CN112272780A

CN112272780A - Ground clutter suppression and terrain estimation method, unmanned aerial vehicle, rotary radar and storage medium

Info

Publication number: CN112272780A
Application number: CN201980034408.1A
Authority: CN
Inventors: 王春明; 石仁利; 刘双
Original assignee: SZ DJI Technology Co Ltd
Current assignee: SZ DJI Technology Co Ltd; SZ DJI Innovations Technology Co Ltd
Priority date: 2019-11-04
Filing date: 2019-11-04
Publication date: 2021-01-26
Also published as: WO2021087643A1

Abstract

A ground clutter suppression and terrain estimation method, an unmanned aerial vehicle (10), a rotating radar (12) and a storage medium. The method provides a mode of vertically installing the rotary radar (12), namely, a rotating shaft of the rotary radar (12) is parallel or basically parallel to a course shaft of the unmanned aerial vehicle (10), and an array antenna of the rotary radar (12) rotates around the rotating shaft, so that the rotary radar (12) can perform mechanical rotary scanning in the horizontal direction, can flexibly detect in the horizontal direction, is beneficial to improving the detection range in the horizontal direction, and meets the requirement of the whole machine in the aspect of safety.

Description

Ground clutter suppression and terrain estimation method, unmanned aerial vehicle, rotary radar and storage medium

Technical Field

The embodiment of the application relates to the technical field of unmanned aerial vehicles, in particular to a ground clutter suppression and terrain estimation method, an unmanned aerial vehicle, a rotary radar and a storage medium.

Background

Agricultural unmanned aerial vehicle (for short agricultural machinery) is a unmanned aerial vehicle with wider application. Some agricultural unmanned aerial vehicles are provided with radar systems, and environmental information around the unmanned aerial vehicle is detected through the radar systems. With continuous iteration of the agricultural unmanned aerial vehicle in the aspects of structure and intelligent control, the requirement on the detection range of the agricultural unmanned aerial vehicle in the horizontal direction is higher and higher, and even the requirement of 360-degree comprehensive detection on the horizontal plane is provided. However, the existing agricultural unmanned aerial vehicle is limited by the Field Of View (FOV) Of the radar system, and the detection range in the horizontal direction is relatively limited, so that the safety requirement Of the whole machine cannot be met.

Disclosure of Invention

The embodiment of the application provides a ground clutter suppression and terrain estimation method, an unmanned aerial vehicle, a rotary radar and a storage medium, and is used for enlarging the detection range of the unmanned aerial vehicle in the horizontal direction and meeting the requirement of the whole machine in the safety direction.

An embodiment of the present application provides an unmanned aerial vehicle, include:

a body;

the rotary radar is vertically arranged on the machine body; the array antenna of the rotary radar can rotate around a rotating shaft, and the rotating shaft is parallel or basically parallel to the course axis of the unmanned aerial vehicle;

the flight control system is in communication connection with the rotary radar; the rotary radar sends the position information of the target detected by the rotary radar to the flight control system, and the flight control system controls the unmanned aerial vehicle to fly according to the position information of the target detected by the rotary radar.

An embodiment of the present application further provides an autonomous mobile device, including:

an apparatus body;

the rotary radar is vertically arranged on the equipment body; the array antenna of the rotating radar can rotate around a rotating shaft, and the rotating shaft is parallel or basically parallel to the heading axis of the autonomous mobile equipment;

a control system in communication with the rotary radar; the rotary radar sends the position information of the target detected by the rotary radar to a control system; and the control system controls the autonomous mobile equipment to move according to the position information of the target detected by the rotary radar.

The embodiment of the present application further provides a rotary radar, including: the device comprises a rotating device, an array antenna and a processing system;

the rotating device is used for being installed on a body of the unmanned aerial vehicle and comprises a rotating support and a motor for driving the rotating support to rotate;

the array antenna is carried on the rotating support of the rotating device, and the rotating device drives the array antenna to continuously rotate in the course direction of the unmanned aerial vehicle;

and the processing system is used for controlling the array antenna to emit electromagnetic waves and determining the position information of the target detected by the rotary radar according to the echo information received by the array antenna.

The embodiment of the application further provides a ground clutter suppression method, which is suitable for a rotary radar, wherein the rotary radar is vertically installed on an unmanned aerial vehicle, an array antenna of the rotary radar performs electronic scanning in the pitching direction of the unmanned aerial vehicle, the array antenna can rotate around a rotating shaft, and the rotating shaft is parallel or basically parallel to a course shaft of the unmanned aerial vehicle; the method comprises the following steps:

adopting a phase angle measurement technology in the electronic scanning direction to carry out ground clutter suppression on echo information of the electromagnetic waves;

determining position information of obstacles in the surrounding environment of the unmanned aerial vehicle according to the echo information after ground clutter suppression;

and transmitting the position information of the obstacle to a flight control system of the unmanned aerial vehicle so as to control the unmanned aerial vehicle to carry out obstacle avoidance flight.

The embodiment of the application also provides a terrain estimation method, which is suitable for a rotary radar, wherein the rotary radar is vertically arranged on an unmanned aerial vehicle, an array antenna of the rotary radar can rotate around a rotating shaft, and the rotating shaft is parallel or basically parallel to a course axis of the unmanned aerial vehicle; the method comprises the following steps:

calculating ground point information according to the echo information received by the rotary radar;

carrying out terrain estimation according to the ground point information to obtain terrain parameters of the ground;

and transmitting the terrain parameters of the ground to a flight control system of the unmanned aerial vehicle so as to control the unmanned aerial vehicle to carry out terrain following flight.

Embodiments of the present application also provide a computer-readable storage medium storing a computer program, which, when executed by a processor, causes the processor to execute the steps in the ground clutter suppression method or the terrain estimation method provided by the embodiments of the present application.

In this application embodiment, the mode of rotatory radar of perpendicular installation is proposed, and the rotation axis of rotatory radar is parallel or is on a parallel with unmanned aerial vehicle's course axle basically promptly, and the array antenna of rotatory radar rotates around the rotation axis, and this means rotatory radar can carry out mechanical rotation scanning in the horizontal direction, can survey in the horizontal direction in a flexible way, is favorable to improving the detection scope in the horizontal direction, satisfies the demand of complete machine in the aspect of the safety.

Drawings

The accompanying drawings, which are included to provide a further understanding of the application and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the application and together with the description serve to explain the application and not to limit the application. In the drawings:

fig. 1a is a schematic structural diagram of an unmanned aerial vehicle according to an exemplary embodiment of the present application;

fig. 1b is a schematic structural diagram of another drone provided in an exemplary embodiment of the present application;

FIGS. 1 c-1 e are several schematic views of the electronic scanning direction of the array antenna provided in the exemplary embodiment of the present application;

fig. 2 is a schematic structural diagram of a drone including a downward-looking radar according to an exemplary embodiment of the present application;

fig. 3a is a schematic structural diagram of a drone including a downward-looking radar and an upward-looking radar according to an exemplary embodiment of the present application;

fig. 3b is an exemplary schematic diagram of coverage relations between FOVs of three radars on a drone according to an exemplary embodiment of the present application;

FIG. 4a is a schematic diagram of a state in which a rotary radar according to an exemplary embodiment of the present application performs mechanical scanning in a horizontal direction and electronic scanning in a vertical direction;

fig. 4b is a cloud top view of a ground point obtained by ground clutter suppression performed by a rotating radar according to an exemplary embodiment of the present disclosure;

FIG. 4c is a side view of a ground point cloud obtained after ground clutter suppression by a rotating radar according to an exemplary embodiment of the present disclosure;

FIG. 5 is a schematic diagram of a rotary radar according to an exemplary embodiment of the present application;

FIG. 6a is a flowchart illustrating a ground clutter suppression method according to an exemplary embodiment of the present disclosure;

fig. 6b is a flowchart illustrating a terrain estimation method according to an exemplary embodiment of the present application.

Detailed Description

In order to make the objects, technical solutions and advantages of the present application more apparent, the technical solutions of the present application will be described in detail and completely with reference to the following specific embodiments of the present application and the accompanying drawings. It should be apparent that the described embodiments are only some 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.

The detection range of the existing unmanned aerial vehicle in the horizontal direction is limited, and the requirement of the whole unmanned aerial vehicle on safety can not be met. To this technical problem, in some embodiments of the present application, a way of vertically installing a rotating radar is proposed, that is, a rotation axis of the rotating radar is parallel or substantially parallel to a course axis of an unmanned aerial vehicle, and an array antenna of the rotating radar rotates around the rotation axis, which means that the rotating radar can perform mechanical rotation scanning in a horizontal direction, and can flexibly perform detection in the horizontal direction, thereby being beneficial to improving a detection range in the horizontal direction and meeting the requirement of the whole machine in the aspect of safety.

The technical solutions provided by the embodiments of the present application are described in detail below with reference to the accompanying drawings.

Fig. 1a is a schematic structural diagram of an unmanned aerial vehicle 10 according to an exemplary embodiment of the present application. The drone 10 may be a rotorcraft (rotorcraft), for example, a multi-rotor aircraft propelled through the air by a plurality of propulsion devices, to which embodiments of the present invention are not limited.

As shown in fig. 1a, the drone 10 includes at least: a body 11, a rotary radar 12 and a flight control system 13. In addition to the components or modules shown in fig. 1a, the drone 10 may also include other components or modules, such as propellers on the airframe, electric motors, pan-tilt heads, and the like.

The body 11 is a bearing platform of the drone 10, and can bear other components of the drone 10 to fly in the air. The flight control system 13 is equivalent to the brain of the unmanned aerial vehicle 10, and can perform various flight controls on the unmanned aerial vehicle 10, such as controlling the flying height and the flying orbit of the unmanned aerial vehicle 10, determining whether to brake suddenly, changing the course of the unmanned aerial vehicle, changing the flying speed of the unmanned aerial vehicle 10, and the like. The rotary radar 12 refers to a radar whose array antenna can be rotated about its rotation axis. The rotating radar 12 is a perception system of the drone 10 that can perceive the position information of objects present in the environment surrounding the drone.

In this embodiment, a rotating radar 12 is installed on the body 11 of the unmanned aerial vehicle 10, and the rotating radar 12 is mainly used for detecting a target existing in the surrounding environment of the unmanned aerial vehicle 10 and sending the position information of the detected target to the flight control system 13. The target detected by the rotating radar 12 may include an obstacle existing in the surrounding environment of the drone 10, and may also include a ground point in the surrounding environment of the drone 10, which is not limited to this.

The flight control system 13 can control the unmanned aerial vehicle 10 to fly according to the position information of the target detected by the rotary radar 12. It should be understood that the flight control system 13 may control the drone 10 according to preprogrammed program instructions, or may control the drone 10 by responding to one or more control instructions from a control terminal (e.g., a remote control). Optionally, the unmanned aerial vehicle 10 can carry out wireless communication with a control terminal, and the control terminal can display flight information and the like of the unmanned aerial vehicle 10, and can also communicate with the unmanned aerial vehicle 10 in a wireless manner for remotely operating the unmanned aerial vehicle 10.

In the present embodiment, the rotary radar 12 is vertically mounted on the body 11 of the drone 10. The vertical installation mode provided by the embodiment of the present application is defined by the position relationship between the rotation axis of the rotating radar 12 and the heading axis of the unmanned aerial vehicle 10. The vertical installation manner of the present embodiment means that the rotation axis of the rotating radar 12 is parallel or substantially parallel to the heading axis of the unmanned aerial vehicle 10.

In the embodiments of the present application, the three coordinate axes of the drone 10 are defined as follows: the origin of coordinates is taken at the centroid of the unmanned aerial vehicle 10, and a coordinate system is fixedly connected with the airplane; the x axis is in the plane of symmetry of the unmanned aerial vehicle 10 and points to the aircraft nose parallel to the design axis of the unmanned aerial vehicle 10; the y axis is perpendicular to the symmetry plane of the unmanned aerial vehicle 10 and points to the right of the body 11; the z-axis is in the plane of symmetry of the drone 10, perpendicular to the x-axis and pointing below the airframe 11, as shown in fig. 1 a. The x-axis is also called a roll axis, the y-axis is also called a pitch axis, and the z-axis is also called a course axis.

It should be noted that, in addition to the vertical installation manner proposed in the embodiment of the present application being defined in the above manner, the vertical installation manner proposed in the embodiment of the present application may also be roughly defined in other manners from different perspectives. For example, the plane of the propeller of the drone 10 may be used as a reference, and the vertical installation manner proposed in the embodiment of the present application means that the rotation axis of the rotating radar 12 is perpendicular or approximately perpendicular to the plane of the propeller. Considering that the plane of the propeller will generally have an angle, and not be perfectly horizontal, this definition is a rough definition.

Under perpendicular mounting means, the array antenna of rotatory radar 12 rotates around the rotation axis, means that rotatory radar 12 can carry out mechanical rotation scanning on the horizontal direction, that is to say, rotatory radar 12 can survey the target that exists in the unmanned aerial vehicle surrounding environment on the horizontal direction in a flexible way, is favorable to improving the detection scope on the horizontal direction, is convenient for satisfy the demand of unmanned aerial vehicle 10 to the environmental perception, and then can satisfy the demand of complete machine in the aspect of safety.

For convenience of description, a direction in which the array antenna rotates around the rotation axis is referred to as a mechanical scanning direction of the antenna array, and an angular range in which the array antenna can rotate around the rotation axis is referred to as a mechanical scanning range of the array antenna. The embodiment of the present application does not limit the mechanical scanning direction of the array antenna, for example, the array antenna may rotate clockwise around the rotation axis, and may also rotate counterclockwise around the rotation axis. Similarly, the embodiment of the present application also does not limit the mechanical scanning range of the array antenna, and the mechanical scanning range can be flexibly implemented as required, for example, 90 degrees (i.e., -45 degrees), 180 degrees (i.e., -90 degrees, 90 degrees), 200 degrees (i.e., -100 degrees, 100 degrees), and the like.

In some embodiments, the mechanical scanning range of the array antenna may be 360 degrees, that is, the array antenna can rotate 360 degrees around the rotation axis, that is, 360 degrees of detection can be carried out on the horizontal direction by the rotary radar 12, and the omnidirectional coverage to the horizontal direction is reached, and the unmanned aerial vehicle 10 can carry out 360 degrees of obstacle avoidance and terrain estimation on the horizontal direction, which is favorable for improving the performance of the unmanned aerial vehicle 10 in the aspects of obstacle avoidance, terrain following and the like, and further can improve the user experience.

In the embodiments of the present application, the mounting position of the rotary radar 12 on the body 11 is not limited. For example, the rotary radar 12 may be installed above the body 11 or below the body 11. The rotating radar 12 is vertically arranged below the machine body 11, so that the shielding of the machine body 11 can be avoided, and the detection range and the detection precision can be improved. In fig. 1a, the rotary radar 12 is vertically mounted below the body 11, specifically, directly below. Alternatively, the rotary radar 12 may also be mounted in other locations such as the foot rests of the drone 10.

In the embodiments of the present application, the rotating radar 12 is not limited in other ways, and any radar that can rotate around the rotation axis and can be vertically installed on the body 11 is suitable for the embodiments of the present application. For example, the antenna array of the rotating radar 12 may be an electronically scanned antenna array or a conventional antenna array. In some embodiments below, the application of a rotating radar 12 using an array of electronically scanned antennas to a drone 10 is described.

In some embodiments, as shown in fig. 1b, the body 11 of the drone 10 is vertically mounted with a rotating radar 12, the rotating axis of the rotating radar 12 is parallel or substantially parallel to the heading axis of the drone 10; the array antenna of the rotating radar 12 can rotate around a rotation axis, and the array antenna can be electronically scanned in a pitching direction (or referred to as a vertical direction).

Wherein, array antenna carries out electronic scanning in the pitch direction, means that rotatory radar 12 not only can follow the target that exists in the horizontal direction in surveying the unmanned aerial vehicle surrounding environment, can also follow the target that exists in the vertical direction in surveying the unmanned aerial vehicle surrounding environment, is favorable to improving detection range from level and two vertical directions, is convenient for satisfy the demand of unmanned aerial vehicle 10 to the environmental perception, and then can satisfy the demand of complete machine in the aspect of safety.

For convenience of description, a direction in which the array antenna performs electronic scanning in the elevation direction is referred to as an electronic scanning direction of the array antenna. The electronic scanning direction of the array antenna is not limited in the embodiments of the present application. For example, the array antenna may be scanned in elevation from top to bottom as shown in fig. 1 c. Alternatively, the array antenna may scan from bottom to top in elevation, as shown in fig. 1 d. Alternatively, the array antenna can be scanned from both the top and bottom directions simultaneously, as shown in fig. 1 e.

In order to facilitate a more intuitive understanding of the mechanical scanning direction and the electrical scanning direction of the array antenna in the vertical mounting mode, the mechanical scanning direction and the electrical scanning direction are explained in the following manner. For example, with reference to the xy plane (a plane formed by the x axis and the y axis), the electronic scanning direction of the array antenna is perpendicular or substantially perpendicular to the xy plane, and the mechanical scanning direction of the array antenna is parallel or substantially parallel to the xy plane. For another example, with a paddle plane where a propeller of the unmanned aerial vehicle 10 is located as a reference, the electronic scanning direction of the array antenna is perpendicular or substantially perpendicular to the paddle plane; the mechanical scan direction of the array antenna is parallel or substantially parallel to the paddle plane. Considering that the plane of the propeller blades will generally be at an angle and not perfectly horizontal, the term vertical or parallel is used herein to refer primarily to approximately vertical or parallel, rather than perfectly vertical or parallel.

In this embodiment, the type of the electromagnetic wave used by the array antenna is also not limited, and may be, for example, microwave, millimeter wave, or laser. Accordingly, the rotary radar 12 in the embodiment of the present application may be a microwave radar, a millimeter wave radar, or a laser radar.

Referring to fig. 1b, the electronic scanning of the array antenna in the elevation direction has a certain scanning range, which is related to the shape, structure, size, and the like of the array antenna. The electronic scanning range of the array antenna of different rotating radars in the elevation direction is different. As shown in fig. 1b, the electronic scanning range of the array antenna is about 60 degrees, i.e., (-30 degrees, +30 degrees), and the 60 degrees is only an exemplary and not limited thereto. The electronic scanning range of the array antenna may also be 100 degrees, i.e., -50 degrees, +50 degrees, etc.

Wherein, if array antenna can carry out 360 degrees electronic scanning in the every single move orientation, mean that rotatory radar 12 can carry out 360 degrees surveys in the vertical direction, reach the omnidirectional coverage to the vertical direction, unmanned aerial vehicle 10 can carry out 360 degrees on level and two vertical directions and keep away barrier and topography estimation, this is favorable to promoting unmanned aerial vehicle 10 and keeps away the barrier and the performance in the aspect of topography following etc. and then can improve user experience. However, in more cases, the array antenna of the rotating radar 12 may not be able to electronically scan 360 degrees in elevation. In the case where the array antenna cannot perform 360-degree electronic scanning in the elevation direction, the rotating radar 12 may have a view angle blind area in the vertical direction.

In order to increase the detection range of the rotating radar 12 in the vertical direction, as shown in fig. 2, the unmanned aerial vehicle 10 includes, in addition to the rotating radar 12: the downward looking radar 14. The downward-looking radar 14 is mounted below the rotating radar 12, and the viewing angle of the downward-looking radar 14 at least partially covers the viewing angle blind area of the rotating radar 12 in the lower area. The entire field angle range of the drone 10 is shown in fig. 2. The overall field angle in the vertical direction is covered by both the downward-looking radar 14 and the rotating radar 12.

In the present embodiment, the type of the downward radar 14 is not limited. For example, the down-view radar 14 may be a microwave radar, a millimeter wave radar, a laser radar, or the like. In addition, the present embodiment also does not limit the implementation structure of the downward radar 14. For example, the downward-looking radar 14 may be a separate radar device, or may be an array antenna disposed at the bottom of the rotating radar 12.

Further, in order to increase the detection range of the rotating radar 12 in the vertical direction, as shown in fig. 3a, the drone 10 includes, in addition to the rotating radar 12 and the downward-looking radar 14: the upward-looking radar 15. And the upper view radar 15 is arranged above the machine body 11, and the view angle of the upper view radar at least partially covers the view angle blind area of the upper area of the rotating radar 12. The coverage of the entire field angle of the unmanned aerial vehicle 10 is shown in fig. 3a, and the entire field angle range in the vertical direction is composed of the field angles of the downward-looking radar 14, the rotational radar 12, and the upward-looking radar 15.

Here, in fig. 3a, the unmanned aerial vehicle 10 includes the rotating radar 12, the downward-looking radar 14, and the upward-looking radar 15 at the same time, but the present invention is not limited thereto. The drone 10 may also include only the rotating radar 12 and the up-view radar 15, or the drone 10 may include only the rotating radar 12 and the down-view radar 14, as shown in fig. 2.

In the embodiment of the present application, the respective field angle (FOV) ranges of the rotation radar 12, the downward-looking radar 14, and the upward-looking radar 15 are not limited. For example, the FOV of the rotating radar 12 in the electronic scan direction may be ± 50 degrees, the FOV of the down-view radar 14 may be 25 degrees, and the FOV of the up-view radar 15 is 100 degrees, but is not limited thereto. In this example, the coverage relationship between the FOV of the rotation radar 12, the down-view radar 14, and the up-view radar 15 is shown in FIG. 3 b. In addition, the angle of view of the down-view radar 14 or the up-view radar 15 may or may not overlap with the angle of view of the rotation radar 12 in the vertical direction.

As can be seen from fig. 3b, in combination with the rotating radar 12, the downward-looking radar 14 and the upward-looking radar 15, the detection range of the drone in the vertical direction is larger, and targets in the environment above and below the drone can be detected. For example, can detect targets such as the birds that fly above unmanned aerial vehicle or below, based on this, unmanned aerial vehicle can in time avoid the birds of flight, can guarantee flight safety.

In the present embodiment, the type of the upward radar 15 is not limited. For example, the upward-looking radar 15 may be a microwave radar, a millimeter wave radar, a laser radar, or the like.

In the above-described embodiment, the rotary radar 12 can perform not only mechanical scanning in the horizontal direction but also electronic scanning in the vertical direction. In the context of figure 4a of the drawings,

indicating rotary mineThe mechanical rotation scanning of the radar 12 in the horizontal direction, and the angle theta represents the electronic scanning range of the rotation radar 12 in the vertical direction; h denotes the height of the drone or rotating radar 12 from the meadow (ground).

The array antenna of the rotary radar 12 includes a transmitting antenna and a receiving antenna, the transmitting antenna transmits electromagnetic waves to the outside, the electromagnetic waves are reflected back after touching a target to form echo information, and the echo information is received by the receiving antenna. The rotary radar 12 can determine position information of an obstacle existing in the flight environment of the unmanned aerial vehicle 10 according to the echo information, and provide the position information of the obstacle to the flight control system 13, so that the flight control system 13 can control the unmanned aerial vehicle to perform obstacle avoidance flight.

In some cases, ground clutter prolongation may occur due to constraints on the beam resolution of the array antenna, falsely identifying some ground points as obstacles, which false obstacles (such as the dashed circles in fig. 4 a) may falsely trigger the obstacle avoidance function. In order to reduce the probability of false obstacle false triggering of the obstacle avoidance function due to ground clutter continuation, in some embodiments of the present application, the rotary radar 12 may perform ground clutter suppression on echo information of electromagnetic waves by using a phase angle measurement technique in an electronic scanning direction (i.e., a vertical direction or a pitching direction), and determine position information of an obstacle in the surrounding environment of the unmanned aerial vehicle according to the echo information after ground clutter suppression; and providing the determined position information of the obstacle for a flight control system 13 of the unmanned aerial vehicle 10, so that the flight control system 13 controls the unmanned aerial vehicle 10 to carry out obstacle avoidance flight according to the position information of the obstacle. For the flight control system 13, the unmanned aerial vehicle can be controlled to perform obstacle avoidance flight according to the position information of the obstacle detected by the rotary radar 12.

In the embodiment, ground clutter suppression is performed on echo information, ground points and obstacles can be distinguished more accurately, so that position information of the obstacles in the surrounding environment of the unmanned aerial vehicle can be accurately found in the beam resolution, and adverse effects of the ground clutter on the obstacle avoidance function are reduced.

Further optionally, one embodiment of the rotating radar 12 that uses phase goniometry techniques to ground clutter address the echo information includes: calculating the phase difference between echo information from the same target received by different receiving antennas in the array antenna; calculating the information of the angle of arrival of the target according to the phase difference between the echo information from the same target received by different receiving antennas; judging whether the target is in an obstacle avoidance range of the unmanned aerial vehicle or not according to the information of the angle of arrival of the target; if the target is not in the obstacle avoidance range of the unmanned aerial vehicle, the target is determined to be a ground point, the echo information from the target belongs to the ground clutter, and the echo information from the target can be used as the ground clutter to be suppressed. And if the target is in the obstacle avoidance range of the unmanned aerial vehicle, determining that the target belongs to the obstacle.

In the embodiment of the present application, the number of receiving antennas included in the array antenna is not limited, and may be two or more. Depending on the number of receiving antennas, there may be differences in the way angle of arrival information is calculated, but the principle is basically the same. To facilitate understanding of the phase angle measurement technique, the following describes a process of calculating information of the angle of arrival with reference to fig. 4a and two receiving antennas as an example.

As shown in fig. 4a, since the rotating radar 12 is vertically installed, the two adjacent receiving antennas Rx1 and Rx2 in the array antenna are vertically separated by a distance d, which means that the echo information after the electromagnetic wave transmitted by the same transmitting antenna Tx reaches the same target (black dots in fig. 4) will reach the two receiving antennas in tandem, or the echo information received by the two receiving antennas Rx1 and Rx2 at the same time are different in phase by an angle Φ, and the arrival angle information α of the target can be determined based on the phase difference Φ, which is the phase angle measurement technology.

With reference to fig. 4, equation (1) can be obtained by using trigonometric function relationships: α ═ arcsin (Δ R/d). Where α denotes the angle of arrival of the target, Δ R is the path difference between the reception antennas Rx1 and Rx2, and d is the distance between the reception antennas Rx1 and Rx 2.

The formula (2) can be obtained according to the relationship among the wavelength λ of the electromagnetic wave, the phase difference and the wave path difference: Φ/Δ R ═ 2 pi/λ.

Substituting equation (2) into equation (1) may result in equation (3): α ═ arcsin (Φ λ/2 π d).

In the formula (3), the phase difference Φ between the two reception antennas Rx1 and Rx2 and the distance d are known quantities, and therefore the angle of arrival α of the target can be calculated. The position of the target can be determined based on the angle of arrival α, and it can be distinguished whether the target is within the flight range of the drone 10; if the target is determined to belong to the obstacle, otherwise, the target is determined to be a ground point, and echo information from the ground point is suppressed under the condition that the ground point is determined to be the target, so that the aim of suppressing the ground clutter is fulfilled.

The effect of ground clutter suppression in this embodiment will be described below with reference to top and side views of ground point cloud data obtained by ground clutter suppression by the rotating radar shown in fig. 4b and 4 c. In fig. 4b and 4c, the east (E) is taken as the flight direction of the drone, see fig. 4b, there are no significant clutter in both the front and rear directions of the drone; referring to fig. 4c, ground clutter is suppressed low with no extension in the vertical direction. Therefore, through ground clutter suppression, the obstacles and ground points in the flight range of the unmanned aerial vehicle can be accurately identified, the obstacle avoidance function can be accurately triggered, and the probability of mistakenly triggering the obstacle avoidance function is reduced.

The unmanned aerial vehicle provided by the embodiment of the application can be applied to various scenes, for example, the unmanned aerial vehicle can be applied to the power industry, and can be used for large-scale cable inspection, real-time cable 3D image reconstruction and the like; also, for example, it can be applied to agriculture, spraying agricultural chemicals to agricultural and forestry plants, environmental detection, and the like. Under these operation scenes, unmanned aerial vehicles mostly need to fly near the ground, and the ground is hit by mistake when climbing the slope. Especially in rugged topography, unmanned aerial vehicle need move in advance and adjust, carries out operations such as climbing, downhill path, speed reduction, brake, realizes near-ground flight even high altitude flight, just so can make unmanned aerial vehicle accomplish above-mentioned operation better. Therefore, it is necessary to predict the terrain information of the ground in the surrounding environment of the drone.

Based on the above, in some embodiments of the present application, the rotating radar 12 may further calculate ground point information in the flight environment of the unmanned aerial vehicle 10 according to the echo information of the electromagnetic wave; carrying out terrain estimation according to the ground point information to obtain terrain parameters of the ground; and transmitting the terrain parameters of the ground to the flight control system 13 so that the flight control system 13 can control the unmanned aerial vehicle 10 to follow the terrain according to the terrain parameters of the ground. Wherein, the terrain parameters of the ground include but are not limited to: the slope of ground, the height of unmanned aerial vehicle apart from ground.

Optionally, the rotating radar 12 may specifically map the ground point information to a geodetic coordinate system when performing terrain estimation according to the ground point information; calculating elevation difference and horizontal distance between ground point information in a geodetic coordinate system; and calculating the gradient of the ground according to the elevation difference and the horizontal distance between the ground point information.

For the flight control system 13, the unmanned aerial vehicle 10 is controlled to perform terrain following flight according to the terrain parameters of the ground, including but not limited to: fixed-height flight, mountain AB point flight and the like.

Taking the case that the flight control system 13 controls the unmanned aerial vehicle 10 to perform level flight as an example, the flight control system 13 can calculate the speed control amount required by the unmanned aerial vehicle 10 to perform parallel flight along the ground at a specified height according to the slope of the ground; decomposing the speed control quantity into two control components of ascending and advancing; both the ascent and forward control components are provided to the power system of the drone 10 to control the drone 10 for terrain following flight. Wherein the amount of speed control required for the drone 10 to fly parallel along the ground at a given altitude varies as the slope of the ground varies.

In this application embodiment, unmanned aerial vehicle 10 is including installing the rotatory radar 12 on organism 11 perpendicularly, can both survey the target in unmanned aerial vehicle 10 surrounding environment in wider range on level and perpendicular two directions based on rotatory radar 12, compares in current unmanned aerial vehicle, and unmanned aerial vehicle 10 that this application embodiment provided all has very big promotion on the level is kept away the barrier and the topography is followed functions such as flight, is favorable to promoting user experience. For example, the unmanned aerial vehicle 10 may implement an obstacle avoidance function in a wider range in the horizontal direction, and may even implement horizontal omnidirectional (360 degrees) obstacle avoidance, thereby improving flight safety. For another example, because the terrain information in a wider range can be detected, the unmanned aerial vehicle 10 can more accurately perform terrain following flight, and also can more accurately realize the mountain AB point function, reduce the probability of collision, and improve the flight safety.

In addition to the drone, the embodiment of the present application further provides a rotating radar, as shown in fig. 5, the rotating radar 50 includes: a rotating device 51, an array antenna 52 and a processing system 53. Among them, the shape and structure of the rotating radar 50 shown in fig. 5 are only exemplary and not limiting. In addition, the rotary radar 50 may include other components, such as a radome, motors, supports, etc., in addition to the noted parts.

Wherein, rotating device 51 for install on unmanned aerial vehicle's organism, this rotating device 51 includes runing rest and drives runing rest pivoted motor.

The array antenna 52 is mounted on a rotating bracket of the rotating device 51, and the rotating device 51 drives the array antenna 52 to continuously rotate in the heading direction of the unmanned aerial vehicle.

Alternatively, the array antenna 52 may be rotatable about an axis of rotation that is parallel or substantially parallel to the heading axis of the drone, such that the turning device 51 may cause the array antenna 52 to continuously turn in the heading direction of the drone.

Optionally, the rotating device 51 may drive the array antenna 52 to rotate 360 degrees in the heading direction of the drone, but is not limited thereto.

And the processing system 53 is used for controlling the array antenna 52 to emit electromagnetic waves and determining the position information of the target detected by the rotating radar 50 according to the echo information received by the array antenna 52.

In an alternative embodiment, the array antenna 52 is electronically scanned in the pitch direction of the drone.

Alternatively, in the vertical direction, the rotating radar 50 may have a view angle blind spot, considering that the array antenna 52 may not be able to perform 360-degree electronic scanning in the elevation direction. Based on this, in an alternative embodiment, another array antenna is disposed at the bottom of the rotating radar 50, and the field angle of the other array antenna at least partially covers the blind zone of the rotating radar in the lower area.

Further optionally, the processing system 53 is specifically configured to: adopting a phase angle measurement technology in the electronic scanning direction to carry out ground clutter suppression on echo information; determining position information of obstacles in the surrounding environment of the unmanned aerial vehicle according to the echo information after the ground clutter suppression; and transmitting the position information of the obstacle to a flight control system of the unmanned aerial vehicle so as to control the unmanned aerial vehicle to avoid obstacle flight.

Further optionally, the processing system 53 employs a phase angle measurement technique in the electronic scanning direction, and when performing ground clutter suppression on the echo information, is specifically configured to: calculating the phase difference between echo information from the same target received by different receiving antennas; calculating the information of the angle of arrival of the target according to the phase difference; judging whether the target is in an obstacle avoidance range of the unmanned aerial vehicle or not according to the information of the angle of arrival of the target; and if the target is not in the obstacle avoidance range of the unmanned aerial vehicle, the echo information from the target is used as ground clutter to be suppressed.

In an alternative embodiment, the processing system 53 is further configured to: calculating the detected ground point information according to the echo information; carrying out terrain estimation according to the ground point information to obtain terrain parameters of the ground; the terrain parameters of the ground are transmitted to a flight control system of the unmanned aerial vehicle so as to control the unmanned aerial vehicle to carry out terrain following flight.

Alternatively, the rotary radar of the present embodiment may be a microwave radar, a millimeter wave radar, a laser radar, or the like.

In this embodiment, the rotating device of the rotating radar can drive the array antenna to rotate continuously in the course direction of the unmanned aerial vehicle. This means that rotatory radar can carry out the rotatory scanning of machinery on the horizontal direction, that is to say, rotatory radar can survey the target that exists in the unmanned aerial vehicle surrounding environment in the horizontal direction in a flexible way, is favorable to improving the detection scope on the horizontal direction, is convenient for satisfy unmanned aerial vehicle to the demand of environmental perception, and then can satisfy the complete machine to the demand in the aspect of safety.

Furthermore, array antenna can carry out electronic scanning in the pitch direction, means that rotatory radar not only can follow the target that exists in the horizontal direction in surveying the unmanned aerial vehicle surrounding environment, can also follow the target that exists in the vertical direction in surveying the unmanned aerial vehicle surrounding environment, is favorable to improving detection range from level and two vertical directions, is convenient for satisfy unmanned aerial vehicle to the demand of environmental perception, and then can satisfy the demand of complete machine to the aspect of safety.

The embodiment of the application provides a ground clutter suppression method, and the method is applicable to rotary radar, and this rotary radar installs perpendicularly on unmanned aerial vehicle, and the array antenna of this rotary radar carries out electronic scanning in unmanned aerial vehicle's every single move direction, and the array antenna can rotate around a rotation axis, and this rotation axis is parallel to or is basically parallel to unmanned aerial vehicle's course axle. For other descriptions of the rotating radar, reference may be made to the foregoing embodiments of the drone or the rotating radar, and further description is omitted here.

As shown in fig. 6a, the ground clutter suppression method includes the following steps:

61a, a phase angle measurement technique is adopted in the electronic scanning direction to suppress ground clutter of the echo information of the electromagnetic wave.

And 62a, determining the position information of the obstacles in the surrounding environment of the unmanned aerial vehicle according to the echo information after the ground clutter suppression.

63a, transmitting the position information of the obstacle to a flight control system of the unmanned aerial vehicle so as to control the unmanned aerial vehicle to carry out obstacle avoidance flight.

Optionally, one embodiment of step 61a comprises: calculating the phase difference between echo information from the same target received by different receiving antennas on the upper array antenna; calculating the information of the angle of arrival of the target according to the phase difference; judging whether the target is in an obstacle avoidance range of the unmanned aerial vehicle or not according to the information of the angle of arrival of the target; and if the target is not in the obstacle avoidance range of the unmanned aerial vehicle, the echo information from the target is used as ground clutter to be suppressed.

For detailed description of each step in this embodiment, reference may be made to corresponding description in the unmanned aerial vehicle embodiment, and details are not described herein.

In the present embodiment, the rotary radar performs mechanical rotary scanning in the horizontal direction, and detection can be performed in a wide range in the horizontal direction; furthermore, the phase angle measurement technology is adopted to suppress ground clutter of echo information, so that obstacles in a larger flight range can be identified more accurately, the obstacle avoidance function can be triggered more accurately, and the probability of mistakenly triggering the obstacle avoidance function is reduced.

Accordingly, embodiments of the present application provide a computer readable storage medium storing a computer program, which when executed by a processor causes the processor to:

adopting a phase angle measurement technology in the electronic scanning direction to carry out ground clutter suppression on echo information of the electromagnetic waves; determining position information of obstacles in the surrounding environment of the unmanned aerial vehicle according to the echo information after the ground clutter suppression; and transmitting the position information of the obstacle to a flight control system of the unmanned aerial vehicle so as to control the unmanned aerial vehicle to avoid obstacle flight.

In addition to the above operations, the processor may also perform other operations in the embodiment shown in fig. 6a, and for the other operations, reference may be made to the description in the embodiment shown in fig. 6a, and details are not repeated here.

The embodiment of the application provides a terrain estimation method, which is suitable for a rotary radar, wherein the rotary radar is vertically arranged on an unmanned aerial vehicle, an array antenna of the rotary radar can rotate around a rotating shaft, and the rotating shaft is parallel or basically parallel to a course shaft of the unmanned aerial vehicle. For other descriptions of the rotating radar, reference may be made to the foregoing embodiments of the drone or the rotating radar, and further description is omitted here.

As shown in fig. 6b, the terrain estimation method includes the steps of:

and 61b, calculating the detected ground point information according to the echo information received by the rotary radar.

And 62b, carrying out terrain estimation according to the ground point information to obtain terrain parameters of the ground.

63b, transmitting the terrain parameters of the ground to a flight control system of the unmanned aerial vehicle so as to control the unmanned aerial vehicle to carry out terrain following flight.

For detailed description of each step in this embodiment, reference may be made to the foregoing embodiments, which are not repeated herein.

In this embodiment, rotatory radar is installed perpendicularly in unmanned aerial vehicle's organism, and rotatory radar can both survey the topography information in the unmanned aerial vehicle surrounding environment in level and perpendicular two directions more than so for unmanned aerial vehicle can carry out the topography more accurately and follow the flight, also can realize mountain region AB point function more accurately, reduces and hits the quick-witted probability, improves flight safety.

calculating the detected ground point information according to the echo information received by the rotary radar; carrying out terrain estimation according to the ground point information to obtain terrain parameters of the ground; the terrain parameters of the ground are transmitted to a flight control system of the unmanned aerial vehicle so as to control the unmanned aerial vehicle to carry out terrain following flight.

In addition to the above operations, the processor may also perform other operations in the embodiment shown in fig. 6b, and for the other operations, reference may be made to the description in the embodiment shown in fig. 6b, and details are not repeated here.

It should be noted that the scheme of the rotatory radar of vertical installation that this application embodiment provided not only is applicable to unmanned aerial vehicle, can be applicable to any autonomous mobile device such as unmanned vehicles. Based on this, the embodiment of the present application further provides an autonomous mobile device, including: the equipment comprises an equipment body, a rotary radar and a control system.

Wherein, the rotary radar is vertically arranged on the equipment body; the array antenna of the rotating radar can rotate around a rotation axis that is parallel or substantially parallel to the heading axis of the autonomous mobile device. A control system in communication with the rotary radar; the rotary radar sends the position information of the target detected by the rotary radar to the control system; the control system controls the autonomous mobile device to travel according to the position information of the target detected by the rotating radar.

In this embodiment, the heading axis of the autonomous mobile device is defined the same as or similar to the heading axis of the drone, which can be referred to the above definition of the heading axis of the drone, and is not described herein again.

In an alternative embodiment, the array antenna of the rotary radar is capable of 360 degree rotation about the axis of rotation.

In an alternative embodiment, the rotary radar may be a microwave radar, a millimeter wave radar, or a laser radar.

In an alternative embodiment, the array antenna of the rotating radar is electronically scanned in elevation.

In an alternative embodiment, the rotary radar may perform ground clutter suppression on echo information of the electromagnetic wave by using a phase angle measurement technology in an electronic scanning direction (i.e. a vertical direction or a pitching direction), and determine position information of obstacles in the surrounding environment of the autonomous mobile device according to the echo information after the ground clutter suppression; and providing the determined position information of the obstacle to a control system of the autonomous mobile equipment, so that the control system can control the autonomous mobile equipment to avoid the obstacle according to the position information of the obstacle.

For the description related to the rotating radar, reference may be made to the foregoing embodiments, which are not described herein again.

In an alternative embodiment, the autonomous mobile device is an unmanned vehicle and the rotary radar is mounted on top of or in front of the body of the unmanned vehicle. Alternatively, the unmanned vehicle may be an automated delivery vehicle, an unmanned car, an unmanned tractor, or the like.

In this embodiment, install rotatory radar perpendicularly on the autonomous mobile device, based on rotatory radar can both survey the target in the autonomous mobile device surrounding environment in more extensive on level and perpendicular two directions, the autonomous mobile device that this embodiment provided has very big promotion on functions such as obstacle is kept away to the level, is favorable to promoting user experience.

As will be appreciated by one skilled in the art, embodiments of the present invention may be provided as a method, system, or computer program product. Accordingly, the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the present invention may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, and the like) having computer-usable program code embodied therein.

The present invention is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each flow and/or block of the flow diagrams and/or block diagrams, and combinations of flows and/or blocks in the flow diagrams and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

In a typical configuration, a computing device includes one or more processors (CPUs), input/output interfaces, network interfaces, and memory.

The memory may include forms of volatile memory in a computer readable medium, Random Access Memory (RAM) and/or non-volatile memory, such as Read Only Memory (ROM) or flash memory (flash RAM). Memory is an example of a computer-readable medium.

Computer-readable media, including both non-transitory and non-transitory, removable and non-removable media, may implement information storage by any method or technology. The information may be computer readable instructions, data structures, modules of a program, or other data. Examples of computer storage media include, but are not limited to, phase change memory (PRAM), Static Random Access Memory (SRAM), Dynamic Random Access Memory (DRAM), other types of Random Access Memory (RAM), Read Only Memory (ROM), Electrically Erasable Programmable Read Only Memory (EEPROM), flash memory or other memory technology, compact disc read only memory (CD-ROM), Digital Versatile Discs (DVD) or other optical storage, magnetic cassettes, magnetic tape magnetic disk storage or other magnetic storage devices, or any other non-transmission medium that can be used to store information that can be accessed by a computing device. As defined herein, a computer readable medium does not include a transitory computer readable medium such as a modulated data signal and a carrier wave.

It should also be noted that the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other like elements in a process, method, article, or apparatus that comprises the element.

As will be appreciated by one skilled in the art, embodiments of the present application may be provided as a method, system, or computer program product. Accordingly, the present application may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the present application may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, and the like) having computer-usable program code embodied therein.

The above description is only an example of the present application and is not intended to limit the present application. Various modifications and changes may occur to those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included in the scope of the claims of the present application.

Claims

1. An unmanned aerial vehicle, comprising:

a body;

2. A drone according to claim 1, characterised in that the array antenna of the rotating radar scans electronically in elevation.

3. A drone according to claim 1, characterised in that the array antenna of the rotary radar is capable of 360 degree rotation around the rotation axis.

4. A drone according to claim 1, characterised in that the rotating radar is mounted vertically below the body.

5. The drone of claim 4, further comprising:

and the downward-looking radar is arranged below the rotary radar, and the field angle of the downward-looking radar at least partially covers the view angle blind area of the lower area of the rotary radar.

6. A drone according to claim 5, characterised in that the downward-looking radar is an array antenna arranged at the bottom of the rotating radar.

7. The drone of claim 3, further comprising:

and the upper view radar is arranged above the machine body, and the field angle of the upper view radar at least partially covers the view angle blind area of the upper area of the rotating radar.

8. The drone of claim 1, wherein the rotating radar is a microwave radar.

9. The drone of claim 2, wherein the rotating radar is further to:

adopting a phase angle measurement technology in the electronic scanning direction to carry out ground clutter suppression on echo information of the electromagnetic waves; determining position information of obstacles in the surrounding environment of the unmanned aerial vehicle according to the echo information after ground clutter suppression; transmitting the position information of the obstacle to the flight control system;

and the flight control system specifically controls the unmanned aerial vehicle to carry out obstacle avoidance flight according to the position information of the obstacle.

10. A drone according to claim 9, characterised in that the rotating radar, when performing ground clutter suppression, is particularly adapted to:

calculating the phase difference between echo information from the same target received by different receiving antennas; calculating the information of the angle of arrival of the target according to the phase difference; judging whether the target is in an obstacle avoidance range of the unmanned aerial vehicle or not according to the information of the angle of arrival of the target; and if the target is not in the obstacle avoidance range of the unmanned aerial vehicle, inhibiting echo information from the target as a ground clutter.

11. A drone according to any one of claims 1 to 10, characterised in that the rotary radar is also configured to: calculating ground point information according to the echo information of the electromagnetic waves; carrying out terrain estimation according to the ground point information to obtain terrain parameters of the ground; transmitting the terrain parameters of the ground to the flight control system;

the flight control system specifically controls the unmanned aerial vehicle to carry out terrain following flight according to the terrain parameters of the ground.

12. A drone according to claim 10, characterised in that the terrestrial topographic parameters comprise at least: the slope of the ground;

the flight control system is specifically configured to: calculating the speed control amount required by the unmanned aerial vehicle to fly in parallel along the ground at a specified height according to the gradient of the ground; decomposing the speed control quantity into two control components of ascending and advancing; providing both a rise and a forward control component to a power system of the drone to control the drone for terrain following flight.

13. An autonomous mobile device, comprising:

an apparatus body;

14. The autonomous mobile apparatus of claim 13 wherein the array antenna of the rotating radar electronically scans in elevation.

15. The autonomous mobile apparatus of claim 13 or 14, wherein the autonomous mobile apparatus is an unmanned vehicle and the rotating radar is mounted on top of or in front of a body of the unmanned vehicle.

16. A rotary radar, comprising: the device comprises a rotating device, an array antenna and a processing system;

17. The rotary radar of claim 16, wherein the array antenna electronically scans in a pitch direction of the drone.

18. The rotary radar of claim 17, wherein the processing system is specifically configured to: performing ground clutter suppression on the echo information by adopting a phase angle measurement technology in the electronic scanning direction; determining position information of obstacles in the surrounding environment of the unmanned aerial vehicle according to the echo information after ground clutter suppression; and transmitting the position information of the obstacle to a flight control system of the unmanned aerial vehicle so as to control the unmanned aerial vehicle to avoid obstacle flight.

19. The rotary radar of claim 18, wherein the processing system is specifically configured to: calculating the phase difference between echo information from the same target received by different receiving antennas; calculating the information of the angle of arrival of the target according to the phase difference; judging whether the target is in an obstacle avoidance range of the unmanned aerial vehicle or not according to the information of the angle of arrival of the target; and if the target is not in the obstacle avoidance range of the unmanned aerial vehicle, inhibiting echo information from the target as a ground clutter.

20. The rotary radar of any one of claims 16 to 19, wherein the processing system is specifically configured to: calculating ground point information according to the echo information; carrying out terrain estimation according to the ground point information to obtain terrain parameters of the ground; and transmitting the terrain parameters of the ground to a flight control system of the unmanned aerial vehicle so as to control the unmanned aerial vehicle to carry out terrain following flight.

21. The rotary radar of any one of claims 16 to 19, wherein the rotation device is configured to rotate the array antenna 360 degrees in a heading direction of the drone.

22. A rotary radar as claimed in any one of claims 16 to 19, wherein the rotary radar is provided with a further array antenna at a base portion, the field of view of the further array antenna at least partially covering a blind field of view of the rotary radar in an area below.

23. A rotary radar as claimed in any one of claims 16 to 19, wherein the rotary radar is a microwave radar.

24. A ground clutter suppression method is suitable for a rotary radar, and is characterized in that the rotary radar is vertically installed on an unmanned aerial vehicle, an array antenna of the rotary radar performs electronic scanning in the pitching direction of the unmanned aerial vehicle, the array antenna can rotate around a rotating shaft, and the rotating shaft is parallel or basically parallel to a course axis of the unmanned aerial vehicle; the method comprises the following steps:

25. The method of claim 24, wherein performing ground clutter suppression on echo information of the electromagnetic wave using a phase goniometry technique in the electronic scan direction comprises:

calculating the phase difference between echo information from the same target received by different receiving antennas;

calculating the information of the angle of arrival of the target according to the phase difference;

judging whether the target is in an obstacle avoidance range of the unmanned aerial vehicle or not according to the information of the angle of arrival of the target;

and if the target is not in the obstacle avoidance range of the unmanned aerial vehicle, inhibiting echo information from the target as a ground clutter.

26. A method according to claim 24 or 25, wherein the array antenna of the rotating radar is capable of 360 degree rotation about the axis of rotation.

27. A method according to claim 24 or 25, wherein the rotary radar is mounted vertically below the body.

28. The method of claim 24 or 25, wherein the rotary radar is a microwave radar.

29. A terrain estimation method is suitable for a rotary radar, and is characterized in that the rotary radar is vertically arranged on an unmanned aerial vehicle, an array antenna of the rotary radar can rotate around a rotating shaft, and the rotating shaft is parallel or basically parallel to a course axis of the unmanned aerial vehicle; the method comprises the following steps:

30. The method of claim 29, wherein the array antenna of the rotating radar is electronically scanned in a pitch direction.

31. A method according to claim 29 or 30, wherein the array antenna of the rotating radar is capable of 360 degree rotation about the axis of rotation.

32. A method according to claim 29 or 30, wherein the rotary radar is mounted vertically below the body.

33. The method of claim 29 or 30, wherein the rotary radar is a microwave radar.

34. A computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, causes the processor to carry out the steps of the method of any one of claims 24-33.