阅读说明：本技术 一种无人机复合立体测绘系统及方法 (Unmanned aerial vehicle composite three-dimensional surveying and mapping system and method ) 是由 张俊 蔡莹 于 2021-08-11 设计创作，主要内容包括：本发明涉及了一种无人机复合立体测绘系统及方法,涉及测绘领域,该系统可实现高效率、高精度主被动复合测绘,获取目标区域三维DEM信息。无人机复合立体测绘系统由无人机作业分系统和地面控制处理分系统组成。无人机作业分系统包括无人机平台、激光雷达、五拼相机、GNSS/IMU组合导航单元、数据交互子系统1,地面控制处理分系统包括地面站、地面基站、数据交互子系统2。两个分系统通过无线指令实现控制指令与系统状态数据的双向传输,激光雷达获取的三维激光点云数据与五拼相机采集的倾斜摄影测量数据融合,获取工作区域的高精度地表DEM信息。(The invention relates to an unmanned aerial vehicle composite three-dimensional mapping system and method, relates to the field of mapping, and can realize high-efficiency and high-precision active and passive composite mapping and acquire three-dimensional DEM information of a target area. The unmanned aerial vehicle composite three-dimensional mapping system is composed of an unmanned aerial vehicle operation subsystem and a ground control processing subsystem. The unmanned aerial vehicle operation subsystem comprises an unmanned aerial vehicle platform, a laser radar, a five-spelling camera, a GNSS/IMU combined navigation unit and a data interaction subsystem 1, and the ground control processing subsystem comprises a ground station, a ground base station and a data interaction subsystem 2. The two subsystems realize bidirectional transmission of control instructions and system state data through wireless instructions, three-dimensional laser point cloud data acquired by the laser radar is fused with oblique photogrammetry data acquired by the five-spelling camera, and high-precision earth surface DEM information of a working area is acquired.)

1. The utility model provides a compound three-dimensional mapping system of unmanned aerial vehicle which characterized in that: comprises an unmanned aerial vehicle operation subsystem and a ground control processing subsystem,

the unmanned aerial vehicle operation subsystem comprises an unmanned aerial vehicle platform (1), a laser radar (2), a five-piece camera (3), a GNSS/IMU combined navigation unit (4) and a data interaction subsystem (1) (5);

the ground control processing subsystem comprises a ground station (6), a data interaction subsystem 2(7) and a ground base station (8);

the GNSS/IMU combined navigation unit (4) is integrally and rigidly connected with the laser radar (2) and the five-spelling camera (3) to acquire high-precision attitude positioning information in real time;

the data interaction subsystem 1 of the unmanned aerial vehicle operation subsystem transmits the system working state and part of operation data back to the data interaction subsystem 2 of the ground control processing subsystem through a wireless link, so that state monitoring and data display are realized;

and the data interaction subsystem 2 transmits the control instruction to the unmanned aerial vehicle operation subsystem to realize the flight control and the load workflow control of the unmanned aerial vehicle.

The ground station realizes flight control, air route planning and airborne service state monitoring and display.

2. The unmanned aerial vehicle composite stereo mapping system of claim 1, wherein: laser radar (2) and five camera (3) are arranged before and after the axis of unmanned aerial vehicle, place unmanned aerial vehicle's cabin in laser radar (2) in to the cabin is explored out, and five camera (3) are installed in unmanned aerial vehicle's belly below.

3. The unmanned aerial vehicle composite stereo mapping system of claim 1, wherein: the imaging mode of the laser radar (2) is scanning imaging, and the ground width determined by the scanning range of the laser radar is consistent with the ground width of the five-camera.

4. The unmanned aerial vehicle composite stereo mapping system of claim 1, wherein: 4 cameras of the five-camera are fixedly arranged on the bracket according to an inclination angle of 30-45 degrees, 1 camera is fixedly arranged at the end of the camera frame according to an orthographic angle, and the five cameras are exposed simultaneously.

5. The unmanned aerial vehicle composite stereo mapping system of claim 1, wherein: laser radar (2), five spelling camera (3), the integrative fixed mounting of GNSS IMU integrated navigation unit (4) to with unmanned aerial vehicle shock insulation installation, system stability and security when the guarantee flight operation acquire the attitude positioning information of high accuracy simultaneously.

6. The unmanned aerial vehicle composite stereo mapping system according to claim 1, characterized in that: the data acquisition comprises the following contents:

before measurement begins, a monitoring system of a ground station is started, an unmanned aerial vehicle is started to climb to a preset operation height, the aircraft hovers or flies in a cruising mode, a control command is sent through a data interaction subsystem 2, the composite three-dimensional mapping system of the unmanned aerial vehicle is started, the running state of equipment is monitored through returned system state information, the unmanned aerial vehicle flies to a measurement area to operate after the equipment normally runs, and a data interaction subsystem 1 summarizes system state data and part of operation data and returns the data according to a work command of the ground station.

7. The unmanned aerial vehicle composite stereo mapping system of claim 1, wherein: the laser radar (2) and the five-spelling camera (3) carry out laser emission and visible light exposure according to a fixed time sequence under the synchronization of second pulses output by the GNSS/IMU combined navigation unit (4) so as to realize the high-precision acquisition of the laser emission time and the exposure time.

8. An unmanned aerial vehicle composite stereo mapping method is characterized in that: and point cloud data of the laser radar and three-dimensional imaging data are acquired at one time in the one-time operation process, and the point cloud data of the laser radar is used for compensating a cavity area caused by poor illumination conditions in the imaging data, so that composite three-dimensional mapping is realized.

9. The unmanned aerial vehicle composite stereo mapping method according to claim 8, wherein: composite imaging, comprising the steps of:

step 1, a laser radar acquires ground object laser point cloud data, and the point cloud data is subjected to cluster filtering and denoising processing to generate laser three-dimensional imaging data;

step 2, acquiring ground object imaging data of 5 angles by a five-spelling camera, performing wavelet transformation denoising processing on the imaging data, setting special ground objects at the edge of an imaging area and in the area, wherein the special ground objects are a plurality of typical ground objects or mark points, setting control points and check points at the plurality of typical ground objects or mark points, acquiring position parameters of the control points and the check points through field RTK measurement, correcting the camera image geometry through the control points, correcting the geometric errors and the geographic position information of the camera image, and performing precision evaluation and quality control on the camera image through the check points;

step 3, after the camera image geometric correction, matching the feature points on different images through extracting the feature points of the processed multi-angle image according to the feature points, and generating the ground object three-dimensional imaging data after matching;

and 4, judging a cavity area caused by poor illumination conditions in the ground object three-dimensional imaging data by adopting a manual or automatic judging mode, extracting characteristic ground objects in the laser three-dimensional imaging data and the ground object three-dimensional imaging data, and overlapping and filling the laser radar point cloud data into the cavity area in the ground object three-dimensional imaging data through characteristic ground object matching to realize composite imaging.

Technical Field

The invention relates to the field of surveying and mapping, and provides a composite three-dimensional surveying and mapping system and method for an unmanned aerial vehicle.

Background

The laser radar is a new three-dimensional data acquisition means, can quickly acquire topographic surface data, surface feature and the like, is an active measurement technology with high precision, high density and high efficiency, can perform field scanning under various severe observation conditions, quickly acquires mass three-dimensional laser point cloud data on the surface of a target object in a large area, and realizes three-dimensional imaging of the target object. The technology has some defects, such as the limited contour capability of the ground object, the non-ideal shooting angle of the camera, etc.

The oblique photography measurement technology is to utilize an oblique photography device to simultaneously and rapidly obtain an oblique image and an orthoimage, then utilize a computer automatic graphic processing technology to carry out automatic space-three processing, and through image matching and surface texture mapping technical means, the real scenery on the earth surface is really restored to the maximum extent, but the problem of measurement accuracy also exists.

The three-dimensional laser scanning and oblique photogrammetry technologies have respective advantages and disadvantages, the two technical means are combined to mutually make up for the defects, high-precision and high-density three-dimensional imaging can be rapidly and comprehensively obtained, and the surface change of the terrain can be obviously reflected.

Disclosure of Invention

The invention aims to provide an unmanned aerial vehicle composite stereo mapping system, which aims to solve the problem that three-dimensional information provided in the background is difficult to be acquired in an integral manner and provide a composite stereo imaging system with high efficiency, high precision and high detail.

In order to achieve the purpose, the invention realizes the unmanned aerial vehicle composite three-dimensional mapping system through the following technical scheme, which comprises an unmanned aerial vehicle operation subsystem and a ground control processing subsystem.

The unmanned aerial vehicle operation subsystem comprises a suspended wing or fixed wing unmanned aerial vehicle, a laser radar, a five-spelling camera, a GNSS/IMU combined navigation unit, a data interaction subsystem and auxiliary equipment.

The ground control processing subsystem comprises a ground station, a ground base station, a data interaction subsystem and emergency remote control equipment.

The laser radar is a scanning imaging laser radar, and the ground width determined by the scanning range of the laser radar is consistent with the ground width of the five-camera.

The five-camera system is characterized in that 4 cameras of the five-camera system are fixedly arranged on the support according to a certain inclination angle, the inclination angle is 30-45 degrees, 1 camera is fixedly arranged at the end of the camera frame according to an orthographic angle, and the five cameras are exposed simultaneously and used for acquiring ground feature pictures at different angles and generating three-dimensional images of the ground features.

The GNSS/IMU integrated navigation unit is rigidly mounted with the onboard laser radar and the five-camera in an integrated manner and is mounted with the aircraft platform in a shock insulation manner, so that the stability and the safety of the system during flight operation are guaranteed, and high-precision attitude positioning information is obtained.

The on-board data interaction subsystem 1 can realize control and management of a platform and a load, the working state of the system is returned in real time through the data transmission module of the data interaction subsystem 1 to monitor the working state, meanwhile, part of data can be returned in real time through the data transmission module, and all operation data can be stored on the on-board data interaction subsystem.

The ground station realizes the functions of flight control, air route planning and airborne service state monitoring and display.

The ground base station and the on-board GNSS/IMU combined navigation unit realize differential solution of positioning data and obtain more accurate airplane position information.

The whole system data acquisition comprises the following contents:

before the measurement is started, a monitoring system of a ground station is started, an unmanned aerial vehicle is started to climb to a preset operation height, the aircraft flies in a hovering or cruising mode, a load device is started, the operation state of the device is monitored, the unmanned aerial vehicle flies to a measurement area for operation after the device normally operates, a data transmission module collects system state data and part of operation data, and data are returned according to a work instruction of the ground station.

The invention also provides a composite three-dimensional surveying and mapping method of the unmanned aerial vehicle, wherein the laser radar and the five-spelling camera carry out laser emission and visible light exposure according to a fixed time sequence under the synchronization of the second pulse output by the GNSS/IMU combined navigation unit so as to realize the high-precision acquisition of the laser emission time and the exposure time. And point cloud data of the laser radar and three-dimensional imaging data are acquired at one time in the one-time operation process, and the point cloud data of the laser radar is used for compensating a cavity area caused by poor illumination conditions in the imaging data, so that composite three-dimensional mapping is realized.

Composite imaging, comprising the steps of:

step 1, a laser radar acquires ground object laser point cloud data, and the point cloud data is subjected to cluster filtering and denoising processing to generate laser three-dimensional imaging data;

step 2, acquiring ground object imaging data of 5 angles by a five-spelling camera, performing wavelet transformation denoising processing on the imaging data, setting special ground objects at the edge of an imaging area and in the area, wherein the special ground objects are a plurality of typical ground objects or mark points, setting control points and check points at the plurality of typical ground objects or mark points, acquiring position parameters of the control points and the check points through field RTK measurement, correcting the camera image geometry through the control points, correcting the geometric errors and the geographic position information of the camera image, and performing precision evaluation and quality control on the camera image through the check points;

step 3, after the camera image geometric correction, matching the feature points on different images through extracting the feature points of the processed multi-angle image according to the feature points, and generating the ground object three-dimensional imaging data after matching;

and 4, judging a cavity area caused by poor illumination conditions in the ground object three-dimensional imaging data by adopting a manual or automatic judging mode, extracting characteristic ground objects in the laser three-dimensional imaging data and the ground object three-dimensional imaging data, and overlapping and filling the laser radar point cloud data into the cavity area in the ground object three-dimensional imaging data through characteristic ground object matching to realize composite imaging.

Due to the adoption of the technical scheme, the invention has the following beneficial effects:

the invention realizes synchronous three-dimensional imaging of the same area through the laser radar and the five-spelling camera, performs quality control on radar and camera data through control points and check points acquired by field measurement, and realizes three-dimensional composite three-dimensional mapping of the laser and the five-spelling camera through image registration. The point cloud three-dimensional image acquired by the laser radar can compensate a cavity area caused by poor illumination conditions in the three-dimensional imaging data of the five-piece camera, so that the surveying and mapping cavity area is reduced, the data effectiveness is improved, and the method is more suitable for topographic surveying and mapping operation under complex topographic environments.

Drawings

FIG. 1 is a schematic diagram of an implementation of a composite three-dimensional mapping system for unmanned aerial vehicles

Detailed Description

An implementation schematic diagram of a composite stereo mapping system of an unmanned aerial vehicle is shown in fig. 1.

The following is a detailed description of the overall system:

the system comprises an unmanned aerial vehicle operation subsystem and a ground control processing subsystem, wherein the unmanned aerial vehicle operation subsystem comprises an unmanned aerial vehicle, a laser radar, a five-spelling camera, a GNSS/IMU combined inertial navigation unit and a data interaction subsystem 1. The ground control processing subsystem comprises a ground base station, a data interaction subsystem 2 and emergency remote control equipment. And the ground control processing subsystem and the unmanned aerial vehicle operation subsystem realize data transmission through wireless instructions.

The GNSS/IMU integrated navigation unit is rigidly mounted with the onboard laser radar and the five-spelling camera in an integrated manner and is mounted with the aircraft platform in a shock insulation manner, so that the stability and the safety of the system during flight operation are guaranteed, and high-precision attitude positioning information is obtained. The specific information comprises the azimuth, the roll and the course angle of the acquisition system and the geographic coordinate information of the flight platform, is used for the coordinate calculation and data processing of the laser radar, and provides the exterior orientation element information of the five-spelling camera. The measurement accuracy of the azimuth, the roll and the course angle is better than 0.05 degrees, and the position accuracy is better than 3 m.

The laser radar and the five-piece camera are arranged in the front and back direction along the axis. The laser radar is arranged in the cabin and extends out of the cabin, and the five-piece camera is arranged below the belly. The laser radar is externally provided with a cooling fan device so as to provide sufficient air convection and be conveniently used in places with difficult air circulation. Five piece together the camera and fix 5 cameras installation on the support according to certain angle, in this embodiment, 4 cameras that the focus is 55mm are fixed on the camera frame according to the angle of slope 40, 1 camera focus is fixed at the camera frame end according to the angle of orthographic, controls the synchronous exposure of 5 cameras through the singlechip at last.

Before unmanned aerial vehicle began to measure, start the monitored control system of ground station, start unmanned aerial vehicle and climb to predetermineeing the operation height, the aircraft hovers or flies to cruising, starts load equipment, monitoring facilities running state, and equipment operation normal back unmanned aerial vehicle flies to the operation of surveying the district, and data transmission module summary system status data and part operation data pass back data according to ground station work order.

The onboard and ground data interaction subsystems can realize control management of the platform and the load. The working state of the system is transmitted back in real time through the data transmission interface to monitor the working state, partial data can be transmitted back in real time through the data transmission interface, and all operation data can be stored in the on-board system.

The composite imaging comprises the following steps

Step 1, a laser radar acquires ground object laser point cloud data, and the point cloud data is subjected to cluster filtering and denoising processing to generate laser three-dimensional imaging data;

step 2, acquiring ground object imaging data of 5 angles by a five-spelling camera, performing wavelet transformation denoising processing on the imaging data, setting special ground objects at the edge of an imaging area and in the area, wherein the special ground objects are a plurality of typical ground objects or mark points, setting control points and check points at the plurality of typical ground objects or mark points, acquiring position parameters of the control points and the check points through field RTK measurement, correcting the camera image geometry through the control points, correcting the geometric errors and the geographic position information of the camera image, and performing precision evaluation and quality control on the camera image through the check points;

step 3, after the camera image geometric correction, matching the feature points on different images through extracting the feature points of the processed multi-angle image according to the feature points, and generating the ground object three-dimensional imaging data after matching;

and 4, judging a cavity area caused by poor illumination conditions in the ground object three-dimensional imaging data by adopting a manual or automatic judging mode, extracting characteristic ground objects in the laser three-dimensional imaging data and the ground object three-dimensional imaging data, and overlapping and filling the laser radar point cloud data into the cavity area in the ground object three-dimensional imaging data through characteristic ground object matching to realize composite imaging.