CN112368663A

CN112368663A - Terrain prediction method and device for sloping field, radar, unmanned aerial vehicle and operation control method

Info

Publication number: CN112368663A
Application number: CN201980040205.3A
Authority: CN
Inventors: 祝煌剑; 王春明; 胡文鑫
Original assignee: SZ DJI Technology Co Ltd
Current assignee: SZ DJI Technology Co Ltd
Priority date: 2019-11-04
Filing date: 2019-11-04
Publication date: 2021-02-12
Also published as: WO2021087702A1

Abstract

A terrain prediction method and device for a sloping field, a radar, an unmanned aerial vehicle and an operation control method are provided, wherein the unmanned aerial vehicle carries the radar, and the method comprises the following steps: acquiring detection data of an omnidirectional scanning area obtained by the radar in a ground rotation scanning process (S110); fitting out a fitting plane of the omnidirectional scanning area according to the detection data (S120); determining terrain parameters of the omni-directional scanning area according to the fitting plane (S130); and adjusting the flight action of the unmanned aerial vehicle according to the terrain parameters (S140).

Description

Terrain prediction method and device for sloping field, radar, unmanned aerial vehicle and operation control method

Technical Field

The specification relates to the technical field of unmanned aerial vehicles, in particular to a terrain prediction method and device for sloping fields, a radar, an unmanned aerial vehicle and an operation control method.

Background

In some work scenarios, the drone needs to fly over some uneven terrain, such as the ground where there is a slope. For example, in the process of mountain land operation, the unmanned aerial vehicle can fly, for example, to follow the terrain by detecting the vertical distance to the ground below the ground and keeping a certain height difference with the ground below the unmanned aerial vehicle.

But through the difference in height that detects unmanned aerial vehicle and ground directly below, readjust flying height, this kind of method belongs to a back feedback, and the topography is followed the response and is slow, and when unmanned aerial vehicle flying speed is very fast or the violent region of relief, great threat to flight safety is produced.

Disclosure of Invention

Based on the above, the present specification provides a method and an apparatus for predicting a terrain on a sloping field, a radar, an unmanned aerial vehicle, and an operation control method, which can more comprehensively predict the terrain of an area where the unmanned aerial vehicle is located according to the detection of each direction of the unmanned aerial vehicle, such as the ground in front, behind, on the left side, and on the right side.

In a first aspect, the present specification provides a method of terrain prediction for a sloping field, the method comprising:

acquiring detection data of an omnidirectional scanning area obtained by a radar in a ground rotation scanning process;

fitting a fitting plane of the omnidirectional scanning area according to the detection data;

determining terrain parameters of the omnidirectional scanning area according to the fitting plane, wherein the terrain parameters comprise the gradient of the omnidirectional scanning area.

In a second aspect, the present application provides a terrain prediction device for a sloping field, the terrain prediction device comprising a memory and a processor;

the memory is used for storing a computer program;

the processor is configured to execute the computer program and, when executing the computer program, implement the following steps:

In a third aspect, the present application provides a radar comprising a memory and a processor;

the memory is used for storing a computer program;

In a fourth aspect, the present application provides a method for controlling operations of an unmanned aerial vehicle, where the unmanned aerial vehicle carries a radar and operates on a sloping field, and the method includes:

acquiring detection data of an omnidirectional scanning area obtained by the radar in a ground rotation scanning process;

determining terrain parameters of the omnidirectional scanning area according to the fitting plane, wherein the terrain parameters comprise the gradient of the omnidirectional scanning area;

and adjusting the flight action of the unmanned aerial vehicle according to the terrain parameters.

In a fifth aspect, the present application provides a drone, the drone comprising a memory and a processor;

the memory is used for storing a computer program;

In a sixth aspect, the present specification provides a computer readable storage medium having stored thereon a computer program which can be processed by a processor to implement the method described above.

The embodiment of the specification provides a terrain prediction method and device for a sloping field, a radar, an unmanned aerial vehicle, an operation control method and a computer readable storage medium, wherein detection data of an omnidirectional scanning area obtained in a ground rotation scanning process of the radar carried by the unmanned aerial vehicle is obtained, and a fitting plane of the omnidirectional scanning area is fitted according to the detection data; so as to determine the terrain parameters of the omnidirectional scanning area according to the fitting plane; and adjusting the flight action of the unmanned aerial vehicle according to the terrain parameters. Because the omnidirectional scanning area comprises the front direction, the rear direction, the left direction and the right direction of the unmanned aerial vehicle, the obtained terrain parameters are more global and accurate, and the flight action of the unmanned aerial vehicle can be controlled more safely.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the disclosure as claimed.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present disclosure, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are some embodiments of the present disclosure, and it is obvious for those skilled in the art to obtain other drawings based on the drawings without creative efforts.

Fig. 1 is a schematic flowchart of an operation control method for an unmanned aerial vehicle according to an embodiment of the present disclosure;

fig. 2 is a schematic structural diagram of an unmanned aerial vehicle according to an embodiment of the present disclosure;

FIG. 3 is a schematic structural diagram of a radar provided by an embodiment of the present disclosure, wherein a housing is not shown;

FIG. 4 is a cross-sectional view of a radar provided by embodiments of the present description, with the housing not shown;

FIG. 5 is a schematic view of a rotating shaft intersecting a predetermined plane according to an embodiment of the present disclosure;

FIG. 6 is a schematic structural diagram of a radar according to an embodiment of the present disclosure;

FIG. 7 is a schematic structural diagram of a terrain prediction apparatus according to an embodiment of the present disclosure;

FIG. 8 is a schematic diagram of an omnidirectional scanning area scanned during rotation by a radar in an embodiment of the present disclosure;

FIG. 9 is a schematic illustration of radar scanning a ground point to obtain survey data;

FIG. 10 is a schematic diagram of the distribution of several ground points in an omnidirectional scanning area on a geodetic coordinate system;

FIG. 11 is a schematic illustration of a plane of fit for an omni-directional scanning region;

fig. 12 is a schematic block diagram of a drone provided by an embodiment of this specification.

Detailed Description

The technical solutions in the embodiments of the present disclosure will be clearly and completely described below with reference to the drawings in the embodiments of the present disclosure, and it is obvious that the described embodiments are some, but not all, of the embodiments of the present disclosure. All other embodiments obtained by a person of ordinary skill in the art based on the embodiments in the present specification without any creative effort belong to the protection scope of the present specification.

The flow diagrams depicted in the figures are merely illustrative and do not necessarily include all of the elements and operations/steps, nor do they necessarily have to be performed in the order depicted. For example, some operations/steps may be decomposed, combined or partially combined, so that the actual execution sequence may be changed according to the actual situation.

Some embodiments of the present description will be described in detail below with reference to the accompanying drawings. The embodiments described below and the features of the embodiments can be combined with each other without conflict.

Referring to fig. 1, fig. 1 is a schematic flowchart of an operation control method for an unmanned aerial vehicle according to an embodiment of the present disclosure.

The unmanned aerial vehicle operation control method can be applied to an unmanned aerial vehicle and is used for controlling the processes of flying action and the like of the unmanned aerial vehicle according to the terrain. Wherein unmanned aerial vehicle can be for rotating wing type unmanned aerial vehicle, for example four rotor unmanned aerial vehicle, six rotor unmanned aerial vehicle, eight rotor unmanned aerial vehicle, also can be fixed wing unmanned aerial vehicle.

Fig. 2 is a schematic structural diagram of the drone according to an embodiment. The unmanned aerial vehicle of rotor is exemplified to explain this specification embodiment.

Referring to fig. 2, an embodiment of the present application provides a drone 1000, where the drone 1000 may include a body 100, a spraying mechanism 220, a power system 300, and a flight control system. Unmanned aerial vehicle 1000 can carry out wireless communication with control terminal, and this control terminal can show unmanned aerial vehicle 1000's flight information etc. and control terminal can communicate with unmanned aerial vehicle 1000 through wireless mode for carry out remote control to unmanned aerial vehicle 1000.

The body 100 may include a body 110 and a landing gear 120, among others. The fuselage 110 may include a central frame 111 and one or more arms 112 coupled to the central frame 111, the one or more arms 112 extending radially from the central frame 111. The landing gear 120 is connected to the fuselage 110 for support when the drone 1000 lands.

In some embodiments, the spraying mechanism 220 is disposed on the body 110, and the spraying mechanism 220 is connected to the accommodating box 210 for spraying the object to be sprayed in the accommodating box 210. The object to be sprayed can be liquid medicine, water or fertilizer and the like. Specifically, referring again to fig. 2, the spraying mechanism 220 includes a water pump and a spray head 221. The receiving tank 210 is used to store liquid medicine or water. The storage box 210 and the water pump are mounted on the body 110. The head 221 is mounted on the end of the arm 112. The liquid in the container 210 is pumped to the spray head 221 by a water pump and sprayed out by the spray head 221. The power system 300 can drive the machine body 100 to move, rotate, turn, etc., so as to drive the nozzle 221 to move to different positions or different angles for spraying in a predetermined area.

The power system 300 may include one or more electronic governors (abbreviated as electric governors), one or more propellers 310, and one or more power motors 320 corresponding to the one or more propellers 310, where the power motors 320 are connected between the electronic governors and the propellers 310, and the power motors 320 and the propellers 310 are disposed on the horn 112 of the drone 1000; the electronic governor is used for receiving a driving signal generated by the flight control system and providing a driving current to the power motor 320 according to the driving signal so as to control the rotating speed of the power motor 320. The power motor 320 is used to drive the propeller 310 to rotate, thereby providing power for the flight of the drone 1000, which power enables the drone 1000 to achieve one or more degrees of freedom of motion. In certain embodiments, the drone 1000 may rotate about one or more axes of rotation. For example, the above-mentioned rotation axes may include a roll axis (roll axis), a yaw axis (yaw axis), and a pitch axis (pitch axis). In some embodiments, the roll axis is the Y-axis of fig. 2, the pitch axis is the X-axis of fig. 2, and the heading axis is the Z-axis of fig. 2. It should be understood that the power motor 320 may be a dc motor or an ac motor. In addition, the power motor 320 may be a brushless motor or a brush motor.

The flight control system may include a flight controller and a sensing system. The sensing system is used for measuring attitude information of the unmanned aerial vehicle 1000, that is, position information and state information of the unmanned aerial vehicle 1000 in space, for example, three-dimensional position, three-dimensional angle, three-dimensional velocity, three-dimensional acceleration, three-dimensional angular velocity, and the like. The sensing system may include, for example, at least one of a gyroscope, an ultrasonic sensor, an electronic compass, an Inertial Measurement Unit (IMU), a vision sensor, a global navigation satellite system, and a barometer. For example, the Global navigation satellite System may be a Global Positioning System (GPS). The flight controller is used to control the flight of the drone 1000, for example, the flight of the drone 1000 may be controlled according to attitude information measured by the sensing system. It should be understood that the flight controller may control the drone 1000 according to preprogrammed program instructions, or may control the drone 1000 by responding to one or more control instructions from a control terminal.

As shown in fig. 2, the landing gear 120 of the drone 1000 carries a radar 400, and the radar 400 can detect objects, such as obstacles. Specifically, the radar 400 may measure a distance, a distance change rate, an azimuth, an altitude, and the like of an object to a transmission point of the radar 400, thereby implementing functions such as scanning the ground. In some embodiments, the radar 400 is a millimeter wave radar 400. Of course, in other embodiments, the radar 400 may be beyond-the-horizon radar 400, microwave radar 400, laser radar 400, or the like.

Referring to fig. 3 and 4, the radar 400 includes a base 410, an antenna mechanism 420, and a driving mechanism 430. The antenna mechanism 420 can rotate around a preset rotation axis R with respect to the main body 110, and is used for detecting an obstacle on the side of the drone 1000.

In some embodiments, the base 410 is mounted on the landing gear 120. The antenna mechanism 420 includes a transmitter (not shown) and a receiver (not shown). The transmitter is used for generating a radar signal and transmitting the radar signal, and the radar signal is transmitted forwards along the transmitted direction and is reflected when meeting an obstacle. The receiver is used for receiving the reflected echo signals.

The antenna mechanism 420 can be rotated about the rotation axis R by the driving mechanism 430, so that the antenna mechanism 420 can selectively transmit signals toward a plurality of directions and receive echo signals reflected from a plurality of directions. Therefore, the distances between the drone 1000 and obstacles in a plurality of directions can be selectively detected by one antenna mechanism 420, and the structure of the drone 1000 is simple.

In some embodiments, the rotation axis R intersects the predetermined plane ω, i.e., the rotation axis R is disposed non-parallel to the predetermined plane ω. The preset plane ω is a plane where the pitch axis and the roll axis of the drone 1000 are located. From this, the radar 400 not only can survey unmanned aerial vehicle 1000's the place ahead field of vision and rear field of vision and realize scanning the place ahead and rear, can survey unmanned aerial vehicle 1000 in addition except that the place ahead field of vision and rear field of vision other side fields of vision, has enlarged unmanned aerial vehicle 1000's detection angle and detection coverage, has guaranteed the omnidirectionality of scanning.

In some embodiments, the drive mechanism 430 is disposed on the base 410. The rotating part of the driving mechanism 430 is connected to the antenna mechanism 420 to drive the antenna mechanism 420 to rotate around the rotation axis R. Specifically, the driving mechanism 430 includes a motor including a stator 431 and a rotor 432, the rotor 432 is a rotating component of the driving mechanism 430, and the rotor 432 can rotate relative to the stator 431, so as to drive the antenna mechanism 420 to rotate. More specifically, the stator 431 is mounted on the base 410, the antenna mechanism 420 is mounted on a rotor 432 of the motor, and the rotor 432 rotates with respect to the base 410 such that the antenna mechanism 420 rotates about the rotation axis R with respect to the base 410.

Specifically, the antenna mechanism 420 of the radar 400 is driven by the rotor 432 to rotate around the rotation axis R in the forward direction or the reverse direction with reference to the head direction of the drone 1000, and scans a sector area within an angle range each time. The antenna mechanism 420 rotates one turn, i.e., 360 °, to scan a complete circular area centered around the center of the radar 400, thereby obtaining the detection data of the circular omnidirectional scanning area.

In some embodiments, the rotor 432 of the motor is capable of rotating at least one revolution in a forward or reverse direction, thereby causing the antenna mechanism 420 to rotate omni-directionally in a forward or reverse direction by at least 360 °. Specifically, the rotation angle range of the antenna mechanism 420 around the rotation axis R is greater than or equal to 360 °, for example, 450 °, 540 °, 720 °, 1020 °, and the like, and continuous rotation is achieved, so that data acquisition points of the antenna mechanism 420 are increased, and the measurement accuracy of the radar 400 is improved.

In some embodiments, referring to FIG. 5, the angle α between the rotation axis R and the predetermined plane ω is 60-90 °. Specifically, the included angle α between the rotation axis R and the preset plane ω may be 60 °, 65 °, 70 °, 80 °, 85 °, 90 °, and any other suitable angle between 60 ° and 90 °. An included angle alpha between the rotating shaft R and the preset plane omega is within a range of 60-90 degrees, so that the scanning visual field can include a front visual field and a rear visual field, and can also include other side visual fields except the front visual field and the rear visual field as far as possible, the detection angle and the detection coverage range of the unmanned aerial vehicle 1000 are enlarged as far as possible, and omnidirectional scanning is realized.

In some embodiments, the rotation axis R substantially coincides with the center line of the fuselage 110, so as to avoid the problem of unbalanced center of gravity of the drone 1000 caused by the installation of the radar 400, thereby ensuring the reliability of the flight of the drone 1000. Wherein, the substantial coincidence means that the included angle between the rotating shaft R and the central line of the machine body 110 is 0-10 degrees, namely any angle between 0 degree, 10 degrees and 0-10 degrees.

In some embodiments, the rotation axis R is at an acute angle to the heading axis of the drone 1000. Wherein the acute angle may be any suitable angle, for example 0 ° -30 °, i.e. 0 °, 5 °, 10 °, 15 °, 20 °, 25 °, 30 ° and any other suitable angle between 0 ° and 30 °.

In some embodiments, the rotation axis R is substantially perpendicular to the preset plane ω, or the rotation axis R substantially coincides with the heading axis of the unmanned aerial vehicle 1000, and at this time, the omnidirectional scanning area of the radar 400 is a perfect circle with the center of the radar 400 as the center of the circle, and is a 360-degree area surrounding the side surface of the unmanned aerial vehicle 1000, and can represent ground detection information of the unmanned aerial vehicle 1000 in different directions.

When the rotation axis R of the rotor 432 of the driving mechanism 430 is perpendicular to the preset plane ω, that is, the rotation axis R of the rotor 432 is perpendicular to the plane where the pitch axis and the roll axis of the drone 1000 are located, by adjusting the rotation angle of the antenna mechanism 420, the antenna mechanism 420 can transmit microwave signals to the left, right, front, and back of the drone 1000 and receive echo signals reflected by obstacles on the left, right, front, and back, and at this time, the radar 400 can be used to realize functions such as left-side scanning, right-side scanning, front scanning, back scanning, left-side terrain prediction, right-side terrain prediction, front terrain prediction, and back terrain prediction. Of course, the rotation axis R of the rotor 432 may intersect with the plane of the pitch axis and the roll axis of the drone 1000 in other specific situations, and is not limited herein.

It can be understood that a preset included angle exists between the rotating shaft R and the preset plane ω, or when the rotating shaft R and the course axis of the unmanned aerial vehicle 1000 form an acute angle, the omnidirectional scanning area is not a perfect circle, but is a 360-degree area surrounding the unmanned aerial vehicle 1000, and therefore the ground detection information of the unmanned aerial vehicle 1000 in different directions around the unmanned aerial vehicle can be reflected.

The rotation axis R may be a real axis or an imaginary axis. When the rotation axis R is a real axis, the antenna mechanism 420 can rotate relative to the rotation axis R; alternatively, the antenna mechanism 420 rotates together with the rotation axis R.

In some embodiments, antenna mechanism 420 is disposed on a side of base 410 facing away from body 110 such that antenna mechanism 420 of radar 400 is furthest away from a sensor disposed on body 110, reducing interference of radar signals (e.g., electromagnetic waves) generated by antenna mechanism 420 with the sensor on body 110.

Referring to fig. 3 and 4, in some embodiments, radar 400 further includes a sensing mechanism 440. The sensing mechanism 440 is disposed at an end of the antenna mechanism 420 away from the base 410, and is used for detecting a height of the drone 1000 relative to the ground. When the driving mechanism 430 drives the antenna mechanism 420 to rotate, the sensing mechanism 440 also rotates together with the antenna mechanism 420. Wherein the sensing mechanism 440 includes at least one of a vision sensor, an ultrasonic ranging sensor, a depth camera, a radar antenna structure, and the like.

It will be appreciated that the shape of the antenna mechanism 420 and the sensing mechanism 440 may be designed into any suitable shape, such as a plate shape, according to actual requirements. Illustratively, when the antenna mechanism 420 and the sensing mechanism 440 are both substantially plate-shaped, the antenna mechanism 420 is substantially perpendicular to the sensing mechanism 440. Specifically, the antenna mechanism 420 is substantially perpendicular to the plane in which the pitch and roll axes of the drone 1000 lie. Sensing mechanism 440 is substantially parallel to the plane of the pitch and roll axes of drone 1000.

Referring to fig. 3 and 4, in some embodiments, radar 400 further includes a circuit board 450. The circuit board 450 is disposed on the base 410 opposite to the antenna mechanism 420 for processing signals of the antenna mechanism 420. In particular, the circuit board 450 may process signals of the antenna mechanism 420, such as amplifying echo signals; filtering the interference signal; and converting the echo signals into radar data signals for control of back-end equipment, terminal observation and/or recording and the like.

In some embodiments, the circuit board 450 is plate-shaped, but may be designed in any other suitable shape. Because the center of gravity of antenna mechanism 420 deviates from the rotating shaft R of antenna mechanism 420, the center of gravity of radar 400 may deviate from the rotating shaft R of antenna mechanism 420, and further the center of gravity of drone 1000 may be unbalanced, so that drone 1000 may fly unreliably. To this end, the circuit board 450 and the antenna mechanism 420 are disposed opposite to each other at both ends of the sensing mechanism 440, and the circuit board 450 and the antenna mechanism 420 are disposed symmetrically about the rotation axis R, thereby balancing the center of the antenna mechanism 420 such that the center of the radar 400 is substantially located on the rotation axis R of the antenna mechanism 420. Specifically, antenna mechanism 420, sensing mechanism 440, and circuit board 450 form a "Π" structure having an opening facing body 110.

Referring to fig. 2 again, in some embodiments, the radar 400 further includes a housing 460, the housing 460 and the base 410 cooperate to form an accommodating space, and the antenna mechanism 420, the driving mechanism 430, the sensing mechanism 440 and the circuit board 450 are accommodated in the accommodating space, so as to protect the antenna mechanism 420, the driving mechanism 430, the sensing mechanism 440 and the circuit board 450 from being influenced by the external environment and avoid the external environment from interfering with or damaging the components. It is understood that the signals transmitted or received by the antenna mechanism 420 and the sensing mechanism 440 can pass through the housing 460, i.e., the housing 460 does not affect the normal transmission or reception of the signals by the antenna mechanism 420 and the sensing mechanism 440.

Because the antenna mechanism of radar can revolve around the rotation axis, this pivot is crossing with the plane at every single move axis and roll place, not only can survey unmanned aerial vehicle's the place ahead field of vision and rear field of vision, can survey other side fields of vision except place ahead field of vision and rear field of vision to unmanned aerial vehicle side field of vision moreover, enlarged unmanned aerial vehicle's detection angle and detection coverage, realized the omnidirectional scanning to ground.

It is to be understood that the above-mentioned nomenclature for the components of the drone is for identification purposes only, and should not be construed as limiting the embodiments of this specification.

As shown in fig. 1, the unmanned aerial vehicle operation control method of the present embodiment includes steps S110 to S140.

And S110, acquiring detection data of the omnidirectional scanning area, which is acquired by the radar in the process of the ground rotation scanning.

Exemplarily, a radar is mounted below an unmanned aerial vehicle, and detection data of a circular omnidirectional scanning area with the center of circle directly below the radar can be acquired.

And S120, fitting a fitting plane of the omnidirectional scanning area according to the detection data.

Illustratively, the detection data comprises azimuth information of a plurality of ground points in the omnidirectional scanning area, and a fitting plane of the ground in the omnidirectional scanning area is obtained through fitting, wherein most ground points in the omnidirectional scanning area are located on the fitting plane or have a small distance from the fitting plane.

And S130, determining the terrain parameters of the omnidirectional scanning area according to the fitting plane.

For example, when the drone operates on a sloping ground, the slope of the omni-directional scanning area may be of greater concern, so the determined terrain parameter may include the slope.

For example, the slope of the omni-directional scanning area and other information can be determined according to the inclination direction of the fitting plane.

For example, when the drone is operating on rough ground, the flatness of the omni-directional scanning area needs to be more concerned, so the determined terrain parameters may include flatness.

For example, whether the omni-directional scanning area is flat or not can be determined according to the number of ground points with larger distance from the fitting plane and the distance.

It will be appreciated that in some embodiments, the aforementioned steps S110 to S130 may be implemented by a drone.

It is understood that, in some embodiments, the foregoing steps S110 to S130, that is, the steps of the method for predicting the terrain of a sloping field in the embodiment of the present specification, may be implemented by radar.

Illustratively, as shown in FIG. 6, the radar 400 includes a processor 401 and a memory 402.

For example, referring to fig. 3 and 4, the processor 401 and the memory 402 may be disposed on a circuit board 450 of the radar 400.

Illustratively, the processor 401 and the memory 402 are connected by a bus 403, such as an I2C (Inter-integrated Circuit) bus.

Specifically, the Processor 401 may be a Micro-controller Unit (MCU), a Central Processing Unit (CPU), a Digital Signal Processor (DSP), or the like.

Specifically, the Memory 402 may be a Flash chip, a Read-only Memory (ROM) magnetic disk, an optical disk, a usb disk, or a removable hard disk.

The memory 402 is used for storing computer programs;

the processor 401 is configured to execute the computer program and, when executing the computer program, implement the foregoing steps S110 to S130, that is, the steps of the method for predicting the topography of a sloping field according to the embodiment of the present specification.

It is understood that, in some embodiments, the foregoing steps S110 to S130, that is, the steps of the method for predicting the terrain of a sloping field in the embodiment of the present specification, may be implemented by a terrain prediction device.

The terrain prediction device may be, for example, a server or a terminal. The terminal can be an electronic device such as a mobile phone, a tablet computer, a notebook computer, a desktop computer, a personal digital assistant and the like; the servers may be independent servers or server clusters.

Illustratively, as shown in fig. 7, the terrain prediction apparatus 600 includes a processor 601 and a memory 602.

Illustratively, the processor 601 and the memory 602 are coupled by a bus 603, such as an I2C (Inter-integrated Circuit) bus.

Specifically, the Processor 601 may be a Micro-controller Unit (MCU), a Central Processing Unit (CPU), a Digital Signal Processor (DSP), or the like.

Specifically, the Memory 602 may be a Flash chip, a Read-Only Memory (ROM) magnetic disk, an optical disk, a usb disk, or a removable hard disk.

The memory 602 is used for storing computer programs;

the processor 601 is configured to execute the computer program and, when executing the computer program, implement the foregoing steps S110 to S130, that is, the steps of the method for predicting the topography of a sloping field according to the embodiment of the present specification.

In the method, the apparatus, and the radar for predicting the terrain of a sloping field provided in the embodiments of the present specification, by acquiring detection data of an omnidirectional scanning area obtained by the radar in a process of rotating and scanning the ground, a fitting plane of the omnidirectional scanning area is fitted according to the detection data; the terrain parameters of the omni-directional scanning area are determined according to the fitting plane, and the terrain of the area where the unmanned aerial vehicle is located can be predicted more comprehensively according to detection of all directions of the unmanned aerial vehicle, such as the ground of the front, the rear, the left side and the right side.

In some embodiments, the drone may also perform step S140.

S140, adjusting the flight action of the unmanned aerial vehicle according to the terrain parameters.

For example, the drone may obtain the terrain parameters from radar, from a terrain prediction device, or the drone may implement the aforementioned steps S110 to S130 to obtain the terrain parameters.

Exemplarily, the unmanned aerial vehicle can adjust the flight action of the unmanned aerial vehicle according to the information such as the flatness and the gradient of the ground, and the safe flight of the unmanned aerial vehicle and the reliable execution of the operation task are guaranteed.

In some embodiments, the acquiring, in step S110, omnidirectional scanning area detection data obtained by the radar in the process of ground rotation scanning includes: the returned data of the radar is obtained, the spectrum of the returned data is extracted, processed and analyzed, and the relative space position between the radar and a scanning target, such as an obstacle, can be calculated.

Illustratively, the radar is a continuous wave radar. The detection data can be obtained according to a continuous wave radar ranging and angle measuring algorithm. For example, the returned data of the radar is processed to complete spectrum extraction and further spectrum refinement, and finally the refined frequency point position is converted into the azimuth information of the ground point.

For example, as shown in fig. 8, the radar mounted below the drone rotates with the direction of the head of the drone as a reference, and scans a sector area within an angular range at a time. The radar rotates for a circle, namely 360 degrees, so that a complete circular area can be scanned, and detection data of a circular omnidirectional scanning area with the center of a circle under the radar is obtained.

Exemplarily, the direction of rotation of radar can be the same with unmanned aerial vehicle's upper and lower direction, and the omnidirectional scanning area is a perfect circle that uses under the radar as the centre of a circle this moment, is a 360 region around unmanned aerial vehicle, can embody the ground detection information of unmanned aerial vehicle around the front and back different positions about.

Exemplarily, the rotation direction of the radar can also have a preset angle with the unmanned aerial vehicle in the up-down direction, and the omni-directional scanning area is not a perfect circle at the moment, but is an area surrounding the unmanned aerial vehicle by 360 degrees, so that the ground detection information of the unmanned aerial vehicle in all directions can be embodied.

In the present embodiment, a certain area below the drone is scanned based on the rotating radar, and spatial azimuth information of ground points in the omni-directional scanning area is obtained.

In some embodiments, the detection data of several ground points in the omni-directional scanning area may also be acquired by a vision sensor, a Time of Flight (TOF) sensor, or a sensor module with ranging and angle measurement, such as a laser radar, an ultrasonic module, or the like. For example, a two-dimensional image of the omni-directional scanning area is acquired by a vision sensor, and then a three-dimensional point cloud is extracted from the two-dimensional image. However, the vision sensor has higher requirements on the illumination environment and is easily influenced by light intensity, background target color, dust in the environment, water mist and the like.

In some embodiments, the acquiring omnidirectional scanning area detection data obtained by the radar during the ground rotation scanning process includes: and acquiring the detection distance and azimuth angle of a plurality of ground points of the omnidirectional scanning area relative to the radar.

Fig. 9 is a schematic diagram of a beam level of a radar detected target object, such as a ground point. Illustratively, the radar outputs a detection range r and an azimuth angle θ of the ground point relative to the radar.

Specifically, the detection distance r of the ground point with respect to the radar represents the radial distance of the ground point with respect to the center of the radar.

Illustratively, the method further comprises: acquiring the corresponding radar rotation angle of the radar when detecting each ground point

E.g. radar rotation angle

And the rotation angle of the radio frequency plate of the radar relative to the initial position, such as the direction of a machine head, in the current frame is shown.

It is understood that, in step S110, coordinates of a plurality of ground points in the omni-directional scanning area in a coordinate system with the radar as an origin may be acquired, which may be referred to as a coordinate system of the radar, and the radar coordinate system may be, for example, a spherical coordinate system, a cylindrical coordinate system, or a rectangular coordinate system.

The coordinates of the ground point on a rectangular coordinate system with the radar as the origin may be expressed in terms of distances of the ground point in a plurality of directions with respect to the radar.

For example, the spherical coordinate system coordinates, the cylindrical coordinate system coordinates, and the like of the ground point acquired from the radar may be converted to coordinates on a rectangular coordinate system. The method is convenient for plane fitting calculation, has smaller calculation amount, and realizes faster judgment of the terrain.

Illustratively, the acquiring the detection data of the omnidirectional scanning area obtained by the radar in the process of rotating and scanning the ground further includes: and determining the distances of the ground points in a plurality of directions relative to the radar according to the radar rotation angle, the detection distance and the azimuth angle corresponding to the ground points.

It is to be understood that, the acquiring of the omnidirectional scanning area detection data obtained by the radar in the process of the ground rotation scanning may include: and acquiring distances of a plurality of ground points of the omnidirectional scanning area relative to the radar in a plurality of directions.

Specifically, the distances of the ground point in a plurality of directions with respect to the radar include: the position coordinates of the ground point in a radar coordinate system of the radar.

The radar coordinate system takes a rotation center of the radar as an origin, takes the position right below the radar as a first axis direction, takes the position right before the radar as a second axis direction, and takes the direction perpendicular to the first axis direction and the second axis direction as a third axis direction.

Illustratively, the position coordinates of the ground point in the radar coordinate system of the radar are given by { x, y, z }_AThe representation is expressed by a Cartesian coordinate system of a radar observation system of a ground point, wherein subscript A represents that the origin of the coordinate system is determined according to the center of the radar, and x, y and z respectively represent three mutually perpendicular coordinate axes of the Cartesian coordinate system.

Exemplary, spherical coordinate system coordinates of ground points

And then, converting the ground point position representation from a spherical coordinate system to a Cartesian coordinate system can be completed by the following model:

in some embodiments, the coordinate data of several ground points in the omni-directional scanning area in the geodetic coordinate system may be acquired in step S110.

Specifically, the geodetic coordinate system uses a certain point on the ground as an origin. For example the origin of the geodetic coordinate system is located directly below the radar. So that the fitting curved surface of the omnidirectional scanning area below the radar can be obtained through subsequent fitting.

The geodetic coordinate system takes the positive north direction or the positive south direction of the origin of the geodetic coordinate system as the fourth axis direction, the positive east direction or the positive west direction of the origin of the geodetic coordinate system as the fifth axis direction, and the direction perpendicular to the fourth axis direction and the fifth axis direction as the sixth axis direction.

For example, the coordinate data of the ground points in the geodetic coordinate system includes distances of the ground points in the fourth, fifth and sixth axis directions relative to the geodetic origin.

Illustratively, the geodetic coordinate system adopted is ENU (East-North-UP coordinate system). May be represented by x_GRepresenting the distance, y, of the ground point in the direction due to the north of the origin of coordinates_GDenotes the distance of the ground point in the east-ward direction with respect to the origin of coordinates, z_GRepresenting the distance of the ground point in the perpendicular direction with respect to the origin of coordinates.

Specifically, the radar may convert coordinates of the ground point on the coordinate system with the radar as the origin into coordinates on the geodetic coordinate system according to a conversion model between the coordinate system with the radar as the origin and the geodetic coordinate system. The transformation model may be determined, for example, from the pose of the radar.

In some embodiments, the drone may acquire coordinates of the ground point on a coordinate system with the radar as an origin from the radar, and acquire a pose of the radar, and then obtain coordinates of the ground point on a geodetic coordinate system from the pose of the radar by the drone.

Illustratively, the step S120 of fitting a fitting plane of the omnidirectional scanning area according to the detection data includes: determining coordinate data of a plurality of ground points in the omnidirectional scanning area in a geodetic coordinate system according to the detection data; and fitting a fitting plane of the omnidirectional scanning area according to the coordinate data of the plurality of ground points.

By converting the ground point from the radar observation system to the geodetic coordinate system, the influence of the radar or radar carrier, such as the posture of an unmanned aerial vehicle, on the ground observation can be eliminated, and the plane model obtained by ground fitting is more accurate.

For example, the coordinates of the ground point on the coordinate system with the radar as the origin are converted into coordinates on the geodetic coordinate system by the calculation model of the following formula:

wherein the content of the first and second substances,

denotes a homogeneous transformation matrix between a coordinate system with the origin of radar and a geodetic coordinate system, and G denotes the geodetic coordinate system.

In some embodiments, the method further comprises: and acquiring the attitude information of the radar through an Inertial Measurement Unit (IMU) carried by the unmanned aerial vehicle and/or an inertial measurement unit carried by the radar.

Illustratively, the determining coordinate data of a plurality of ground points in the omnidirectional scanning area in a geodetic coordinate system according to the probe data includes: and determining coordinate data of a plurality of ground points in a geodetic coordinate system according to the attitude information of the radar and the detection data.

Illustratively, the attitude quaternion q of the radar is obtained from the inertial measurement unit in real time₀，q₀，q₀，q₀And determining a homogeneous transformation matrix between a coordinate system taking the radar as an origin and a geodetic coordinate system according to the attitude quaternion of the radar.

Exemplary, there are:

wherein the content of the first and second substances,

is a rotation matrix determined from the attitude quaternion of the radar,

is a constant vector.

The preprocessing can obtain a plurality of ground points in the omnidirectional scanning areaCoordinate data on the geodetic coordinate system, as shown in FIG. 10, each ground point may be represented as { x }_G，y_G，z_G}。

In some embodiments, the fitting plane of the omnidirectional scanning area according to the detection data in step S120 includes: and fitting a fitting plane of the omnidirectional scanning area according to the coordinate data of the plurality of ground points.

In some embodiments, the fitting plane of the omnidirectional scanning area according to the coordinate data of the ground points in step S120 includes: and screening the coordinate data of the plurality of ground points, and fitting a fitting plane of the omnidirectional scanning area according to the screened coordinate data of the ground points.

Due to interference of the internal and external environments of the radar, outliers exist in the distance measured by the radar. For example: for the same ranging point, the distance between the ranging point and the radar is large actually, but the radar is interfered, so that the data obtained by ranging is small, and further, a fitted plane and a predicted terrain parameter have large errors. Especially in complex application scenarios such as farmland, tea mountain and the like, the presence of outliers can lead to inaccurate terrain prediction.

The outlier points and ground object points present in the original radar observation make the assumption of the ground as a flat plane unrealistic. If the plane fitting is directly carried out on the coordinate data of the ground points, the fitting result has larger deviation with the actual result.

In order to make the fitting plane of the omnidirectional scanning area closer to the actual plane, the outlier point and the ground object point can be removed before the plane fitting is carried out. Where a ground point represents a ground appendage, such as a ground point of a building, that is not true ground.

Therefore, accurate estimation of the ground can be realized by eliminating outlier points and non-ground points and then fitting the fitting plane of the omnidirectional scanning area according to the coordinate data of the ground points which are not eliminated.

In some embodiments, the plurality of ground points are clustered according to the coordinate data of the plurality of ground points, and the ground points meeting the clustering condition are determined; and then fitting a fitting plane of the omnidirectional scanning area according to the coordinate data of the ground points meeting the clustering condition.

Illustratively, outlier points and ground object points in the original observation can be removed through a clustering algorithm of the DBSCAN, and effective ground points are extracted.

For example, the performing cluster analysis on the ground points according to the coordinate data of the ground points to determine the ground points meeting the clustering condition includes:

circularly executing the following steps until the plurality of ground points are determined as points to be clustered, and stopping circulation: determining one ground point as a point to be clustered, determining the number of the ground points in the search range of the point to be clustered, and if the number is not more than a preset clustering threshold value, rejecting the point to be clustered; and if the circulation is stopped, determining that the points to be clustered which are not eliminated are the ground points meeting the clustering condition.

For example, a KDTREE data structure is used to build a tree structure for all ground points based on their coordinate data; then, sequentially determining one ground point as a point to be clustered, finding out all ground points which are less than a preset searching radius away from the point to be clustered in the tree, if the number of the ground points in the searching radius of the point to be clustered is more than a preset minimum point cluster threshold value, considering that the current point to be clustered is an effective point to be reserved, otherwise, considering that the current point to be clustered is a outlier or a miscellaneous point is eliminated; until traversing each ground point within the omni-directional scanning area.

It can be understood that the coordinate data of the ground points in the omnidirectional scanning area may also be filtered in other manners to remove outliers and miscellaneous points in the original observation, for example, by filtering manners such as feature segmentation.

In some embodiments, the fitting plane of the omnidirectional scanning area is fitted according to the coordinate data of the ground points, and the plane fitting may be performed by a least square method. For example, a fitting plane of the omnidirectional scanning area is fitted according to the coordinate data of the screened ground points by a least square method.

Illustratively, with the height z in the vertical direction as the variable with the highest degree of independence, a plane equation is established:

Z＝aX+bY+c

the coordinate data of the ground points may then be fitted using a least squares method. The least square method, also known as the least squares method, is a mathematical optimization method. It finds the best functional match of the data by minimizing the sum of the squares of the errors. Unknown data can be easily obtained by the least square method, and the sum of squares of errors between these obtained data and actual data is minimized. The "least squares" method is a standard method for solving an approximate solution by regression analysis for an overdetermined equation set, i.e., an equation set in which the number of equations is larger than the number of unknowns. In this overall solution, the least squares algorithm works out to minimize the sum of the residual sum of squares in the result of each equation.

The parameters of the plane equation are determined, for example, using the rule of claimm:

wherein the coordinates of the center point of the target can be determined according to

Coordinates of ground points participating in the fitting { x_G，y_G，z_G-determination of the average value of the values,

as coordinates of ground points { x_G，y_G，z_GSubtract the target center point

And obtaining a normalization result.

Therefore, the fitting plane Z of the omnidirectional scanning area can be fitted according to the coordinate data of the ground points, wherein the fitting plane Z is aX + bY + c.

In other embodiments, the least square method based on RANSAC may be used to screen out valid points in the original observation, that is, to screen the coordinate data of the plurality of ground points, so as to obtain the coordinate data of the ground points after screening.

Random sample Consensus (RANSAC) estimates the parameters of a mathematical model from a set of observed data that includes outliers in an iterative manner. RANSAC is a non-deterministic algorithm that in some sense produces a reasonable result with a certain probability, while more iterations increase this probability.

Illustratively, the fitting plane of the omnidirectional scanning area according to the coordinate data of the ground points includes: determining at least three ground points from the plurality of ground points, and determining a target plane according to the at least three ground points; determining the plane distance from each ground point to the target plane according to the coordinate data of the plurality of ground points; and if the number of the ground points with the plane distance not greater than the distance threshold is not less than the preset number threshold, fitting according to the ground points with the plane distance not greater than the distance threshold to obtain a fitting plane of the omnidirectional scanning area.

Illustratively, the fitting plane of the omnidirectional scanning area according to the coordinate data of the ground points includes the following steps:

the first step is as follows: at least three non-collinear ground points (x) are randomly selected from all the ground points in the omnidirectional scanning area₁,y₁,z₁)、(x₂,y₂,z₂)、(x₃,y₃,z₃) (ii) a And establishing a plane through the at least three points, for example: aX + bY + Cz + D ═ 0, where:

a＝(y₂-y₁)×(z₃-z₁)-(y₃-y₁)×(z₂-z₁)；

b＝(z₂-z₁)×(x₃-x₁)-(z₃-z₁)×(x₂-x₁)；

c＝(x₂-x₁)×(y₃-y₁)-(x₃-x₁)×(y₂-y₁)；

D＝a×x₁-b×y₁-c×z₁。

the second step is as follows: calculate all ground points { x_i，y_i，z_iDistance to the plane established in the first step:

the third step: and if the distance from a certain ground point to the plane is less than a preset threshold value, the ground point is considered to be an intra-office point, and the number n of the intra-office points corresponding to the plane is counted.

The fourth step: if the number N of the local points is larger than the number N (preset value) of the local points required for establishing a credible plane, performing plane fitting by using all the local points corresponding to the plane to obtain a fitting plane, for example, fitting by a least square method.

Exemplarily, the fitting plane of the omnidirectional scanning area according to the coordinate data of the ground points further includes: according to height of local point, e.g. z₃And judging whether the fitting plane obtained by fitting the local points is accurate or not according to the intercept D of the fitting plane.

For example, if the difference between the intercept D of the fitting plane and the height values of all the local points is smaller than the preset threshold, the fitting plane obtained by fitting the local points is accurate, and the fitting result may be retained.

Illustratively, if the difference between the intercept D of the fitting plane and the height values of all the local points is not less than the preset threshold value, the fitting plane of the fitting is discarded. The method may further include returning to the determining of the at least three ground points from the plurality of ground points, determining a target plane based on the at least three ground points; determining the plane distance from each ground point to the target plane according to the coordinate data of the plurality of ground points; and if the number of the ground points with the plane distance not greater than the distance threshold is not less than the preset number threshold, fitting the ground points with the plane distance not greater than the distance threshold to obtain a fitting plane of the omnidirectional scanning area, and continuously executing the step, wherein the at least three ground points are different from at least one of the three ground points determined last time.

For example, if the outliers are eliminated, that is, the number of ground points after screening is smaller than the number required for establishing a credible plane, it is determined that the detection data of the plurality of ground points in the omni-directional scanning area obtained by the radar in the rotation process is invalid. And the acquisition, screening and fitting can be carried out again.

For example, the fitting plane of the omni-directional scanning area fitted in step S120 is shown in fig. 11.

In some embodiments, the terrain parameters of the omni-directional scanning area may be determined from the fitting plane, and include at least one of: the gradient of the omnidirectional scanning area, the flatness of the omnidirectional scanning area and the height value of the ground right below the radar.

In some embodiments, the drone performs work on sloping fields, such as spraying pesticides on terraces, hillside orchards, and the like. At least some areas of these terrains are at an angle, i.e. slope, to the horizontal.

In this scene, if the change of aircraft nose the place ahead topography is only forecasted through the survey data in unmanned aerial vehicle aircraft nose the place ahead, then unable comprehensive reflection unmanned aerial vehicle is in the slope of region, for example the topography of unmanned aerial vehicle rear, left side, right side, the topography is followed the effect relatively poor, the security of unmanned aerial vehicle operation is relatively poor.

Illustratively, the topographic parameters of the omni-directional scanning area determined according to the fitting plane in step S130 include a slope of the omni-directional scanning area.

Illustratively, the determining the terrain parameters of the omni-directional scanning area according to the fitting plane comprises: determining a gradient direction; determining a slope of the fitted plane in the slope direction.

For example, the slope of the fitting plane in the slope direction may be determined from a normal vector of the fitting plane.

For example, the direction of the nose of the drone may be determined to be the direction of the grade; or the flight direction of the drone may be determined to be the direction of the grade. Of course, other directions may be used as the slope direction, for example, the left side, the right side, and the tail direction of the unmanned aerial vehicle body, or the left side, the right side, and the like in the flight direction of the unmanned aerial vehicle are determined as the slope direction.

Illustratively, the attitude, e.g., the angle of rotation, of the radar is referenced to the orientation of the handpiece.

For example, as shown in fig. 11, if the direction of the head is the slope direction, or the flight direction of the drone is the same as the head although the flight direction of the drone is the slope direction, the slope of the flight direction may be directly determined by the normal vector of the fitting plane

Obtaining:

for example, if the determined slope direction is determined, if the flight direction of the drone is determined to be the slope direction, and the slope direction has a certain angle with the handpiece, the slope of the fitting plane in the slope direction may be obtained by the following formula:

wherein, { V_x，V_yDenotes the direction of the slope, e.g. the projection of the unmanned aerial vehicle flight direction onto the fitting plane.

As can be understood, by acquiring the detection data of a plurality of ground points in the omnidirectional scanning area and determining the fitting plane of the omnidirectional scanning area according to the detection data, the determination of the terrain slope in any direction of the omnidirectional scanning area, for example, the determination of the ground slope in the flight direction of the unmanned aerial vehicle, can be realized according to the fitting plane.

In some embodiments, the drone operates on undulating ground, such as where the drone has an appendage on the ground, if trees, water towers, or has a pond, pothole, or the like. These topography is not level enough, can cause the influence even potential safety hazard to unmanned aerial vehicle's normal operation. For example, a drone needs to maintain a safe height from the ground when working on uneven ground, or a drone needs to land on even ground when landing.

In this scene, if only according to the terrain data prediction ground flatness in unmanned aerial vehicle aircraft nose the place ahead, the global terrain environment of unmanned aerial vehicle position can't be embodied to the roughness that obtains, for example the roughness of prediction can't embody other positions of unmanned aerial vehicle, like the terrain on rear, left side, right side, the security of unmanned aerial vehicle operation is relatively poor.

Illustratively, the terrain parameters of the omni-directional scanning area determined according to the fitting plane in step S130 include the flatness of the omni-directional scanning area.

Illustratively, the determining the terrain parameters of the omni-directional scanning area according to the fitting plane comprises: and determining the mean value of the distances from the plurality of ground points to the fitting plane according to the coordinate data of the plurality of ground points, and determining the flatness of the omnidirectional scanning area according to the mean value.

For example, the flatness of the omni-directional scanning area may be determined according to the filtered ground points, i.e., the mean of the distances from the coordinate data of the effective ground points to the fitting plane.

Illustratively, the ground points { x are calculated_i，y_i，z_iDistance of straight line to fitting plane:

then the mean of the distances of the various ground points, for example n, to the fitting plane is calculated:

for example, the average of the distances from the n ground points to the fitting plane may be taken as the flatness of the omni-directional scanning area. If the mean value is larger, the ground in the omnidirectional scanning area is more uneven; if the average value is smaller, the ground is smoother.

It will be appreciated that the flatness may also be determined by the residuals of the distances of the ground points to the fitting plane, e.g. the sum of the squares of the residuals of the distances of the n ground points to the fitting plane is determined as flatness. But the residual error cannot well depict the flatness of the ground with the slope, and the residual error value can be increased due to the slope. Therefore, to eliminate the effect of the ground slope on the flatness, the ground flatness can be determined by using the mean of the distances of the valid ground points to the fitted plane.

The method can be understood that the detection data of a plurality of ground points in the omnidirectional scanning area are obtained, and the fitting plane of the omnidirectional scanning area is determined according to the detection data, so that the flatness of the omnidirectional scanning area can be determined according to the fitting plane, and the flatness can reflect the terrain flatness of the unmanned aerial vehicle in different directions.

Illustratively, a height value of the ground directly below the radar is determined from an intercept of the fitted plane.

Illustratively, the origin of the geodetic coordinate system is directly below the radar, and the intercept of the fitted plane may be equal to the height of the ground directly below the center of the radar.

In some embodiments, the adjusting the flight action of the drone according to the terrain parameter in step S140 includes: and adjusting at least one of the flying speed, the pitch angle, the roll angle and the yaw angle according to the gradient.

For example, if the slope in the flight direction of the unmanned aerial vehicle is large, the flight speed can be reduced, and the pitch angle can be increased; if the slope in the left side direction of the unmanned aerial vehicle is smaller, the unmanned aerial vehicle can fly to the left side by adjusting the yaw angle.

Exemplarily, can utilize the projection of unmanned aerial vehicle flight speed direction in the fitting plane, the change of the topography on the prediction unmanned aerial vehicle flight direction carries out the control of unmanned aerial vehicle speed in advance for unmanned aerial vehicle can be under environment such as mountain region, along arbitrary direction, the safe quick operation of imitating the ground. Can solve the problem that unmanned aerial vehicle can only fly along slope ascending/descending direction when mountain region operation, can real-time detection arbitrary direction, relief change condition as current flight direction relatively for unmanned aerial vehicle can fly along the imitative ground of arbitrary direction in the mountain region.

Illustratively, by predicting the topographic fluctuation change of the flight direction, the speed control of the unmanned aerial vehicle responds in advance, and therefore the safety of the unmanned aerial vehicle in mountain operation is guaranteed.

In some embodiments, the adjusting the flight action of the drone according to the terrain parameter in step S140 includes: and adjusting at least one of the flying speed, the pitch angle, the roll angle and the yaw angle according to the height value of the ground under the radar.

For example, in some working scenes, such as pesticide spraying, the distance between the unmanned aerial vehicle and a working target such as a fruit tree needs to be kept within a distance range, and the unmanned aerial vehicle can be better controlled to keep the distance between the working targets by determining the height value of the ground right below.

For example, when the height value of the ground right below the radar is reduced, the height can be reduced by adjusting a pitch angle and the like; if the altitude value of the ground under the radar changes when great, can control unmanned aerial vehicle and reduce flying speed in order to guarantee flight safety.

In some embodiments, the adjusting the flight action of the drone according to the terrain parameter in step S140 includes: and adjusting at least one of the flying speed, the pitch angle, the roll angle and the yaw angle according to the flatness.

For example, if the omni-directional scanning area is not flat, the flight speed can be reduced or the action amplitude of the pitch angle, the roll angle and the yaw angle can be reduced to ensure the flight safety.

Illustratively, the adjusting the flight action of the drone according to the terrain parameter includes: and adjusting the speed control sensing quantity according to the flatness.

The sensitivity is also the sensitivity, if the omnidirectional scanning area is not flat, the sensitivity of speed control can be adjusted to be low, so that more time is provided for actions such as obstacle avoidance, error correction and the like.

In some embodiments, the adjusting the flight action of the drone according to the terrain parameter in step S140 includes: and judging whether landing is performed in the omnidirectional scanning area or not according to the flatness, and if so, landing is performed in the omnidirectional scanning area.

For example, if the omni-directional scanning area is judged to be flat enough according to the flatness, the vehicle will land in the omni-directional scanning area.

Because the roughness can embody the topography leveling condition of unmanned aerial vehicle all around different directions, consequently the landing area of confirming is safer, can realize the unmanned aerial vehicle independently landing placement selection based on ground roughness.

In some embodiments, the adjusting the flight action of the drone according to the terrain parameter in step S140 includes: determining a flight route according to the terrain parameters; and flying along the flight path.

For example, the flight route can be determined according to the information of terrain parameters such as the gradient of the omnidirectional scanning area in different directions, the flatness of the omnidirectional scanning area, the height of the ground and/or the change amplitude, frequency and the like of the terrain parameters, so that safer self-planning route flight is realized.

In the method for controlling the operation of the unmanned aerial vehicle provided by the embodiment of the description, the detection data of the omnidirectional scanning area obtained in the process of the ground rotation scanning of the radar carried by the unmanned aerial vehicle is obtained, and the fitting plane of the omnidirectional scanning area is fitted according to the detection data; so as to determine the terrain parameters of the omnidirectional scanning area according to the fitting plane; and adjusting the flight action of the unmanned aerial vehicle according to the terrain parameters. Because the omnidirectional scanning area comprises the front direction, the rear direction, the left direction and the right direction of the unmanned aerial vehicle, the obtained terrain parameters are more global and accurate, and the flight action of the unmanned aerial vehicle can be controlled more safely.

Referring to fig. 12, fig. 12 is a schematic block diagram of a drone 700 provided in an embodiment of the present description. The drone 700 includes an integrally provided radar, or may additionally carry an independent radar.

The drone 700 includes a processor 701 and memory 702.

Illustratively, the processor 701 and the memory 702 are connected by a bus 703, such as an I2C (Inter-integrated Circuit) bus.

Specifically, the Processor 701 may be a Micro-controller Unit (MCU), a Central Processing Unit (CPU), a Digital Signal Processor (DSP), or the like.

Specifically, the Memory 702 may be a Flash chip, a Read-Only Memory (ROM) magnetic disk, an optical disk, a usb disk, or a removable hard disk.

The processor 701 is configured to run a computer program stored in the memory 702, and when executing the computer program, implement the unmanned aerial vehicle operation control method.

Illustratively, the processor 701 is configured to run a computer program stored in the memory 702 and to implement the following steps when executing the computer program:

The specific principle and implementation of the unmanned aerial vehicle provided by the embodiment of the specification are similar to those of the unmanned aerial vehicle operation control method of the foregoing embodiment, and are not repeated here.

Embodiments of the present disclosure also provide a computer-readable storage medium, where a computer program is stored in the computer-readable storage medium, where the computer program includes program instructions, and the processor executes the program instructions to implement the steps of the method provided in the foregoing embodiments.

The computer readable storage medium may be any one of the radar, the terrain prediction apparatus, and an internal storage unit of the drone described in any one of the foregoing embodiments, such as a hard disk or a memory of the drone. The computer readable storage medium may also be an external storage device of the radar, the terrain prediction apparatus, the drone, such as a plug-in hard disk equipped on the drone, a Smart Media Card (SMC), a Secure Digital (SD) Card, a Flash memory Card (Flash Card), and the like.

In the unmanned aerial vehicle and the computer-readable storage medium provided in the above embodiments of the present specification, by obtaining detection data of an omnidirectional scanning area obtained in a process of rotating and scanning a ground by a radar carried by the unmanned aerial vehicle, a fitting plane of the omnidirectional scanning area is fitted according to the detection data; so as to determine the terrain parameters of the omnidirectional scanning area according to the fitting plane; and adjusting the flight action of the unmanned aerial vehicle according to the terrain parameters. Because the omnidirectional scanning area comprises the front direction, the rear direction, the left direction and the right direction of the unmanned aerial vehicle, the obtained terrain parameters are more global and accurate, and the flight action of the unmanned aerial vehicle can be controlled more safely.

It is to be understood that the terminology used in the description herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the description.

It should also be understood that the term "and/or" as used in this specification and the appended claims refers to and includes any and all possible combinations of one or more of the associated listed items.

The above description is only for the specific embodiments of the present disclosure, but the scope of the present disclosure is not limited thereto, and any person skilled in the art can easily conceive various equivalent modifications or substitutions within the technical scope of the present disclosure, and these modifications or substitutions should be covered within the scope of the present disclosure. Therefore, the protection scope of the present specification shall be subject to the protection scope of the claims.

Claims

1. A method of terrain prediction for a sloping field, the method comprising:

2. The method of claim 1, wherein the topographical parameters of the omni-directional scanning area further comprise at least one of:

the flatness of the omnidirectional scanning area and the height value of the ground right below the radar.

3. The method of claim 1, wherein the acquiring omni-directional scanning area detection data obtained by the radar during a ground rotation scanning process comprises:

and acquiring the detection distance and azimuth angle of a plurality of ground points of the omnidirectional scanning area relative to the radar.

4. The method of claim 3, further comprising:

and acquiring a radar rotation angle corresponding to the radar when detecting each ground point.

5. The method of claim 4, wherein the acquiring omni-directional scanning area sounding data obtained by the radar during a ground rotation scanning process further comprises:

and determining the distances of the ground points in a plurality of directions relative to the radar according to the radar rotation angle, the detection distance and the azimuth angle corresponding to the ground points.

6. The method of claim 1, wherein the acquiring omni-directional scanning area detection data obtained by the radar during a ground rotation scanning process comprises:

and acquiring distances of a plurality of ground points of the omnidirectional scanning area relative to the radar in a plurality of directions.

7. The method of claim 6 wherein the distances of the ground points in a plurality of directions relative to the radar comprise:

the position coordinates of the ground point in a radar coordinate system of the radar;

the radar coordinate system takes the rotation center of the radar as an origin, takes the position right below the radar as a first axis direction, takes the position right before the radar as a second axis direction, and takes the direction perpendicular to the first axis direction and the second axis direction as a third axis direction.

8. The method according to any one of claims 1-7, wherein said fitting out a fitting plane of the omni-directional scanning region from the probe data comprises:

determining coordinate data of a plurality of ground points in the omnidirectional scanning area in a geodetic coordinate system according to the detection data;

and fitting a fitting plane of the omnidirectional scanning area according to the coordinate data of the plurality of ground points.

9. The method of claim 8, further comprising:

and acquiring the attitude information of the radar through an inertial measurement unit carried by the unmanned aerial vehicle and/or the inertial measurement unit carried by the radar.

10. The method of claim 9 wherein said determining from said probe data coordinate data of each of said ground points in said omni-directional scanning area in a geodetic coordinate system comprises:

and determining coordinate data of each ground point in a geodetic coordinate system according to the attitude information of the radar and the detection data.

11. The method according to claim 8, wherein an origin of the geodetic coordinate system is located directly below the radar, the geodetic coordinate system having a true north direction or a true south direction of the geodetic origin as a fourth axis direction, a true east direction or a true west direction of the geodetic origin as a fifth axis direction, and a direction perpendicular to the fourth axis direction and the fifth axis direction as a sixth axis direction;

the coordinate data of the ground points in the geodetic coordinate system includes distances of the ground points in the fourth axis direction, the fifth axis direction, and the sixth axis direction with respect to the geodetic origin.

12. The method of claim 8 wherein said fitting a plane of said omni-directional scanning area from coordinate data of said plurality of ground points comprises:

and screening the coordinate data of the plurality of ground points, and fitting a fitting plane of the omnidirectional scanning area according to the screened coordinate data of the ground points.

13. The method of claim 12 wherein the screening the coordinate data of the plurality of ground points and fitting the fitting plane of the omni-directional scanning area based on the screened coordinate data of the ground points comprises:

carrying out clustering analysis on the plurality of ground points according to the coordinate data of the plurality of ground points, and determining the ground points meeting clustering conditions;

and fitting a fitting plane of the omnidirectional scanning area according to the coordinate data of the ground points meeting the clustering condition.

14. The method of claim 13 wherein the clustering the plurality of ground points based on the coordinate data of the plurality of ground points to determine ground points that satisfy a clustering condition comprises:

and (3) circularly executing: determining one ground point as a point to be clustered, determining the number of the ground points in the search range of the point to be clustered, and if the number is not more than a preset clustering threshold value, rejecting the point to be clustered;

until the plurality of ground points are all determined as points to be clustered;

and determining the points to be clustered which are not eliminated as the ground points meeting the clustering condition.

15. The method of claim 8 wherein said fitting a plane of said omni-directional scanning area from coordinate data of said plurality of ground points comprises:

determining at least three ground points from the plurality of ground points, and determining a target plane according to the at least three ground points;

determining the plane distance from each ground point to the target plane according to the coordinate data of the plurality of ground points;

and if the number of the ground points with the plane distance not greater than the distance threshold is not less than the preset number threshold, fitting according to the ground points with the plane distance not greater than the distance threshold to obtain a fitting plane of the omnidirectional scanning area.

16. The method of claim 15 wherein said fitting a plane of said omni-directional scanning area from coordinate data of said plurality of ground points further comprises:

if the difference value between the intercept of the fitting plane and the height values of all the local interior points is not less than the preset threshold value, returning to the step of determining at least three ground points from the plurality of ground points, and determining a target plane according to the at least three ground points; determining the plane distance from each ground point to the target plane according to the coordinate data of the plurality of ground points; and if the number of the ground points with the plane distance not greater than the distance threshold is not less than the preset number threshold, fitting the ground points with the plane distance not greater than the distance threshold to obtain a fitting plane of the omnidirectional scanning area, and continuously executing the step, wherein the at least three ground points are different from at least one of the three ground points determined last time.

17. The method of claim 8, wherein said determining the terrain parameters of the omni-directional scanning area from the fitted plane comprises:

and determining the mean value of the distances from the plurality of ground points to the fitting plane according to the coordinate data of the plurality of ground points, and determining the flatness of the omnidirectional scanning area according to the mean value.

18. The method of claim 2, wherein said determining the terrain parameters of the omni-directional scanning area from the fitted plane comprises:

determining a gradient direction;

determining a slope of the fitted plane in the slope direction.

19. The method of claim 18, wherein the determining a slope direction comprises:

and determining the flight direction of the unmanned aerial vehicle carrying the radar as the gradient direction.

20. The method of claim 18, wherein the determining the slope of the fitted plane in the slope direction comprises:

and determining the slope of the fitting plane in the slope direction according to the normal vector of the fitting plane.

21. The method of claim 2, wherein said determining the terrain parameters of the omni-directional scanning area from the fitted plane comprises:

and determining the height value of the ground right below the radar according to the intercept of the fitting plane.

22. The method according to any one of claims 1 to 7, wherein the radar is mounted on a drone, the radar including an antenna mechanism rotatable about a predetermined axis of rotation relative to the body of the drone for detecting obstacles to the side of the drone; the radar is located the bottom below of fuselage, just the pivot is crossing with predetermineeing the plane, predetermine the plane and be unmanned aerial vehicle's every single move axle and roll axis place's plane.

23. The method of claim 22, wherein the angle between the axis of rotation and the predetermined plane is between 60 ° and 90 °.

24. The method of claim 23, wherein the axis of rotation is substantially perpendicular to the predetermined plane; and/or the rotating shaft is approximately coincident with the center line of the machine body.

25. The method of claim 23, wherein the radar is mounted on a landing gear of the drone by a mounting structure located between the radar and the fuselage.

26. The method of claim 22, wherein the axis of rotation is at an acute angle to a heading axis of the drone.

27. The method of claim 26, wherein the acute angle is 0 ° -30 °.

28. The method of claim 22, wherein the antenna mechanism is rotated about the rotation axis through a range of angles greater than or equal to 360 °.

29. The method of any one of claims 1-7, wherein the radar is a continuous wave radar.

30. A terrain prediction apparatus for a sloping field, characterized in that the terrain prediction apparatus comprises a memory and a processor;

the memory is used for storing a computer program;

31. A radar, comprising a memory and a processor;

the memory is used for storing a computer program;

32. An unmanned aerial vehicle operation control method, wherein the unmanned aerial vehicle carries a radar and operates on a sloping field, the method comprising:

33. The method of claim 32, wherein the topographical parameters of the omni-directional scanning area further comprise at least one of:

34. The method of claim 32, wherein the acquiring omni-directional scanning area sounding data obtained by the radar during a ground rotation scanning process comprises:

35. The method of claim 34, further comprising:

36. The method of claim 35, wherein the acquiring omni-directional scanning area sounding data obtained by the radar during a ground rotation scanning process, further comprises:

37. The method of claim 32, wherein the acquiring omni-directional scanning area sounding data obtained by the radar during a ground rotation scanning process comprises:

38. The method of claim 37 wherein the distances of the ground points in a plurality of directions relative to the radar comprise:

39. The method according to any one of claims 32-38, wherein said fitting out a fitting plane of the omni-directional scanning region from the probe data comprises:

40. The method of claim 39, further comprising:

and acquiring the attitude information of the radar through the inertial measurement unit carried by the unmanned aerial vehicle and/or the inertial measurement unit carried by the radar.

41. The method of claim 40 wherein said determining from said probe data coordinate data of a plurality of ground points in said omni-directional scanning area in a geodetic coordinate system comprises:

and determining coordinate data of a plurality of ground points in a geodetic coordinate system according to the attitude information of the radar and the detection data.

42. The method of claim 39, wherein an origin of the geodetic coordinate system is located directly below the radar, the geodetic coordinate system having a true north or south direction of the geodetic origin as a fourth axis direction, a true east or west direction of the geodetic origin as a fifth axis direction, and a direction perpendicular to the fourth axis direction and the fifth axis direction as a sixth axis direction;

43. The method of claim 39 wherein said fitting a plane of said omni-directional scanning area from coordinate data of said plurality of ground points comprises:

44. The method of claim 43 wherein said screening the coordinate data of the plurality of ground points and fitting a fitting plane of the omni-directional scanning area based on the screened coordinate data of the ground points comprises:

45. The method of claim 44 wherein said clustering said plurality of ground points based on said plurality of ground point coordinate data to determine ground points satisfying a clustering condition comprises:

46. The method of claim 39 wherein said fitting a plane of said omni-directional scanning area from coordinate data of said plurality of ground points comprises:

47. The method of claim 46 wherein said fitting a plane of said omni-directional scanning area from coordinate data of said plurality of ground points further comprises:

48. The method of claim 39, wherein said determining the topographical parameters of the omni-directional scanning area from the fitted plane comprises:

49. The method according to any one of claims 32-38, wherein said determining a topographical parameter of the omni-directional scanning area from the fitted plane comprises:

determining a gradient direction;

determining a slope of the fitted plane in the slope direction.

50. The method of claim 49, wherein the determining a slope direction comprises:

and determining the flight direction of the unmanned aerial vehicle as the gradient direction.

51. The method of claim 49, wherein the determining the slope of the fitted plane in the slope direction comprises:

52. The method of claim 33, wherein said determining the topographical parameters of the omni-directional scanning area from the fitted plane comprises:

53. The method of any of claims 32-38, wherein said adjusting the flight behavior of the drone as a function of the terrain parameter comprises:

and adjusting at least one of the flying speed, the pitch angle, the roll angle and the yaw angle according to the gradient.

54. The method of claim 33 or 52, wherein said adjusting the flight behavior of said drone according to said terrain parameters comprises:

and adjusting at least one of the flying speed, the pitch angle, the roll angle and the yaw angle according to the height value of the ground under the radar.

55. The method of claim 39, wherein said adjusting the flight activity of said drone according to said terrain parameters comprises:

adjusting at least one of a flight speed, a pitch angle, a roll angle and a yaw angle according to the flatness of the omnidirectional scanning area; and/or

Adjusting the speed control sensing quantity according to the flatness; and/or

And judging whether landing is performed in the omnidirectional scanning area or not according to the flatness, and if so, landing is performed in the omnidirectional scanning area.

56. The method of claim 33 or 52, wherein said adjusting the flight behavior of said drone according to said terrain parameters comprises:

determining a flight route according to the terrain parameters;

and flying along the flight path.

57. The method according to any one of claims 32-38, wherein the radar is mounted on a drone, the radar including an antenna mechanism rotatable about a predetermined axis of rotation relative to the body of the drone for detecting obstacles to the side of the drone; the radar is located the bottom below of fuselage, just the pivot is crossing with predetermineeing the plane, predetermine the plane and be unmanned aerial vehicle's every single move axle and roll axis place's plane.

58. The method of claim 57, wherein the angle between the axis of rotation and the predetermined plane is between 60 ° and 90 °.

59. The method of claim 58, wherein the axis of rotation is substantially perpendicular to the predetermined plane; and/or the rotating shaft is approximately coincident with the center line of the machine body.

60. The method of claim 58, wherein the radar is mounted on a landing gear of the drone by a mounting structure located between the radar and the fuselage.

61. The method of claim 57, wherein the axis of rotation is at an acute angle to a heading axis of the drone.

62. The method of claim 61, wherein the acute angle is 0 ° -30 °.

63. The method of claim 57, wherein the antenna mechanism is rotated about the rotation axis through a range of angles greater than or equal to 360 °.

64. The method of any one of claims 32-38, wherein the radar is a continuous wave radar.

65. An unmanned aerial vehicle carrying a radar, the unmanned aerial vehicle comprising a memory and a processor;

the memory is used for storing a computer program;

66. A computer-readable storage medium, characterized in that the computer-readable storage medium stores a computer program which, when executed by a processor, causes the processor to implement:

the method of any one of claims 1-29; and/or

The method of any one of claims 32-64.