claim 2, characterized in that: The step of obtaining the correction angle of the UAV and the current flight energy of the current control cycle according to the historical flight energy of the UAV in the previous control cycle and the flight acceleration of the yaw state includes: Performing orthogonal decomposition on the orthographic projection plane of the UAV on the flight acceleration of the yaw state to obtain a first acceleration of the UAV on the target path and a second acceleration perpendicular to the target path; Obtaining an energy correction value of the yaw state according to the flight acceleration of the UAV in the heading state, the first acceleration, and the second acceleration; Obtaining the current flight energy according to a correction result of the historical flight energy by the energy correction value; The correction angle is obtained according to a tangent angle between the first acceleration and the second acceleration.

4. The method for collecting UAV surveying and mapping information according to claim 1, characterized in that: Correcting the longitude position and latitude position in the acquired abnormal data according to the flight acceleration corresponding to different flight deviation states to obtain the mission longitude and mission latitude of the UAV on the target path includes: When the flight offset state is flight advance, obtaining the advance offset of the UAV according to the flight acceleration, cycle duration and flight speed of adjacent monitoring cycles; Obtaining a first mission longitude and a first mission latitude of the UAV according to a correction result of the longitude position and the latitude position in the abnormal data by the advance offset; When the flight offset state is flight hysteresis, obtaining the hysteresis offset of the UAV according to the flight acceleration, cycle duration and flight speed of adjacent monitoring cycles; According to the correction result of the hysteresis offset on the longitude position and the latitude position in the abnormal data, the second mission longitude and the second mission latitude of the UAV are obtained.

5. The method for collecting UAV surveying and mapping information according to claim 4, characterized in that: After obtaining the lead offset or the hysteresis offset of the drone, the method further includes: According to the formula Get offset confidence , is the amount of acceleration data acquired in the flight deviation state, is the ith flight acceleration of the flight deviation state, is the i+1th flight acceleration of the flight deviation state, is the normalization function; The leading offset or the lagging offset is updated according to the offset credibility to obtain an actual offset of the flight offset state.

6. The method for collecting UAV surveying and mapping information according to claim 1, characterized in that: Determining the offset distance and offset angle of the UAV in a direction vertical to the ground according to the flight acceleration of the yaw state includes: Obtaining a path deviation of the UAV according to the flight acceleration of the UAV on the target path in the yaw state; Obtaining a vertical offset of the UAV according to the flight acceleration of the UAV in the vertical direction in the yaw state; Obtaining an offset distance of the UAV according to the path offset and the vertical offset; The offset angle of the UAV is obtained according to the sine angle of the vertical offset and the path offset.

7. The method for collecting UAV surveying and mapping information according to claim 6, characterized in that: The step of obtaining the offset distance of the UAV according to the path offset and the vertical offset includes: According to the formula , get the offset distance ,in, is the path offset, is the vertical offset, is the first credibility of the path offset, is the second reliability of the vertical offset.

8. The method for collecting UAV surveying and mapping information according to claim 1, characterized in that: The correcting the initial measurement value in the acquired abnormal data according to the offset distance and the offset angle to obtain the altitude measurement height of the UAV on the target path includes: According to the offset distance and the offset angle, a first vertical offset of laser emission and a second vertical offset of laser reception are obtained when the UAV performs ground ranging; The altitude measurement height is obtained according to the initial measurement value, the first vertical offset and the second vertical offset.

9. An unmanned aerial vehicle surveying and mapping information collection system, characterized in that: The system comprises: A data acquisition terminal is used to obtain mission data and flight acceleration of the UAV performing surveying and mapping missions, wherein the mission data includes the longitude position, latitude position and corresponding altitude measurement height of the UAV; A control terminal connected to the data acquisition terminal, the control terminal being used to monitor and adjust the heading of the UAV according to the acquired flight acceleration, so that the UAV is on the target path of the surveying and mapping task; A data processing terminal connected to the data acquisition terminal, the data processing terminal is used to determine that the mission data acquired in the yaw state is abnormal data when the UAV is disturbed by airflow and deviates from the target path; The data processing terminal is also used to correct the abnormal data according to the flight acceleration in the yaw state to obtain corrected mission data; The data processing terminal is further used to obtain the surveying and mapping information of the surveying and mapping task according to the task data that has completed the correction and the task data obtained when it is not in the yaw state; The step of correcting the abnormal data according to the flight acceleration in the yaw state to obtain corrected mission data includes: Determining a flight deviation state of the UAV according to the flight acceleration in the yaw state, wherein the flight deviation state includes flight hysteresis or flight advance on the target path; Correcting the longitude and latitude positions in the acquired abnormal data according to the flight accelerations of different flight deviation states to obtain the mission longitude and latitude of the UAV on the target path; Determining the offset distance and offset angle of the UAV in a direction vertical to the ground according to the flight acceleration in the yaw state; Correcting the initial measurement value in the acquired abnormal data according to the offset distance and the offset angle to obtain the altitude measurement height of the UAV on the target path; The mission longitude, the mission latitude and the corresponding altitude measurement height are determined as the mission data for completing the correction.

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