Urban engineering surveying methods, devices, equipment, and storage media based on unmanned aerial vehicles (UAVs).

Abstract

This application discloses a method, apparatus, equipment, and storage medium for urban engineering surveying based on unmanned aerial vehicles (UAVs), relating to the field of UAV surveying technology. It aims to solve the problems of blind spots and large measurement errors in traditional UAV surveying. The method includes: real-time scanning of the terrain contour of the surveying area using a terrain sensing device mounted on the UAV to obtain terrain height data; constructing a three-dimensional flight profile based on the terrain height data, and determining the UAV's flight altitude in real-time according to the three-dimensional flight profile and the ground safety distance range, generating a flight path adapted to the terrain; adjusting the attitude of the surveying pod according to the flight path and the direction of the surveying target using a rotatable pod drive device, so that the main sensors inside the surveying pod are vertically aligned with the surface of the surveying target; receiving ground reference station data through a dynamic reference correction module, and correcting the positioning data during the surveying process in real-time using ground control points as a reference, and outputting the surveying results.

Description

Technical Field

[0001] This application relates to the field of unmanned aerial vehicle (UAV) surveying technology, and in particular to a method, apparatus, equipment and storage medium for urban engineering surveying based on UAVs. Background Technology

[0002] In recent years, UAV mapping technology has been widely used in urban planning, geological disaster monitoring, engineering surveying and other fields due to its advantages of high efficiency and flexibility.

[0003] Traditional UAV mapping solutions typically employ a preset flight path + fixed altitude mode: data is collected by planning the flight route in advance and setting a fixed altitude. This approach cannot cope with sudden terrain changes (such as steep slopes and gullies), and data gaps are likely to occur in areas with large surface undulations. Furthermore, measurement errors increase with the complexity of the terrain. In steep slope areas, a fixed flight altitude can easily create measurement blind spots, resulting in incomplete measurement data.

[0004] Therefore, existing UAV surveying solutions have problems such as measurement blind spots and large measurement errors, making it difficult to meet the requirements of urban engineering surveying for horizontal and vertical accuracy. Summary of the Invention

[0005] The purpose of this application is to provide an urban engineering surveying method, device, equipment and storage medium based on unmanned aerial vehicles (UAVs), which aims to solve the problem of low accuracy and timeliness of traditional geological disaster early warning.

[0006] To achieve the above objectives, this application adopts the following technical solution: This application provides a method for urban engineering surveying based on unmanned aerial vehicles (UAVs). The method includes: real-time scanning of the terrain contour of the survey area using a terrain sensing device mounted on the UAV to obtain terrain height data; the terrain sensing device is a laser rangefinder installed at the bottom of the UAV's landing gear; constructing a three-dimensional flight profile based on the terrain height data, and determining the UAV's flight altitude in real-time according to the three-dimensional flight profile and the ground safety distance range, generating a flight path adapted to the terrain contour; adjusting the attitude of the surveying pod according to the flight path and the direction of the surveying target using a rotatable pod drive device, so that the main sensors inside the surveying pod are vertically aligned with the surface of the surveying target, the surveying pod being connected to the UAV's fuselage via the pod drive device; receiving ground reference station data through a dynamic reference correction module, and using ground control points as a reference to perform real-time correction of the positioning data during the surveying process, outputting the surveying results.

[0007] The urban engineering surveying method based on UAVs provided in this application uses a laser rangefinder at the bottom of the landing gear to scan the terrain contour in real time, capturing subtle surface undulations and avoiding data gaps caused by the fixed altitude of the UAV in steep slope areas. It calculates the flight altitude in real time based on the three-dimensional flight profile and safe distance range, generating variable-altitude flight paths to ensure the UAV maintains a constant relative distance to irregular terrain, eliminating measurement blind spots caused by altitude mismatch in traditional surveying. It automatically adjusts the pod attitude by combining the flight path direction with the spatial orientation of the survey target, ensuring the main sensor is always vertically aligned with the target surface, achieving complete acquisition of building facade data. Finally, a dynamic benchmark correction module integrates ground control point data to correct the positioning in real time, suppressing the cumulative effect of elevation and planar measurement errors, thereby eliminating measurement blind spots and improving measurement accuracy in complex urban environments.

[0008] In some embodiments, the above-mentioned construction of a three-dimensional flight profile based on terrain height data, and the determination of the UAV's flight altitude in real time based on the three-dimensional flight profile and the ground safety distance range, and the generation of a flight path adapted to the terrain contour, includes: converting the terrain height data into a digital elevation model for intuitively presenting the terrain undulations; extracting the terrain curvature of the digital elevation model and automatically classifying the terrain complexity level; generating multiple flight sub-paths based on the ground safety distance range for different terrain complexity levels, each flight sub-path including flight altitude, pitch angle, and flight speed; wherein, the flight path contains multiple flight sub-paths.

[0009] Based on this, this application achieves refined segmented control of flight routes by dynamically classifying complexity levels according to terrain curvature, significantly improving the scanning coverage of steep slopes and ravine areas, and effectively eliminating terrain blind spots caused by traditional fixed-altitude flight.

[0010] In some embodiments, the above-mentioned generation of multiple flight sub-paths based on ground safety distance for different terrain complexity levels includes: in the case of a steep slope, reducing the flight altitude, increasing the pitch angle, and increasing the scanning frequency to generate a first flight sub-path; in the case of a flat area, increasing the flight speed and increasing the flight altitude to reach the maximum value of the ground safety distance range to generate a second flight sub-path; wherein, the multiple flight sub-paths include the first flight sub-path and the second flight sub-path.

[0011] Based on this, this application directly overcomes the problem of missing elevation data by actively reducing altitude and increasing scanning frequency in steep slope areas; and maximizes safe altitude and extends single flight range in flat areas, while simultaneously optimizing data integrity and operational efficiency.

[0012] In some embodiments, the target being surveyed is a building facade. The above-mentioned adjustment of the attitude of the surveying pod by a rotatable pod drive device according to the flight path and the direction of the target being surveyed includes: driving the surveying pod by the pod drive device; and automatically adjusting and locking the scanning plane of the sensor when the building facade is detected, so that the sensor is parallel to the normal of the building facade.

[0013] Based on this, this application completely solves the image distortion caused by tilted shooting by automatically aligning the sensor with the facade normal, ensuring the complete acquisition of building facade texture and geometric data at the millimeter level.

[0014] In some embodiments, the above-mentioned method of receiving ground reference station data through the dynamic reference correction module and correcting the positioning data in the mapping process in real time with the ground control point as a reference, and outputting the mapping result, includes: receiving carrier phase differential signals sent from the ground reference station using the signal receiving device in the dynamic reference correction module; comparing and analyzing the positioning data with the coordinates of the ground control point in real time to obtain the difference data; and using a filtering algorithm to compensate for the difference data and output the mapping result.

[0015] Based on this, this application uses carrier phase differential and real-time filtering compensation to suppress multipath effects and signal drift, thereby reducing positioning errors in urban high-rise building obstruction environments and improving mapping accuracy.

[0016] In some embodiments, the urban engineering surveying method based on UAVs provided in this application may further include: triggering an emergency climb command when the deviation between the flight altitude of the UAV and the ground safety distance exceeds the normal deviation threshold; and automatically switching to binocular visual obstacle avoidance mode during the execution of the emergency climb command to avoid collision with obstacles.

[0017] Based on this, this application uses height deviation monitoring and visual obstacle avoidance to avoid collisions caused by sudden terrain changes, ensuring the safety and data continuity of operations in complex urban areas.

[0018] In some embodiments, the urban engineering mapping method based on UAVs provided in this application may further include: predicting the remaining flight time of the UAV in real time based on the correlation between terrain complexity and sensor power consumption, wherein terrain complexity is proportional to sensor power consumption; and automatically switching to a low-power data acquisition mode when the remaining flight time is lower than a safe flight time threshold, mapping key terrain, and sending a power reminder message to the mobile terminal.

[0019] Based on this, this application predicts energy consumption based on terrain complexity and switches to a low-power mode to prioritize the mapping of critical terrain and solve the problem of operation interruption caused by power depletion.

[0020] This application provides an urban engineering surveying device based on an unmanned aerial vehicle (UAV). The device includes: an acquisition unit, used to scan the terrain contour of the surveying area in real time using a terrain sensing device mounted on the UAV to acquire terrain height data; the terrain sensing device is a laser rangefinder installed at the bottom of the UAV's landing gear; a generation unit, used to construct a three-dimensional flight profile based on the terrain height data, and determine the UAV's flight altitude in real time according to the three-dimensional flight profile and the ground safety distance range, generating a flight path adapted to the terrain contour; an adjustment unit, used to adjust the attitude of the surveying pod according to the flight path and the direction of the surveying target through a rotatable pod drive device, so that the main sensors inside the surveying pod are vertically aligned with the surface of the surveying target, and the surveying pod is connected to the UAV's fuselage through the pod drive device; and a correction unit, used to receive ground reference station data through a dynamic reference correction module, and correct the positioning data in the surveying process in real time using ground control points as a reference, and output the surveying results.

[0021] In some embodiments, the above-mentioned generation unit is specifically used to: convert terrain height data into a digital elevation model for intuitively presenting terrain undulations; extract the terrain curvature of the digital elevation model and automatically classify the terrain complexity level; generate multiple flight sub-paths according to the ground safety distance range for different terrain complexity levels, each flight sub-path including flight altitude, pitch angle, and flight speed; wherein, the flight path contains multiple flight sub-paths.

[0022] In some embodiments, the above-mentioned generation unit is specifically used to: when the terrain complexity level is steep slope, reduce the flight altitude, increase the pitch angle and increase the scanning frequency to generate a first flight sub-path; when the terrain complexity level is flat area, increase the flight speed and increase the flight altitude to reach the maximum value of the ground safety distance range to generate a second flight sub-path; wherein, the multiple flight sub-paths include the first flight sub-path and the second flight sub-path.

[0023] In some embodiments, the adjustment unit is specifically used to: drive the mapping pod through the pod drive device; and automatically adjust and lock the scanning plane of the sensor when the building facade is identified, so that the sensor is parallel to the normal of the building facade.

[0024] In some embodiments, the above-mentioned correction unit is specifically used to: receive a carrier phase differential signal sent from a ground reference station using the signal receiving device in the dynamic reference correction module; perform real-time comparison and analysis of the positioning data and the coordinates of the ground control points to obtain the difference data; and use a filtering algorithm to compensate for the difference data and output the mapping results.

[0025] In some embodiments, the adjustment unit is further configured to: trigger an emergency climb command when the deviation between the flight altitude of the UAV and the safe distance between the ground exceeds the normal deviation threshold; and automatically switch to binocular visual obstacle avoidance mode during the execution of the emergency climb command to avoid collision with obstacles.

[0026] In some embodiments, the urban engineering mapping device based on UAV provided in this application further includes: a prediction unit, used to predict the remaining flight time of the UAV in real time based on the correlation between terrain complexity and sensor power consumption, wherein terrain complexity is proportional to sensor power consumption; the adjustment unit is also used to automatically switch to a low-power data acquisition mode to map key terrain when the remaining flight time is lower than a safe flight time threshold, and send a power reminder message to the mobile terminal.

[0027] This application provides an electronic device, including: a processor; and a memory for storing processor-executable instructions; wherein the processor is configured to execute instructions to implement the above-described UAV-based urban engineering surveying method.

[0028] This application provides a computer-readable storage medium storing instructions that, when executed on a terminal, cause the terminal to perform the above-described UAV-based urban engineering surveying method.

[0029] This application provides a computer program product containing instructions that, when executed by a computer, cause the computer to perform the urban engineering surveying method based on unmanned aerial vehicles described above.

[0030] This application provides a chip including a processor and a communication interface, the communication interface and the processor being coupled together. The processor is used to run computer programs or instructions to implement the above-described UAV-based urban engineering surveying method.

[0031] Specifically, the chip provided in this application embodiment also includes a memory for storing computer programs or instructions. Attached Figure Description

[0032] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0033] Figure 1 A flowchart of an urban engineering surveying method based on unmanned aerial vehicles (UAVs) is provided for embodiments of this application. Figure 2A structural diagram of an urban engineering surveying device based on an unmanned aerial vehicle (UAV) provided in this application embodiment; Figure 3 This is a structural diagram of an electronic device provided in an embodiment of this application. Detailed Implementation

[0034] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0035] In the description of this application, it should be understood that the terms "upper," "lower," "left," "right," "front," "rear," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or relative positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this application and for simplification, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application. Unless otherwise specified, the above-mentioned orientational descriptions can be flexibly set in practical applications, provided that the relative positional relationships shown in the accompanying drawings are satisfied.

[0036] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "a plurality of" means two or more.

[0037] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "communication" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection. They can refer to a direct connection or an indirect connection through an intermediate medium, or a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0038] In some embodiments, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, article, or apparatus that includes that element.

[0039] In some embodiments, the words "exemplary" or "for example" are used to indicate that something is an example, illustration, or illustration. Any embodiment or design described as "exemplary" or "for example" in the embodiments of this application should not be construed as being more preferred or advantageous than other embodiments or designs. Specifically, the use of the words "exemplary" or "for example" is intended to present the relevant concepts in a specific manner.

[0040] In the description of this specification, specific features, structures, materials, or characteristics may be combined in any suitable manner in one or more embodiments or examples.

[0041] To address the terrain adaptability issues in traditional surveying methods, existing technologies primarily employ the following two approaches: 1) Pre-planned flight path + fixed altitude mode: Data is collected by pre-planning the flight route and setting a fixed altitude. This method is simple to control, but it cannot cope with sudden changes in terrain (such as steep slopes and gullies). Data gaps are likely to occur in areas with large surface undulations, and the elevation measurement error increases with the complexity of the terrain.

[0042] 2) Manual intervention to adjust flight parameters: Real-time monitoring and manual correction of flight altitude or path via ground station. This method is highly flexible, but it relies on operator experience and has a response delay, making it unable to meet the needs of real-time dynamic adjustment, especially in steep slope areas where measurement blind spots are still difficult to avoid.

[0043] Against this backdrop, to address the issues of blind spots and large measurement errors in UAV surveying schemes, this application provides a UAV-based urban engineering surveying method, apparatus, equipment, and storage medium. A three-dimensional terrain model is constructed in real time using an airborne laser rangefinder, and the flight altitude is dynamically adjusted in real time using a safety distance to eliminate blind spots. A rotatable pod drive mechanism ensures the main sensor is vertically aligned with the surveying surface, and a dynamic reference correction module corrects the positioning data in real time, minimizing surveying errors.

[0044] The following is a reference. Figure 1 The urban engineering surveying method based on unmanned aerial vehicles (UAVs) provided in the embodiments of this application is described.

[0045] Figure 1 The flowchart of the urban engineering surveying method based on UAV provided in the embodiments of this application is shown. The subject executing the method can be an electronic device or various devices / modules in the electronic device, such as integrated circuits or chips. The embodiments of this application do not specifically limit this.

[0046] For example, such as Figure 1 As shown, the urban engineering surveying method based on UAVs provided in this application embodiment may include the following steps S101 to S104: S101. The terrain contour of the survey area is scanned in real time by the terrain sensing device carried by the UAV to obtain terrain height data.

[0047] The terrain sensing device is a laser rangefinder installed at the bottom of the UAV's landing gear. For example, the laser rangefinder can be a light detection and ranging (LiDAR) system. In some embodiments, the lidar can be controlled to operate at a scanning frequency of 10Hz, emitting approximately 300,000 laser pulses per second to the ground surface. The pulse signals are reflected when they encounter the ground, buildings, trees, or other objects. The lidar records the round-trip time of the pulse signals through a high-precision time measurement module, and then calculates the three-dimensional coordinates of each reflection point by combining the real-time location information of the UAV (e.g., obtained through positioning via a global navigation satellite system (GNSS)).

[0048] The Z-axis data represents the terrain height data.

[0049] One example is a drone scanning a slope in an old residential area. LiDAR can capture the continuous change in height from the bottom of the slope (25.3 meters) to the top (32.7 meters), ensuring that subtle features of the terrain height data are not missed.

[0050] Another example involves using a drone to scan narrow alleyways or obstructed areas between tall buildings in a city. LiDAR can perform multi-line scanning to scan the terrain contours, minimizing data blind spots. For instance, when a drone flies between two tall buildings 5 ​​meters apart, 16 laser beams will illuminate both walls and the ground, allowing for the reconstruction of the alley's true terrain through subsequent data stitching.

[0051] S102. Construct a three-dimensional flight profile based on terrain height data, and determine the UAV's flight altitude in real time according to the three-dimensional flight profile and the ground safety distance range, and generate a flight path that adapts to the terrain contour.

[0052] In this embodiment of the application, the three-dimensional flight profile is a longitudinal profile obtained by spatially reconstructing continuously collected terrain height data according to the flight path.

[0053] For example, consider surveying a main urban road. Multiple terrain height sampling points can be taken at fixed intervals (e.g., 5 meters) along the road's extension direction. The coordinates of each terrain height sampling point (horizontal distance from the starting point and terrain height) can be plotted as a curve to obtain a three-dimensional flight profile reflecting the terrain undulations on both sides of the road.

[0054] In this embodiment, the ground safety distance range refers to the minimum and maximum vertical distance that the UAV must maintain between itself and the ground surface. The ground safety distance range can be preset according to the actual environment of the surveying area.

[0055] For example, consider an area containing trees (up to 15 meters) and buildings (up to 80 meters). The minimum vertical distance can be set to 20 meters, and the maximum vertical distance can be set to 100 meters, ensuring that the drone maintains an appropriate scanning distance while avoiding obstacles.

[0056] In some embodiments, when generating a flight path, the flight altitude can be dynamically calculated based on the terrain altitude of each terrain altitude sampling point in the three-dimensional flight profile.

[0057] For example, let's take a minimum vertical distance of 20 meters and a maximum vertical distance of 100 meters as an example. If the terrain height of a certain point is 30 meters, then the flight altitude needs to be set between 50 meters (30+20) and 130 meters (30+100).

[0058] Furthermore, the flight altitude change rate of adjacent terrain height sampling points must not be preset with a threshold (such as 5 meters / second) to avoid attitude instability caused by the drone's violent ascent and descent.

[0059] Optionally, the above flight routes may include multiple flight sub-routes.

[0060] For example, consider the mapping of a new urban area. The entire flight path can be divided into three sub-flight paths: the first segment covers the steep slope area at the edge of the new area, the second segment covers the flat residential area in the middle, and the third segment covers the gentle slope area near the river.

[0061] In this embodiment of the application, coordinate markers (such as latitude and longitude coordinates and elevation) can also be set at the start and end points of each sub-route to ensure a smooth transition at the connection of the routes and avoid route overlap or gaps.

[0062] In some embodiments, terrain height data can be first converted into a digital elevation model (DEM) for visually representing terrain undulations, and the terrain curvature of the DEM can be extracted to automatically classify terrain complexity levels.

[0063] In this embodiment of the application, the above-mentioned DEM generation process is as follows: First, the original terrain height data is denoised to remove abnormal points caused by birds, cloud cover or abnormal laser reflection. Then, sparse data points are interpolated to generate a raster DEM.

[0064] Each grid cell represents the average altitude of that area.

[0065] For example, a statistical filtering algorithm can be used to calculate the mean and standard deviation of the height of all points, and points that are more than three times the standard deviation of the mean can be identified as outliers and removed. Then, Kriging interpolation is used to interpolate the sparse data points to generate a raster DEM with a resolution of 0.5 m × 0.5 m.

[0066] In this embodiment of the application, a spherical variogram model can be used to fit the spatial correlation of the data during the interpolation process, ensuring that the interpolation results can truly reflect the trend of terrain change. For example, when processing terrain data of a mountainous area bordering an urban area, the DEM can show a continuous transition from an elevation of 80 meters in the mountainous area to an elevation of 30 meters in the urban area.

[0067] Furthermore, multiple flight sub-routes are generated based on the ground safety distance range, targeting different levels of terrain complexity.

[0068] In the embodiments of this application, each flight sub-path includes flight altitude, pitch angle, and flight speed.

[0069] In one example, for steep slope areas with high complexity (e.g., |K|=0.06m⁻¹), the flight sub-flight parameters can be set as follows: flight altitude 50m (i.e., 30m at the highest point of the terrain + 20m safety distance), pitch angle 30° (i.e., the lidar tilts downwards by 30° to enhance the scanning coverage of the steep slope facade), and flight speed 3m / s (to reduce speed and increase point cloud density).

[0070] In another example, for a gentle slope area of ​​medium complexity (e.g., |K|=0.03 m⁻¹), the flight sub-path parameters can be set as follows: flight altitude 70 m, pitch angle 15°, and flight speed 5 m / s.

[0071] In another example, for a flat area with low complexity (e.g., |K|=0.01 m⁻¹), the flight sub-path parameters can be set as follows: flight altitude 100 m, pitch angle 0°, and flight speed 8 m / s.

[0072] Optionally, during actual flight, the terrain complexity can be reassessed every 50 meters. If the terrain changes from high complexity to medium complexity, the flight parameters will be automatically adjusted to the corresponding level of settings to ensure that the flight path always adapts to terrain changes.

[0073] Thus, this application achieves refined segmented control of flight routes by dynamically classifying complexity levels based on terrain curvature, significantly improving the scanning coverage of steep slopes and ravine areas, and effectively eliminating terrain blind spots caused by traditional fixed-altitude flight.

[0074] Optionally, the aforementioned multiple flight sub-routes may include a first flight sub-routes and a second flight sub-routes.

[0075] In some embodiments, when the terrain complexity level is steep slope, the flight altitude is reduced, the pitch angle is increased, and the scanning frequency is increased to generate a first flight sub-path.

[0076] For example, consider a steep slope on the edge of a city (e.g., 35° slope, maximum elevation 60 meters). If the starting coordinates of the first flight sub-path are (E116.3, N39.9, H80 meters) and the ending coordinates are (E116.31, N39.9, H80 meters), then to adapt to the steep slope terrain, the flight altitude can be adjusted from 100 meters to 80 meters (i.e., the terrain maximum is 60 meters + a safety distance of 20 meters), and the pitch angle can be increased from 0° to 40°. This allows the lidar scanning range to cover more of the steep slope's vertical surface, avoiding data loss caused by the scanning direction being parallel to the slope. The lidar scanning frequency can be increased from 5Hz to 15Hz, and the point cloud acquisition density can be increased from 80 points / square meter to 240 points / square meter, ensuring that details such as rock outcrops and vegetation cover on the steep slope are clearly recorded.

[0077] In addition, to address the risk of falling rocks on steep slopes, the first flight sub-path can be set with an offset (e.g., 10 meters) along the edge of the slope to ensure flight safety.

[0078] In other embodiments, when the terrain complexity level is flat, the flight speed and flight altitude are increased to reach the maximum value of the ground safety distance range to generate a second flight sub-path.

[0079] For example, consider a plaza area in the city center (e.g., at an altitude of 20 meters). If the maximum safe distance range on the ground is 80 meters, the altitude of the second flight sub-route can be adjusted from 80 meters to 100 meters (i.e., terrain altitude 20 meters + safe distance 80 meters); the pitch angle is kept at 0°, and the lidar is used for horizontal scanning to ensure that the data of the plaza ground and the tops of surrounding buildings are completely collected; the flight speed is increased to 8 meters per second.

[0080] Thus, this application directly overcomes the problem of missing elevation data by actively reducing altitude and increasing scanning frequency in steep slope areas; and maximizes safe altitude and extends single flight range in flat areas, while simultaneously optimizing data integrity and operational efficiency.

[0081] S103. Based on the flight path and the direction of the surveying target, adjust the attitude of the surveying pod using a rotatable pod drive device so that the main sensors inside the surveying pod are vertically aligned with the surface of the surveying target.

[0082] The mapping pod is connected to the UAV fuselage via a pod drive unit. The pod drive unit can be a three-axis stabilized gimbal, including three rotational degrees of freedom: pitch, roll, and yaw.

[0083] Optionally, the above-mentioned survey target can be the building facade.

[0084] In some embodiments, the mapping pod can be driven by a pod drive device to automatically adjust and lock the scanning plane of the sensor when the building facade is identified, so that the sensor remains parallel to the normal of the building facade.

[0085] For example, the image of the survey area is first captured by the airborne vision sensor of the drone (such as a wide-angle camera) to identify the building facade. Then, the identified facade image is processed by an edge detection algorithm (such as the Canny operator) to extract the outline of the facade. The plane equation of the facade is then fitted by the least squares method, and the normal direction of the facade is calculated.

[0086] Specifically, taking the east facade of a north-facing office building as an example, its planar equation is ax + by + cz + d = 0. By solving for the normal vector (a, b, c) of this equation, the direction of the normal can be determined to be due east (the horizontal direction makes a 90° angle with due north). Next, the yaw axis of the drive unit of the pod is rotated 90° to align the sensor optical axis with the due east direction. At the same time, the pitch axis is dynamically adjusted according to the facade height (for example, for a 10-story (30-meter-high) building, the pitch angle changes continuously from -10° (top) to +20° (bottom) to ensure that the sensor optical axis is always parallel to the facade normal).

[0087] Optionally, the current attitude of the mapping pod can be fed back in real time through an angle sensor. If the deviation exceeds a certain angle (such as 0.5°) due to the shaking of the drone, the gimbal will be driven to correct it and lock the scanning plane.

[0088] Furthermore, for building facades with complex structures such as decorative lines and reliefs, the accuracy of normal calculation can be improved by increasing the number of sampling points. For example, a feature point can be taken at fixed intervals (such as 5 meters) for plane fitting to ensure that the posture adjustment can adapt to the subtle undulations of the facade.

[0089] Thus, this application completely solves the image distortion caused by tilted shooting by automatically aligning the sensor with the facade normal, ensuring the complete acquisition of building facade texture and geometric data at the millimeter level.

[0090] S104. Receive ground reference station data through the dynamic reference correction module, and use the ground control points as a reference to correct the positioning data in the surveying process in real time, and output the surveying results.

[0091] In this embodiment, the dynamic reference correction module includes a GNSS receiver, a data processing unit, and a wireless communication module (4G / 5G dual-mode), which can realize real-time data interaction with the ground reference station.

[0092] In this embodiment, the ground reference station supports multi-system fusion positioning and can send carrier phase differential signals to the UAV via radio broadcast.

[0093] In some embodiments, the signal receiving device in the dynamic reference correction module can be used to receive the carrier phase differential signal sent from the ground reference station.

[0094] In this embodiment, the carrier phase differential signal refers to the difference between the satellite carrier phase data received simultaneously by the ground reference station and the UAV receiver. It improves positioning accuracy by eliminating common errors (such as satellite clock errors and ionospheric delay).

[0095] For example, if the carrier phase of a certain Beidou satellite is measured to be φ1 by the ground reference station, and the carrier phase of the same Beidou satellite is measured to be φ2 by the UAV, then the differential signal is Δφ=φ1-φ2. After being analyzed by the data processing unit, the differential signal is fused with the UAV's own GNSS raw positioning data to initially eliminate systematic errors.

[0096] Furthermore, the positioning data is compared and analyzed in real time with the coordinates of the ground control points to obtain the difference data. Then, a filtering algorithm is used to compensate for the difference data and output the mapping results.

[0097] In this embodiment, the ground control points are known coordinate points pre-established during urban engineering surveying. For example, the target object can be buried deep underground, with its top flush with the ground surface, to ensure long-term stability.

[0098] For example, the coordinates of ground control points can be obtained through static measurement using a total station. For instance, the coordinates of a control point at a corner of a square are (X=352000.500 meters, Y=485000.300 meters, H=50.200 meters).

[0099] Alternatively, in densely built-up areas, ground control points can be deployed on rooftops (to avoid obstruction) or on paved plaza surfaces (for easy observation) to ensure that drones can clearly identify them.

[0100] Specifically, taking the ground control point coordinates (X=352000.500 meters, Y=485000.300 meters, H=50.200 meters) as an example, during the flight of the UAV, whenever it passes within a preset distance (e.g., 500 meters) above the ground control point, the real-time UAV positioning data (e.g., X=352001.200 meters, Y=485000.900 meters, H=50.800 meters) can be compared with the control point coordinates to obtain the difference data (ΔX=0.700 meters, ΔY=0.600 meters, ΔH=0.600 meters).

[0101] Furthermore, filtering algorithms (such as Kalman filtering) are employed to dynamically correct errors through the prediction-update process, thus smoothly correcting the difference data.

[0102] Specifically, the state equation is: X(k) = A・X(k-1) + B・U(k) + W(k).

[0103] Where X(k) is the positioning correction at time k, A is the state transition matrix (a 3×3 identity matrix), B is the control matrix (a 3×3 zero matrix), U(k) is the input, and W(k) is the process noise (which follows a Gaussian distribution with a mean of 0 and a variance of 0.01).

[0104] Specifically, the observation equation is: Z(k) = H・X(k) + V(k).

[0105] Where Z(k) represents the difference data, H is the observation matrix (3×3 identity matrix), and V(k) represents the observation noise (variance 0.005). The calculation is performed iteratively.

[0106] Thus, by employing carrier phase differential and real-time filtering compensation, this application suppresses multipath effects and signal drift, reduces positioning errors in urban high-rise building obstruction environments, and thereby improves mapping accuracy.

[0107] In the urban engineering surveying method based on UAVs provided in this application embodiment, the terrain contour is scanned in real time by a laser rangefinder at the bottom of the landing gear to capture the subtle undulations of the ground surface, avoiding the data discontinuity problem caused by the fixed altitude of the UAV in steep slope areas; the flight altitude is calculated in real time based on the three-dimensional flight profile and the safe distance range to generate a variable altitude flight path, ensuring that the UAV maintains a constant relative distance with irregular terrain, eliminating the measurement blind spots caused by altitude mismatch in traditional surveying; the pod attitude is automatically adjusted by combining the flight path direction and the spatial orientation of the survey target, so that the main sensor is always vertically aligned with the target surface, realizing the complete acquisition of building facade data; finally, the positioning is corrected in real time by fusing ground control point data through a dynamic benchmark correction module, suppressing the cumulative effect of elevation and plane measurement errors, thereby eliminating measurement blind spots and improving measurement accuracy in complex urban environments.

[0108] Optionally, the urban engineering surveying method based on UAVs provided in this application embodiment may further include: triggering an emergency climb command when the deviation between the flight altitude of the UAV and the ground safety distance range exceeds the normal deviation threshold.

[0109] In this embodiment, the normal deviation threshold for the ground safety distance range can be a manually set value, which can be flexibly adjusted according to the actual scenario. For example, the normal deviation threshold can be -4 meters.

[0110] In this embodiment of the application, the difference between the current flight altitude of the UAV and the terrain altitude can be calculated in real time by using a laser rangefinder in conjunction with a barometric altimeter to obtain the actual safe distance.

[0111] For example, taking a normal deviation threshold of -4 meters as an example. If the calculated difference between the drone's current flight altitude and the terrain altitude is 15 meters, and the safe ground clearance range for this area is 20-100 meters, then since 15-20=-5 meters, which exceeds the normal deviation threshold of -4 meters, an emergency climb command will be immediately triggered.

[0112] The emergency climb command includes the climb speed (e.g., 2 m / s), target altitude (current terrain altitude + 30 m, i.e., ground safety distance of 30 m), and a course-keeping strategy during the climb (e.g., climb in a straight line along the original course direction to avoid lateral deviation) to ensure the stability of the climb process.

[0113] Alternatively, during the emergency climb command phase, the system can automatically switch to binocular vision obstacle avoidance mode to avoid collisions with obstacles.

[0114] In this embodiment of the application, the binocular visual obstacle avoidance mode refers to using a depth camera containing two infrared cameras and an infrared projector to acquire images, then using a semi-global block matching (SGBM) algorithm to calculate the image disparity to obtain a depth map, and then converting it into actual distance based on the principle of triangulation.

[0115] For example, during an emergency climb, the depth camera continuously scans the space in front of the drone (e.g., within 10 meters). If an obstacle is detected (e.g., a suddenly appearing tower crane boom or an unmarked high-voltage line), an obstacle avoidance path is calculated.

[0116] The obstacle avoidance decision follows the principle of "safety first, shortest path". When the distance to the obstacle is less than the preset distance (e.g., 5 meters), a detour is triggered, with the detour priority being left detour > right detour > climb.

[0117] Specifically, when the drone climbs to 70 meters, it detects a horizontally extending tower crane boom (74 meters high) 4 meters ahead. It then generates a fly-around command to shift 3 meters to the left, bypassing the obstacle (tower crane boom) before resuming the original flight path, thus ensuring the safety of the climbing process.

[0118] Thus, this application, through the linkage of height deviation monitoring and visual obstacle avoidance, avoids collision accidents caused by sudden terrain changes, ensuring the safety and data continuity of operations in complex urban areas.

[0119] Optionally, the urban engineering surveying method based on UAVs provided in this application embodiment may further include: predicting the remaining flight time of the UAV in real time based on the correlation between terrain complexity and sensor power consumption.

[0120] The complexity of the terrain is directly proportional to the power consumption of the sensor. For example, high-complexity areas require high-frequency scanning and attitude adjustment, which increases power consumption.

[0121] In this embodiment of the application, terrain complexity can be obtained by quantifying the terrain curvature level. For example, high complexity = 3, medium complexity = 2, and low complexity = 1.

[0122] In this embodiment of the application, the power consumption of the sensors (unit: watts, W) can be monitored in real time through the power management module of the UAV.

[0123] For example, the above-mentioned terrain complexity is proportional to the sensor power consumption, which can be expressed by the formula: power consumption P = 20 × C + 20.

[0124] Where C represents the terrain complexity level, P=80W when it is high complexity 3; P=60W when it is medium complexity 2; and P=40W when it is low complexity 1.

[0125] Specifically, when a drone flies from a flat area (e.g., low complexity, C=1) into a steep slope area (e.g., high complexity, C=3), the sensor power consumption increases from 40W to 80W, doubling the power consumption per unit time.

[0126] In this embodiment of the application, after determining the sensor power consumption of the drone, the remaining flight time of the drone can be calculated based on the drone's battery capacity.

[0127] For example, the remaining flight time can be calculated using the formula T = (E × S) / P.

[0128] Where E is the remaining power (in Wh), S is the battery discharge efficiency (e.g., 0.9), and P is the current power consumption.

[0129] Specifically, taking a drone with a battery capacity of 6000mAh, a voltage of 14.8V, and a sensor power consumption of 80W as an example, the total battery energy of the drone is 6000mAh × 14.8V = 88.8Wh. If the drone has 30% battery remaining, the battery energy is 88.8 × 0.3 = 26.64Wh, and the remaining flight time T = (26.64 × 0.9) / 80 ≈ 0.3 hours = 18 minutes.

[0130] Furthermore, when the remaining flight time is below the safe flight time threshold, it automatically switches to a low-power data acquisition mode to map key terrain features and send a battery level reminder to the mobile terminal.

[0131] In this embodiment of the application, the safe duration threshold can be a value set manually, which can be flexibly adjusted according to the actual scenario. For example, the safe duration threshold can be 15 minutes.

[0132] For example, taking a safe duration threshold of 15 minutes as an example, if the calculated remaining flight time is 14 minutes, the system will automatically switch to a low-power data acquisition mode.

[0133] Specifically, the current sensor power consumption is 80W, which can reduce the LiDAR scanning frequency from 15Hz to 5Hz and the point cloud density from 200 points / m². 2 Reduced to 80 points / m 2 The camera shooting interval was increased from 1 second to 3 seconds, and the resolution was reduced from 61 million pixels to 24 million pixels. The gimbal adjustment accuracy was increased from ±0.02° to ±0.1°. At this time, the sensor power consumption was reduced to 40W, and the remaining flight time was extended to (26.64×0.9) / 40≈0.6 hours=36 minutes.

[0134] In this embodiment of the application, key terrain refers to pre-marked key surveying areas (such as buildings to be demolished, road intersections, and pipeline burial areas). When switching to low-power data acquisition mode, data acquisition of key terrain can be prioritized, and the sampling density of non-key areas (such as open land and wasteland) can be reduced.

[0135] In this embodiment of the application, the mobile terminal can be an operator's smartphone, smartwatch, or other mobile device.

[0136] For example, a battery level reminder message can be sent to the operator's smartphone via a Bluetooth module. The message may include: 14 minutes of flight time remaining, low power mode has been switched, and it is recommended to prioritize the mapping of areas A and B.

[0137] Furthermore, real-time flight path maps can be sent to operators' smartphones, marking the locations of unfinished critical areas, allowing operators to adjust their work plans. For example, surveying of non-critical areas can be paused, and the shortest path can be planned to prioritize data collection in critical areas.

[0138] In this way, energy consumption can be predicted based on terrain complexity and a low-power mode can be switched to prioritize the mapping of critical terrain, thus solving the problem of operation interruption caused by power depletion.

[0139] The above primarily describes the solutions provided by the embodiments of this application from a methodological perspective. To achieve the above functions, the UAV-based urban engineering surveying device or electronic device includes hardware structures and / or software modules corresponding to the execution of each function. Those skilled in the art should readily recognize that, based on the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein, this application can be implemented in hardware or a combination of hardware and computer software. Whether a function is executed in hardware or by computer software driving hardware depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0140] This application embodiment can, according to the above method, exemplarily divide a UAV-based urban engineering surveying device or electronic device into functional modules. For example, the UAV-based urban engineering surveying device or electronic device may include functional modules corresponding to each functional division, or two or more functions may be integrated into one processing module. The integrated module can be implemented in hardware or as a software functional module. It should be noted that the module division in this application embodiment is illustrative and only represents one logical functional division; in actual implementation, there may be other division methods.

[0141] Figure 2This is a structural diagram of an urban engineering surveying device based on an unmanned aerial vehicle (UAV) according to an embodiment of this application. The UAV-based urban engineering surveying device 200 includes: an acquisition unit 201, a generation unit 202, an adjustment unit 203, and a correction unit 204.

[0142] The system comprises: an acquisition unit 201, used to scan the terrain contour of the survey area in real time using a terrain sensing device mounted on the UAV, and acquire terrain height data; the terrain sensing device is a laser rangefinder installed at the bottom of the UAV's landing gear; a generation unit 202, used to construct a three-dimensional flight profile based on the terrain height data, and determine the UAV's flight altitude in real time according to the three-dimensional flight profile and the ground safety distance range, and generate a flight path adapted to the terrain contour; an adjustment unit 203, used to adjust the attitude of the surveying pod according to the flight path and the direction of the surveying target through a rotatable pod drive device, so that the main sensors inside the surveying pod are vertically aligned with the surface of the surveying target, and the surveying pod is connected to the UAV's fuselage through the pod drive device; and a correction unit 204, used to receive ground reference station data through a dynamic reference correction module, and correct the positioning data in the surveying process in real time with ground control points as a reference, and output the surveying results.

[0143] In some embodiments, the generation unit 202 is specifically used to: convert terrain height data into a digital elevation model for visually representing terrain undulations; extract the terrain curvature of the digital elevation model and automatically classify terrain complexity levels; generate multiple flight sub-paths based on ground safety distance range for different terrain complexity levels, each flight sub-path including flight altitude, pitch angle, and flight speed; wherein, the flight path includes multiple flight sub-paths.

[0144] In some embodiments, the generation unit 202 is specifically used to: reduce the flight altitude, increase the pitch angle and increase the scanning frequency when the terrain complexity level is steep slope, and generate a first flight sub-path; when the terrain complexity level is flat area, increase the flight speed and increase the flight altitude to reach the maximum value of the ground safety distance range, and generate a second flight sub-path; wherein, the multiple flight sub-paths include the first flight sub-path and the second flight sub-path.

[0145] In some embodiments, the adjustment unit 203 is specifically used to: drive the mapping pod through the pod drive device; and automatically adjust and lock the scanning plane of the sensor when the building facade is identified, so that the sensor is parallel to the normal of the building facade.

[0146] In some embodiments, the correction unit 204 is specifically used to: receive a carrier phase differential signal sent from a ground reference station using the signal receiving device in the dynamic reference correction module; perform real-time comparison and analysis of the positioning data and the coordinates of the ground control points to obtain the difference data; and use a filtering algorithm to compensate for the difference data and output the mapping results.

[0147] In some embodiments, the adjustment unit 203 is further configured to: trigger an emergency climb command when the deviation between the flight altitude of the UAV and the ground safety distance range exceeds the normal deviation threshold; and automatically switch to binocular visual obstacle avoidance mode during the execution of the emergency climb command to avoid collision with obstacles.

[0148] In some embodiments, the urban engineering mapping device based on UAV provided in this application further includes: a prediction unit, used to predict the remaining flight time of the UAV in real time based on the correlation between terrain complexity and sensor power consumption, wherein terrain complexity is proportional to sensor power consumption; the adjustment unit 203 is also used to automatically switch to a low-power data acquisition mode when the remaining flight time is lower than the safe flight time threshold, to map key terrain, and to send a power reminder message to the mobile terminal.

[0149] In the urban engineering surveying device based on UAVs provided in this application embodiment, the terrain contour is scanned in real time by a laser rangefinder at the bottom of the landing gear to capture the subtle undulations of the ground surface, avoiding data gaps caused by the fixed altitude of the UAV in steep slope areas. The flight altitude is calculated in real time based on the three-dimensional flight profile and the safe distance range, and a variable altitude flight path is generated to ensure that the UAV maintains a constant relative distance with irregular terrain, eliminating measurement blind spots caused by altitude mismatch in traditional surveying. The pod attitude is automatically adjusted by combining the flight path direction and the spatial orientation of the survey target, so that the main sensor is always vertically aligned with the target surface, realizing the complete acquisition of building facade data. Finally, the positioning is corrected in real time by fusing ground control point data through a dynamic benchmark correction module, suppressing the cumulative effect of elevation and plane measurement errors, thereby eliminating measurement blind spots and improving measurement accuracy in complex urban environments.

[0150] Regarding the apparatus in the above embodiments, the specific manner in which each module performs its operation has been described in detail in the embodiments related to the method, and will not be elaborated upon here.

[0151] Figure 3 This is a structural diagram of an electronic device provided in an embodiment of this application. Figure 3 As shown, the electronic device 300 includes, but is not limited to, a processor 301 and a memory 302.

[0152] The aforementioned memory 302 is used to store the executable instructions of the aforementioned processor 301. It is understood that the processor 301 is configured to execute instructions to implement the UAV-based urban engineering surveying method in the above embodiments.

[0153] It should be noted that those skilled in the art will understand that Figure 3 The electronic device structure shown does not constitute a limitation on the electronic device; the electronic device may include, but is not limited to, other electronic devices. Figure 3 This may indicate more or fewer components, or combinations of certain components, or different component arrangements.

[0154] Processor 301 is the control center of the electronic device. It connects various parts of the electronic device via various interfaces and lines. By running or executing software programs and / or modules stored in memory 302, and by calling data stored in memory 302, it performs various functions and processes data, thereby providing overall monitoring of the electronic device. Processor 301 may include one or more processing units. Optionally, processor 301 may integrate an application processor and a modem processor. The application processor mainly handles the operating system, user interface, and applications, while the modem processor mainly handles wireless communication. It is understood that the modem processor may not be integrated into processor 301.

[0155] The memory 302 can be used to store software programs and various data. The memory 302 may mainly include a program storage area and a data storage area, wherein the program storage area may store the operating system, application programs required by at least one functional module (such as a determination unit, a processing unit, etc.), etc. In addition, the memory 302 may include high-speed random access memory, and may also include non-volatile memory, such as at least one disk storage device, flash memory device, or other volatile solid-state storage device.

[0156] In an exemplary embodiment, a computer-readable storage medium including instructions is also provided, such as a memory 302 including instructions, which can be executed by a processor 301 of an electronic device 300 to implement the UAV-based urban engineering surveying method in the above embodiments.

[0157] In actual implementation, Figure 2 The steps performed by the acquisition unit 201, generation unit 202, adjustment unit 203, and correction unit 204, as well as the prediction unit, can all be performed by [the following]. Figure 3 The processor 301 calls the computer program stored in the memory 302 to implement the process. The specific execution process can be found in the method section of the previous embodiment, and will not be repeated here.

[0158] Optionally, the computer-readable storage medium may be a non-transitory computer-readable storage medium, such as a read-only memory (ROM), random access memory (RAM), CD-ROM, magnetic tape, floppy disk, and optical data storage device.

[0159] In an exemplary embodiment, this application also provides a computer program product including one or more instructions, which can be executed by the processor 301 of an electronic device to complete the UAV-based urban engineering surveying method in the above embodiments.

[0160] It should be noted that when one or more instructions in the computer-readable storage medium or computer program product are executed by the processor of an electronic device, they implement the various processes of the above method embodiments and achieve the same technical effect as the above method. To avoid repetition, they will not be described again here.

[0161] Through the above description of the embodiments, those skilled in the art can clearly understand that, for the sake of convenience and brevity, only the division of the above functional modules is used as an example. In actual applications, the above functions can be assigned to different functional modules as needed, that is, the internal structure of the device can be divided into different functional modules to complete all or part of the functions described above.

[0162] In the several embodiments provided in this application, it should be understood that the disclosed apparatus and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of modules or units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another apparatus, or some features may be ignored or not executed. Furthermore, the mutual coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between apparatuses or units may be electrical, mechanical, or other forms.

[0163] The units described as separate components may or may not be physically separate. A component shown as a unit can be one or more physical units; that is, it can be located in one place or distributed in multiple different locations. Some or all of the classified units can be selected to achieve the purpose of this embodiment, depending on actual needs.

[0164] Furthermore, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0165] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a readable storage medium. Based on this understanding, the technical solution of the embodiments of this application, essentially, or the part that contributes to the prior art, or a complete or partial classification of the technical solution, can be embodied in the form of a software product. This software product is stored in a storage medium and includes several instructions to cause a device (which may be a microcontroller, chip, etc.) or processor to execute all or part of the steps of the methods of the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, ROM, RAM, magnetic disks, or optical disks.

[0166] The above are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A method for urban engineering surveying based on unmanned aerial vehicles (UAVs), characterized in that, include: The terrain sensing device on the drone scans the terrain outline of the survey area in real time to obtain terrain height data; The terrain sensing device is a laser rangefinder installed at the bottom of the UAV landing gear. A three-dimensional flight profile is constructed based on the terrain height data, and the flight altitude of the UAV is determined in real time according to the three-dimensional flight profile and the ground safety distance range, and a flight path adapted to the terrain contour is generated. According to the flight path and the direction of the mapping target, the attitude of the mapping pod is adjusted by a rotatable pod drive device so that the main sensors inside the mapping pod are vertically aligned with the surface of the mapping target. The mapping pod is connected to the fuselage of the UAV through the pod drive device. The system receives data from ground reference stations via a dynamic benchmark correction module, and uses ground control points as a reference to correct the positioning data during the surveying process in real time, outputting the surveying results.

2. The urban engineering surveying method based on unmanned aerial vehicles (UAVs) according to claim 1, characterized in that, The process of constructing a three-dimensional flight profile based on the terrain height data, and determining the UAV's flight altitude in real time according to the three-dimensional flight profile and the ground safety distance range, and generating a flight path adapted to the terrain contour, includes: The terrain height data is converted into a digital elevation model for visually representing the terrain undulations; Extract the terrain curvature from the digital elevation model and automatically classify the terrain complexity level; For different levels of terrain complexity, multiple flight sub-paths are generated based on the ground safety distance range. Each flight sub-path includes flight altitude, pitch angle, and flight speed. The flight route includes the plurality of flight sub-routes.

3. The urban engineering surveying method based on unmanned aerial vehicles (UAVs) according to claim 2, characterized in that, The method generates multiple flight sub-routes based on the ground safety distance, according to different terrain complexity levels, including: When the terrain complexity level is steep, the flight altitude is reduced, the pitch angle is increased, and the scanning frequency is increased to generate a first flight sub-path. In the case of a flat area with a terrain complexity level, the flight speed is increased and the flight altitude is increased to reach the maximum value of the ground safety distance range to generate a second flight sub-route; The plurality of flight sub-routes include the first flight sub-routes and the second flight sub-routes.

4. The urban engineering surveying method based on unmanned aerial vehicles (UAVs) according to claim 1, characterized in that, The target being surveyed is the building facade. The process of adjusting the attitude of the surveying pod, based on the flight path and the direction of the target, using a rotatable pod drive device, includes: The mapping pod is driven by the pod drive device; Upon detecting the building facade, the sensor's scanning plane is automatically adjusted and locked to ensure that the sensor remains parallel to the building facade normal.

5. The urban engineering surveying method based on unmanned aerial vehicles (UAVs) according to claim 1, characterized in that, The process involves receiving ground reference station data via a dynamic reference correction module, using ground control points as a reference to perform real-time corrections on the positioning data during the surveying process, and outputting surveying results, including: The signal receiving device in the dynamic reference correction module receives the carrier phase differential signal transmitted from the ground reference station. The positioning data is compared and analyzed in real time with the coordinates of the ground control points to obtain the difference data. The difference data is compensated using a filtering algorithm, and the mapping result is output.

6. The urban engineering surveying method based on unmanned aerial vehicles (UAVs) according to claim 1, characterized in that, The method further includes: If the deviation between the flight altitude of the drone and the ground safety distance exceeds the normal deviation threshold, an emergency climb command is triggered. During the execution of the emergency climb command, the system automatically switches to binocular vision obstacle avoidance mode to avoid collisions with obstacles.

7. The urban engineering surveying method based on unmanned aerial vehicles (UAVs) according to claim 1, characterized in that, The method further includes: Based on the correlation between terrain complexity and sensor power consumption, the remaining flight time of the UAV is predicted in real time, and the terrain complexity is proportional to the sensor power consumption. If the remaining flight time is lower than the safe flight time threshold, the system will automatically switch to a low-power data acquisition mode to map key terrain features and send a battery level reminder to the mobile terminal.

8. A drone-based urban engineering surveying device, characterized in that, The device includes: The acquisition unit is used to scan the terrain outline of the survey area in real time through the terrain sensing device carried by the UAV and acquire terrain height data; the terrain sensing device is a laser rangefinder installed at the bottom of the UAV landing gear. The generation unit is used to construct a three-dimensional flight profile based on the terrain height data, and determine the flight altitude of the UAV in real time according to the three-dimensional flight profile and the ground safety distance range, and generate a flight path adapted to the terrain. An adjustment unit is used to adjust the attitude of the mapping pod according to the flight path and the direction of the mapping target through a rotatable pod drive device, so that the main sensors inside the mapping pod are vertically aligned with the surface of the mapping target. The mapping pod is connected to the fuselage of the UAV through the pod drive device. The correction unit is used to receive ground reference station data through the dynamic reference correction module, and to correct the positioning data in the surveying process in real time based on the ground control points, and output the surveying results.

9. An electronic device, characterized in that, include: processor; Memory used to store the processor's executable instructions; The processor is configured to execute the instructions to implement the UAV-based urban engineering surveying method according to any one of claims 1 to 7.

10. A computer-readable storage medium storing instructions, characterized in that, When the computer executes the instruction, the computer performs the urban engineering surveying method based on unmanned aerial vehicles as described in any one of claims 1 to 7.

Images