U.S. patent application number 15/389458 was filed with the patent office on 2017-11-23 for method an apparatus for controlling unmanned aerial vehicle to land on landing platform.
The applicant listed for this patent is ZEROTECH (Chongqing) Intelligence Technology Co., Ltd.. Invention is credited to Jinhui LUO, Shuaiqin WANG, Jianjun YANG, Lin YANG.
Application Number | 20170336805 15/389458 |
Document ID | / |
Family ID | 56634504 |
Filed Date | 2017-11-23 |
United States Patent
Application |
20170336805 |
Kind Code |
A1 |
LUO; Jinhui ; et
al. |
November 23, 2017 |
METHOD AN APPARATUS FOR CONTROLLING UNMANNED AERIAL VEHICLE TO LAND
ON LANDING PLATFORM
Abstract
A method and an apparatus for controlling an unmanned aerial
vehicle (UAV) to land on a landing platform are provided. The
method includes: receiving a landing preparatory signal instructing
the UAV to enter into a landing preparatory state; monitoring the
landing platform to generate a monitoring signal in response to the
landing preparatory signal; and determining whether to control the
UAV to enter into a landing mode based on the monitoring
signal.
Inventors: |
LUO; Jinhui; (Beijing,
CN) ; WANG; Shuaiqin; (Beijing, CN) ; YANG;
Lin; (Beijing, CN) ; YANG; Jianjun; (Beijing,
CN) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
ZEROTECH (Chongqing) Intelligence Technology Co., Ltd. |
Chongqing |
|
CN |
|
|
Family ID: |
56634504 |
Appl. No.: |
15/389458 |
Filed: |
December 23, 2016 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B64C 2201/18 20130101;
B64C 2201/146 20130101; G05D 1/042 20130101; G05D 1/0011 20130101;
B64C 39/024 20130101; B64D 45/04 20130101; G05D 1/0676 20130101;
B64D 47/08 20130101; B64F 1/007 20130101 |
International
Class: |
G05D 1/04 20060101
G05D001/04; B64C 39/02 20060101 B64C039/02; B64D 45/04 20060101
B64D045/04; B64F 1/00 20060101 B64F001/00 |
Foreign Application Data
Date |
Code |
Application Number |
May 23, 2016 |
CN |
201610346128.2 |
Sep 5, 2016 |
CN |
201610802445.0 |
Claims
1. A method for controlling an unmanned aerial vehicle (UAV) to
land on a landing platform, comprising: receiving a landing
preparatory signal instructing the UAV to enter into a landing
preparatory state; monitoring the landing platform to generate a
monitoring signal in response to the landing preparatory signal;
and determining whether to control the UAV to enter into a landing
mode based on the monitoring signal.
2. The method of claim 1, wherein the monitoring signal indicates a
vertical distance between the UAV and the landing platform; and the
method further comprises: controlling the UAV to enter into the
landing mode when the vertical distance between the UAV and the
landing platform is smaller than or equal to a preset threshold
distance.
3. The method of claim 2, wherein the UAV comprises at least one
rotor, and controlling the UAV to enter into the landing mode
further comprises: controlling the at least one rotor of the UAV to
stop rotating, such that the UAV lands on the landing platform in a
free-fall manner.
4. The method of claim 2, wherein the UAV comprises at least one
rotor, and controlling the UAV to enter into the landing mode
further comprises: controlling the at least one rotor of the UAV to
rotate at a smaller rotation speed, such that the UAV lands on the
landing platform at a predetermined speed.
5. The method of claim 1, wherein the monitoring signal indicates a
speed variation of the UAV with respect to the landing platform,
the UAV comprises at least one rotor, and the method further
comprises: controlling the at least one rotor of the UAV to stop
rotating when the speed variation of the UAV with respect to the
landing platform is greater than a preset speed variation
threshold.
6. The method of claim 2, wherein, after the UAV enters into the
landing mode, the method further comprises: continuing to monitor
the vertical distance between the UAV and the landing platform; and
controlling the UAV to return to a hovering mode or a flying mode
when the vertical distance between the UAV and the landing platform
is greater than the preset threshold distance.
7. The method of claim 2, wherein, after the UAV enters into the
landing mode, the method further comprises: monitoring a tilting
angle of the UAV; and controlling the UAV to return to a hovering
mode or a flying mode when the tilting angle of the UAV is greater
than a preset threshold angle.
8. The method of claim 1, wherein, after receiving the landing
preparatory signal and before monitoring the landing platform, the
method further comprises: obtaining a current height of the UAV;
controlling the UAV to fly to a first preset height at a first
descending speed when the current height of the UAV is greater than
the first preset height; or controlling the UAV to fly to a second
preset height at a second descending speed when the current height
of the UAV is smaller than or equal to the first preset height but
is greater than the second preset height, wherein the second
descending speed is smaller than the first descending speed.
9. The method of claim 8, wherein the determining step further
comprises: based on the monitoring signal, controlling the UAV to
enter into the landing mode during controlling the UAV to fly to
the second preset height at the second descending speed.
10. The method of claim 8, wherein the determining step further
comprises: based on the monitoring signal, controlling the UAV to
enter into the landing mode when the current height of the UAV is
smaller than or equal to the second preset height.
11. The method of claim 10, wherein the UAV is controlled to
descend at a third descending speed during the landing mode.
12. The method of claim 8, wherein, when controlling the UAV to fly
to the first preset height at the first descending speed, the
method further comprises: sending a landing reminder signal to a
user, wherein the landing reminder signal is used to remind the
user to prepare the landing platform.
13. An apparatus for controlling an unmanned aerial vehicle (UAV)
to land on a landing platform, comprising: a processor; and a
memory for storing instructions executable by the processor,
wherein, when executing the instruction, the processor is
configured to: receive a landing preparatory signal instructing the
UAV to enter into a landing preparatory state; monitor the landing
platform to generate a monitoring signal in response to the landing
preparatory signal; and determine whether to control the UAV to
enter into a landing mode based on the monitoring signal.
14. The apparatus of claim 13, wherein the processor is further
configured to control the UAV to enter into the landing mode, when
the monitoring signal indicates a vertical distance between the UAV
and the landing platform, and the vertical distance between the UAV
and the landing platform is smaller than or equal to a preset
threshold distance.
15. The apparatus of claim 14, wherein the UAV comprises at least
one rotor, and the processor is further configured to control the
at least one rotor of the UAV to stop rotating, such that the UAV
lands on the landing platform in a free-fall manner.
16. The apparatus of claim 14, wherein the UAV comprises at least
one rotor, and the processor is further configured to control the
at least one rotor of the UAV to rotate at a smaller rotation
speed, such that the UAV lands on the landing platform at a
predetermined speed.
17. The apparatus of claim 13, wherein the UAV comprises at least
one rotor, and the processor is further configured to control the
at least one rotor of the UAV to stop rotating when the monitoring
signal indicates a speed variation of the UAV with respect to the
landing platform and the speed variation of the UAV is greater than
a preset speed variation threshold.
18. The apparatus of claim 14, wherein, after the UAV enters into
the landing mode, the processor is further configured to: continue
to monitor the vertical distance between the UAV and the landing
platform, and control the UAV to return to a hovering mode or a
flying mode when the vertical distance between the UAV and the
landing platform is greater than the preset threshold distance.
19. The apparatus of claim 14, wherein, after the UAV enters into
the landing mode, the processor is further configured to: monitor a
tilting angle of the UAV, and control the UAV to return to a
hovering mode or a flying mode when the tilting angle of the UAV is
greater than a preset threshold angle.
20. The apparatus of claim 13, wherein, after receiving the landing
preparatory signal and before monitoring the landing platform, the
processor is further configured to: obtain a current height of the
UAV; control the UAV to fly to a first preset height at a first
descending speed when the current height of the UAV is greater than
the first preset height; and control the UAV to fly to a second
preset height at a second descending speed when the current height
of the UAV is smaller than or equal to the first preset height, but
is greater than the second preset height, wherein the second
descending speed is smaller than the first descending speed.
21. The apparatus of claim 20, wherein the processor is further
configured to control the UAV to enter into the landing mode based
on the monitoring signal, during controlling the UAV to fly to the
second preset height at the second descending speed.
22. The apparatus of claim 20, wherein the processor is further
configured to control the UAV to enter into the landing mode based
on the monitoring signal, when the current height of the UAV is
smaller than or equal to the second preset height.
23. The apparatus of claim 22, wherein the processor is further
configured to control the UAV to descend at a third descending
speed during the landing mode.
24. The apparatus of claim 20, wherein, when controlling the UAV to
fly to a first preset height at a first descending speed, the
processor is further configured to: send a landing reminder signal
to a user, wherein the landing reminder signal is used to remind
the user to prepare the landing platform.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to Chinese patent
application No. 201610346128.2 field on May 23, 2016, and Chinese
patent application No. 201610802445.0 filed on Sep. 5, 2016, the
entire contents of which are incorporated herein by reference.
TECHNICAL FIELD
[0002] The present disclosure generally relates to a method and an
apparatus for controlling an unmanned aerial vehicle (UAV) to land
on a landing platform.
BACKGROUND
[0003] With the continuous development of aviation technology,
unmanned aerial vehicles (UAVs) have been widely used in military
and civilian fields. A variety of techniques have been developed in
connection with the operation of the UAVs, including take-off,
flight, and landing. Generally, a skilled user controls landing of
a multi-rotor UAV by manipulating a remote control device
associated with the multi-rotor UAV. During landing, in order to
make the UAVs' landing safe and smooth, the skilled user is
required to control the UAVs' attitude balance and propulsion power
output.
[0004] In addition, as the UAV is usually controlled to land on
ground, the UAV will be stained with dust, soil or water on the
ground and the user needs to pick up the UAV from the ground.
SUMMARY
[0005] An example method for controlling an unmanned aerial vehicle
(UAV) to land on a landing platform is provided. The method
includes: receiving a landing preparatory signal instructing the
UAV to enter into a landing preparatory state; monitoring the
landing platform to generate a monitoring signal in response to the
landing preparatory signal; and determining whether to control the
UAV to enter into a landing mode based on the monitoring
signal.
[0006] An example apparatus for controlling a UAV to land on a
landing platform is provided. The apparatus includes: a receiving
unit configured to receive a landing preparatory signal instructing
the UAV to enter into a landing preparatory state; a monitoring
unit configured to monitor the landing platform to generate a
monitoring signal in response to the landing preparatory signal;
and a control unit configured to determine whether to control the
UAV to enter into a landing mode based on the monitoring
signal.
[0007] Further, another example apparatus for controlling a UAV to
land on a landing platform is provided. The apparatus includes: a
processor; and a memory for storing instructions executable by the
processor, wherein, when executing the instruction, the processor
is configured to: receive a landing preparatory signal instructing
the UAV to enter into a landing preparatory state; monitor the
landing platform to generate a monitoring signal in response to the
landing preparatory signal; and determine whether to control the
UAV to enter into a landing mode based on the monitoring
signal.
[0008] 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 invention.
Further, the accompanying drawings, which are incorporated in and
constitute a part of this specification, illustrate embodiments of
the invention and together with the description, serve to explain
principles of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] In order to more clearly illustrate solutions of embodiments
of the present disclosure, the drawings which are required to be
used in the embodiments will be briefly described below. It should
be understood that the following drawings show only certain
embodiments of the present disclosure, and the scope of the
disclosure is limited thereto. It also should be understood other
related drawings may be obtained by those skilled in the art from
the drawings without departing from the scope of the present
disclosure.
[0010] FIG. 1 illustrates a diagram of an exemplary UAV landing
system environment within which embodiments of the disclosure may
be practiced.
[0011] FIG. 2 is a block diagram of the UAV in the landing system
environment of FIG. 1.
[0012] FIG. 3 is a flow chart of an exemplary method for
controlling the UAV to land on a landing platform according to an
embodiment.
[0013] FIG. 4 is a flow chart of an exemplary method for
controlling the UAV to land on a landing platform according to
another embodiment.
[0014] FIG. 5 is a flow chart of an exemplary method for
controlling the UAV to land on a landing platform according to
another embodiment.
[0015] FIG. 6 is a block diagram of an exemplary landing control
apparatus in the UAV as shown in FIG. 2.
[0016] FIG. 7 is a flow chart of an exemplary method for
controlling the UAV to land on a landing platform according to
another embodiment.
[0017] FIG. 8 is a block diagram of an exemplary landing control
apparatus according to another embodiment.
[0018] The same reference numbers will be used throughout the
drawings to refer to the same or like parts.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0019] Embodiments of the disclosure will be described, by way of
example only, with reference to the accompanying drawings. The
described embodiments are only a part of the embodiments of the
present disclosure, but not all of the embodiments. The components
of embodiments of the present disclosure, which are generally
described and illustrated in the accompanying drawings, may be
arranged and designed in a variety of different configurations.
Accordingly, the following detailed description of embodiments of
the disclosure provided in the drawings is not intended to limit
the scope of the claimed disclosure, but merely to indicate
selected embodiments of the disclosure. All other embodiments
obtained by those skilled in the art without the inventive effort
are within the scope of the present disclosure.
[0020] It should be noted the same reference numbers will be used
throughout the drawings to refer to the same or like parts. Thus,
once an item is defined in a drawing, it is not necessary to
further define and explain it in the subsequent drawings. It should
be noted that relational terms, such as first and second, are used
solely to a separate operating entity from another entity, and do
not necessarily require or imply that the actual such relationship
or order exist between these entities or operations.
[0021] FIG. 1 illustrates a diagram of an exemplary UAV landing
system environment.
[0022] As shown in FIG. 1, a landing control apparatus 100, a UAV
200 and a remote controller 300 are provided in the UAV landing
system environment. A user may send instructions to the UAV 200
through a button on the remote controller 300. The remote
controller 300 may be a mobile phone, a computer, a remote control
and other terminal equipment. In other embodiments, the user may
also send instructions to the UAV 200 through voice commands,
gesture commands or the like. The landing control apparatus 100 may
be mounted on the UAV 200 to control the UAV 200 to land on a
landing platform.
[0023] FIG. 2 is a block diagram schematically illustrating the UAV
200 in the environment of FIG.1.
[0024] As depicted in FIG.2, the UAV 200 includes a memory 210, a
processor 220, an input and output (I/O) unit 230, a function
device 240 and a power unit 250. The memory 210, the processor 220,
the I/O unit 230, the function device 240 and the power unit 250
are directly or indirectly connected to each other to achieve data
transmission or exchange. For example, these elements may be
electrically connected to each other via one or more communication
buses or signal lines. The landing control apparatus 100 may
include at least one software function module in a form of software
or firmware stored in the memory 210 or the processor 220. The
processor 220 is used for performing executable modules stored in
the memory 210, such as software modules or computer programs
included in the landing control apparatus 100. After receiving the
execution instruction, the processor 220 executes programs included
in executable software function module. The method executable by
the UAV disclosed in any embodiment of the present disclosure can
be applied in the processor 220, or implemented by the processor
220.
[0025] The memory 210 is used to store various types of data of the
UAV 200. The memory 210 may be an internal memory of the UAV 200,
or a removable memory. For example, the memory 210 may be, but not
limited to, random access memory (RAM), read only memory (ROM),
programmable read-only memory (PROM), erasable read only memory
(EPROM), electrically erasable read only memory (EEPROM) and the
like.
[0026] The processor 220 may be an integrated circuit chip with the
signal processing capability. The processor 220 as described may be
a general purpose processor, including a central processor (CPU), a
network processor (NP). The processor 220 can also be a digital
signal processor (DSP), application specific integrated circuit
(ASIC), Field-programmable gate array (FPGA) or other programmable
logic device, discrete gate or transistor logic, discrete hardware
components. The processor 220 can execute or implement methods,
steps and logic diagrams disclosed in embodiments of the present
disclosure. The processor 220 may be a microprocessor or any
conventional processor, etc.
[0027] The I/O unit 230 is used to receive data transmitted through
wire or wireless path from a control terminal of the UAV 200, or
the I/O unit 230 is used to transmit data of the UAV 200 through
wire or wireless path to the control terminal of the UAV 200, so as
to achieve interactions between the control terminal and the UAV
200.
[0028] The function device 240 may include a distance monitoring
module, an ultrasonic sensor, an image capturing device, a speed
monitoring module, an LED light and the like. The function device
is used for the UAV 200 performing specific missions (for example,
monitoring the landing platform, taking pictures, flashing lights,
etc.)
[0029] The power unit 250 may include an electronic speed governor,
a motor, a rotor and the like. The electronic speed governor is
electrically connected with the motor, and the rotor is mounted on
the motor. The electronic speed governor may receive a signal
transmitted from the processor 220 and control the motor to rotate,
so as to drive the rotor to rotate. The electronic speed governor
may obtain a rotation speed of the motor, and feed back the
rotation speed of the motor to the landing control apparatus
100.
[0030] In some embodiments, the UAV 200 may have more or fewer
components than those described above, but the present disclosure
is not limited herein.
[0031] FIG. 3 illustrates a flow chart of a method for controlling
the UAV 200 of FIG. 1 to land on a landing platform according to an
embodiment. Referring to FIG. 3, the method includes Steps
S310-S330.
[0032] In Step S310, a landing preparatory signal is received,
wherein the landing preparatory signal is used to instruct the UAV
200 to enter into a landing preparatory state.
[0033] In some embodiments, the user may send a landing preparatory
signal to the UAV 200. The landing preparatory signal may be input
by the user triggering a button on the remote controller 300,
sending a voice command, performing a specific action in a
capturing area of an image capturing device mounted on the UAV 200,
or the like. The inputting manner of the landing preparatory signal
is not limited by embodiments of the present disclosure.
[0034] Specifically, as to inputting the landing preparatory signal
by triggering a button on a remote controller, the user may trigger
the button on the remoter controller 300 of FIG. 1 to generate the
landing preparatory signal. Then, the landing preparatory signal is
transmitted to the UAV 200 through a wireless network and is
received by an antenna of the UAV 200. In an embodiment, the
landing preparatory signal is triggered in a one-touch triggering
manner, that is, the user only needs to touch one button on the
remote controller 300 to trigger the landing preparatory signal,
and then the UAV 200 may automatically perform subsequent
actions.
[0035] As to inputting the landing preparatory signal by voice
control, the UAV 200 may directly receive a specific voice command
(for example, "landing preparation", "preparation for landing",
etc.) input by the user. The UAV 200 may receive the voice command
through a voice sensor, convert the voice command to a landing
preparatory signal and transmit the landing preparatory signal to
the landing control apparatus 100.
[0036] As to inputting the landing preparatory signal through a
specific gesture, the user may perform a specific action (for
example, swinging his palm up and down, or other gestures) in a
capturing area of an image capturing device mounted on the UAV 200.
The image capturing device may take the recognized specific action
as the landing preparatory signal, and send the landing preparatory
signal to the landing control apparatus 100.
[0037] Further, in some embodiments, before the user sends the
landing preparatory signal to the UAV 200, the UAV 200 may be
positioned at a preset position with a preset landing height. For
example, the remote controller 300 may be used to control the UAV
200 to fly to the preset landing height, such as a height similar
to the head of the user (e.g., 2 meters from the ground, etc.), and
the UAV 200 will be controlled to hover to get ready for landing.
The preset landing height can be set according to actual needs, and
is not limited by the above embodiments.
[0038] In some embodiments, the landing preparatory signal is send
to the UAV 200 first, and after receiving the landing preparatory
signal, the UAV 200 will enter into a standby state. Then the UAV
200 is controlled to fly to a preset position with the preset
landing height. For example, when the user inputs the landing
preparatory signal in the voice control manner, the UAV 200 is
initially flying at a relatively high height. Then the user may use
the remote controller 300 to control the UAV 200 to fly down to the
preset position with the preset landing height, and to stay in a
hovering state. In some embodiments, after receiving the landing
preparatory signal, the UAV 200 still responds to control
instructions sent by the remote controller 300. The actions
performed by the UAV 200 are not limited by embodiments of the
present disclosure. For example, the UAV 200 may perform a landing
operation in response to an instruction sent by the remote
controller 300, yet does not stay in a hovering state.
[0039] Before receiving the landing preparatory signal, the UAV 200
may be in a descending state, a hovering state, a flying state or
other states, which is not limited by embodiments of the present
disclosure.
[0040] Further, after receiving the landing preparatory signal, the
UAV 200 enters into a landing preparatory state. In the landing
preparatory state, the UAV 200 may send a warning signal to remind
the user that the UAV 200 has entered into the landing preparatory
state. In some embodiments, a warning device may be an existing LED
lamp mounted on the UAV 200. For example, when the UAV 200 is in a
normal flight, the LED lamp is green, but after the UAV 200
receives the landing preparatory signal and enters the landing
preparatory state, the LED lamp becomes red and flashes. In some
embodiments, the warning device may be a warning lamp other than
the existing LED lamp, or a voice alarm. Taking a warning lamp as
an example, when the UAV 200 is in a normal flight, the warning
lamp is green, but after the UAV 200 receives the landing
preparatory signal and enters the landing preparatory state, the
warning lamp becomes red and flashes. Taking a voice alarm as an
example, after the UAV 200 receives the landing preparatory signal
and enters the landing preparatory state, the voice alarm may send
a voice signal, such as "landing is about to take place", etc. It
should be noted that the warning system can be set according to
actual needs, and the person skilled in the art can change the
warning mode of the warning system.
[0041] As shown in FIG. 3, in Step S320, it monitors the landing
platform to generate a monitoring signal in response to the landing
preparatory signal.
[0042] The landing platform may be a palm of the user's hand or
other platforms (for example, a plate, a book or other objects held
by the user). The landing platform may stay below the UAV 200 at
all time, or it may be merely moved below the UAV 200 by the user
at an appropriate time for the landing of the UAV 200.
[0043] In step S320, the landing platform is monitored to generate
a monitoring signal, which is used to determine whether the landing
platform is ready for landing.
[0044] Specifically, a distance monitoring module, a speed
monitoring module, an image acquiring module or an inertial
measurement module mounted on the UAV 200 may be employed to
monitor the landing platform and generate a monitoring signal.
[0045] For example, the distance monitoring module or the image
acquiring module may be controlled to detect a vertical distance
between the UAV 200 and the landing platform, and the speed
monitoring module may be controlled to detect a speed variation of
the UAV 200 with respect to the landing platform. Then, the
vertical distance between the UAV 200 and the landing platform, and
the speed variation of the UAV 200 with respect to the landing
platform may be taken as the monitoring signal.
[0046] In Step S330, it is determined whether to control the UAV
200 to enter into a landing mode based on the monitoring
signal.
[0047] Specifically, in Step S330, it is determined whether the
landing platform meets a preset condition based on the monitoring
signal. The preset condition indicates the landing platform is
ready for landing the UAV 200. For example, the preset condition
may indicate that a vertical distance between the UAV 200 and the
landing platform is smaller than or equal to a preset threshold
distance, or a speed variation of the UAV 200 with respect to the
landing platform is greater than a preset speed variation
threshold. If the monitoring signal indicates the landing platform
meets the preset condition, it is determined the landing platform
has been prepared for landing, and the UAV 200 is controlled to
enter into the landing mode.
[0048] In some embodiments, the UAV 200 includes at least one
rotor. During the landing mode, the landing control apparatus 100
may control the at least one rotor of the UAV 200 to stop rotating,
such that the UAV 200 lands on the landing platform in a free-fall
manner. In some embodiments, the landing control apparatus 100 may
control the at least one rotor of the UAV 200 to rotate at a
smaller speed, such that the UAV 200 lands on the landing platform
at a predetermined speed. In the above embodiments, in the landing
mode, all the rotors of the UAV 200 are controlled to stop rotating
or rotate at a smaller speed. The UAV 200 may include one or more
rotors. That is, the one or more rotors of the UAV 200 are all
controlled to stop rotating or rotate at a smaller speed. After the
UAV 200 has landed on the landing platform, the landing control
apparatus 100 control the at least one rotor of the UAV 200 to stop
rotating. Further, during the landing mode, the landing control
apparatus 100 may also change a flying attitude of the UAV 200, and
then control the UAV 200 to land on the landing platform. It could
be understood that, the above-mentioned embodiments are merely
specific embodiments, and may be modified according to actual
needs.
[0049] FIG. 4 illustrates a flow chart of another exemplary method
for controlling the UAV 200 of FIG. 1 to land on a landing platform
according to another embodiment of the present disclosure.
[0050] Step S410 in FIG. 4 is substantially identical to Step S310
in FIG. 3, which will not be elaborated here.
[0051] In Step S420, a vertical distance between the UAV 200 and
the landing platform is monitored.
[0052] In one example, a distance monitoring module may be employed
to monitor the landing platform. Specifically, after receiving the
landing preparatory signal, the distance monitoring module is
controlled to monitor a vertical distance, for example, a vertical
distance from the ground to the UAV 200. When the user places a
landing platform below the UAV 200, the vertical distance below the
UAV 200 is reduced quickly (e.g., the vertical distance is changed
from a distance between the UAV 200 and the ground to a distance
between the UAV 200 and the landing platform). After obtaining the
updated vertical distance between the UAV 200 and the landing
platform, the distance monitoring module transmits the vertical
distance to the landing control apparatus 100. In this embodiment,
the vertical distance between the UAV 200 and the landing platform
is a distance in vertical direction between the UAV 200 and the
landing platform. The vertical distance itself might be used as the
monitoring signal.
[0053] In another example, a distance monitoring module, such as an
ultrasonic sensor which has limits of its measuring capability, is
employed to monitor the landing platform. The ultrasonic sensor has
a lower limit of measuring capability, and will output an invalid
signal to indicate that an object is within its minimum measuring
distance. When the user places the landing platform below the UAV
200 and the distance between the UAV 200 and the landing platform
is smaller than the minimum measuring distance, the ultrasonic
sensor cannot output an effective measured distance, but outputs an
invalid signal. Thus, in this embodiment, the invalid signal may be
used as the monitoring signal.
[0054] In another example, an image acquiring module is employed to
monitor the landing platform. The image acquiring module may be a
binocular camera or a monocular camera, and may be disposed
directly below the UAV 200. The image acquiring module is used to
acquire and output an image of the landing platform. When the user
places the landing platform below the UAV 200, if the landing
platform is within the focus range of the image acquiring module,
the image acquiring module can output a clear image; and if the
landing platform is very close to the UAV 200 and the image
acquiring module cannot focus on the landing platform, the image
acquiring module outputs an unclear image. That is, the small
distance between the UAV 200 and the landing platform causes loss
of focus of the image acquiring module. An image corner detection
method may be used to calculate a characteristic value of the
image, so as to determine whether the distance between the UAV 200
and the landing platform causes the loss of focus. Thus, in this
embodiment, the monitoring signal depends on whether the image
output by the image acquiring module is clear.
[0055] In Step S430, it is determined whether the vertical distance
between the UAV 200 and the landing platform is smaller than or
equal to a preset threshold distance.
[0056] If the vertical distance between the UAV 200 and the landing
platform is greater than the preset threshold distance, the method
goes back to Step S420.
[0057] If the vertical distance between the UAV 200 and the landing
platform is smaller than or equal to the preset threshold distance,
the method goes to Step S440 in which the UAV 200 is controlled to
enter into the landing mode.
[0058] The preset threshold distance may be smaller than 40 cm, for
example, 15 cm or 30 cm. Namely, when the distance monitoring
module detects the vertical distance between the UAV 200 and the
landing platform is smaller than the preset threshold distance, it
is determined the landing platform has been prepared for landing,
and Step S440 is performed to control the UAV 200 to enter into the
landing mode.
[0059] Further, the distance monitoring module may be used to
monitor a distance variation of the UAV 200 with respect to the
landing platform, so as to determine whether to control the UAV 200
to enter into the landing mode. For example, before the user places
the landing platform below the UAV 200, a distance between the UAV
200 and the ground is 2 m, but after the user places the landing
platform below the UAV 200, the distance between the UAV 200 and
the landing platform is 0.5 m. Thus, the distance variation
monitored by the distance monitoring module is 1.5 m. If it is
determined the distance variation is greater than a preset distance
variation threshold, the UAV 200 may be controlled to enter into
the landing platform.
[0060] In another example, when the ultrasonic sensor is employed
to monitor the landing platform, it is determined whether the
ultrasonic sensor outputs an invalid signal. Specifically, when the
vertical distance between the UAV 200 and the landing platform is
within the measuring range of the ultrasonic sensor, the ultrasonic
sensor may output an effective (i.e., valid) distance. When the
vertical distance between the UAV 200 and the landing platform is
out of the measuring range of the ultrasonic sensor, the ultrasonic
sensor cannot output an effective distance, but outputs an invalid
signal. If the output of the ultrasonic sensor is changed from the
effective distance to the invalid signal, it can be determined the
landing platform has been prepared for landing, and Step S440 is
performed to control the UAV 200 to enter into the landing
mode.
[0061] In another example, when the image acquiring module is
employed to monitor the landing platform, it is determined whether
the image of the landing platform output by the image acquiring
module meets a predetermined criterion. Specifically, when the
landing platform is very close to the UAV 200, the image acquiring
module cannot focus on the landing platform and cannot output a
clear image meeting the predetermined criterion. Thus, when the
image output by the image acquiring module doesn't meet the
predetermined criterion because the landing platform becomes an
obstacle of the imaging module, it is determined the landing
platform has been prepared for landing, and Step S440 is performed
to control the UAV 200 to enter into the landing mode.
[0062] In Step S440, the UAV 200 is controlled to enter into the
landing mode, after it is determined the vertical distance between
the UAV 200 and the landing platform is smaller than or equal to
the preset threshold distance.
[0063] More details about Step S440 may refer to the description of
Step S330 in FIG. 3, and is not described in detail herein.
[0064] FIG. 5 illustrates a flow chart of another exemplary method
for controlling the UAV 200 of FIG. 1 to land on a landing platform
according to another embodiment of the present disclosure.
[0065] Step S510 in FIG. 5 is substantially identical to Step S310
in FIG. 3, which will not be elaborated here.
[0066] In Step S520, a speed variation of the UAV 200 with respect
to the landing platform is monitored.
[0067] In one example, a speed monitoring module is employed to
monitor speed variation of the UAV 200, e.g., with respect the
landing platform. The speed monitoring module may be used to
monitor a vertical descending speed of the UAV 200. Specifically,
the speed monitoring module may be used to monitor a vertical
descending speed of the UAV 200 with respect to the landing
platform. The vertical descending speed of the UAV 200 is a speed
of the UAV 200 in the vertical downward direction. In a process the
UAV 200 is descending at a preset speed, if the user places the
landing platform below the UAV 200 and holds up the descending UAV
200 quickly, the UAV 200 contacts the landing platform and there
will be a sudden change in the vertical descending speed of the UAV
200. Moreover, the airflow generated by the rotor of the UAV 200
may also be reflected by the landing platform, and has a reverse
effect on the descending of the UAV 200. Thus, a downward
acceleration of the UAV 200 may be abruptly reduced, or even
changed into an upward acceleration. It should be noted that, the
sudden change of the vertical descending speed refers to a
situation that the vertical descending speed of the UAV 200 changes
from the preset descending speed to a speed smaller than a
threshold speed, for example, 0.05 m/s.
[0068] In some embodiments, the speed monitoring module may be an
acceleration monitoring module, a GPS sensor, an ultrasonic sensor,
a barometer or the like. For example, the vertical descending speed
of the UAV 200 may be obtained by accelerometer integration. Since
a drift problem is present in the accelerometer, a long integration
process will lead to a big deviation to the speed. Thus, other
sensors may be used to address the deviation. For example, an
instantaneous motion speed of the UAV 200 can be obtained through
GPS, an ultrasonic sensors or a barometer are used to address the
integration deviation of the accelerometer to get a more accurate
speed of the UAV 200. Specific adaptions may be implemented by
Kalman filter algorithm. Kalman filter algorithm would give a
better estimate of the vertical descending speed of the UAV 200 by
combining instantaneous vertical descending speed outputs from the
accelerometer, the GPS and the ultrasonic sensors. In this
embodiment, the vertical descending speed of the UAV 200 is the
monitoring signal.
[0069] In Step S530, it is determined whether a speed variation of
the UAV 200 with respect to the landing platform is greater than a
preset speed variation threshold.
[0070] If the speed variation of the UAV 200 with respect to the
landing platform is smaller than or equal to a preset speed
variation threshold, it goes back to Step S520.
[0071] If the speed variation of the UAV 200 with respect to the
landing platform is greater than a preset speed variation
threshold, Step S540 is performed.
[0072] In one example, when the speed monitoring module is employed
to monitor the landing platform, it is determined whether the speed
variation of the UAV with respect to the landing platform is
greater than a preset speed variation threshold. Specifically, if
the user places the landing platform below the UAV 200 and holds up
the descending UAV 200 quickly, the UAV 200 contacts the landing
platform and there will be a sudden change in the vertical
descending speed of the UAV 200. The speed monitoring module may
output a speed variation of the UAV with respect to the landing
platform. Thus, when the speed variation of the UAV with respect to
the landing platform is greater than the preset speed variation
threshold, it is determined the landing platform has been prepared
for landing, and Step S540 is performed to control the UAV 200 to
enter into the landing mode. In this case, when the UAV 200
contacts the landing platform, the landing control apparatus 100
may directly control the at least one rotor of the UAV 200 to stop
rotating during the landing mode.
[0073] In Step S540, the UAV 200 is controlled to enter into the
landing mode, after it is determined the speed variation of the UAV
200 with respect to the landing platform is greater than the preset
speed variation threshold.
[0074] More details about Step S540 may refer to the description of
Step S330 in FIG. 3, and is not described in detail herein.
[0075] It should be noted that, the distance monitoring module, the
speed monitoring module, the image acquisition module and the like
are only specific examples. The present disclosure is not limited
by the above embodiments. Other monitoring methods may also be
employed as long as it can be determined whether the landing
platform meets the preset condition. Moreover, in the above steps
for determining whether the landing platform meets the preset
conditions, if any one (or one specific) of the preset conditions
is met, the landing platform is determined to be prepared, and the
UAV 200 is controlled to enter into the landing mode.
[0076] In addition to the flow charts shown in FIGS. 3, 4 and 5,
the present disclosure also incorporates certain mechanisms/steps
for UAV's safety considerations, e.g., interruption of landing
operation, restoring the hovering state or flying mode, as
described in details below.
[0077] In some embodiments, after the UAV 200 enters into the
landing mode, the landing control apparatus 100 continues to
monitor the vertical distance between the UAV 200 and the landing
platform. If the vertical distance between the UAV 200 and the
landing platform is greater than the preset threshold distance, the
UAV 200 is controlled to return to a hovering mode or a flying
mode.
[0078] In an example, after the UAV 200 is controlled to enter into
the landing mode, the distance monitoring module is further
controlled to monitor the vertical distance between the UAV 200 and
the landing platform. When the vertical distance between the UAV
200 and the landing platform is greater than the preset threshold
distance, the landing control apparatus 100 may determine the
landing platform has been removed/withdrawn or is no longer
suitable for landing, and it increases the rotation speed of the
rotor to control the UAV to return to a hovering mode or a flying
mode, so as to avoid accidents. In some embodiments, the preset
threshold distance may be smaller than 40 cm, for example, 15
cm.
[0079] In another example, after the UAV 200 is controlled to enter
into the landing mode, the ultrasonic sensor is further controlled
to monitor the vertical distance between the UAV 200 and the
landing platform. When the vertical distance between the UAV 200
and the landing platform is greater than the minimum measuring
distance of the ultrasonic sensor, the output of the ultrasonic
sensor changes from an invalid signal to an effective distance.
Accordingly, the landing control apparatus 100 may determine the
landing platform has been removed/withdrawn or is no longer
suitable for landing, and it increase the rotation speed of the
rotor to control the UAV to return to a hovering mode or a flying
mode.
[0080] In another example, after the UAV 200 is controlled to enter
into the landing mode, the image acquiring module is further
controlled to output the image of the landing platform. When the
image of the landing platform meets the predetermined criterion,
the landing control apparatus 100 may determine the distance
between the UAV 200 and the landing platform becomes large, and the
landing platform has been removed/withdrawn or is no longer
suitable for landing. Thus, the landing control apparatus 100 may
increase the rotation speed of the rotor to control the UAV 200 to
return to a hovering mode or a flying mode.
[0081] In some embodiments, after the UAV 200 enters into the
landing mode, the landing control apparatus 100 monitors a tilting
angle of the UAV 200. If the tilting angle of the UAV 200 is
greater than a preset threshold angle, the UAV 200 is controlled to
return to a hovering mode or a flying mode.
[0082] In an example, after the UAV 200 is controlled to enter into
the landing mode, a real-time detection of altitude of the UAV 200
is performed to get a tilting angle of the UAV 200. Specifically,
the altitude of the UAV 200 can be detected by an inertial
measurement unit (IMU) including gyroscopes and accelerometers.
When the tilting angle of the UAV 200 is greater than a preset
threshold, the landing control apparatus 100 may increase the
rotation speed of the rotor to control the UAV 200 to return to a
hovering mode or a flying mode. The threshold may be set according
to actual needs, such as 60 degrees. When there is a tilt or a flip
to the UAV 200 exceeding the threshold, the landing control
apparatus 100 increases the rotation speed of the rotor, thus
stopping the process of landing.
[0083] FIG. 6 provides a schematic view of the structure of the
landing control apparatus 100 shown in FIG. 1 and FIG. 2.
[0084] As shown in FIG. 6, the landing control apparatus 100 may
include a receiving unit 610, a monitoring unit 620 and a control
unit 630.
[0085] The receiving unit 610 is configured to receive a landing
preparatory signal instructing the UAV 200 to enter into a landing
preparatory state.
[0086] In some embodiments, the user may send a landing preparatory
signal to the UAV 200. The landing preparatory signal refers to an
instruction from the user that instructs the UAV 200 to enter into
a landing preparatory state. The landing preparatory signal may be
input by the user triggering a button on the remote controller 300,
sending a voice command, performing a specific action in a
capturing area of an image capturing device mounted on the UAV 200,
or the like. Then, an antenna, a voice sensor or an image capturing
device mounted on the UAV 200 may be employed to receive the
landing preparatory signal. Thus the receiving unit 610 receives
the landing preparatory signal from the antenna, the voice sensor
or the image capturing device.
[0087] The monitoring unit 620 is configured to monitor the landing
platform to generate a monitoring signal in response to the landing
preparatory signal.
[0088] In some embodiments, the monitoring unit 620 may control a
distance monitoring module, a speed monitoring module, an image
acquiring module or an inertial measurement module mounted on the
UAV 200 (now shown in FIG. 6) to monitor the landing platform and
generate a monitoring signal. The distance monitoring module may be
an ultrasonic sensor, a laser distance measuring sensor, an
infrared distance measuring sensor or the like mounted on the UAV
200.
[0089] When the distance monitoring module or the image acquiring
module is employed to monitor the landing platform, a vertical
distance between the UAV 200 and the landing platform may be
detected. The vertical distance between the UAV 200 and the landing
platform is taken as the monitoring signal to indicate whether the
landing platform meets a preset condition indicating whether the
landing platform is ready for landing the UAV 200.
[0090] When the speed monitoring module is employed to monitor the
landing platform, a speed variation of the UAV 200 with respect to
the landing platform may be detected. The speed variation of the
UAV 200 with respect to the landing platform is taken as the
monitoring signal to indicate whether the landing platform meets a
preset condition.
[0091] The control unit 630 is configured to determine whether to
control the UAV 200 to enter into a landing mode based on the
monitoring signal.
[0092] In some embodiments, the control unit 630 may be a flying
controller of the UAV 200. The control unit 630 is configured to
determine whether the landing platform meets the preset condition
based on the monitoring signal. For example, the preset condition
may be that a vertical distance between the UAV 200 and the landing
platform is smaller than or equal to a preset threshold distance,
or that a speed variation of the UAV 200 with respect to the
landing platform is greater than a preset speed variation
threshold. If the monitoring signal from the monitoring module 620
indicates the landing platform meets the preset condition, the
control unit 630 determines the landing platform has been prepared
for landing, and controls the UAV 200 to enter into the landing
mode.
[0093] For example, the control unit 630 may be configured to
control the UAV 200 to enter into the landing mode when the
vertical distance between the UAV 200 and the landing platform is
smaller than or equal to the preset threshold distance, or when the
speed variation of the UAV 200 is greater than the preset speed
variation threshold.
[0094] In some embodiments, the UAV 200 includes at least one
rotor. During the landing mode, the control unit 630 is further
configured to control the at least one rotor of the UAV 200 to stop
rotating, such that the UAV 200 lands on the landing platform in a
free-fall manner.
[0095] In some embodiments, the control unit 630 is further
configured to control the at least one rotor of the UAV 200 to
rotate at a smaller rotation speed, such that the UAV 200 lands on
the landing platform at a predetermined speed. After the UAV 200
has landed on the landing platform, the control unit 630 is
configured to control the at least one rotor of the UAV 200 to stop
rotating.
[0096] In addition, in some embodiments, for safety considerations,
after the UAV 200 enters into the landing mode, the monitoring unit
620 is further configured to continue to monitor the vertical
distance between the UAV 200 and the landing platform, and the
control unit 630 is further configured to control the UAV 200 to
return to a hovering mode or a flying mode, e.g., when the vertical
distance between the UAV 200 and the landing platform is greater
than the preset threshold distance.
[0097] In some embodiments, after the UAV 200 enters into the
landing mode, the monitoring unit 620 is further configured to
monitor a tilting angle of the UAV 200, and the control unit 630 is
further configured to control the UAV 200 to return to a hovering
mode or a flying mode, when the tilting angle of the UAV 200 is
greater than a preset threshold angle.
[0098] More details about the landing control apparatus 100 may
refer to the description of the above method, and is not described
in detail herein.
[0099] In addition to the above monitoring/landing/determination
operations related to FIG. 3-5, the present invention also proposes
a more comprehensive landing control process. Referring to FIG. 7,
a flow chart of an exemplary method for controlling an UAV 200 to
land on a landing platform is illustrated according to another
embodiment. The method includes Steps S710-S790.
[0100] In Step S710, a landing preparatory signal is received,
wherein the landing preparatory signal is used to instruct the UAV
200 in FIG. 1 to enter into a landing preparatory state.
[0101] Step S710 is substantially identical to Step S310 of FIG. 3,
and will not be elaborated here.
[0102] In Step S720, a current height of the UAV 200 is
obtained.
[0103] The current height of the UAV 200 may be a relative height,
such as a vertical distance between the current position of the UAV
200 and the landing location. Or, the current height can be an
absolute height, if desired. Further, the current height of the UAV
200 may be monitored in real time according to a preset program, or
may be obtained after receiving the landing preparatory signal.
[0104] In Step 730, the current height of the UAV 200 is compared
with a first preset height, and it is determined whether the
current height of the UAV is greater than the first preset
height.
[0105] The first preset height may be set according to actual
needs. In some embodiment, the first preset height ranges from 1.5
m to 3 m. For example, the first preset height may be 2.2 m.
[0106] If the current height of the UAV 200 is greater than the
first preset height, the method goes to Step 740, wherein a first
preset descending process may be performed.
[0107] In Step S740, the first preset descending process is
performed. That is, the UAV 200 is controlled to fly to the first
preset height at a first descending speed.
[0108] If the current height of the UAV 200 is smaller than or
equal to the first preset height, the method goes to Step S750,
wherein the current height of the UAV 200 is further compared with
a second preset height.
[0109] In Step S750, the current height of the UAV 200 is further
compared with a second preset height, and it is determined whether
the current height of the UAV 200 is greater than the second preset
height.
[0110] The second preset height is smaller than the first preset
height, and can be set according to actual needs, such as
structural characteristics of the UAV 200. In some embodiments, the
second preset height ranges from 0.5 m to 1.5 m. For example, the
second preset height may be 0.9 m.
[0111] If the current height of the UAV 200 is greater than the
second preset height, the method goes to Step 760, wherein a second
preset descending process may be performed.
[0112] If the current height of the UAV 200 is smaller than or
equal to the second preset height, the method goes to Step S790,
wherein the UAV 200 is controlled to enter into the landing
mode.
[0113] In Step S760, the second preset descending process is
performed. That is, the UAV 200 is controlled to fly to the second
preset height at a second descending speed, wherein the second
descending speed is smaller than the first descending speed.
[0114] In above steps, different preset descending processes may be
performed according to different heights of the UAV 200 obtained in
Step S720.
[0115] Specifically, when the flying height of the UAV 200 is
higher than the first preset height, it is determined the UAV 200
is at a relatively high position, and thus the UAV 200 performs a
first preset descending process. The first preset descending
process can control the UAV 200 to fly to the first preset height
at a relatively fast speed, so as to reduce the time of the landing
process. The program of the first preset descending process may be
stored in the UAV 200 in advance, in the remote controller 300
shown in FIG. 1 or be available from online storage, which can be
determined according to actual needs.
[0116] The first descending speed may be a vertical descending
speed of the UAV 200, or a speed at which the UAV 200 flies to the
landing location, which can be determined according to actual
needs. The first descending speed may be set by the control unit
630. In this embodiment, the first descending speed is a vertical
descending speed of the UAV 200, and the UAV 200 is controlled to
descend at the first descending speed until it reaches the first
preset height. The first descending speed ranges from 0.2 m/s to 1
m/s, which can be determined according to actual need. For example,
the first descending speed may be 0.5 m/s.
[0117] Further, when the flying height of the UAV 200 is lower than
the first preset height, or when the current height of the UAV 200
obtained in Step S710 is lower than the first preset height, the
UAV 200 performs the second preset descending process, so as to
control the UAV 200 to descend at the second descending speed.
Specifically, the rotation speed of the rotor of the UAV 200 is
decreased to control the UAV 200 to descend at the second
descending speed.
[0118] The second descending speed is smaller than the first
descending speed. The magnitude of the second descending speed may
be determined according to the second preset height. Specifically,
when the second preset height is relatively high, namely, when the
UAV 200 is at a relatively high height, the second descending speed
is selected to be relatively low. When the second preset height is
relatively low, namely, when the UAV 200 is at a relatively low
height, the second descending speed is selected to be relatively
high. Thus, safety concerns to the UAV 200 during landing and the
long time of the landing process can both be addressed.
[0119] In some embodiments, the second descending speed may range
from 0.1 m/s to 0.5 m/s, and can be determined according to actual
needs. In this embodiment, the second descending speed is 0.1 m/s,
so as to ensure the user has enough time to put out his palm or set
the landing platform, and avoid fast speed collision on the user
palm or the landing platform.
[0120] In some embodiments, the second descending process may
further include changing a flying attitude of the UAV 200. For
example, the second descending process may control the UAV 200 to
perform landing preparation operation, such as putting down the
landing support and retracting the sensors. In addition, the second
descending process may control monitoring devices on the UAV 200 to
monitor surrounding environment, and determine whether the
surrounding environment is suitable for landing. It could be
understood that, when the surrounding environment is suitable for
landing, the second descending process can directly control the UAV
200 to land on the landing platform.
[0121] In some embodiments, when the UAV 200 is controlled to fly
to the first preset height at the first descending speed, the UAV
200 may send a landing reminder to the user to remind the user to
prepare the landing platform.
[0122] Specifically, the UAV 200 may set a landing wait signal, so
as to indicate the UAV 200 has entered into a landing wait stage.
When entering into the landing wait stage, the UAV 200 may transmit
a landing-platform preparatory signal wirelessly to the remote
controller 300 through an instruction transmitting module, so as to
control the remote controller 300 to output the landing-platform
preparatory signal. The landing-platform preparatory signal
indicates that the UAV 200 has entered into the landing wait stage,
and reminds the user to put out his hand or prepare other landing
platform. The remote controller 300 may remind the user the UAV 200
has entered into the landing wait stage through lighting, sounds,
images, vibrations, and other means.
[0123] In Step S770, it monitors the landing platform to generate a
monitoring signal in response to the landing preparatory
signal.
[0124] Step S770 is substantially identical to Step S320 of FIG. 3,
and will not be described in detail herein.
[0125] In Step S780, it is determined whether the landing platform
meets a preset condition based on the monitoring signal, wherein
the preset condition is used to indicate whether the landing
platform is ready for landing the UAV 200.
[0126] As described above, the preset condition may be one of the
following: a vertical distance between the UAV 200 and the landing
platform being smaller than or equal to a preset threshold
distance, or a speed variation of the UAV 200 with respect to the
landing platform being greater than a preset speed variation
threshold.
[0127] If the monitoring signal indicates the landing platform
meets the preset condition, the method goes to Step S790, wherein
the UAV 200 is controlled to enter into a landing mode. Otherwise,
the method goes back to Step S770.
[0128] More details about Step S780 may refer to the descriptions
of Step S430 in FIG. 4 and Step S530 in FIG. 5, and are not
described in detail herein.
[0129] In Step S790, the UAV 200 is controlled to enter into the
landing mode.
[0130] Step S790 is substantially identical to Step S440 in FIG. 4
and Step S540 in FIG. 4, and will not be described in detail
herein.
[0131] It should be noted that, in Step S750, if it is determined
the current height of the UAV 200 is smaller than or equal to the
second preset height, it goes to Step S790, wherein the UAV 200 is
directly controlled to enter into the landing mode.
[0132] Additionally or optionally, in Step S790, a third preset
descending process may be performed.
[0133] Specifically, the third descending process may control the
UAV 200 to land on the landing platform at a predetermined speed or
in a free-fall manner. In some embodiments, the third descending
process may control the UAV 200 to descend at a third descending
speed. The third descending speed may be greater or smaller than
the second descending speed. In some embodiments, in the descending
process of the UAV 200, the descending speed of the UAV 200 may be
monitored in real time. When the descending speed of the UAV 200 is
detected to be smaller than 0.1 m/s in a preset period, the rotor
of the UAV 200 may be controlled to stop rotating, and the landing
process is completed. In some embodiments, the third preset landing
process may turn off the power unit of the UAV 200. Thus, the rotor
of the UAV 200 is controlled to stop rotating, such that the UAV
200 may descend in a free-fall manner. In this case, the free-fall
speed may be greater than the second descending speed.
[0134] Referring to FIG. 8, a block diagram of the landing control
apparatus shown in FIG. 1 is illustrated according to an
embodiment.
[0135] As shown in FIG. 8, the landing control apparatus 100 may
include a receiving unit 810, a height obtaining unit 820, a
monitoring unit 830, a control unit 840 and a reminding unit. The
landing control apparatus 100 may be employed to perform the method
shown in FIG. 7.
[0136] The receiving unit 810 is configured to receive a landing
preparatory signal, wherein the landing preparatory signal is used
to instruct the UAV 200 to enter into a landing preparatory
state.
[0137] The height obtaining unit 820 is configured to obtain a
current height of the UAV 200.
[0138] The monitoring unit 830 is configured to monitor the landing
platform to generate a monitoring signal in response to the landing
preparatory signal.
[0139] The control unit 840 is configured to determine whether to
control the UAV 200 to enter into a landing mode based on the
monitoring signal.
[0140] The receiving unit 810, the monitoring unit 830 and the
control unit 840 in FIG. 8 are substantially identical to the
receiving unit 310, the monitoring unit 320 and the control unit
330 in FIG. 3, respectively. Thus, more details about the receiving
unit 810, the monitoring unit 830 and the control unit 840 may
refer to the receiving unit 310, the monitoring unit 320 and the
control unit 330 in FIG. 3, and are not described in detail
herein.
[0141] In some embodiments, the control unit 840 is further
configured to: control the UAV to fly to a first preset height at a
first descending speed when the current height of the UAV 200 is
greater than the first preset height; and control the UAV 200 to
fly to a second preset height at a second descending speed when the
current height of the UAV 200 is smaller than or equal to the first
preset height but is greater than the second preset height, wherein
the second descending speed is smaller than the first descending
speed.
[0142] In some embodiments, during controlling the UAV 200 to fly
to the second preset height at the second descending speed, the
control unit 840 is further configured to control the UAV 200 to
enter into the landing mode if the monitoring signal indicates the
landing platform meets a preset condition.
[0143] In some embodiments, the control unit 840 is further
configured to control the UAV 200 to enter into the landing mode
when the current height of the UAV 200 is smaller than or equal to
the second preset height.
[0144] The reminding unit 850 is configured to send a landing
reminder signal to a user when the control unit 840 controls the
UAV 200 to fly to a first preset height at a first descending
speed, wherein the landing reminder signal is used to remind the
user to prepare the landing platform.
[0145] Moreover, an apparatus for controlling an unmanned aerial
vehicle (UAV) to land on a landing platform is provided in
embodiments of the present disclosure. The apparatus includes: a
processor; and a memory for storing instructions executable by the
processor, wherein, when executing the instruction, the processor
is configured to: receive a landing preparatory signal instructing
the UAV to enter into a landing preparatory state; monitor the
landing platform to generate a monitoring signal in response to the
landing preparatory signal; and determine whether to control the
UAV to enter into a landing mode based on the monitoring
signal.
[0146] More details about the above apparatus may refer to the
description of the above method, and are not described in detail
herein.
[0147] By employing the method and apparatus provided in the
present application, the UAV can be controlled to land on a hand of
the user or other landing platforms, the landing operations are
simplified. As the UAV is controlled to land on the landing
platform, the UAV will not be stained with dust, soil or water on
the ground, and the user doesn't need to pick up the UAV from the
ground.
[0148] Further, the landing operations can be triggered in a
one-touch triggering manner. The user only needs to touch one
button on the remote controller, and then the UAV 200 may
automatically perform subsequent actions. Thus, a control interface
of the remote controller can be simplified.
[0149] Further, after the landing preparatory signal is received,
different preset descending processes may be performed according to
different heights of the UAV. When the UAV is at a relatively high
position, the UAV is controlled to descend at a higher speed; and
when the UAV is at a relatively low position, the UAV is controlled
to descend at a smaller speed. Thus, damage to the UAV during
landing can be reduced or avoided, and the waiting time in the
landing process can be reduced.
[0150] The apparatus and methods disclosed in the embodiments of
the present disclosure can be implemented by other ways. The
aforementioned apparatus embodiments are merely illustrative. For
example, flow charts and block diagrams in the figures show the
architecture and the function operation according to a plurality of
apparatus, methods and computer program products disclosed in
embodiments of the present disclosure. In this regard, each frame
of the flow charts or the block diagrams may represent a module, a
program segment, or portion of the program code. The module, the
program segment, or the portion of the program code includes one or
more executable instructions for implementing predetermined logical
function. It should also be noted that in some alternative
embodiments, the function described in the block can also occur in
a different order as described from the figures. For example, two
consecutive blocks may actually be executed substantially
concurrently. Sometimes they may also be performed in reverse
order, depending on the functionality. It should also be noted
that, each block of the block diagrams and/or flow chart block and
block combinations of the block diagrams and/or flow chart can be
implemented by a dedicated hardware-based systems execute the
predetermined function or operation or by a combination of a
dedicated hardware and computer instructions. Further, the
functional modules disclosed in embodiments of the present
disclosure may be integrated together to form a separate part.
Alternatively, each module can be alone, or two or more modules can
be integrated to form a separate section.
[0151] If the functions are implemented in the form of software
modules and sold or used as a standalone product, the functions can
be stored in a computer readable storage medium. Based on this
understanding, the technical nature of the present disclosure, part
contributing to the prior art, or part of the technical solutions
may be embodied in the form of a software product. The computer
software product is stored in a storage medium, including several
instructions to instruct a computer device (may be a personal
computer, server, or network equipment) to perform all or part of
the steps of various embodiments of the present. The aforementioned
storage media include: U disk, removable hard disk, read only
memory (ROM), a random access memory (RAM), floppy disk or CD-ROM,
which can store a variety of program codes.
[0152] It should be noted that relational terms, such as first and
second, are used solely to a separate operating entity from another
entity, and do not necessarily require or imply that the actual
such relationship or order exist between these entities or
operations. Moreover, the term "comprising", "including" or any
other variation thereof are intended to cover a non-exclusive
inclusion, such that processes, methods, articles, or apparatus
including a series of factors includes not only those elements, but
also includes other elements not explicitly listed, or further
includes inherent factors for such processes, methods, articles or
devices. Without more constraints, elements defined by the
statement "includes a " does not exclude the presence of other
elements included in the processes, methods, articles or
devices.
[0153] Further, other embodiments will be apparent to those skilled
in the art from consideration of the specification and practice of
one or more embodiments of the disclosure disclosed herein. Any
modifications, equivalent substitutions, improvements and the like
within the spirit and principles of the present disclosure are
intended to be included within the scope of the present disclosure.
It is intended, therefore, that this disclosure and the examples
herein be considered as exemplary only, with a true scope and
spirit of the disclosure being indicated by the following listing
of exemplary claims.
* * * * *