CN113268085A

CN113268085A - Air route planning method and device and flight equipment of airborne laser radar

Info

Publication number: CN113268085A
Application number: CN202110803535.2A
Authority: CN
Inventors: 黎治坤; 刘金沧; 黄小川; 雷雳; 马云峰; 刘述超; 杨建�; 杨珂
Original assignee: SURVEYING AND MAPPING INSTITUTE LANDS AND RESOURCE DEPARTMENT OF GUANGDONG PROVINCE; Chengdu Zongheng Dapeng Unmanned Plane Technology Co ltd
Current assignee: SURVEYING AND MAPPING INSTITUTE LANDS AND RESOURCE DEPARTMENT OF GUANGDONG PROVINCE; Chengdu Zongheng Dapeng Unmanned Plane Technology Co ltd
Priority date: 2021-07-16
Filing date: 2021-07-16
Publication date: 2021-08-17
Anticipated expiration: 2041-07-16
Also published as: CN113268085B

Abstract

The application discloses a route planning method and device and flight equipment of an airborne laser radar. And obtaining an elevation maximum value point set and an elevation minimum value point set of the polygonal measuring area. And obtaining a non-recommended course angle list according to the corresponding elevation maximum value in the elevation maximum value point set, the corresponding elevation minimum value in the elevation minimum value point set and the maximum climbing angle of the flight equipment of the airborne laser radar. When the list is not empty, planning the flight path of the flight equipment of the airborne laser radar to the polygonal survey area according to the reference flight path angle and the non-recommended flight path angle list, wherein the reference flight path angle is the flight path angle corresponding to the flight path planned for the polygonal survey area according to the preset constraint condition, and the preset constraint condition is that the total flight path is shortest. And planning the air route of the flight equipment of the airborne laser radar to the polygonal survey area according to the reference air route angle and the non-recommended air route angle list, so that the air route can avoid the non-recommended air route angle, the safety of the flight equipment is improved, and the data quality of the laser radar is ensured.

Description

Air route planning method and device and flight equipment of airborne laser radar

Technical Field

The application relates to the technical field of communication, in particular to a route planning method and device and flight equipment of an airborne laser radar.

Background

In recent years, along with the rapid development of laser radar technology and unmanned aerial vehicle technology, the application of unmanned aerial vehicle-mounted laser radar system in various fields is more and more extensive. Such as surveying and mapping, agricultural plant protection, forestry investigation, power routing inspection, and the like. Because fixed wing unmanned aerial vehicle flying speed is fast, and the time of staying empty is long, consequently, fixed wing unmanned aerial vehicle carries laser radar's operating efficiency very high, receives the pursuit of drawing trade user deeply.

Laser radar can acquire advantages such as echo data many times because its laser point penetrability is strong, is particularly useful for forestry investigation and topography survey and drawing etc.. The traditional mapping application generally selects a polygonal survey area, then rules the survey area into equidistant air routes, and due to the particularity of the laser radar, the relative air height of the unmanned aerial vehicle and the ground needs to be kept fixed, namely the air route of the unmanned aerial vehicle is a ground-imitating flight air route.

Under the condition that the ground elevation changes, the unmanned aerial vehicle needs to adjust the relative altitude between the unmanned aerial vehicle and the ground in real time, and the unmanned aerial vehicle often needs to climb or descend in the flight process. In some mountainous regions or canyon terrains, the ground elevation changes are often severe, the ground slope angle of some road sections on the air route may be larger than or close to the maximum climbing angle of the airplane, so that the danger that the ground cannot be imitated normally, even the airplane collides with the mountain and the like may be caused, and huge loss is brought to users.

ExistingThe route planning method of (2) is usually based on the total shortest route principle. After a user designates a polygonal measuring area, the coordinates of the control points of the measuring area are used as input, the major axis direction (the direction of the main axis) of the circumscribed ellipse of the measuring area is found by using a principal component analysis method, and the direction is used as a route angle to plan the route. As shown in FIG. 1, A, B, C, D, E, F, G are control points for a polygon plot. Direction vectorρIn the direction of the major axis of the polygon. The total mileage of the air route obtained by the method is shortest, and the method has the advantage of saving power supply or fuel of the air route and the unmanned aerial vehicle.

However, through research, it is found that when the ground-imitating flight route planning is performed with the shortest flight path as a constraint condition, it is likely that the ground slope angle (the angle between the tangent line of the ground contour and the horizontal plane, as shown by α in fig. 2) is larger than or close to the maximum climbing angle of the airplane (the angle between the climbing direction of the airplane and the horizontal plane, as shown by γ in fig. 2) in a certain flight segment.

Taking a fixed wing drone as an example, the maximum climb angle is typically no greater than 10 degrees. When the ground slope angle is larger than the maximum climbing angle of the airplane, the ground imitation flight cannot be normally carried out. That is, the relative altitude of the aircraft to the ground in some flight segments may be smaller than a given altitude, and the relative altitude of the drone to the ground cannot be kept fixed, which may result in the data quality of the lidar being reduced, such as uneven point cloud density. In some special cases, if the aircraft is too close to the ground, some protection mechanisms of the aircraft, such as return flight, etc., may be triggered, but due to terrain limitation, the return flight path of the aircraft may trigger a mountain hitting danger, thereby causing great loss to users.

Disclosure of Invention

Based on the problems, the invention provides a flight path planning method and device and flight equipment of an airborne laser radar, so that the safety of the flight equipment of the airborne laser radar is improved, and the data quality of the laser radar is improved.

The embodiment of the application discloses the following technical scheme:

a first aspect of the present application provides a route planning method, including:

obtaining an elevation maximum value point set and an elevation minimum value point set of a polygonal measuring area;

obtaining a non-recommended course angle list according to an elevation maximum value corresponding to a point in the elevation maximum value point set, an elevation minimum value corresponding to a point in the elevation minimum value point set and a maximum climbing angle of flight equipment of the airborne laser radar; the non-recommended route angle list comprises a plurality of natural non-recommended route angles;

when the non-recommended course angle list is not empty, planning a course of the flight equipment of the airborne laser radar to the polygonal survey area according to the reference course angle and the non-recommended course angle list; the reference route angle is a route angle corresponding to a route planned for the polygonal survey area according to a preset constraint condition; the preset constraint condition is that the total voyage is shortest.

Optionally, the obtaining of the elevation maximum point set and the elevation minimum point set of the polygonal measurement area specifically includes:

acquiring an elevation data set corresponding to a circumscribed rectangular area of the polygonal measuring area; the elevation data set comprises elevation values of each grid point in the circumscribed rectangular area;

obtaining the gradient of each grid point according to the elevation data set;

for each grid point, determining that the grid point is a local elevation maximum point, a local elevation minimum point or neither a local elevation maximum point nor a local elevation minimum point according to the gradient of the grid point and the gradients of the four adjacent grid points;

and adding the local elevation maximum value points into the elevation maximum value point set, and adding the local elevation minimum value points into the elevation minimum value point set.

Optionally, the obtaining a non-recommended route angle list according to the elevation maximum value corresponding to the point in the elevation maximum value point set, the elevation minimum value corresponding to the point in the elevation minimum value point set, and the maximum climbing angle of the flight device of the airborne laser radar specifically includes:

calculating a slope angle of each point in the elevation maximum value point set when the point is combined with all points in the elevation minimum value point set; the gradient angle is obtained according to an elevation maximum value corresponding to one point of the two combined points and an elevation minimum value corresponding to the other point;

and adding the flight path angle corresponding to the slope angle larger than the maximum climbing angle into the non-recommended flight path angle list.

Optionally, the method further comprises: and when the non-recommended course angle list is empty, planning a course of the flight equipment of the airborne laser radar to the polygonal survey area according to a preset constraint condition.

Optionally, the planning of the flight path of the airborne laser radar to the polygonal survey area according to the reference course angle and the non-recommended course angle list specifically includes:

setting an angle increment and the number of times of increase of the angle increment;

obtaining a current route angle according to the reference route angle, the angle increment and the increasing times;

comparing the current airline angle with each non-recommended airline angle in the non-recommended airline angle list to obtain an angle deviation absolute value;

and planning the air route of the flight equipment of the airborne laser radar to the polygonal survey area according to the absolute value of the angle deviation.

Optionally, the planning, according to the absolute value of the angle deviation, a route of the flight device of the airborne laser radar to the polygonal survey area specifically includes:

when the absolute value of the angle deviation between the current airline angle and any non-recommended airline angle in the non-recommended airline angle list is smaller than the angle increment, adding 1 to the increase times; the initial value of the increase times is 0;

and when the absolute value of the angle deviation between the current course angle and all the non-recommended course angles in the non-recommended course angle list is greater than or equal to the angle increment, planning the course of the flight equipment of the airborne laser radar to the polygonal survey area according to the current course angle.

Optionally, the planning, according to the current route angle, a route of the flight device of the airborne laser radar to the polygonal survey area specifically includes:

setting a safety factor; the safety factor is greater than 0 and less than 1;

obtaining a first product of the safety factor and the maximum climbing angle;

obtaining the maximum slope angle of the projection contour line of the current course angle in the polygonal survey area;

comparing the maximum slope angle with the first product, and planning the flight path of the flight equipment of the airborne laser radar to the polygonal survey area according to the current flight path angle when the maximum slope angle is determined to be smaller than the first product; and when the maximum slope angle is determined to be greater than or equal to the first product, adding 1 to the increase times.

Optionally, the obtaining a current route angle according to the reference route angle, the angle increment, and the number of times of increase specifically includes:

obtaining a second product of the angular increment and the number of increments;

taking the sum of the reference course angle and the second product as the current course angle;

before the adding 1 to the increase number, the method further comprises:

judging whether the absolute value of the second product and the angle deviation of 360 degrees is smaller than the angle increment or not, if not, adding 1 to the increasing times; and if so, determining that the flight path of the flight equipment of the airborne laser radar to the polygonal survey area fails to be planned.

Optionally, after the determining fails to plan a course of the flying apparatus of the airborne lidar to the polygonal geodesic region, the method further comprises:

increasing the safety factor.

Optionally, the method further comprises:

respectively carrying out external expansion on four sides of the external rectangular area by preset external expansion distances to obtain external expansion rectangular areas;

the obtaining of the elevation data set corresponding to the circumscribed rectangular area of the polygonal survey area specifically includes:

and acquiring an elevation data set corresponding to the external rectangular area.

A second aspect of the present application provides a route planning apparatus comprising: the system comprises an elevation extreme point set acquisition module, a non-recommended route angle list acquisition module and a route planning module;

the elevation extreme point set acquisition module is used for acquiring an elevation extreme point set and an elevation minimum point set of the polygonal measuring area;

the non-recommended route angle list acquisition module is used for acquiring a non-recommended route angle list according to an elevation maximum value corresponding to a point in the elevation maximum value point set, an elevation minimum value corresponding to a point in the elevation minimum value point set and a maximum climbing angle of flight equipment of the airborne laser radar; the non-recommended route angle list comprises x non-recommended route angles, wherein x is a natural number;

when the non-recommended course angle list is not empty, the course planning module is used for planning a course of the flight equipment of the airborne laser radar to the polygonal survey area according to a reference course angle and the non-recommended course angle list; the reference route angle is a route angle corresponding to a route planned for the polygonal survey area according to a preset constraint condition; the preset constraint condition is that the total voyage is shortest.

Optionally, the elevation extreme point set obtaining module specifically includes:

the elevation data set acquisition unit is used for acquiring an elevation data set corresponding to a circumscribed rectangular area of the polygonal measuring area; the elevation data set comprises elevation values of each grid point in the circumscribed rectangular area;

a grid point gradient obtaining unit, configured to obtain a gradient of each grid point according to the elevation data set;

the local elevation extreme point determining unit is used for determining that each grid point is a local elevation maximum point or a local elevation minimum point or neither the local elevation maximum point nor the local elevation minimum point according to the gradient of the grid point and the gradients of the four adjacent grid points;

the elevation maximum value point set acquisition unit is used for adding local elevation maximum value points into the elevation maximum value point set;

and the elevation minimum value point set acquisition unit is used for adding the local elevation minimum value points into the elevation minimum value point set.

Optionally, the non-recommended route angle list obtaining module specifically includes:

the slope angle calculation unit is used for calculating the slope angle of each point in the elevation maximum value point set when the point is respectively combined with all points in the elevation minimum value point set; the gradient angle is obtained according to an elevation maximum value corresponding to one point of the two combined points and an elevation minimum value corresponding to the other point;

and the route angle adding unit is used for adding the route angle corresponding to the slope angle larger than the maximum climbing angle into the non-recommended route angle list.

Optionally, when the non-recommended route angle list is empty, the route planning module is configured to plan a route of the flight device of the airborne laser radar to the polygonal survey area according to a preset constraint condition.

Optionally, the route planning module specifically includes:

a first setting unit configured to set an angle increment and the number of times of increase of the angle increment;

the current route angle obtaining unit is used for obtaining a current route angle according to the reference route angle, the angle increment and the increasing times;

the first angle comparison unit is used for comparing the current airline angle with each non-recommended airline angle in the non-recommended airline angle list to obtain an angle deviation absolute value;

and the route planning unit is used for planning the route of the flight equipment of the airborne laser radar to the polygonal survey area according to the absolute value of the angle deviation.

Optionally, the route planning unit specifically includes:

a first execution unit, configured to add 1 to the increase times when the absolute value of the angle deviation between the current lane angle and any one of the non-recommended lane angles in the non-recommended lane angle list is smaller than the angle increment; the initial value of the increase times is 0;

and the second execution unit is used for planning the flight path of the flight equipment of the airborne laser radar to the polygonal survey area according to the current flight path angle when the absolute value of the angle deviation between the current flight path angle and all the non-recommended flight path angles in the non-recommended flight path angle list is greater than or equal to the angle increment.

Optionally, the second execution unit specifically includes:

the second setting unit is used for setting a safety factor; the safety factor is greater than 0 and less than 1;

a first calculation unit for obtaining a first product of the safety factor and the maximum climbing angle;

the maximum slope angle obtaining unit is used for obtaining the maximum slope angle of the projection contour line of the route formed by the current route angle in the polygonal survey area;

a second angle comparison unit for comparing the maximum slope angle with the first product;

a third execution unit, configured to plan a course of the airborne laser radar flying device for the polygonal survey area according to the current course angle when it is determined that the maximum slope angle is smaller than the first product;

a fourth execution unit, configured to add 1 to the increase number when it is determined that the maximum slope angle is greater than or equal to the first product.

Optionally, the current route angle obtaining unit specifically includes:

a second calculation unit for obtaining a second product of the angle increment and the number of increments;

a third calculation unit, configured to use the sum of the reference course angle and the second product as the current course angle;

before the fourth execution unit adds 1 to the increase number of times and before the first execution unit adds 1 to the increase number of times, the apparatus further includes:

a third angle comparing unit, configured to determine whether an absolute value of an angle deviation between the second product and 360 ° is smaller than the angle increment, and if not, the fourth executing unit executes the addition of 1 to the increase number of times or the first executing unit executes the addition of 1 to the increase number of times; and if so, the route planning result determining unit is used for determining that the planning of the route of the flight equipment of the airborne laser radar to the polygonal survey area fails.

Optionally, after the route planning result determining unit determines that planning the route of the flight device of the airborne lidar to the polygonal survey area fails, the second setting unit is further configured to:

increasing the safety factor.

Optionally, the apparatus further comprises:

the region outward expansion module is used for outward expanding four edges of the external rectangular region by preset outward expansion distances respectively to obtain an outward expanded rectangular region;

the elevation data set acquisition unit is specifically configured to:

The third aspect of the present application provides an airborne laser radar flight apparatus, comprising: a controller, a processor, and a memory; the controller and the memory are both communicatively coupled to the processor;

the memory is used for storing a computer program;

the processor is configured to execute the route planning method as provided in the first aspect according to the computer program;

the controller is used for obtaining a planned route of flight equipment of the airborne laser radar to the polygonal survey area from the processor; and controlling the flight according to the flight path.

Compared with the prior art, the method has the following beneficial effects:

in the technical scheme, firstly, an elevation maximum value point set and an elevation minimum value point set of a polygonal measuring area are obtained. And secondly, obtaining a non-recommended course angle list according to the corresponding elevation maximum value in the elevation maximum value point set, the corresponding elevation minimum value in the elevation minimum value point set and the maximum climbing angle of the flight equipment of the airborne laser radar. The non-recommended route angle list comprises a plurality of natural non-recommended route angles. When the non-recommended course angle list is not empty, a course of the flight equipment of the airborne laser radar to the polygonal survey area is planned according to the reference course angle and the non-recommended course angle list, the reference course angle is a course angle corresponding to a course planned for the polygonal survey area according to a preset constraint condition, and the preset constraint condition is that the total course is shortest. According to the technical scheme, the air route of the flight equipment of the airborne laser radar to the polygonal survey area is planned according to the reference air route angle and the non-recommended air route angle list, so that the planned air route can avoid the non-recommended air route angle, the safety of the flight equipment of the airborne laser radar is improved, and the data quality of the laser radar is guaranteed.

Drawings

In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings needed to be used in the description of the embodiments or the prior art will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art that other drawings can be obtained according to the drawings without inventive exercise.

FIG. 1 is a schematic diagram of a planned route based on the shortest total voyage principle;

FIG. 2 is a schematic diagram of a ramp angle and a climb angle of an aircraft;

FIG. 3 is a flow chart of a method for planning routes according to an embodiment of the present application;

FIG. 4 is a flowchart illustrating obtaining an elevation maximum point set and an elevation minimum point set for a polygonal measurement area according to an embodiment of the present disclosure;

fig. 5 is a schematic diagram of a circumscribed rectangular region and an extended rectangular region obtained according to a polygonal measurement area according to an embodiment of the present application;

fig. 6 is a schematic diagram of a ground elevation extreme point according to an embodiment of the present disclosure;

FIG. 7 is a flowchart of obtaining a list of non-recommended airline angles provided by an embodiment of the present application;

FIG. 8 is a schematic diagram of a slope angle provided in an embodiment of the present application;

FIG. 9 is a flow chart of another route planning method provided by an embodiment of the present application;

FIG. 10 is a flowchart illustrating a method for planning a flight path of an airborne lidar flight device to a polygonal survey area according to a current path angle according to an embodiment of the application;

FIG. 11 is a flow chart of yet another route planning method provided by an embodiment of the present application;

FIG. 12 is a schematic structural diagram of an airline planning apparatus according to an embodiment of the present application;

fig. 13 is a schematic structural diagram of an elevation extreme point set obtaining module according to an embodiment of the present disclosure;

FIG. 14 is a schematic structural diagram of a non-recommended route angle list obtaining module according to an embodiment of the present disclosure;

FIG. 15 is a schematic structural diagram of a route planning module according to an embodiment of the present application.

Detailed Description

As described above, when planning routes for flight equipment of an airborne laser radar at present, the problem that the maximum climbing angle of the flight equipment is small is often ignored. In some areas with large ground elevation change amplitude, the flight equipment cannot imitate the ground normally. On one hand, the quality of data is influenced, and on the other hand, the operation safety is low. Based on the problem, the inventor provides a flight path planning method and device and flight equipment of an airborne laser radar through research, plans the flight path of the flight equipment of the airborne laser radar to a polygonal survey area according to a reference flight path angle and a non-recommended flight path angle list, and can enable the planned flight path to avoid the non-recommended flight path angle, improve the safety of the flight equipment of the airborne laser radar and ensure the data quality of the laser radar.

In order to make the technical solutions of the present application better understood, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all of the embodiments. 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 application.

Method embodiment

Referring to fig. 3, the figure is a flowchart of a route planning method provided in an embodiment of the present application. As shown in fig. 3, the route planning method includes:

step 301: and obtaining an elevation maximum value point set and an elevation minimum value point set of the polygonal measuring area.

The polygonal measuring area is an area to be measured which comprises three or more control points and is formed by connecting lines between each control point and adjacent control points. In this step, the polygonal measurement area is a two-dimensional measurement area obtained by observing the three-dimensional area to be measured in a overlooking angle. Taking fig. 1 as an example, the shaded area is a polygon measuring area, and the control points include a point a, a point B, a point C, a point D, a point E, a point F, and a point G. Wherein, two adjacent control points are connected by a straight line.

In a possible implementation manner, step 301 specifically includes the following steps 301a to 301d, which can be seen in the flowchart shown in fig. 4.

Step 301 a: and obtaining an elevation data set corresponding to a circumscribed rectangular area of the polygonal measuring area.

Since the shape of the polygon is generally irregular, in order to obtain the elevation data set and facilitate subsequent operations and processing, a bounding rectangle of the polygon may be first obtained in step 301 a. Obtaining the circumscribed rectangle according to the two-dimensional polygonal area belongs to a relatively mature technology, and therefore, the implementation process of obtaining the circumscribed rectangle is not described herein. The dotted line area in fig. 5 is a circumscribed rectangle of the polygon measurement area.

In a possible implementation mode, in order to process the turning of a good route and realize the comprehensive coverage of the polygonal survey area, the method can further perform outward expansion on the basis of the circumscribed rectangular area. For example, four sides of the circumscribed rectangular area are respectively subjected to outward expansion by preset outward expansion distances, so that an outward expansion rectangular area is obtained. In fig. 5, the rectangle OPQR is an externally-expanded rectangular region obtained by externally expanding four sides of an externally-connected rectangular region indicated by a dotted line by a preset externally-expanding distance L. The preset outward expansion distance L can be set according to actual requirements, and specific numerical values of L are not limited here.

For the circumscribed rectangular region or the extended rectangular region obtained by the above operation, since both are two-dimensional regions, the circumscribed rectangular region or the extended rectangular region can be divided into a plurality of grids arranged along rows and columns. The division size of the grid can be determined according to actual requirements. Each grid corresponds to a small area in the circumscribed rectangular area or the outward-extended rectangular area, and in practical application, the elevation value of each position in the circumscribed rectangular area or the outward-extended rectangular area can be obtained in advance through geographical mapping data, prior information and the like before the air route is planned.

In order to facilitate subsequent arithmetic processing and simplify the data amount, one grid may be regarded as one point in a rectangular region characterized by grid data. The grid will therefore be referred to as grid points in the subsequent description. The elevation value of a grid point may be the elevation value of the center point of the grid, or may be the average value of the elevation values of all points in the area corresponding to the grid. An elevation data set I is thus obtained.

If the circumscribed rectangular area is not subjected to outward expansion, the elevation data set I comprises the elevation value of each grid point in the circumscribed rectangular area. If the circumscribed rectangular area is subjected to outward expansion, the elevation data set I comprises the elevation value of each grid point in the outward expansion rectangular area. The storage format of the elevation data set I is consistent with that of the common image data, and the elevation values in the elevation data set I take the raster data as indexes.

Step 301 b: the gradient of each grid point is obtained from the elevation data set.

The gradient G (i, j) for each grid point (i, j) is calculated as follows:

g (i, j) = dx (i, j) + dy (i, j) formula (1)

In formula (1), x and y are the arrangement directions of the grids in the circumscribed rectangular region or the extended rectangular region, respectively, and the grids are arranged along the x direction and the y direction. i is the ordinal number of the grid arranged in the x direction, and j is the ordinal number of the grid arranged in the y direction.

In the formula (1), dx (i, j) and dy (i, j) are respectively expressed as follows:

dx (I, j) = I (I +1, j) -I (I, j) formula (2)

dy (I, j) = I (I, j +1) -I (I, j) formula (3)

Step 301 c: and for each grid point, determining that the grid point is a local elevation maximum point, a local elevation minimum point or neither a local elevation maximum point nor a local elevation minimum point according to the gradient of the grid point and the gradients of the four adjacent grid points.

For grid point (i, j), the gradients of its neighboring four grid points are respectively expressed as: g (i-1, j), G (i +1, j), G (i, j-1) and G (i, j + 1).

In a specific implementation, as a possible implementation manner, step 301c may first search all grid points with gradient values of 0, and then determine whether the grid points are extreme points according to gradients of four surrounding points. For example, if G (i-1, j) <0 and G (i +1, j) >0, and G (i, j-1) <0 and G (i, j +1) >0, then the grid point is determined to be a local elevation minimum point. And if G (i-1, j) >0 and G (i +1, j) <0, and G (i, j-1) >0 and G (i, j +1) <0, determining the grid point as the local elevation maximum point. If neither of the two conditions is met, the grid point is neither a local elevation maxima point nor a local elevation minima point.

Step 301 d: and adding the local elevation maximum point into the elevation maximum point set, and adding the local elevation minimum point into the elevation minimum point set.

Assume that the local elevation maxima are P1, P2 … PM, respectively, and the local elevation minima are V1, V2 … VN, respectively, as determined by performing step 301c above. Then P1, P2 … PM may be added to the set of elevation maxima P { P1, P2 … PM }, and V1, V2 … VN may be added to the set of elevation minima V { V1, V2 … VN }. Fig. 6 is a schematic diagram of a ground elevation extreme point according to an embodiment of the present application. In FIG. 6, P1-P4 are illustrated as local elevation maximum points, and V1-V4 are illustrated as local elevation minimum points.

Through the steps 301a to 301d, the elevation maximum point set P and the elevation minimum point set V are obtained. In the subsequent step 302, a non-recommended route angle list is obtained according to the elevation maximum point set P and the elevation minimum point set V.

Step 302: and obtaining a non-recommended course angle list according to the corresponding elevation maximum value in the elevation maximum value point set, the corresponding elevation minimum value in the elevation minimum value point set and the maximum climbing angle of the flight equipment of the airborne laser radar.

In the embodiment of the present application, the step 302 is performed to determine some non-recommended route angles, so as to avoid the non-recommended route angles when planning a route to implement safer navigation detection and obtain data with better quality. As mentioned above, if the ground slope angle may be greater than or close to the maximum climbing angle of the airplane, the danger of the airplane colliding with the mountain and the like may be caused, which may result in great loss to the user. Thus, the list of non-recommended course angles may be obtained in connection with a maximum climb angle of the flying apparatus of the airborne lidar.

In a possible implementation manner, the step 302 specifically includes the following steps 302a to 302b, which can be seen in the flowchart shown in fig. 7.

Step 302 a: and calculating the slope angle of each point in the elevation maximum value point set when the point is respectively combined with all points in the elevation minimum value point set.

In step 301 above, a set of elevation maxima points P { P1, P2 … PM } and a set of elevation minima points V { V1, V2 … VN } are obtained. Taking any local elevation maximum point P1 in the set P as an example, P1 is respectivelyAnd connecting lines with all points in the set V, and obtaining the route angle according to the connecting lines. In fig. 6, the route angle when P1 and V1 are combined is obtained according to the connecting line of P1 and V1, the route angle when P1 and V2 are combined is obtained according to the connecting line of P1 and V2, the route angle when P1 and V3 are combined is obtained according to the connecting line of P1 and V3, and the route angle when P1 and V4 are combined is obtained according to the connecting line of P1 and V4. And analogizing the mode of calculating other local elevation maximum points in the set P and each route angle in the set V. The course angle is referenced to a fixed direction in the rectangle. For example, the course angle A of P2 combined with V3 can be based on the horizontal direction x₂₃As shown in fig. 6.

The way of obtaining the course angle is described above. The manner of obtaining the slope angle is described below.

The slope angle is obtained according to an elevation maximum value corresponding to one point of the two combined points and an elevation minimum value corresponding to the other point. Taking the combination of P2 and V3 as an example, the elevation value of P2 is the maximum elevation value, and the elevation value of V3 is the minimum elevation value. According to the positions of P2 and V3 in the two-dimensional plane and the respective elevation values of P2 and V3, two points in the three-dimensional space can be obtained, and according to the connecting line of the two points and the horizontal plane, the included angle between the connecting line and the horizontal plane can be obtained, wherein the included angle is the slope angle obtained in the step 302a

。

Fig. 8 illustrates two ramp angles. In FIG. 8, Pi is a local elevation maximum point in the elevation maximum point set P, and Vk and Vj are both local elevation minimum points in the elevation minimum point set V. The included angle α ik between the connecting line and the horizontal plane (shown by a dotted line) can be obtained according to the elevation values of Pi and Vk, and the included angle α ij between the connecting line and the horizontal plane can be obtained according to the elevation values of Pi and Vj. Obviously, the slope angle α ij is greater than the slope angle α ik.

Step 302 b: and adding the flight path angle corresponding to the slope angle larger than the maximum climbing angle into the non-recommended flight path angle list.

Because the slope angle is based on two of the sets P and VThe slope angle and the course angle have a corresponding relation because the course angle is obtained according to two points in the sets P and V. For example, a slope angle

Corresponding to the course angle A₂₃。

In the embodiment of the application, in order to obtain the non-recommended course angle list, the slope angle corresponding to each course angle obtained according to the sets P and V may be compared with the maximum climbing angle of the flight device of the airborne laser radar. Once the slope angle corresponding to a certain flight path angle is larger than the maximum climbing angle, the flight path is planned along the flight path angle, and therefore the flight equipment cannot normally fly in a simulated ground manner easily. Thus adding this type of course angle to the non-recommended course angle list V_invalidIn (1).

Non-recommended route angle list V formed through steps 302 a-302 b_invalidMay include one or more non-recommended course angles (i.e., course angles having a corresponding ramp angle greater than the maximum climb angle), and may also include the list V_invalidAnd if the flight device is empty, namely the slope angles corresponding to all the route angles obtained by the sets P and V are not larger than the maximum climbing angle of the flight device.

Step 303: and when the non-recommended course angle list is not empty, planning a course of the flight equipment of the airborne laser radar to the polygonal survey area according to the reference course angle and the non-recommended course angle list.

When the angle of the non-recommended route is listed as V_invalidNon-empty, it means: some route angles are not suitable for planning routes in each route angle obtained by the elevation maximum value point set P and the elevation minimum value point set V of the polygonal survey area. Specifically, a list of non-recommended airline angles V_invalidThe non-recommended course angles included in (a) are not suitable for planning courses, and therefore need to be avoided.

The reference route angle is a route angle corresponding to a route planned for the polygonal survey area according to a preset constraint condition; the preset constraint condition is that the total voyage is shortest. That is, the reference course angle is a course angle corresponding to a course planned for the polygonal survey area according to the principle that the total range is the shortest. Planning the route according to the total voyage shortest principle is a relatively mature technology in the field, and under the condition that the polygonal survey area is known, the reference route angle can be obtained according to a mature technical means in the field, so the implementation process for obtaining the reference route angle is not described in detail here.

In the non-recommended course angle list V_invalidIf the reference route angle is not empty, the list V of the non-recommended route angles_invalidIs close to or equal to the reference route angle, it is unsafe to plan the route according to the reference route angle, and the list V needs to be determined additionally_invalidAnd a course angle other than the reference course angle. And in the non-recommended course angle list V_invalidIf the reference route angle is not empty, the list V of the non-recommended route angles_invalidThe angle deviation of each angle in the reference course angle is larger, and the corresponding maximum slope angle is smaller than the maximum climbing angle of the flight equipment (or smaller than the product of the maximum climbing angle and a safety factor), so that the reference course angle is safer, and the course can be planned by the reference course angle.

The above is the route planning method provided by the embodiment of the application. Firstly, obtaining an elevation maximum value point set and an elevation minimum value point set of a polygonal measuring area; then obtaining a non-recommended course angle list according to the corresponding elevation maximum value in the elevation maximum value point set, the corresponding elevation minimum value in the elevation minimum value point set and the maximum climbing angle of the flight equipment of the airborne laser radar; the non-recommended route angle list comprises a plurality of non-recommended route angles. Finally, when the non-recommended course angle list is not empty, planning a course of the flight equipment of the airborne laser radar to the polygonal survey area according to the reference course angle and the non-recommended course angle list; the reference route angle is a route angle corresponding to a route planned for the polygonal survey area according to a preset constraint condition; the preset constraint condition is that the total voyage is shortest. According to the technical scheme, the air route of the flight equipment of the airborne laser radar to the polygonal survey area is planned according to the reference air route angle and the non-recommended air route angle list, so that the planned air route can avoid the non-recommended air route angle, the safety of the flight equipment of the airborne laser radar is improved, and the data quality of the laser radar is guaranteed.

It should be noted that the above-described sets, lists, etc. all refer to categories that may contain 0, one or more elements, where sets may be replaced by lists or other forms, and lists may be replaced by sets or other forms. In the present embodiment, the description is given only by a collection or a list, and the specific form of the category including the element is not limited.

On the basis of the route planning method provided by the foregoing embodiment, the present application further provides a further implementation scheme of route planning. It should be noted that the method embodiment described later is one possible implementation manner of the embodiment shown in fig. 3, and is not limited to the specific implementation manner of the method shown in fig. 3.

Referring to fig. 9, a flowchart of another route planning method provided in the embodiments of the present application is shown. As shown in figure 9 of the drawings,

step 901: and obtaining an elevation maximum value point set and an elevation minimum value point set of the polygonal measuring area.

Step 902: and obtaining a non-recommended course angle list according to the corresponding elevation maximum value in the elevation maximum value point set, the corresponding elevation minimum value in the elevation minimum value point set and the maximum climbing angle of the flight equipment of the airborne laser radar.

The implementation manners of the steps 901 to 902 are basically the same as the implementation manners of the steps 301 to 302 in the foregoing embodiment. The related description may refer to the foregoing embodiments, which are not repeated herein.

Step 903: judging whether the angle list of the non-recommended routes is empty, if so, executing a step 904; if not, steps 905-910 are performed.

Step 904: and when the non-recommended course angle list is empty, planning a course of the flight equipment of the airborne laser radar to the polygonal survey area according to a preset constraint condition.

When the non-recommended route angle list is empty, the method shows that the slope angle does not exceed the maximum climbing angle even if the route angle is formed and the route is planned according to the local elevation maximum value point and the local elevation minimum value point. Therefore, the routes of the polygonal survey area can be directly planned according to the principle of the shortest total route.

Because planning the route according to the total shortest route principle belongs to a relatively mature technology, the specific implementation process of the step is not limited.

Step 904 above describes a list V of non-recommended airline angles_invalidAnd (4) planning the empty route. The following description of the non-recommended course angle list V in conjunction with the subsequent steps_invalidA specific route planning mode when the route is not empty.

Step 905: and when the angle list of the non-recommended route is not empty, setting the angle increment and the increasing times of the angle increment.

The angle increment dA and the number of times of increase t of the angle increment dA are set. As an example, dA =5 °, t initial value is 0. It should be noted that the angle increment dA may be selected according to actual requirements, for example, a larger angle increment dA may be set to improve safety. The magnitude of the angular increment dA is not limited here.

Step 906: and obtaining the current course angle according to the reference course angle, the angle increment and the increasing times.

The calculation formula of the current route angle is as follows:

A_t= A_F0+ tda formula (4)

In the formula (4), dA represents an angle increment, t represents the number of times of increase of the angle increment, A_F0Representing the angle of the reference course, A_tRepresenting the current course angle. Obtaining a second product t × dA of the angle increment dA and the increment times t according to the formula (4); will refer to the course angle A_F0The sum of the current course angle A and the second product t dA is taken as the current course angle A_t. According to the formula (4), when t =0, the current route angle a_tEqual to the reference course angle A_F0。

Step 907: and comparing the current airline angle with each non-recommended airline angle in the non-recommended airline angle list to obtain an absolute value of the angle deviation.

The current route angle A_tAngle list V of non-recommended routes_invalidIs compared with each non-recommended course angle in order to determine the current course angle A_tWhether or not to list V_invalidAny of the non-recommended course angle approaches. In one possible implementation, list V may be used_invalidEach of the non-recommended course angles and the current course angle A_tAnd performing subtraction operation, and taking an absolute value of the obtained difference value to obtain an absolute value of the angle deviation. It will be appreciated that if the non-recommended route angle list V is not available_invalidThe method comprises w non-recommended route angles, wherein w is a positive integer, and then the absolute value of w angle deviation is obtained after the step is executed. Among the w absolute values of angular deviation, there may be partially repeated absolute values of angular deviation.

And then, planning the air route of the flight equipment of the airborne laser radar to the polygonal survey area according to the absolute value of the angle deviation. It will be appreciated that if the absolute value of the angular deviation is small, it represents the current course angle A_tAngle list V of non-recommended routes_invalidOne of the non-recommended course angles is relatively close, so that the current course angle A is used_tTo plan a route, safety is relatively poor. A re-comparison by changing the current course angle is required. And if the absolute value of the angle deviation is larger, the current course angle A is represented_tThe safety performance is relatively high when planning the air route, and the specific safety performance needs to be further judged by combining the relative size of the slope angle and the maximum climbing angle of the flight equipment. The following describes the route planning operation performed after obtaining the absolute value of the angle deviation in conjunction with steps 908-910.

Step 908: judging whether the absolute value of the angle deviation of the current airline angle from any non-recommended airline angle in the non-recommended airline angle list is smaller than the angle increment, if so, executing step 909; if not, step 910 is performed.

If the current course angle A_tWhether or not to list V of angles of non-recommended routes_invalidIf the absolute value of the angle deviation of any non-recommended course angle is less than the angle increment, the current course angle A is represented_tToo close to at least one non-recommended course angle.

If the current course angle A_tNot with non-recommended course angle list V_invalidIf the absolute value of the angle deviation of any non-recommended course angle is less than the angle increment, the current course angle A is represented_tAngle list V of non-recommended routes_invalidIs greater than or equal to the angle increment. I.e. the current course angle a, viewed from the dimension of the course angle_tIs relatively safe.

Step 909: and if the absolute value of the angle deviation of the current airline angle from any non-recommended airline angle in the non-recommended airline angle list is smaller than the angle increment, adding 1 to the increase times, and entering step 906.

I.e. take t = t + 1. For the current course angle A_tThe calculation formula (2) can be referred to as formula (4). It will be appreciated that when the number of increases t for the angle increment dA is increased by 1, the current course angle A_tThe angle dA is increased relative to before t is increased.

By adding 1 to the increase times t, the current flight path angle A in a two-dimensional plane by taking dA as an angle increment is realized_tPolling and iteration of the process.

Step 910: and if the absolute value of the angle deviation of all the non-recommended route angles in the current route angle and non-recommended route angle list is greater than or equal to the angle increment, planning the route of the flight equipment of the airborne laser radar to the polygonal survey area according to the current route angle.

If the current course angle A_tAngle list V of non-recommended routes_invalidThe absolute value of the angle deviation of all the non-recommended course angles in (A) is greater than or equal to the angle increment, and represents the current course angle A in the dimension of the course angle_tIs safer. But there is one possible case: at the current course angle A_tThe slope angle corresponding to the planning route is closer to or larger than the maximum climbing angle of the flight equipment of the airborne laser radar. At this point, the planned route is still relatively dangerous. A method for determining the current course angle A is described below in connection with steps 910a-910f_tPlanning possible implementation modes of flight equipment of the airborne laser radar on the routes of the polygonal survey area.

Fig. 10 shows a flow of one implementation of step 910. As shown in FIG. 10, according to the current course angle A_tPlanning the flight path of the flight device of the airborne laser radar to the polygonal survey area may specifically include:

step 910 a: a safety factor is set.

The safety factor is the safety factor in the slope angle dimension. The greater the safety factor, the smaller the safety factor and the lower the safety of the airlines planned according to the safety factor. Conversely, if the safety factor is smaller, the safety factor is larger, which indicates that the safety of the air route planned according to the safety factor is higher. The safety factor is specifically a value greater than 0 and less than 1.

Step 910 b: a first product of the safety factor and the maximum climb angle is obtained.

The first product is denoted δ × γ, where δ is the safety factor described in step 910a and γ denotes the maximum climb angle of the airborne flying apparatus. The maximum climbing angle γ is shown in fig. 2.

Step 910 c: and obtaining the maximum slope angle of the projection contour line of the course formed by the current course angle in the polygonal survey area.

Planning a route according to the determined route angle belongs to a relatively mature technology. In this step, the current course angle A_tThe formed route is not necessarily the final planned route, here at the current route angle A_tThe purpose of forming the course is only to determine the maximum bank angle. Specifically, whether the current route angle A is selected_tThe planned route also needs to be determined based on the results of subsequent comparisons.

After forming the route, in the three-dimensional space of the polygon survey areaAnd a projection contour line can be formed by taking the plane of the lens as a plane in the overlooking direction. Under the condition that the projection contour is known, the maximum gradient angle can be obtained through a mature calculation mode. The maximum slope angle alpha_kIs the acute angle formed by the tangent line with the steepest slope on the projection contour line and the horizontal plane. Maximum slope angle alpha_kThe obtaining manner of (2) can refer to the slope angle α shown in fig. 2.

Step 910 d: comparing the maximum slope angle with the first product, judging whether the maximum slope angle is smaller than the first product, if so, executing step 910 e; if not, step 910f is performed.

α_k< δ γ, representing the current course angle A_tThe planning of the air route is safer in the dimension of the slope angle. And alpha is_kΔ δ γ, representing the current course angle A_tThe safety of the planned route is insufficient in the slope angle dimension, the safety easily exceeds the climbing capacity of the flight equipment, the ground-imitating flight cannot be caused, and the data acquisition quality is poor.

Step 910 e: and when the maximum slope angle is determined to be smaller than the first product, planning the flight path of the flight equipment of the airborne laser radar to the polygonal survey area according to the current flight path angle.

Step 910 f: when it is determined that the maximum grade angle is greater than or equal to the first product, then 1 is added to the increment count and step 906 is entered.

I.e. take t = t + 1. For the current course angle A_tThe calculation formula (2) can be referred to as formula (4). By adding 1 to the increase times t, the current flight path angle A in a two-dimensional plane by taking dA as an angle increment is realized_tPolling and iteration of the above process.

In the route planning method described in the above embodiment, step 909 and step 910f both describe operations of adding 1 to t. Wherein, step 909 is the current route angle A in the dimension of the route angle_tDoes not satisfy the safety requirement, therefore, the A needs to be changed_t. Step 910f is the current course angle A in the dimension of the grade angle_tDoes not satisfy the safety requirement, therefore, the A needs to be changed_t. The security is measured by two dimensions, such thatThe route planned at the finally determined route angle meets the safety requirements of the two dimensions. Furthermore, the safety of flight equipment of the airborne laser radar is further improved, and the data quality of the laser radar is improved. The air route planned by the scheme has important utility in the operation of airborne laser radar of flight equipment in the fields of surveying and mapping, agricultural plant protection, forestry investigation, electric power inspection and the like.

When t =0, if the current course angle A_F0Not only meets the safety requirement on the angle aspect of the air route, but also meets the safety requirement on the slope angle aspect, and the finally planned air route is based on the reference air route angle A_F0A planned route. That is, the finally adopted route coincides with the route planned according to the preset constraint conditions (based on the total voyage minimum principle).

In the above embodiment, a cutoff condition for iteration may also be set. It can be understood in connection with equation (4) that if the absolute value of the angular deviation of the second product t x dA from 360 ° approaches the angular increment dA, this indicates that a substantial one week (360 °) has been polled at dA intervals for the current course angle in the two-dimensional plane. At this time, it is not necessary to add 1 to the increased number t of dA any more, and the route planning fails. Therefore, before each execution of

steps

909 and 910f, the following operations may be performed to confirm whether it is necessary to continue to add 1 to the increase number t:

step 000: judging whether the absolute value of the angle deviation between the second product and 360 degrees is smaller than the angle increment, if not, executing steps 909 and/or 910 f; if so, step 001 is performed.

Step 001: and determining that the flight path of the flight equipment for planning the airborne laser radar to the polygonal survey area fails.

The planning fails, indicating that each current route angle obtained with the previous embodiment is not safe enough. Therefore, on the premise that a route meeting the safety requirement cannot be planned, the aerial navigation detection of the airborne laser radar of the flight equipment in the polygonal survey area should not be controlled. The reasons for failure to plan a route may be: the three-dimensional topography of the polygonal survey area is too steep, possibly due to too low a safety factor setting. Therefore, after step 001, the following operations may also be performed to increase the probability of successful route planning.

Step 002: raise the security factor and proceed to step 910 b.

For example, the safety factor may be raised from 0.5 to 0.8. In conjunction with the above description, when the safety factor is adjusted up, the safety factor of the planned route is also adjusted down accordingly. However, the safety factor is improved within a reasonable range, so that the safety factor is not more than 1, and the maximum slope angle corresponding to the current air route angle for planning the air route is always smaller than the maximum climbing angle of the flight equipment.

FIG. 11 is a flowchart of a route planning method including the steps 910a to 910f and the steps 000 to 002. It is convenient to understand various possible implementation results in the implementation process of the above embodiment in combination with fig. 11.

Based on the route planning method provided by the embodiment, correspondingly, the application also provides a route planning device. Specific implementations of the apparatus are described below in conjunction with the embodiments and the figures.

Device embodiment

Referring to fig. 12, the diagram is a schematic structural diagram of an airline planning apparatus according to an embodiment of the present application. As shown in fig. 12, the route planning device 120 includes:

an elevation extreme point set obtaining module 1201, a non-recommended route angle list obtaining module 1202 and a route planning module 1203;

an elevation extreme point set obtaining module 1201, configured to obtain an elevation maximum point set and an elevation minimum point set of a polygon measurement area;

a non-recommended course angle list obtaining module 1202, configured to obtain a non-recommended course angle list according to an elevation maximum value corresponding to a point in the elevation maximum value point set, an elevation minimum value corresponding to a point in the elevation minimum value point set, and a maximum climbing angle of a flight device of an airborne laser radar; the non-recommended route angle list comprises x non-recommended route angles, wherein x is a natural number;

when the non-recommended course angle list is not empty, a course planning module 1203 is used for planning a course of the flight equipment of the airborne laser radar to the polygonal survey area according to the reference course angle and the non-recommended course angle list; the reference route angle is a route angle corresponding to a route planned for the polygonal survey area according to a preset constraint condition; the preset constraint condition is that the total voyage is shortest.

According to the technical scheme, the air route of the flight equipment of the airborne laser radar to the polygonal survey area is planned according to the reference air route angle and the non-recommended air route angle list, so that the planned air route can avoid the non-recommended air route angle, the safety of the flight equipment of the airborne laser radar is improved, and the data quality of the laser radar is guaranteed.

As an optional implementation manner, as shown in fig. 13, the elevation extreme point set obtaining module 1201 specifically includes:

an elevation data set acquisition unit 12011, configured to obtain an elevation data set corresponding to a circumscribed rectangular area of a polygonal measurement area; the elevation data set comprises elevation values of each grid point in the circumscribed rectangular area;

a grid point gradient obtaining unit 12012, configured to obtain a gradient of each grid point according to the elevation data set;

a local elevation extreme point determining unit 12013, configured to determine, for each grid point, that the grid point is a local elevation maximum point, a local elevation minimum point, or neither a local elevation maximum point nor a local elevation minimum point according to the gradient of the grid point and the gradients of four adjacent grid points;

an elevation maximum point set acquisition unit 12014, configured to add a local elevation maximum point to an elevation maximum point set;

an elevation minimum point set obtaining unit 12015, configured to add a local elevation minimum point to the elevation minimum point set.

As an alternative implementation manner, as shown in fig. 14, the non-recommended route angle list obtaining module 1202 specifically includes:

the slope angle calculation unit 12021 is configured to calculate, for each point in the elevation maximum value point set, a slope angle at which the point and all points in the elevation minimum value point set are combined respectively; the slope angle is obtained according to an elevation maximum value corresponding to one point of the two combined points and an elevation minimum value corresponding to the other point;

and the route angle adding unit 12022 is configured to add a route angle corresponding to a gradient angle larger than the maximum climbing angle to the non-recommended route angle list.

As an optional implementation manner, when the non-recommended route angle list is empty, the route planning module 1203 is configured to plan a route of the flight device of the airborne laser radar to the polygonal survey area according to a preset constraint condition.

As an alternative implementation, as shown in fig. 15, the route planning module 1203 specifically includes:

a first setting unit 12031 for setting an angle increment and the number of times of increase of the angle increment;

a current course angle obtaining unit 12032, configured to obtain a current course angle according to the reference course angle, the angle increment, and the increase times;

the first angle comparison unit 12033 is configured to compare the current lane angle with each non-recommended lane angle in the non-recommended lane angle list to obtain an angle deviation absolute value;

and the route planning unit 12034 is used for planning the route of the flight equipment of the airborne laser radar to the polygonal survey area according to the absolute value of the angle deviation.

As an optional implementation manner, the route planning unit 12034 specifically includes:

the first execution unit is used for adding 1 to the increase times when the absolute value of the angle deviation of the current airline angle and any non-recommended airline angle in the non-recommended airline angle list is smaller than the angle increment; the initial value of the number of times of increase is 0;

and the second execution unit is used for planning the flight path of the flight equipment of the airborne laser radar to the polygonal survey area according to the current flight path angle when the absolute value of the angle deviation of all the non-recommended flight path angles in the current flight path angle and the non-recommended flight path angles in the non-recommended flight path angle list is greater than or equal to the angle increment.

As an optional implementation manner, the second execution unit specifically includes:

the maximum slope angle acquisition unit is used for acquiring the maximum slope angle of a projection contour line of a course formed by the current course angle in the polygonal survey area;

the third execution unit is used for planning the flight path of the flight equipment of the airborne laser radar to the polygonal survey area according to the current flight path angle when the maximum slope angle is determined to be smaller than the first product;

and a fourth execution unit for adding 1 to the increase times when it is determined that the maximum gradient angle is greater than or equal to the first product.

And measuring the safety through two dimensions of the route angle and the slope angle, so that the route planned at the finally determined route angle meets the safety requirements of the two dimensions. Furthermore, the safety of flight equipment of the airborne laser radar is further improved, and the data quality of the laser radar is improved. The air route planned by the scheme has important utility in the operation of airborne laser radar of flight equipment in the fields of surveying and mapping, agricultural plant protection, forestry investigation, electric power inspection and the like.

As an optional implementation manner, the current route angle acquiring unit 12032 specifically includes:

a second calculation unit for obtaining a second product of the angle increment and the number of increases;

the third calculation unit is used for taking the sum of the reference route angle and the second product as the current route angle;

before the fourth execution unit adds 1 to the increase number, and before the first execution unit adds 1 to the increase number, the route planning apparatus further includes:

the third angle comparison unit is used for judging whether the absolute value of the second product and the angle deviation of 360 degrees is smaller than the angle increment or not, if not, the fourth execution unit adds 1 to the increase times or the first execution unit adds 1 to the increase times; and if so, the route planning result determining unit is used for determining that the planning of the route of the flight equipment of the airborne laser radar to the polygonal survey area fails.

Optionally, after the route planning result determination unit determines that the route of the flight device for planning the airborne laser radar to the polygonal survey area fails, the second setting unit is further configured to:

the safety factor is improved.

Optionally, the route planning apparatus further comprises:

the region outward expansion module is used for outward expanding four edges of the externally-connected rectangular region by preset outward expansion distances respectively to obtain an outward-expanded rectangular region;

the elevation data set acquisition unit is specifically configured to:

The four sides of the external rectangular area are expanded through the area expansion module, so that the processing of turning of the good air route can be facilitated.

Based on the flight path planning method and the flight path planning device provided by the embodiment, correspondingly, the application also provides flight equipment of the airborne laser radar. The implementation of this device is described below with reference to an embodiment.

Apparatus embodiment

The aircraft equipment of airborne laser radar that this application embodiment provided includes: a controller, a processor, and a memory; the controller and the memory are in communication connection with the processor;

wherein the memory is used for storing a computer program;

the processor is used for executing one or more steps in the route planning method introduced as the embodiment of the method according to the computer program;

the controller is used for obtaining a planned flight route of the flight equipment of the airborne laser radar to the polygonal survey area from the processor; and controlling the flight equipment to fly according to the flight path.

The above description is only one specific embodiment of the present application, but the scope of the present application is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present application should be covered by the scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

1. A method of route planning, comprising:

2. The route planning method according to claim 1, wherein the obtaining of the sets of elevation maxima and elevation minima of the polygonal survey area comprises:

obtaining the gradient of each grid point according to the elevation data set;

3. The route planning method according to claim 1, wherein obtaining a list of non-recommended route angles according to the corresponding elevation maxima in the set of elevation maxima points, the corresponding elevation minima in the set of elevation minima points, and the maximum climb angle of the airborne lidar's flying equipment comprises:

4. The airline planning method according to claim 1, further comprising: and when the non-recommended course angle list is empty, planning a course of the flight equipment of the airborne laser radar to the polygonal survey area according to a preset constraint condition.

5. The route planning method according to claim 1, wherein the planning of routes of a flying device of an airborne lidar to the polygonal geodetic region according to a reference route angle and the list of non-recommended route angles specifically comprises:

6. The route planning method according to claim 5, wherein the planning of the route of the airborne lidar flying device to the polygonal survey area according to the absolute value of the angle deviation specifically comprises:

7. The route planning method according to claim 6, wherein the planning of the route of the airborne lidar flying device to the polygonal survey area according to the current route angle specifically comprises:

setting a safety factor; the safety factor is greater than 0 and less than 1;

obtaining a first product of the safety factor and the maximum climbing angle;

8. The airline planning method according to claim 7, wherein the obtaining a current airline angle according to the reference airline angle, the angle increment, and the number of increments specifically includes:

before the adding 1 to the increase number, the method further comprises:

9. The route planning method according to claim 8, wherein after the determining that the route of the flying apparatus planning the airborne lidar to the polygonal geodesic has failed, the method further comprises:

increasing the safety factor.

10. The planning method according to claim 2, further comprising:

11. An airline planning apparatus, comprising: the system comprises an elevation extreme point set acquisition module, a non-recommended route angle list acquisition module and a route planning module;

12. The air route planning device according to claim 11, wherein the module for acquiring the set of elevation extreme points specifically comprises:

13. The airline planning device according to claim 11, wherein the non-recommended airline angle list obtaining module specifically includes:

14. The airline planning device of claim 11, wherein the airline planning module is configured to plan the airline of the airborne lidar to the polygonal survey area according to a preset constraint when the list of non-recommended airline angles is empty.

15. The airline planning device according to claim 11, wherein the airline planning module specifically comprises:

16. The airline planning device according to claim 15, wherein the airline planning unit comprises:

17. The airline planning device according to claim 16, wherein the second execution unit specifically includes:

18. The airline planning device according to claim 17, wherein the current airline angle obtaining unit specifically includes:

19. The route planning device according to claim 18, wherein after the route planning result determining unit determines that planning the route of the airborne lidar flying device to the polygonal survey area has failed, the second setting unit is further configured to:

increasing the safety factor.

20. The airline planning device of claim 12, further comprising:

the elevation data set acquisition unit is specifically configured to:

21. Airborne laser radar's flight equipment, its characterized in that includes: a controller, a processor, and a memory; the controller and the memory are both communicatively coupled to the processor;

the memory is used for storing a computer program;

the processor is configured to execute the route planning method according to any one of claims 1-10 in accordance with the computer program;