CN108286965B

CN108286965B - Unmanned aerial vehicle height-variable air route method, terminal and system based on fine three-dimensional terrain

Info

Publication number: CN108286965B
Application number: CN201810017165.8A
Authority: CN
Inventors: 戴凌云; 刘伟丰
Original assignee: Shenzhen Feima Robotics Co ltd
Current assignee: Shenzhen Pegasus Robotics Co ltd
Priority date: 2018-01-09
Filing date: 2018-01-09
Publication date: 2020-11-24
Anticipated expiration: 2038-01-09
Also published as: CN108286965A

Abstract

The invention discloses an unmanned aerial vehicle variable altitude route method based on fine three-dimensional terrain, wherein a camera is carried on an unmanned aerial vehicle, and a basic route is generated according to camera parameters, image overlapping degree and route quality; the unmanned aerial vehicle flies according to the basic route, the camera shoots images, the elevation data of the fine three-dimensional terrain is extracted from the shot images, the altitude data and the altitude constraint conditions of the unmanned aerial vehicle are used for calculating, filtering and selecting altitude route waypoints, and the route data is generated by combining the sequence points of the basic route. The generated route data simultaneously considers terrain change and height-changing constraint conditions, and under the condition of meeting the height-changing constraint conditions, height-changing flight is realized according to the terrain change, so that the ground resolution of images shot by the cameras is consistent, and the matching difficulty of interior images is reduced.

Description

Unmanned aerial vehicle height-variable air route method, terminal and system based on fine three-dimensional terrain

Technical Field

The invention relates to the technical field of unmanned aerial vehicles, in particular to a method, a terminal and a system for changing a high air route of an unmanned aerial vehicle based on a fine three-dimensional terrain.

Background

Along with the development of the unmanned aerial vehicle from military use to civil use, the unmanned aerial vehicle has the advantages of low cost, all weather, convenience in taking off and landing, capability of entering dangerous area operation and the like, so that more and more of the unmanned aerial vehicle is well known and applied by civil enterprises, and plays an important role in supplementing the traditional remote sensing. In the process of acquiring images in the field operation of the unmanned aerial vehicle, the design of the air route plays a crucial role, a good air route design can ensure that the acquired images meet the industrial standard, and the number of flying frames can be reduced in the process of acquiring the images in a large area, so that the waste of manpower and material resources is avoided. By discussing several key factors influencing the image quality of the unmanned aerial vehicle and analyzing the change conditions of all the factors along with the environment and the terrain, the main variable factors of the air route design are obtained, and reference is provided for the air route design of the unmanned aerial vehicle.

In the prior art, the unmanned aerial vehicle technique has been used in the survey and drawing operation, when acquireing the remote sensing image in plain area, because plain area topography is comparatively mild, under the condition of not considering weather effect, when unmanned aerial vehicle was taking photo by plane to plain area, the relative height on unmanned aerial vehicle and ground can be maintained at relatively stable height, and the ground resolution ratio of acquireing the image can obtain better control, and the interior trade is handled relatively easily. And unmanned aerial vehicle receives self or external restraint when flying, needs to fly under the restrictive conditions.

The inventor finds that at least the following problems exist in the prior art: for the mountain region, because the topography is great, the relative altitude of unmanned aerial vehicle and ground is the dynamic state of change, and relative altitude is the important factor that influences image resolution, when using unmanned aerial vehicle for mountain area aerial photograph, there is the ground resolution ratio of aerial photograph image and is uneven, the condition of good time bad, this degree of difficulty that has increased interior trade image matching, and in order to guarantee the uniformity of ground resolution ratio, need frequently take off and land unmanned aerial vehicle to carry out the repeated shooting operation of co-altitude in same region many times, troublesome poeration, equipment loss is serious, and along with taking off the increase of time, the probability of appearing the accident also relatively increases.

Disclosure of Invention

In view of the above, the invention provides a fine three-dimensional terrain-based unmanned aerial vehicle variable altitude route method, a fine three-dimensional terrain-based unmanned aerial vehicle variable altitude route terminal, a fine three-dimensional terrain-based unmanned aerial vehicle variable altitude route system and a fine three-dimensional terrain-based unmanned aerial vehicle variable altitude route storage medium, aiming at the technical problems that ground resolution of aerial images is inconsistent and the matching difficulty of interior work images is increased when aerial shooting is performed in mountainous regions in the prior art.

The technical scheme adopted by the invention for solving the technical problems is as follows:

one or more embodiments of the invention disclose a fine three-dimensional terrain-based unmanned aerial vehicle high-altitude route method, wherein a camera is carried on the unmanned aerial vehicle, and the method comprises the following steps:

generating a basic route according to the camera parameters, the image overlapping degree and the route quality;

controlling the unmanned aerial vehicle to fly according to the basic route, acquiring images shot by the camera and extracting elevation data of the fine three-dimensional terrain;

and calculating, filtering and selecting a high-altitude route waypoint according to the elevation data and the high-altitude constraint condition of the unmanned aerial vehicle, and generating route data by combining the sequence points of the basic route.

In one or more embodiments of the invention, generating the base route includes pre-processing steps of: constructing an OXY rectangular coordinate system for mapping a camera shooting image to a ground range, controlling the camera to shoot at a forward-looking inclined preset angle, and realizing the acquisition of four-direction textures of a target in a measuring area in the south, east, west and north directions by controlling the unmanned aerial vehicle to fly according to mutually perpendicular cultivated land routes;

the camera parameters comprise pixel size, focal length mm, equivalent image width Ws and equivalent image height Hs; the equivalent image width Ws is a pixel width value corresponding to a focal point when the camera is forward-looking and shot by inclining a preset angle and being parallel to an X axis, and an end point is a line segment of two boundaries of the shot image; the equivalent image amplitude height Hs is a pixel height value corresponding to a focal point when the camera is forward-looking and shot by inclining a preset angle and being parallel to the Y axis, and an end point is a line segment of two boundaries of the shot image;

the image overlapping degree comprises a first course overlapping degree and a first side direction overlapping degree;

the course quality comprises a baseline flare number for ensuring the course overlapping degree, and is calculated by using the following formula:

N2＝L2/(Hs*(1-along_overlap))

wherein N2 is the base line extension number, L2 is the coordinate of the optical axis projection of the camera to the X axis, Hs is the equivalent image amplitude, and along _ overlap is the course overlap.

In one or more embodiments of the invention, the front view of the camera is tilted by a predetermined angle of 33 degrees.

In one or more embodiments of the invention, the course overlap is 80%, the baseline flare number N2 is 4, and the side overlap is 80%.

In one or more embodiments of the present invention, the controlling the unmanned aerial vehicle to fly according to the basic route, acquiring the image captured by the camera, and extracting the elevation data of the fine three-dimensional terrain specifically includes:

acquiring three-dimensional terrain layered fine level data;

controlling the unmanned aerial vehicle to fly according to the basic route and obtain the images shot by the camera, matching the images with the three-dimensional terrain layered fine level data to form a fine terrain block combination, generating a terrain database, and taking the height value of the images shot by the camera and projected onto each fine terrain block at intervals of preset length for each fine terrain block;

and arranging the height value set of the combined projection of the fine terrain blocks according to the sequential points of the basic route to obtain the elevation data.

In one or more embodiments of the invention, the constraint condition for the unmanned aerial vehicle to go high comprises a maximum ascent rate v1 of the unmanned aerial vehicle, a current flight rate limit v2 and a minimum sampling interval D.

In one or more embodiments of the invention, the minimum ascent height H1 is calculated according to the minimum sampling interval D, the maximum ascent rate v1 of the drone and the current flight rate limit v2, using the following equation:

H1＝sqrt(D*D/((v1*v1)/(v2*v2)-1))

the calculating, filtering and selecting a high-altitude route point, and generating route data by combining the sequence points of the basic route specifically comprises the following steps:

and filtering waypoints in the elevation data which are larger than the minimum rising height H1, selecting waypoints which are smaller than or equal to the minimum rising height H1 in the elevation data by combining the time required for the unmanned aerial vehicle to reach the maximum rising speed v1 and the current flight speed limit value v2, and generating route data by combining the sequential points of the basic route.

One or more embodiments of the invention disclose a terminal, comprising a processor and a memory; the processor is used for executing the fine three-dimensional terrain-based unmanned aerial vehicle high-altitude route method program stored in the memory so as to realize the method.

One or more embodiments of the invention disclose the unmanned aerial vehicle based on meticulous three-dimensional topography becomes the air route system, including unmanned aerial vehicle and ground apparatus, carry on the camera on the said unmanned aerial vehicle, the said unmanned aerial vehicle includes the fuselage picture telegram station transmitter-receiver, is used for sending the said camera and shooting the picture and fuselage picture telegram station receiver used for receiving basic air route and air route data; the ground equipment comprises a ground image telegraph station transceiver and a terminal, wherein the ground image telegraph station transceiver is used for receiving the images shot by the camera and transmitting the images to the terminal; the terminal is used for generating a basic route according to the camera parameters, the image overlapping degree and the route quality; the terminal is also used for controlling the unmanned aerial vehicle to fly according to the basic route, acquiring images shot by the camera and extracting elevation data of the fine three-dimensional terrain; and the terminal is also used for calculating, filtering and selecting a high-altitude route waypoint according to the elevation data and the height-changing constraint condition of the unmanned aerial vehicle, and generating route data by combining the sequence points of the basic route.

One or more embodiments of the present invention disclose a non-transitory computer-readable storage medium storing one or more programs, the one or more programs being executable by one or more processors to implement the above-described methods.

According to the fine three-dimensional terrain-based unmanned aerial vehicle high-altitude route method, a camera is carried on the unmanned aerial vehicle, and a basic route is generated according to parameters of the camera, the image overlapping degree and the route quality; the unmanned aerial vehicle flies according to the basic route, the camera shoots images, the elevation data of the fine three-dimensional terrain is extracted from the shot images, the altitude data and the altitude constraint conditions of the unmanned aerial vehicle are used for calculating, filtering and selecting altitude route waypoints, and the route data is generated by combining the sequence points of the basic route. The generated route data simultaneously considers terrain change and height-changing constraint conditions, and under the condition of meeting the height-changing constraint conditions, height-changing flight is realized according to the terrain change, so that the ground resolution of images shot by the cameras is consistent, and the matching difficulty of interior images is reduced. And the unmanned aerial vehicle is controlled to fly according to the unmanned aerial vehicle high-altitude method, the situation that the unmanned aerial vehicle frequently takes off and lands for multiple times to repeatedly shoot at different heights in the same area is reduced, the single-frame unmanned aerial vehicle is relatively easy to operate in flight control, the equipment loss is low, the cost is reduced, and the probability of accidents is also reduced along with the reduction of the number of frames.

Drawings

While the drawings needed to describe the invention or prior art arrangements in a more complete description of the embodiments or prior art are briefly described below, it should be apparent that the drawings described below are illustrative of some embodiments of the invention and that other drawings may be derived therefrom by those skilled in the art without the benefit of the inventive faculty.

FIG. 1 is a flow chart of a fine three-dimensional terrain-based unmanned aerial vehicle high altitude route method according to an embodiment of the present invention;

FIG. 2a is a schematic diagram of a north-south route of an arable route, FIG. 2b is a schematic diagram of a east-west route of an arable route,

FIG. 2c is a schematic view of the patterns combined into mutually perpendicular arable lands;

FIG. 3 is a footprint map of the camera shot image of the fine three-dimensional terrain-based unmanned aerial vehicle high altitude route method mapped to the ground corner points;

FIG. 4 is a reference diagram of the baseline flare number (course) of the fine three-dimensional terrain-based unmanned aerial vehicle high-altitude route method according to an embodiment of the present invention;

FIG. 5 is a partial flowchart of a fine three-dimensional terrain-based unmanned aerial vehicle high altitude route method according to an embodiment of the present invention;

FIG. 6 is a flow chart of three-dimensional terrain elevation data extraction of a fine three-dimensional terrain-based unmanned aerial vehicle high altitude route method according to an embodiment of the present invention;

FIG. 7 is a schematic diagram of a relationship among a sampling interval, an ascending rate of an unmanned aerial vehicle and a flight rate of the unmanned aerial vehicle high-altitude route method based on a fine three-dimensional terrain according to the embodiment of the present invention;

FIG. 8 is a structural block diagram of a fine three-dimensional terrain-based unmanned aerial vehicle high altitude route system according to an embodiment of the present invention;

FIG. 9 is a diagram illustrating a hardware architecture of a terminal according to an embodiment of the present invention;

FIG. 10 is a schematic diagram of a tolerance arc surface of an irregular curved surface of an unmanned aerial vehicle high altitude method based on a fine three-dimensional terrain according to an embodiment of the present invention;

fig. 11 is a schematic diagram of a fine three-dimensional terrain-based unmanned aerial vehicle high altitude route system according to an embodiment of the present invention.

Detailed Description

In order to make the technical solutions of the present invention better understood, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention. It is to be understood that the described embodiments are merely illustrative of some, but not all, of the embodiments of the invention, and that the preferred embodiments of the invention are shown in the drawings. This invention may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein, but rather should be construed as broadly as the present disclosure is set forth in order to provide a more thorough understanding thereof. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The terms "including" and "having," and any variations thereof, in the description and claims of this invention and the above-described drawings are intended to cover non-exclusive inclusions. For example, a process, method, system, article, or apparatus that comprises a list of steps or elements is not limited to only those steps or elements listed, but may alternatively include other steps or elements not listed, or inherent to such process, method, article, or apparatus.

Reference herein to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the invention. The appearances of the phrase in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. It is explicitly and implicitly understood by one skilled in the art that the embodiments described herein can be combined with other embodiments.

As shown in fig. 1, an embodiment of the present invention provides a fine three-dimensional terrain-based unmanned aerial vehicle high-altitude route method, wherein the unmanned aerial vehicle is provided with a camera, and the method comprises the following steps:

step 10, generating a basic route according to the camera parameters, the image overlapping degree and the route quality;

step 20, controlling the unmanned aerial vehicle to fly according to the basic route, acquiring images shot by the camera and extracting elevation data of the fine three-dimensional terrain;

and step 30, calculating, filtering and selecting a high-altitude route waypoint according to the elevation data and the high-altitude constraint condition of the unmanned aerial vehicle, and generating route data by combining the sequence points of the basic route.

In another embodiment, generating the base lane comprises a preprocessing step: and constructing an OXY rectangular coordinate system for mapping the image shot by the camera to the ground range, controlling the camera to shoot at a forward-looking inclined preset angle, and controlling the unmanned aerial vehicle to fly according to mutually perpendicular cultivated land routes to realize the acquisition of the texture of the target in four directions of south, east, west and north in the measuring area.

Considering that the main factors for restricting the flight efficiency come from the route lateral interval, the oblique photography selects the forward view as the basic photographing mode, and the short edge of the image shot by the camera is along the flight direction, and the long edge is perpendicular to the flight direction. The camera parameters comprise pixel size, focal length mm, equivalent image width Ws and equivalent image height Hs.

In one or more embodiments of the invention, the camera parameters are specifically set as follows:

size of picture element	um	2.41
			Focal length	mm	8.8
Equivalent image width	pixel	6525
			Equivalent image height	pixel	5796

As shown in fig. 2a-2c, fig. 2a is a schematic diagram of north and south courses of an arable route, fig. 2b is a schematic diagram of east-west courses of the arable route, and fig. 2c is a schematic diagram of courses of arable routes combined to be perpendicular to each other. The deeper the overlay in the illustration, the more the representative image repeats.

Adopting a cultivated land route flight mode, and taking interlaced zones as same-direction visual angle data. The course overlap is set to 80%, the side overlap is set to 70%, and the interlace data overlap is 40%. When the side overlap is set to 80%, the overlap of interlaced band data can be increased to 60%.

Specifically, the course overlap is set to 80% and the side overlap is set to 80%.

The constructed OXY rectangular coordinate system in which the camera image is mapped to the ground is shown in fig. 3, and the rectangular dashed line frame in the figure is the coverage area of the camera mapped to the ground when the front view angle of the camera is 0 degrees (i.e., the camera is vertically shot downwards without inclination). The trapezoid solid frame is a coverage range of the camera mapped to the ground when the front view of the camera is inclined by a preset angle of 33 degrees, and a dotted line which is parallel to the upper bottom and the lower bottom of the trapezoid and is intersected with the waist of the trapezoid is an equivalent image width Ws; the dashed line of the height of the trapezoid (coinciding with the Y-axis in fig. 3) is the equivalent swath height Hs. And the intersection point of the line segment of the equivalent image width Ws and the line segment of the equivalent image width Hs is a camera focus inclined by a preset angle of 33 degrees in front of the camera.

Namely, the equivalent image width Ws is a pixel width value corresponding to a focal point when the camera is forward-looking and shot by inclining a preset angle and being parallel to an X axis, and an end point is a line segment of two boundaries of the shot image; the equivalent image amplitude height Hs is a pixel height value corresponding to a focus when the camera is forward-looking and inclined at a preset angle and is parallel to the Y axis, and the end points are line segments of two boundaries of the shot image.

It should be noted that the front view of the camera of the above embodiment is tilted by a predetermined angle of 33 degrees, and in some embodiments, the front view may also be tilted by a tilt angle range, such as 28-38 degrees, or fixed at 30 degrees, 35 degrees, or 36 degrees. In other embodiments, the equivalent camera parameters may vary with the tilt angle based on freely set parameters, which is not limited by the present invention.

N2＝L2/(Hs*(1-along_overlap))

In order to guarantee the quality assurance of the course, the base line extension quantity of the course overlapping degree of the base line extension quantity of the course overlapping degree is calculated to carry out equivalent calculation, wherein the equivalent width Ws is 6525, and the equivalent height Hs is 5796.

FIG. 4 is a reference graph of baseline flare numbers (headings). According to symmetry, the projection X coordinate of the main optical axis of a forward-looking camera (a camera arranged at a preset forward-looking inclination angle) is 3651.452 (L2), the course overlapping degree is (along _ overlap), and the calculation formula of the number of the base lines needing to be extended to ensure the complete coverage of the side textures of the building is as follows:

N2＝L2/(Hs*(1-along_overlap))

The number of baseline flare is the number of routes required to flare, and in order to ensure the heading overlap degree, namely the transverse overlap degree of images shot by the camera, the number of flare baseline (routes) is required. For example, the following table:

Hs	L2	along_overlap	N2	get round upwards
					5796	3651.452	65％	1.80	2
5796	3651.452	70％	2.10	3
					5796	3651.452	75％	2.52	3
5796	3651.452	80％	3.15	4

As can be seen from the above table, the course overlap is 80%, and the baseline flare number N2 is 4.

The quality of the flight path also comprises the step of finishing the acquisition of the data of the inclined survey area by adopting a single camera and a cross flight path (mutually perpendicular cultivated land flight paths) in order to ensure the outward expansion quantity of the flight path of the side direction overlapping degree, wherein only the outward expansion quantity of the forward-looking camera in the baseline direction is considered, and the numerical value of the outward expansion quantity (side direction) of the flight path is zero.

In one or more embodiments of the present invention, as shown in fig. 5, the step 20 of controlling the unmanned aerial vehicle to fly according to the basic route, and acquiring the image captured by the camera and extracting the elevation data of the fine three-dimensional terrain specifically includes:

step 21, acquiring three-dimensional terrain layered fine hierarchy data;

specifically, the embodiment of the invention uses OSGEARTH to load the terrain, and the LOD terrain simplification algorithm based on the pyramid structure is to form a terrain hierarchical organization structure (three-dimensional terrain hierarchical fine level data) based on the pyramid structure through a series of hierarchical structures. The terrain is managed and scheduled based on a quadtree structure, high-precision TIFF data is loaded, and the current-level terrain is scheduled and loaded along with the distance between a viewpoint and the terrain.

Step 22, controlling the unmanned aerial vehicle to fly according to the basic route and acquire the images shot by the camera, matching the images with the three-dimensional terrain layered fine level data to form a fine terrain block combination, generating a terrain database, and taking the height value of the images shot by the camera and projected onto each fine terrain block at intervals of preset length for each fine terrain block;

and 23, arranging the height value set of the combined projection of the fine terrain blocks according to the sequence points of the basic route to obtain the elevation data.

Specifically, fig. 6 is a flow chart of three-dimensional terrain elevation data extraction. As shown in fig. 6, according to the generated basic route, the basic data of the route is taken. Based on the basic route, searching (such as 20 layers) in three-dimensional terrain hierarchical fine level data according to fine levels, matching the basic route, loading and reading the number of fine terrain blocks, obtaining a fine terrain block combination, and distributing the fine terrain block combination to a plurality of threads for loading on average. For example, considering the performance of the machine, the core of the cpu and the number of threads supported, where the fine-grained block combination is allocated to the 4 threads for loading. For each fine terrain, according to the height value of a route projected on the terrain at preset length intervals, such as 1 meter intervals, after all the fine terrain blocks needing to be loaded are read, the obtained height values are arranged according to the sequence points of the route, and the height data is obtained.

In some embodiments, the high-rise constraints for the drone include a drone maximum rate of ascent v1, a current flight rate limit v2, and a minimum sampling interval D, such as a drone maximum rate of ascent v1 of 8m/s, a current flight rate limit v2 of 12m/s, and a minimum sampling interval D of 20 m.

And (3) solving the minimum climbing height at a sampling interval, namely calculating the minimum climbing height H1 according to the minimum sampling interval D, the maximum ascending rate v1 of the unmanned aerial vehicle and the current flight rate limit value v2, and adopting the following formula:

H1＝sqrt(D*D/((v1*v1)/(v2*v2)-1))

the step 30 of calculating, filtering and selecting the waypoints of the high-altitude route, and generating the route data by combining the sequence points of the basic route specifically comprises the following steps:

Specifically, waypoints greater than the minimum climb altitude are filtered out of the acquired elevation data, which exceed one or both of the drone maximum ascent rate v1 or the current flight rate limit v2 and are therefore not considered.

And selecting a waypoint which is less than or equal to the minimum rising height H1 in the elevation data by combining the time required for the unmanned aerial vehicle to reach the maximum rising speed v1 and the current flight speed limit value v2, namely finding a waypoint which meets the conditions. Fig. 7 is a schematic diagram of a relationship between a sampling interval, a rising rate of an unmanned aerial vehicle and a flight rate, as shown in fig. 7, the sampling interval is a minimum sampling interval D, the rising rate of the unmanned aerial vehicle brings a rising height H, the flight rate brings a flight distance L, and according to the right triangle pythagorean theorem:

L＝sqrt(D*D+H*H)；

T1＝L/V2；

T2＝H/V1；

wherein T1 is the time required for the drone to reach the maximum rate of ascent v1, and T2 is the time required for the drone to reach the current flight rate limit v 2.

The time required for the drone to reach the maximum ascent rate v1 and the current flight rate limit v2 is related to the drone's motors, conversion efficiency, flight attitude IMU, weather conditions, and the like. To the specific means of adjusting of unmanned aerial vehicle flying height, adopt current unmanned aerial vehicle flight attitude control technique to realize, no longer give unnecessary details here. In some embodiments, a waypoint having a smaller difference between TI and T2 is more desirable.

As shown in fig. 8, an embodiment of the present application further provides a fine three-dimensional terrain-based unmanned aerial vehicle variable altitude air route system 300, which includes an unmanned aerial vehicle 310 and ground equipment 330, wherein the unmanned aerial vehicle 310 carries a camera 311 thereon, and is characterized in that the unmanned aerial vehicle 310 includes a body pattern radio transceiver 312, and a body pattern radio transceiver for transmitting images taken by the camera and for receiving basic air routes and air route data; the ground equipment 330 comprises a ground map power transmission station transmitter-receiver 331 and a terminal 332, wherein the ground map power transmission station transmitter-receiver 331 is used for receiving the image shot by the camera 311 and transmitting the image to the terminal 332; the terminal 332 is used for generating a basic route according to the camera parameters, the image overlapping degree and the route quality; the unmanned aerial vehicle 310 is controlled to fly according to the basic route, and the image shot by the camera 311 is acquired and the elevation data of the fine three-dimensional terrain is extracted; and the method is used for calculating, filtering and selecting a high-altitude route waypoint according to the elevation data and the high-altitude constraint condition of the unmanned aerial vehicle 310, and generating route data by combining the sequence points of the basic route.

In some embodiments, the body diagram transmission station transceiver 312 and the ground diagram transmission station transceiver 331 can be decomposed into a station transmitter and a station receiver, and the embodiments of the present invention are not limited to the specific form thereof.

As shown in fig. 9, an embodiment of the present application further provides a schematic diagram of a terminal hardware architecture. The terminal 900 in this embodiment is the same terminal as the terminal 332 in the system embodiment described above. In fig. 9, the terminal includes: a first memory 910, a first processor 920, and a fine three-dimensional terrain based drone high-level airline program 930 stored on the first memory 910 and executable on the first processor 920. In this embodiment, the fine three-dimensional terrain based drone elevation pattern program 930 includes a series of computer program instructions stored in the first memory 910, which when executed by the first processor 920, may implement the fine three-dimensional terrain based drone elevation pattern operations of the various embodiments of the present application.

In particular, terminal 900 can be implemented in various forms. For example, the terminal described in the present application may include a mobile terminal such as a mobile phone, a tablet computer, a notebook computer, a palmtop computer, a Personal Digital Assistant (PDA), a Portable Media Player (PMP), a navigation device, a wearable device, a smart band, a pedometer, and the like, and a fixed terminal such as a Digital TV, a desktop computer, and the like.

In some embodiments, the fine three-dimensional terrain-based unmanned aerial vehicle high-altitude route program 930 may be divided into one or more modules based on the particular operations that the computer program instructs the various portions to implement. As shown in fig. 10, the fine three-dimensional terrain based drone high course program 930 includes: a basic route generation module 931, an elevation data extraction module 932 and a route data generation module 933. Wherein the content of the first and second substances,

the basic route generation module 931 is configured to generate a basic route according to the camera parameters, the image overlapping degree, and the route quality;

an elevation data extraction module 932, configured to control the unmanned aerial vehicle to fly according to the basic route, acquire images captured by the camera, and extract elevation data of the fine three-dimensional terrain;

and the route data generation module 933 is used for calculating, filtering and selecting a route point of a variable altitude route according to the elevation data and a variable altitude constraint condition of the unmanned aerial vehicle, and generating route data by combining the sequence point of the basic route.

The terminal embodiment of the application and the unmanned aerial vehicle variable altitude route method embodiment based on the fine three-dimensional terrain are based on the same inventive concept, and some specific technical features of the terminal can refer to the system embodiment and are not detailed herein.

Specifically, the terminal 900 in the embodiment of the present application may further include a preprocessing module, configured to construct an OXY rectangular coordinate system in which images captured by the camera are mapped to a ground range, control the camera to shoot at a forward-looking inclination preset angle, and control the unmanned aerial vehicle to fly according to mutually perpendicular cultivated land routes, so as to achieve texture acquisition in four directions of a target in the survey area, south, east, west, and north.

Specifically, the camera parameters include pixel size, focal length mm, equivalent image width Ws and equivalent image height Hs; the equivalent image width Ws is a pixel width value corresponding to a focal point when the camera is forward-looking and shot by inclining a preset angle and being parallel to an X axis, and an end point is a line segment of two boundaries of the shot image; the equivalent image amplitude height Hs is a pixel height value corresponding to a focal point when the camera is forward-looking and shot by inclining a preset angle and being parallel to the Y axis, and an end point is a line segment of two boundaries of the shot image;

N2＝L2/(Hs*(1-along_overlap))

Specifically, the front view of the camera is inclined by a preset angle of 33 degrees.

Specifically, the heading overlap degree is 80%, the baseline flare number N2 is 4, and the side overlap degree is 80%.

The elevation data extraction module 932 is further configured to:

acquiring three-dimensional terrain layered fine level data;

Specifically, the constraint condition for the unmanned aerial vehicle to go high comprises the maximum unmanned aerial vehicle ascent rate v1, the current flight rate limit v2 and the minimum sampling interval D.

Specifically, the minimum rise height H1 is calculated according to the minimum sampling interval D, the maximum ascent rate v1 of the unmanned aerial vehicle and the current flight rate limit v2, and the following formula is adopted:

H1＝sqrt(D*D/((v1*v1)/(v2*v2)-1))

the lane data generation module 933 is further configured to:

Fig. 11 is a schematic diagram of a fine three-dimensional terrain-based unmanned aerial vehicle high altitude route system according to an embodiment of the present invention, and as shown in fig. 11, a terminal 900 generates a basic route according to camera parameters, image overlapping degree and route quality; and then realizing the elevation of the air route, specifically, acquiring a camera shooting image shot based on the flight of the basic air route by the terminal through an image transmission receiver, extracting the elevation data (extracting the elevation of the terrain) of the fine three-dimensional terrain from the shooting image, calculating, filtering and selecting an elevation route waypoint (extracting the elevation of the terrain) according to the elevation data and an elevation constraint condition (elevation limit) of the unmanned aerial vehicle, and generating air route data by combining with the sequence points of the basic air route. The generated route data simultaneously considers terrain change and height-changing constraint conditions, and under the condition of meeting the height-changing constraint conditions, height-changing flight is realized according to the terrain change, so that the ground resolution of images shot by the cameras is consistent, and the matching difficulty of interior images is reduced.

The embodiment of the application also provides a computer readable storage medium. The computer-readable storage medium herein stores one or more programs. Among other things, computer-readable storage media may include volatile memory, such as random access memory; the memory may also include non-volatile memory, such as read-only memory, flash memory, a hard disk, or a solid state disk; the memory may also comprise a combination of memories of the kind described above. When the one or more programs in the computer readable storage medium are executable by the one or more processors to implement the fine three-dimensional terrain based drone high-altitude approach provided by the above embodiments.

The embodiment of the present invention further provides a non-volatile computer-readable storage medium, where the non-volatile computer-readable storage medium stores program instructions, specifically, stores a non-volatile software program, a non-volatile computer-executable program, modules, and the like, and when the unmanned aerial vehicle executes the program instructions, the non-volatile computer-readable storage medium is configured to execute the fine three-dimensional terrain-based unmanned aerial vehicle variable altitude route method described in the above method embodiment, and perform corresponding data processing, and when the method steps are executed, the method has the technical effects of the above method embodiment.

Those skilled in the art can understand that all or part of the steps in the method of the foregoing embodiments may be implemented by a program to instruct related hardware, where the program is stored in a storage medium and includes several instructions to enable a device (which may be a single chip, a chip, etc.) or a processor (processor) to execute all or part of the steps of the method described in the embodiments of the present application. And the aforementioned storage medium includes: a U-disk, a removable hard disk, a Read-Only Memory (ROM), a Random Access Memory (RAM), a magnetic disk or an optical disk, and other various media capable of storing program codes.

In the above embodiments provided by the present invention, it should be understood that the disclosed apparatus and method may be implemented in other ways. For example, the above-described apparatus embodiments are merely illustrative, and for example, the division of the modules is merely a logical division, and other divisions may be realized in practice, for example, a plurality of modules or components may be combined or integrated into another system, or some features may be omitted, or not executed.

The modules described as separate parts may or may not be physically separate, and parts displayed as modules may or may not be physical modules, may be located in one place, or may be distributed on a plurality of network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution of the present embodiment.

Although the present invention has been described in detail with reference to the foregoing embodiments, it will be apparent to those skilled in the art that modifications may be made to the embodiments described in the foregoing detailed description, or equivalent changes may be made in some of the features of the embodiments. All equivalent structures made by using the contents of the specification and the attached drawings of the invention can be directly or indirectly applied to other related technical fields, and are also within the protection scope of the patent of the invention.

Claims

1. A fine three-dimensional terrain-based unmanned aerial vehicle high-altitude route method is characterized in that a camera is carried on the unmanned aerial vehicle, and the method comprises the following steps:

calculating, filtering and selecting a variable altitude route waypoint according to the elevation data and a variable altitude constraint condition of the unmanned aerial vehicle, and generating route data by combining the sequence points of the basic route;

wherein the constraint conditions for the unmanned aerial vehicle to change to high comprise the maximum ascending rate v1 of the unmanned aerial vehicle, the current flight rate limit v2 and the minimum sampling interval D;

the method further comprises the following steps:

calculating the minimum rising height H1 according to the minimum sampling interval D, the maximum rising speed v1 of the unmanned aerial vehicle and the current flight speed limit value v2, and adopting the following formula:

H1＝sqrt(D*D/((v1*v1)/(v2*v2)-1))

the calculating, filtering and selecting the high-altitude route waypoints and generating the route data by combining the sequence points of the basic route specifically comprise:

filtering waypoints in the elevation data which are larger than a minimum rising height H1, selecting waypoints in the elevation data which are smaller than or equal to the minimum rising height H1 by combining the time required for the unmanned aerial vehicle to reach the maximum rising speed v1 and the current flight speed limit value v2, and generating route data by combining sequential points of the basic route;

the control the unmanned aerial vehicle flies according to the basic route, acquires images shot by the camera and extracts elevation data of the fine three-dimensional terrain, and specifically comprises the following steps:

acquiring three-dimensional terrain layered fine level data;

2. The method of claim 1, wherein generating a base course comprises a preprocessing step of: constructing an OXY rectangular coordinate system for mapping a camera shooting image to a ground range, controlling the camera to shoot at a forward-looking inclined preset angle, and realizing the acquisition of four-direction textures of a target in a measuring area in the south, east, west and north directions by controlling the unmanned aerial vehicle to fly according to mutually perpendicular cultivated land routes;

N2＝L2/(Hs*(1-along_overlap))

3. The method of claim 2, wherein the camera is tilted forward at a preset angle of 33 degrees.

4. The method of claim 2, wherein the heading overlap is 80%, the baseline flare number N2 is 4, and the side lap is 80%.

5. A terminal, characterized in that the terminal comprises a processor and a memory; the processor is used for executing a fine three-dimensional terrain-based unmanned aerial vehicle high-altitude route method program stored in the memory to realize the fine three-dimensional terrain-based unmanned aerial vehicle high-altitude route method of any one of claims 1-4.

6. An unmanned aerial vehicle high altitude route system based on fine three-dimensional terrain, which comprises an unmanned aerial vehicle and ground equipment, wherein the unmanned aerial vehicle is provided with a camera, and is characterized in that,

the unmanned aerial vehicle includes:

a body diagram telegraph station transceiver, and

the fuselage image telegraph station receiver is used for sending images shot by the camera and receiving basic course and course data;

the ground equipment includes: a terrestrial image telegraph station transmitting receiver and a terminal,

the ground map telegraph station transmitting and receiving device is used for receiving the images shot by the camera and transmitting the images to the terminal;

the terminal is used for generating a basic route according to the camera parameters, the image overlapping degree and the route quality;

the terminal is also used for controlling the unmanned aerial vehicle to fly according to the basic route, acquiring images shot by the camera and extracting elevation data of the fine three-dimensional terrain;

the terminal is further used for calculating, filtering and selecting a high-altitude route waypoint according to the elevation data and a high-altitude constraint condition of the unmanned aerial vehicle, and generating route data by combining the sequence points of the basic route;

the terminal is further used for calculating a minimum rise height H1 according to the minimum sampling interval D, the maximum ascent rate v1 of the unmanned aerial vehicle and the current flight rate limit value v2, and the following formula is adopted:

H1＝sqrt(D*D/((v1*v1)/(v2*v2)-1))

acquiring three-dimensional terrain layered fine level data;

7. A non-transitory computer readable storage medium storing one or more programs, the one or more programs being executable by one or more processors to implement the fine three-dimensional terrain based drone hyperopic route method of any one of claims 1-4.