阅读说明：本技术 背包式近景摄影测量装置及无人机倾斜摄影测量建模方法 (Backpack type close-range photogrammetry device and unmanned aerial vehicle oblique photogrammetry modeling method ) 是由 张晓东 陈从建 钱声源 于 2019-10-09 设计创作，主要内容包括：背包式近景摄影测量装置及无人机倾斜摄影测量建模方法,包括如下步骤：步骤1：采用无人机进行山地特征测区的倾斜摄影测量；步骤2：根据倾斜摄影测量的结果构建初始三维模型；步骤3：采用背包式近景摄影测量装置进行近景摄影测量；步骤4：将倾斜摄影测量和近景摄影测量的影像进行多源数据融合,构建测区的精细化三维模型。本发明不仅能够提高作业效率,而且能够构建高质量、超精细化的三维模型,助力农村不动产三维信息平台的建设。(The backpack close-range photogrammetry device and the unmanned aerial vehicle oblique photogrammetry modeling method comprise the following steps: step 1: carrying out oblique photogrammetry of a mountain characteristic measurement area by adopting an unmanned aerial vehicle; step 2: constructing an initial three-dimensional model according to the result of oblique photogrammetry; and step 3: carrying out close-range photogrammetry by adopting a backpack close-range photogrammetry device; and 4, step 4: and performing multi-source data fusion on the images of the oblique photogrammetry and the close-range photogrammetry to construct a refined three-dimensional model of the measurement area. The method can improve the operation efficiency, construct a high-quality and ultra-fine three-dimensional model and assist the construction of a rural real estate three-dimensional information platform.)

1. Backpack close-range photogrammetry device, its characterized in that includes: the system comprises a tripod head camera (1), an antenna rod (2), a backpack (3) and a GPS receiver (4); the antenna rod (2) is fixed on the backpack (3), the holder camera (1) is fixed on the antenna rod (2), the zenith distance between the holder camera (1) and the antenna rod (2) is 60 degrees, the holder camera (1) is positioned on the right side of the advancing direction, a holder (5) of the holder camera (1) is flexibly connected with the camera (6), the swinging angle of the camera (6) in the horizontal direction is +/-90 degrees, and the swinging angle in the vertical direction is +30 to-90 degrees, wherein the elevation is +; the GPS receiver (4) is fixed at the top of the antenna rod (2), the GPS receiver (4) is a double-pin receiver, and a tilt module is arranged in the double-pin receiver and used for measuring the position of the camera (6) in a motion tilt state.

2. The backpack close-up photogrammetry apparatus of claim 1, wherein: the camera (6) has a focal length of 8.8mm and is provided with 1 inch of 1200 ten thousand pixels of CMOS.

3. The unmanned aerial vehicle oblique photogrammetry modeling method using the backpack type close-range photogrammetry apparatus of claim 1, characterized by comprising the steps of:

step 1: carrying out oblique photogrammetry of a mountain characteristic measurement area by adopting an unmanned aerial vehicle;

step 2: constructing an initial three-dimensional model according to the result of oblique photogrammetry;

and step 3: carrying out close-range photogrammetry by adopting a backpack close-range photogrammetry device;

and 4, step 4: and performing multi-source data fusion on the images of the oblique photogrammetry and the close-range photogrammetry to construct a refined three-dimensional model of the measurement area.

4. The UAV oblique photogrammetry modeling method of claim 3, characterized in that: in the step 1, a survey area range is imported on a mobile terminal flight control platform, and an unmanned aerial vehicle route is automatically planned according to the flight height of 100m, the route overlap degree of 85% and the sidewise overlap degree of 70%; and starting the fixed relative flight height to fly, and automatically adjusting the flight height according to the relief of the terrain in the flying process.

5. The UAV oblique photogrammetry modeling method of claim 3, characterized in that: in the step 2, after the flight is finished, an initial three-dimensional model is constructed through data preprocessing, multi-view image joint adjustment, multi-view image dense matching, high-density point cloud construction, TIN construction and texture fitting; and checking the quality of the initial three-dimensional model, carrying out interior operation labeling on the pattern drawing and the cavity caused by shielding and missed flying, and carrying out additional shooting on the field by adopting a backpack close-range photogrammetry device.

6. The UAV oblique photogrammetry modeling method of claim 3, characterized in that: in the step 3, a backpack close-range photogrammetric device is adopted to perform the supplementary measurement at the position of the interior trade mark: the method comprises the steps of firstly determining the overlapping range of a close-range image and an inclined image, selecting a fixed-focus lens, then calculating a proper shooting distance according to the requirement of modeling resolution and the focal length of adopted equipment, and finally performing field close-range complementary shooting.

7. The UAV oblique photogrammetry modeling method of claim 3, characterized in that: in the step 4, the coordinates of the close-up image and the oblique image are unified and are jointly imported into modeling software; and performing aerial triangulation, TIN construction and texture fitting on multi-source data fusion to construct a refined three-dimensional model.

Technical Field

The invention belongs to the technical field of low-altitude photogrammetry, and particularly relates to a backpack type close-range photogrammetry device and an unmanned aerial vehicle oblique photogrammetry modeling method.

Background

The unmanned aerial vehicle oblique photogrammetry technology overturns the limitation that the original orthoimage can only be shot from a vertical angle, and the information of a ground object which is more complete and accurate is obtained by carrying a plurality of sensors on the same flight platform and simultaneously acquiring images from five different angles such as a vertical angle, four inclinations and the like. The multi-angle live-action three-dimensional model is provided, and the length, width and height of the ground object can be measured off-site.

The unmanned aerial vehicle oblique photogrammetry technology is more and more applied to rural real estate investigation with the technical advantages of being capable of providing efficient, high-precision, real three-dimensional models and the like. However, aiming at the characteristics of tree shielding, scattered, disordered and small real estate distribution and the like, the existing unmanned aerial vehicle oblique photogrammetry technology has the following problems:

1. in the prior art, due to the fact that trees shield, house texture information is lost, and the quality of a three-dimensional model is poor;

2. in the prior art, due to the characteristic that a farm house is scattered and small, the shooting angle of a camera is limited, and the height of an airplane is limited, the eave is seriously scratched.

Disclosure of Invention

Aiming at the defects in the prior art, the invention provides a backpack close-range photogrammetry device and an unmanned aerial vehicle oblique photogrammetry modeling method.

In order to achieve the purpose, the invention adopts the following technical scheme:

backpack close-range photogrammetry device, its characterized in that includes: the system comprises a pan-tilt camera, an antenna rod, a backpack and a GPS receiver; the antenna rod is fixed on the backpack, the holder camera is fixed on the antenna rod, the zenith distance between the holder camera and the antenna rod is 60 degrees, the holder camera is positioned on the right side of the advancing direction, a holder of the cloud platform in the holder camera is flexibly connected with the camera, the swinging angle of the camera in the horizontal direction is +/-90 degrees, and the swinging angle of the camera in the vertical direction is +30 to-90 degrees, wherein the elevation is plus; the GPS receiver is fixed on the top of the antenna mast, is a double-spelling receiver and is internally provided with an inclination module and used for measuring the position of the camera in a movement inclination state.

In order to optimize the technical scheme, the specific measures adopted further comprise:

further, the camera has a focal length of 8.8mm and is provided with 1 inch of 1200 ten thousand pixels of CMOS.

In addition, the invention also provides an unmanned aerial vehicle oblique photogrammetry modeling method adopting the backpack type close-range photogrammetry device, which is characterized by comprising the following steps:

step 1: carrying out oblique photogrammetry of a mountain characteristic measurement area by adopting an unmanned aerial vehicle;

step 2: constructing an initial three-dimensional model according to the result of oblique photogrammetry;

and step 3: carrying out close-range photogrammetry by adopting a backpack close-range photogrammetry device;

and 4, step 4: and performing multi-source data fusion on the images of the oblique photogrammetry and the close-range photogrammetry to construct a refined three-dimensional model of the measurement area.

Further, in the step 1, a survey area range is imported on the mobile terminal flight control platform, and an unmanned aerial vehicle route is automatically planned according to the flight height of 100m, the route overlap degree of 85% and the lateral overlap degree of 70%; and starting the fixed relative flight height to fly, and automatically adjusting the flight height according to the relief of the terrain in the flying process.

Further, in the step 2, after the flight is finished, an initial three-dimensional model is constructed through data preprocessing, multi-view image joint adjustment, multi-view image dense matching, high-density point cloud construction, TIN construction and texture fitting; and checking the quality of the initial three-dimensional model, carrying out interior operation labeling on the pattern drawing and the cavity caused by shielding and missed flying, and carrying out additional shooting on the field by adopting a backpack close-range photogrammetry device.

Further, in step 3, a backpack close-range photogrammetry device is adopted to perform the supplementary measurement at the position of the interior mark: the method comprises the steps of firstly determining the overlapping range of a close-range image and an inclined image, selecting a fixed-focus lens, then calculating a proper shooting distance according to the requirement of modeling resolution and the focal length of adopted equipment, and finally performing field close-range complementary shooting.

Further, in the step 4, coordinates of the close-up image and the oblique image are unified and are jointly imported into modeling software; and performing aerial triangulation, TIN construction and texture fitting on multi-source data fusion to construct a refined three-dimensional model.

The invention has the beneficial effects that: the method can improve the operation efficiency, construct a high-quality and ultra-fine three-dimensional model and assist the construction of the rural real estate three-dimensional information platform.

Drawings

Fig. 1 is a cross-sectional view of a backpack type close-up photogrammetric apparatus.

Fig. 2 is a plan view of the backpack close-up photogrammetric apparatus.

Detailed Description

The present invention will now be described in further detail with reference to the accompanying drawings.

As shown in fig. 1 and 2, in the backpack type close-range photogrammetric apparatus, the pan-tilt camera 1 is rigidly connected to the antenna mast 2, and the antenna mast 2 is rigidly connected to the backpack 3, and the pan-tilt camera 1 is located on the right side in the forward direction. The distance between the holder camera 1 and the antenna mast 2 is 60 degrees, namely the holder camera 1 inclines upwards by 30 degrees in a vertical plane, and the eave is shot better. The holder bracket 5 is flexibly connected with the camera 6, the swing angle of the camera 6 in the horizontal direction is +/-90 degrees, and the swing angle in the vertical direction is plus 30 to minus 90 degrees (viewed as plus +). The GPS receiver 4 is a double-spelling receiver, is internally provided with an inclination module, namely adopts the inertial navigation technology, and can accurately measure the position of the camera in a movement inclination state. The camera 6 has a focal length of 8.8mm and is equipped with 1-inch 1200-ten-thousand-pixel CMOS.

The unmanned aerial vehicle oblique photogrammetry modeling method mainly adopts the following technologies:

1. the space calibration technology of the camera and the GPS comprises calibration of a non-measuring camera and a space position relation of a phase center of the camera and a GPS receiver.

(1) Camera calibration: and (3) distributing more control points by adopting a three-dimensional control field calibration method based on a collinear condition equation, and performing three-dimensional calibration by utilizing a rear intersection method to obtain distortion parameters and internal orientation elements of the camera.

(2) Calibrating the space position of the camera: the device is measured by adopting two high-precision total stations under the same coordinate system to obtain the space position of the camera center and the space position of the GPS phase center, and the lever arm vectors of the camera center relative to the GPS phase center, including delta X, delta Y and delta Z, are calculated.

2. Time registration techniques of camera and GPS.

An active synchronization mode is adopted, a serial port communication technology and a time synchronization controller are utilized, and a collection mobile terminal control system is built. By triggering a photographing command, the time synchronization controller accurately sends a pulse electric signal to controllers of the camera and the GPS receiver, so that image data acquisition and spatial position determination are realized in the same time reference

3. Multi-source data fusion techniques. And (3) unifying the space coordinate systems of the close-range image and the oblique image through coordinate conversion, importing the POS into the photo image, fusing the multi-source images, and constructing a high-quality and ultra-fine three-dimensional model.

The embodiment is further explained in connection with the investigation project of real estate property title in a mountain area.

1. Survey area overview

The elevation of the geodetic region is measured, the gradient is 25-30 degrees, the maximum elevation difference is 258m, and the geodetic region belongs to the typical mountain feature; trees flourish and houses are seriously shielded. The real estate area of the measurement area is 0.3km²The total number of the filter elements is 252, and the density is 840/km²Real estate is distributed in a bulk shape.

2. Unmanned aerial vehicle oblique photogrammetry

And (4) importing the survey area range on the mobile terminal flight control platform, and automatically planning the flight path according to the flight height of 100m, the flight path overlapping degree of 85 percent and the lateral overlapping degree of 70 percent. And starting the fixed relative flight height to fly, and automatically adjusting the flight height according to the relief of the terrain in the flying process.

3. Initially building a three-dimensional model

After the flight is finished, a three-dimensional model is initially constructed through data preprocessing, multi-view image joint adjustment, multi-view image dense matching, high-density point cloud construction, TIN construction and texture fitting. Checking the quality of the three-dimensional model, carrying out interior operation labeling on the model decoration and the cavity caused by shielding, missed flying and the like, and carrying out additional shooting on the field by adopting backpack close-range photogrammetry.

4. Close range photogrammetry

And (4) carrying out supplementary measurement at the position of the interior label by adopting backpack close-range photogrammetry. Firstly, a certain overlapping range of a close-range image and an oblique image is determined, a fixed-focus lens is selected, then a proper shooting distance of 50m is calculated according to the requirement of modeling resolution and the focal length of adopted equipment, and finally field close-range complementary shooting is carried out.

5. Multi-source data fusion construction refined three-dimensional model

And unifying the coordinates of the close-up image and the oblique image, and jointly importing the close-up image and the oblique image into modeling software. And performing aerial triangulation, TIN construction, texture fitting and construction of a refined three-dimensional model by multi-source data fusion.

6. Precision analysis

(1) And extracting house data according to the initial model, and carrying out actual measurement on the house side length by adopting a total station and a laser range finder in the field industry, wherein the ratio of the model side length to the actual measurement is shown in tables 1 and 2.

TABLE 1 actual measurement and comparison statistics of side length of certain village

TABLE 2 side length error statistic table for certain village

According to the statistics, the following results are obtained: the error in the measurement of the house property data extracted by the initial three-dimensional model is 5.7cm, but due to the problems of ground feature shielding, model distortion and the like, the house position which cannot be accurately acquired by the industry exists in a certain range.

(2) And extracting house data according to the refined three-dimensional model, and carrying out actual measurement on the house side length by adopting a total station and a laser range finder in the field industry, wherein the ratio of the model side length to the actual measurement is shown in tables 3 and 4.

TABLE 3 actually-measured contrast statistical table for side length of certain village

TABLE 4 side length error statistic table for certain village

According to the statistics, the following results are obtained: after close-range photogrammetry complementary shooting, multi-source data are fused to construct a high-quality and ultra-fine three-dimensional model, and the error in the measurement of the model extracted house property data is 3.9 cm; the statistics of the side lengths exceeding the tolerance 10cm are respectively 2% and not more than 5%, and the side length error within 5cm reaches about 86%, so that the data precision is improved.

7. Conclusion

The knapsack close-range photogrammetry device can be fine compensate the deficiency of oblique photogrammetry, and to three-dimensional model distortion, eave pull problem that trees shelter from, oblique photography camera angle limitation etc. caused, the close-range image through the device and the integration of unmanned aerial vehicle oblique image can improve three-dimensional model quality, construct high quality, super refined three-dimensional model. Therefore, the device has certain practical popularization value.

It should be noted that the terms "upper", "lower", "left", "right", "front", "back", etc. used in the present invention are for clarity of description only, and are not intended to limit the scope of the present invention, and the relative relationship between the terms and the terms is not limited by the technical contents of the essential changes.

The above is only a preferred embodiment of the present invention, and the protection scope of the present invention is not limited to the above-mentioned embodiments, and all technical solutions belonging to the idea of the present invention belong to the protection scope of the present invention. It should be noted that modifications and embellishments within the scope of the invention may be made by those skilled in the art without departing from the principle of the invention.