U.S. patent application number 14/257955 was filed with the patent office on 2015-10-01 for assisted takeoff.
This patent application is currently assigned to SZ DJI TECHNOLOGY CO., LTD. The applicant listed for this patent is SZ DJI TECHNOLOGY CO., LTD. Invention is credited to Xu Yang Pan, Jun Shi.
Application Number | 20150274309 14/257955 |
Document ID | / |
Family ID | 53696554 |
Filed Date | 2015-10-01 |
United States Patent
Application |
20150274309 |
Kind Code |
A1 |
Shi; Jun ; et al. |
October 1, 2015 |
ASSISTED TAKEOFF
Abstract
Systems, methods, and devices are provided for assisted takeoff
of an aerial vehicle. The aerial vehicle may takeoff using a first
control scheme and switch to a second control scheme for normal
flight when a takeoff threshold is met. The first control scheme
optionally does not use integral control while the second control
scheme may use integral control. The aerial vehicle may determine
that a takeoff threshold is met, based on an output to a motor of
the aerial vehicle and/or an acceleration of the aerial
vehicle.
Inventors: |
Shi; Jun; (Shenzhen City,
CN) ; Pan; Xu Yang; (Shenzhen City, CN) |
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Applicant: |
Name |
City |
State |
Country |
Type |
SZ DJI TECHNOLOGY CO., LTD |
Shenzhen City |
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CN |
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Assignee: |
SZ DJI TECHNOLOGY CO., LTD
Shenzhen City
CN
|
Family ID: |
53696554 |
Appl. No.: |
14/257955 |
Filed: |
April 21, 2014 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
PCT/CN2014/074232 |
Mar 27, 2014 |
|
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14257955 |
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Current U.S.
Class: |
244/63 |
Current CPC
Class: |
B64C 39/024 20130101;
B64C 2201/14 20130101; G05D 1/042 20130101; G05B 11/42 20130101;
B64C 2201/024 20130101; B64C 2201/108 20130101; B64C 29/00
20130101; B64D 31/06 20130101; G05D 1/0669 20130101; B64C 27/00
20130101 |
International
Class: |
B64D 31/06 20060101
B64D031/06; B64C 27/00 20060101 B64C027/00; B64C 39/02 20060101
B64C039/02; B64C 29/00 20060101 B64C029/00; B64D 27/00 20060101
B64D027/00 |
Claims
1. A method of assisted takeoff of an aerial vehicle, said method
comprising: increasing output to an actuator of the aerial vehicle
under a first control scheme, wherein the output to the actuator
results in the increase of an altitude of the aerial vehicle;
determining, with aid of a processor, whether the aerial vehicle
has met a takeoff threshold based on the output to the actuator,
the output measured from the actuator, or velocity or acceleration
of the aerial vehicle, wherein determining whether the aerial
vehicle has met the takeoff threshold is performed without (1)
using signals from a source external to the aerial vehicle, or (2)
using signals reflected to the aerial vehicle; and controlling the
output to the actuator using a second control scheme when the
aerial vehicle has met the takeoff threshold.
2. The method of claim 1, wherein the aerial vehicle is capable of
vertically taking off and/or landing.
3. The method of claim 1, wherein the first control scheme is a
first integral feedback control scheme.
4. The method of claim 3, wherein an integral value under the first
integral feedback control scheme is set to a default value.
5. The method of claim 4, wherein the default value is zero.
6. The method of claim 1, further comprising receiving a command to
increase the altitude of the aerial vehicle.
7. The method of claim 6, wherein the command is provided by a
remote terminal.
8. The method of claim 6, further comprising, prior to receiving
the command to increase the altitude of the aerial vehicle,
receiving a command to start the actuator and placing the actuator
in an idle mode.
9. The method of claim 8, further comprising reducing the output to
the actuator until the actuator is in an idle mode when the command
to increase the altitude does not exceed a predetermined value.
10. The method of claim 1, wherein the second control scheme is a
second integral feedback control scheme.
11. The method of claim 10, wherein controlling the output to the
actuator using the second integral feedback control scheme includes
integral control of the vertical direction.
12. The method of claim 1, wherein determining whether the aerial
vehicle has met the takeoff threshold based on the degree of the
output to the actuator includes determining that the aerial vehicle
has met the takeoff threshold when the degree of the output to the
actuator exceeds a predetermined output value.
13. The method of claim 1, wherein the aerial vehicle is an
unmanned aerial vehicle comprising a plurality of rotors configured
to generate lift for the aerial vehicle.
14. The method of claim 1, wherein determining whether the aerial
vehicle has met the takeoff threshold based on the output to the
actuator or the output measured from the actuator.
15. The method of claim 1, wherein the takeoff threshold is met
when (1) the output to the actuator is greater than a first
predetermined output value and when acceleration of the aerial
vehicle in a vertical direction exceeds a predetermined
acceleration value, or (2) the output to the actuator is greater
than a second predetermined output value.
16. The method of claim 15 wherein the takeoff threshold is met
when (2) the output to the actuator is greater than the second
predetermined output value, and wherein the second predetermined
output value is different from the first predetermined output
value.
17. The method of claim 16, wherein the takeoff threshold is met
when (2) the output to the actuator is greater than the second
predetermined output value, and wherein the second predetermined
output value is greater than the first predetermined output
value.
18. A system for assisted takeoff of an aerial vehicle, said system
comprising: an actuator of the aerial vehicle, wherein an output to
the actuator results in the increase of an altitude of the aerial
vehicle; and one or more processors, individually or collectively
configured to: (a) determine whether the aerial vehicle has met a
takeoff threshold based on the output to the actuator, the output
measured from the actuator, or velocity or acceleration of the
aerial vehicle, wherein said determination whether the aerial
vehicle has met the takeoff threshold is performed without (1)
using signals from a source external to the aerial vehicle, or (2)
using signals reflected to the aerial vehicle, and (b) generate a
signal used to control the output to the actuator (1) using a first
control scheme when the aerial vehicle has not met the takeoff
threshold, and (2) using a second control scheme when the aerial
vehicle has met the takeoff threshold.
19. The system of claim 18, wherein the processor is on-board the
aerial vehicle.
20. The system of claim 18, wherein the processor is provided on an
external device separate from the aerial vehicle.
21. The system of claim 18, wherein the aerial vehicle is capable
of vertically taking off and/or landing.
22. The system of claim 18, wherein the aerial vehicle is an
unmanned aerial vehicle comprising a plurality of rotors configured
to generate lift for the aerial vehicle.
23. The system of claim 22, wherein the unmanned aerial vehicle is
a rotorcraft.
24. The system of claim 18, wherein the actuator is a motor driving
a propulsion unit of the aerial vehicle.
25. The system of claim 18, wherein the first control scheme is a
first integral feedback control scheme.
26. The system of claim 25, wherein an integral value under the
first integral feedback control scheme is set to a default
value.
27. The system of claim 18, wherein the second control scheme is a
second integral feedback control scheme including integral control
of the vertical direction.
28. The system of claim 18, wherein the takeoff threshold is met
when one or more of the following conditions are met: (1) an output
to the actuator is greater than a first predetermined output value
and when acceleration of the aerial vehicle in a vertical direction
exceeds a predetermined acceleration value, or (2) the output to
the actuator is greater than a second predetermined output
value.
29. The system of claim 18 further comprising a receiver configured
to receive a command to increase an altitude of the aerial
vehicle.
30. The system of claim 18 wherein the processor determines whether
the aerial vehicle has met the takeoff threshold based on the
output to the actuator or the output measured from the actuator.
Description
CROSS-REFERENCE
[0001] This application is a continuation application of
International Application No. PCT/CN2014/074232, filed on Mar. 27,
2014, the content of which is hereby incorporated by reference in
its entirety.
BACKGROUND OF THE INVENTION
[0002] Aerial vehicles such as unmanned aerial vehicles can be used
for performing surveillance, reconnaissance, and exploration tasks
for military and civilian applications. Such vehicles may carry a
payload configured to perform a specific function. These aerial
vehicles may take off and land on a surface.
[0003] However, when traditionally controlled aerial vehicles take
off from a surface, the feedback control systems used combined with
the force provided by the surface can cause initial instability.
Particularly, when a surface is sloped, the takeoff may not be
vertical, and there may be a greater probability of crashing or
falling over. The takeoff often presents a challenge for users,
particularly inexperienced users, and if the aircraft is
uncontrolled or unstable during takeoff, users will become nervous
and cause the aircraft to crash.
SUMMARY OF THE INVENTION
[0004] In some instances, it may be desirable to use takeoff
methods which may permit an aerial vehicle takeoff to be
substantially smooth and vertical. Thus, a need exists for improved
takeoff methods. The present invention provides systems, methods,
and devices related to takeoff controls for the aerial vehicle.
Existing proportional-integral-derivative (PID) controllers, due to
memory effects of integration, will result in a ground force, which
may cause the integration expression to be wrong and cause
instability. The invention permits the elimination of integration
during takeoff, until the aerial vehicle is determined to have left
the ground. Control systems and methods described herein may
directly output analog takeoff control values, and after successful
takeoff, seamlessly switch to a PID control. The determination may
be made when to switch to a PID control scheme based on an output
to one or more motors of the aerial vehicle and/or an acceleration
of the aerial vehicle.
[0005] An aspect of the invention is directed to a method of
assisted takeoff of a movable object, said method comprising:
increasing output to an actuator of the movable object under a
first control scheme, wherein the output to the actuator results in
the increase of an altitude of the movable object; determining,
with aid of a processor, whether the movable object has met a
takeoff threshold based on the output to the actuator, the output
measured from an actuator, or velocity or acceleration of the
movable object; and controlling the output to the actuator using a
second control scheme when the movable object has met the takeoff
threshold.
[0006] In some embodiments, the movable object may be an aircraft
capable of vertically taking off and/or landing. The movable object
may be an unmanned aerial vehicle. The unmanned aerial vehicle may
be a rotorcraft. The actuator may be a motor driving a propulsion
unit of the movable object. The propulsion unit may be a rotor
configured to provide lift to the movable object.
[0007] The first control scheme may be a first integral control
scheme. An integral value under the first integral control scheme
may be set to a default value. In some implementations, the default
value may be zero.
[0008] The output may be increased by a constant value. Increasing
the output to the actuator may result in increasing overall
propulsion of the movable object. The command may be provided by a
remote terminal. Prior to receiving the command to increase the
altitude of the movable object, a command may be received to start
the actuator and placing the actuator in an idle mode. The method
may also include reducing the output to the actuator until the
actuator is in an idle mode when the command to increase the
altitude does not exceed a predetermined value.
[0009] Optionally, the second control scheme may be a second
integral control scheme. Controlling the output to the actuator
using the second integral control scheme may include integral
control of the vertical direction. Controlling the output to the
actuator using the second integral control scheme may include
integral control over one or more of the following: front
direction, rear direction, right direction, left direction, or
attitude. In some cases, controlling the output to the actuator
using the second integral control scheme may include using a
proportional-integral-derivative control scheme.
[0010] Determining whether the movable object has met the takeoff
threshold may be based on the degree of output to the actuator.
Determining whether the movable object has met the takeoff
threshold based on the degree of the output to the actuator may
include determining that the movable object has met the takeoff
threshold when the degree of the output to the actuator exceeds a
predetermined output value. Determining whether the movable object
has met the takeoff threshold may also be based on a measured
velocity or acceleration of the movable object, measured altitude,
or output measured from the actuator. Optionally, determining
whether the movable object has met the takeoff threshold does not
depend on signals received from a source external to the movable
object.
[0011] In some instances, the takeoff threshold is met when (1) the
output to the actuator is greater than a first predetermined output
value and acceleration of the movable object in a vertical
direction exceeds a predetermined acceleration value, or (2) the
output the actuator is greater than a second predetermined output
value. The second predetermined output value may be different from
the first predetermined output value. The second predetermined
output value may be greater than the first predetermined output
value.
[0012] Another aspect of the invention may be directed to a system
for assisted takeoff of a movable object, said system comprising: a
receiver configured to receive a command to increase an altitude of
the movable object; an actuator of the movable object, wherein the
output to the actuator results in the increase of the altitude of
the movable object; and a processor configured to determine whether
the movable object has met a takeoff threshold based on the output
to the actuator, output measured from the actuator, or velocity or
acceleration of the movable object, and generate a signal used to
control the output to the actuator (1) using a first control scheme
when the movable object has not met the takeoff threshold, and (2)
using a second control scheme when the movable object has met the
takeoff threshold.
[0013] The processor may be on-board the movable object.
Alternatively, the processor may be provided on an external device
separate from the movable object.
[0014] In some embodiments, the movable object may be an aircraft
capable of vertically taking off and/or landing. The movable object
may be an unmanned aerial vehicle. The unmanned aerial vehicle may
be a rotorcraft. The actuator may be a motor driving a propulsion
unit of the movable object. The propulsion unit may be a rotor
configured to provide lift to the movable object.
[0015] The first control scheme may be a first integral control
scheme. An integral value under the first integral control scheme
may be set to a default value. In some implementations, the default
value may be zero.
[0016] The output may be increased by a constant value. Increasing
the output to the actuator may result in increasing overall
propulsion of the movable object. The command may be provided by a
remote terminal. The receiver may be configured to receive a
command to start the actuator and place the actuator in an idle
mode, prior to receiving the command to increase the altitude of
the movable object. The output to the actuator may be reduced until
the actuator is in an idle mode when the command to increase the
altitude does not exceed a predetermined value.
[0017] The second control scheme may be a second integral control
scheme. The second integral control scheme may include integral
control of the vertical direction. The second integral control
scheme may include integral control over one or more of the
following: front direction, rear direction, right direction, left
direction, or attitude. The second integral control scheme may
include a proportional-integral-derivative control scheme.
[0018] The processor may determine that the movable object has met
the takeoff threshold when the degree of the output to the actuator
exceeds a predetermined output value. In some implementations, the
processor determines whether the movable object has met the takeoff
threshold based on a measured velocity or acceleration, measured
altitude, or measured output from the actuator of the movable
object. The processor may determine whether the movable object has
met the takeoff threshold without relying on signals received from
a source external to the movable object.
[0019] In some embodiments, the takeoff threshold is met when (1)
the output to the actuator is greater than a first predetermined
output value and acceleration of the movable object in a vertical
direction exceeds a predetermined acceleration value, or (2) the
output the actuator is greater than a second predetermined output
value. The second predetermined output value may be different from
the first predetermined output value. The second predetermined
output value may be greater than the first predetermined output
value.
[0020] A method of assisted takeoff of a movable object may be
provided in accordance with another aspect of the invention. The
method may comprise: increasing output to an actuator of the
movable object under a first control scheme; determining, with aid
of a processor, whether (1) the output to the actuator is greater
than a first predetermined output value and when acceleration of
the movable object in a vertical direction exceeds a predetermined
acceleration value, or (2) the output to the actuator is greater
than a second predetermined output value; and controlling the
output to the actuator by using a second control scheme different
from the first control scheme when (1) the output to the actuator
is greater than a first predetermined output value and when
acceleration of the movable object in a vertical direction exceeds
a predetermined acceleration value, or (2) the output to the
actuator is greater than a second predetermined output value.
[0021] In some embodiments, the movable object may be an aircraft
capable of vertically taking off and/or landing. The movable object
may be an unmanned aerial vehicle. The unmanned aerial vehicle may
be a rotorcraft. The actuator may be a motor driving a propulsion
unit of the movable object. The propulsion unit may be a rotor
configured to provide lift to the movable object.
[0022] The output may be increased by a constant value. Increasing
the output to the actuator may result in increasing overall
propulsion of the movable object. The method may also include
receiving a command to increase an altitude of the movable object.
The command may be provided by a remote terminal. Prior to
receiving the command to increase an altitude of the movable
object, a command may be received to start the actuator and placing
the actuator in an idle mode. The method may include reducing the
output to the actuator until the actuator is in an idle mode when
the command to increase the altitude does not exceed a
predetermined value.
[0023] The first control scheme may use an integral value that is
set to a default value. The default value may be zero. The second
control scheme may use integral control of the vertical direction.
Controlling the output to the actuator using integral control may
includes integral control over one or more of the following: front
direction, rear direction, right direction, left direction, or
attitude. Controlling the output to the actuator by using the
second control scheme may include using a
proportional-integral-derivative control scheme.
[0024] The second predetermined output value may be different from
the first predetermined output value. Optionally, the second
predetermined output value is greater than the first predetermined
output value.
[0025] Furthermore, an aspect of the invention may include a system
for assisted takeoff of a movable object, said system comprising:
an actuator of the movable object; and a processor configured to
determine when one or more of the following conditions are met: (1)
an output to the actuator is greater than a first predetermined
output value and when acceleration of the movable object in a
vertical direction exceeds a predetermined acceleration value, or
(2) the output to the actuator is greater than a second
predetermined output value, and generate a signal used to control
the output to the actuator (a) by using a first control scheme when
neither of the conditions (1) or (2) met, and (b) by using a second
control scheme when at least one of the conditions (1) or (2) are
met.
[0026] The processor may be on-board the movable object.
Alternatively, the processor may be provided on an external device
separate from the movable object.
[0027] Optionally, the movable object may be an aircraft capable of
vertically taking off and/or landing. The movable object may be an
unmanned aerial vehicle. The unmanned aerial vehicle may be a
rotorcraft. The actuator may be a motor driving a propulsion unit
of the movable object. The propulsion unit may be a rotor
configured to provide lift to the movable object.
[0028] The output may be increased by a constant value. Increasing
the output to the actuator may result in increasing overall
propulsion of the movable object. A receiver may be provided that
is configured to receive a command to increase an altitude of the
movable object. The command may be provided by a remote terminal.
The receiver may be configured to receive a command to start the
actuator and placing the actuator in an idle mode, prior to
receiving the command to increase an altitude of the movable
object. The output to the actuator may be reduced until the
actuator is in an idle mode when the command to increase the
altitude does not exceed a predetermined value.
[0029] In some embodiments, the first control scheme may use an
integral value that is set to a default value. The default value
may be zero. The second control scheme may use integral control of
the vertical direction. Controlling the output to the actuator
using integral control may includes integral control over one or
more of the following: front direction, rear direction, right
direction, left direction, or attitude. Controlling the output to
the actuator by using the second control scheme may include using a
proportional-integral-derivative control scheme.
[0030] The second predetermined output value may be different from
the first predetermined output value. Optionally, the second
predetermined output value is greater than the first predetermined
output value.
[0031] It shall be understood that different aspects of the
invention can be appreciated individually, collectively, or in
combination with each other. Various aspects of the invention
described herein may be applied to any of the particular
applications set forth below or for any other types of movable
objects. Any description herein of aerial vehicles, such as
unmanned aerial vehicles, may apply to and be used for any movable
object, such as any vehicle. Additionally, the systems, devices,
and methods disclosed herein in the context of aerial motion (e.g.,
flight) may also be applied in the context of other types of
motion, such as movement on the ground or on water, underwater
motion, or motion in space.
[0032] Other objects and features of the present invention will
become apparent by a review of the specification, claims, and
appended figures.
INCORPORATION BY REFERENCE
[0033] All publications, patents, and patent applications mentioned
in this specification are herein incorporated by reference to the
same extent as if each individual publication, patent, or patent
application was specifically and individually indicated to be
incorporated by reference.
BRIEF DESCRIPTION OF THE DRAWINGS
[0034] The novel features of the invention are set forth with
particularity in the appended claims. A better understanding of the
features and advantages of the present invention will be obtained
by reference to the following detailed description that sets forth
illustrative embodiments, in which the principles of the invention
are utilized, and the accompanying drawings of which:
[0035] FIG. 1 illustrates an aerial vehicle taking off, in
accordance with an embodiment of the invention.
[0036] FIG. 2 illustrates an example of a method for controlling
takeoff of an aerial vehicle, in accordance with an embodiment of
the invention.
[0037] FIG. 3 provides a high level schematic of an aerial vehicle,
in accordance with an embodiment of the invention.
[0038] FIG. 4 illustrates an unmanned aerial vehicle, in accordance
with an embodiment of the invention.
[0039] FIG. 5 illustrates a movable object including a carrier and
a payload, in accordance with an embodiment of the invention.
[0040] FIG. 6 is a schematic illustration by way of block diagram
of a system for controlling a movable object, in accordance with an
embodiment of the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0041] The systems, devices, and methods of the present invention
provide assisted takeoff for an aerial vehicle from a surface,
which enables improved control for a user. The aerial vehicle may
be an unmanned aerial vehicle (UAV), or any other type of movable
object. Oftentimes, a feedback control is used during flight of an
aerial vehicle. During normal flight operations, a
proportional-integral-derivative (PID) flight control system is
often used. However, during takeoff, memory effects of integration
combined with ground forces may cause the meaning of the
integration expression to go wrong. This can cause instability
during takeoff and may require complex maneuvers that many novice
users may not be familiar or comfortable with. This can lead to
crashing of the UAV during takeoff.
[0042] An assisted takeoff system, method, and device may be
provided which may reduce this instability during takeoff and
permit novice users to easily control the aerial vehicle during
takeoff. While the aerial vehicle is taking off, the integral
calculation may be removed from the feedback control. This permits
direct output of analog takeoff control values. After it has been
determined that the aerial vehicle has successfully taken off
(i.e., the aircraft is in mid-air), the feedback control scheme may
be switched to normal flight mode, which may include integral
control (e.g., PID control).
[0043] The switch from one feedback control scheme to another may
be made when it is determined that a takeoff threshold has been
met. This may be determined based on information that is provided
from on-board the aerial vehicle. For instance, the takeoff
threshold may be deemed to be met based on information regarding
output to a motor of the aerial vehicle, and/or acceleration of the
aerial vehicle. For instance, the takeoff threshold may be met when
at least one of the following conditions is met: (1) output to the
motor exceeds a first threshold output value and vertical
acceleration of the aerial vehicle exceeds a threshold acceleration
value, or (2) output to the motor exceeds a second threshold output
value. Thus, the switch in the flight control scheme may be made
from a takeoff control scheme to a normal flight control scheme
when the takeoff threshold is met, indicative of when the aircraft
has fully taken off from the surface, and it is safe to switch to
the normal flight control. In some instances, the switch may be
made without requiring any signals from outside the aerial vehicle.
The aerial vehicle may be self-contained in making the
determination of when to make the switch in control schemes.
[0044] FIG. 1 illustrates an aerial vehicle 100 taking off, in
accordance with an embodiment of the invention. The aerial vehicle
100a may initially be resting on a surface 130 prior to takeoff.
The aerial vehicle may include one or more propulsion units 110a.
The propulsion units may provide lift to the aerial vehicle. When
the aerial vehicle receives a command to take off, it may lift off
of the surface under a first control scheme. When the aerial
vehicle 100b meets a threshold 120 indicative of whether the aerial
vehicle has sufficiently taken off, the aerial vehicle may switch
over to a second control scheme. The propulsion units 110b of the
aerial vehicle may then be controlled on the second control scheme,
which may be different from the first control scheme.
[0045] In some embodiments, the aerial vehicle 100a, 100b may be a
UAV, or any other type of movable object. The aerial vehicle may be
a rotorcraft. The aerial vehicle may have propulsion units 110a,
110b that may be capable of causing the aerial vehicle to move. The
propulsion units may provide lift to the aerial vehicle and permit
the aerial vehicle to change altitude. The propulsion units may
also cause the aerial vehicle to move laterally and/or change
orientation. The position of the aerial vehicle may be controlled
(e.g., altered or maintained) by the propulsion units. The
propulsion units may control the aerial vehicle with respect to one
or more degrees of freedom (e.g., e.g., 1-3 degrees of spatial
disposition, 1-3 degrees of orientation).
[0046] The propulsion units 110a, 110b may be rotors that may be
rotated to provide lift to the aerial vehicle. The rotors may
include one or more rotor blades that may spin about an axis. In
some instances, a single propulsion unit may be provided on an
aerial vehicle. Alternatively, multiple propulsion units may be
provided for an aerial vehicle. For example, one, two, three, four,
five, six, seven, eight, nine, ten or more propulsion units may be
provided on an aerial vehicle. The propulsion units may be driven
by one or more actuators. The actuators may be motors, such as AC
or DC motors. The actuators may respond to a command signal from a
flight controller. The command signal may include output to the
actuators. In some embodiments, each propulsion unit may be driven
by a single actuator. Optionally, an actuator may drive multiple
propulsion units, or a single propulsion unit may be driven by
multiple actuators.
[0047] Initially, prior to taking off, the aerial vehicle 100a may
be supported by a surface 130. The surface may be a ground,
structure, street, turf, water, movable object, living being, or
any type of support. In some instances the surface may be static.
For example, the surface may not be moving to a reference frame,
such as the environment. In some implementations, the surface may
be moving or movable relative to a reference frame, such as the
environment. The surface may or may not change altitude or
orientation.
[0048] In some embodiments, the surface 130 may be substantially
flat. When the aerial vehicle is resting on the surface, a takeoff
axis may be substantially parallel to the direction of gravity g.
In other embodiments, the surface may be sloped. For example, when
the vehicle is resting on the surface, a takeoff axis may be at an
angle relative to the direction of gravity. For example, the angle
may be greater than or equal to about 5 degrees, 10 degrees, 15
degrees, 30 degrees, 45 degrees or 60 degrees. In some instances,
the angle may be less than or equal to about 5 degrees, 10 degrees,
15 degrees, 30 degrees, 45 degrees or 60 degrees.
[0049] The aerial vehicle 100a may receive a command to take off,
and a flight controller may control the flight under a first
control scheme before a takeoff threshold 120 is met, and may
control the flight under a second control scheme after the takeoff
threshold is met. The takeoff threshold may be indicative of when
the aerial vehicle has fully taken off so that the vehicle can
utilize a proportional integral derivative (PID) flight without the
detrimental effects described elsewhere herein. Prior to the
takeoff threshold being met, the aerial vehicle may be in a takeoff
phase. After the takeoff threshold has been met, the aerial vehicle
may be in a flight phase. Thus a two-stage process may be provided
when the aerial vehicle takes off. The takeoff phase may use the
first control scheme. The flight phase may use the second control
scheme.
[0050] In some instances, the first control scheme may be a control
scheme where an integral value is set to a default value. For
example, the default value may be zero, or another default value.
In some alternative implementations, the first control scheme does
not use integral control. The second control scheme may be a
control scheme that does use integral control. In one example, the
first control scheme may use proportional-derivative (PD) control,
or proportional-integral-derivative (PID) control where the
integral value may be set to a default value, such as zero. The
second control scheme may use proportional-integral-derivative
(PID) control. In some embodiments, the first control scheme may
have a PID setup where the integral output is always zero. The
second control scheme may permit the integral output to be turned
on. This may be applicable for both altitude and attitude control.
For example, during a takeoff phase, both the altitude and attitude
control may have an integral value set to a default value, such as
zero. Alternatively, only one of the altitude or attitude control
may have an integral value set to a default value, such as zero.
During a flight phase, both the altitude and attitude control may
use normal integral control.
[0051] The first control scheme may have an integral control scheme
where the integral value is set to zero, or other default value, in
the vertical direction of the aircraft. The first control scheme
may optionally have an integral value set to zero, or other default
value, in the lateral directions of the aircraft. The second
control scheme may use integral control in the vertical direction
of the aircraft. The second control scheme may use integral control
in the lateral directions of the aircraft. Optionally, the first
control scheme may result in the use of PD control for both
vertical and lateral directions of the aircraft. The first control
scheme may use PD control or PID control for attitude control of
the aircraft. Optionally, the second control scheme may result in
the use of PID control for both the vertical and lateral directions
of the aircraft. The second control scheme may use PID control for
attitude control of the aircraft. In some instances, a flight
control scheme may have an integral control that is
I.sub.out=K.sub.i.intg..sub.0.sup.te(.tau.)d.tau.. In one example,
the first integral control scheme may keep I.sub.out as a default
value (e.g., constant numerical value). In some examples, I.sub.out
may be kept at zero. In some instances, I.sub.out may be kept as
the same value. In some instances, I.sub.out may vary by a small
amount. In some instances, I.sub.out may vary in a predetermined
manner. Optionally K.sub.i may be set to zero. In some instances,
the first integral control scheme may be implemented while the
aircraft is in a take-off phase. A second integral control scheme
different from the first integral control scheme may be implemented
while the aircraft is in a flight phase. Normal integral control
may be used.
[0052] In some embodiments, the control scheme that dictates flight
may be determined by a flight controller of an aerial vehicle 100a,
100b. The flight controller may output one or more command signals
in response to the control scheme being used. The command signals
may be provided to one or more actuators that drive the propulsion
units of the aerial vehicle.
[0053] The flight controller may determine which control scheme to
use depending on whether a takeoff threshold 120 has been reached.
The flight controller may make the determination whether the
takeoff threshold has been reached based on one or more sensed
condition or data from one or more sensors. In some instances, a
separate processor (on-board or off-board the aerial vehicle) may
be used to determine whether the takeoff threshold has been met.
The separate processor may provide a signal to the flight
controller indicative of whether the takeoff threshold has been
met. In some instances, once the flight controller has determined
which control scheme to use, it may calculate output to the motors
under the selected control scheme.
[0054] Two different flight control schemes may be used, depending
on the phase of a two-stage takeoff process. In various alternative
implementations, any number of flight control schemes may be
provided for a takeoff process that may have any number of stages.
For example, three flight control schemes, four flight control
schemes, five flight control schemes, six flight control schemes or
more control schemes may be used for multi-stage take off processes
having three, four, five, six or more phases. Any description
herein of a two-control scheme system may apply to any type of
multi-control scheme system. Multi-control scheme systems may have
different threshold points indicating different points in the
takeoff process. The methods described herein to determine when a
takeoff threshold has been met may be applied to any number of
threshold points.
[0055] FIG. 1 shows how after a takeoff threshold 120 has been met,
the aerial vehicle 100b may be clear of the surface 130 and may be
ready to switch to a standard flight mode (e.g., PID control). In
some instances, the takeoff threshold may be related to an altitude
of the aerial vehicle, velocity of the aerial vehicle, acceleration
of the aerial vehicle, output to an actuator of an aerial vehicle,
output measured from an actuator of an aerial vehicle, or any other
characteristic of the aerial vehicle.
[0056] FIG. 2 illustrates an example of a method for controlling
takeoff of an aerial vehicle, in accordance with an embodiment of
the invention.
[0057] Initially, an aerial vehicle may be stationary on a surface
210, such as the ground. This may be prior to starting any motors
of the aerial vehicle. Any description herein of a motor of the
aerial vehicle may apply to any number of motors of the aerial
vehicle, or any other types of actuator of the aerial vehicle that
may be used to drive a propulsion unit.
[0058] A command may be received to start one or more motors of the
aerial vehicle 212. The command may be received from a terminal
remote to the aerial vehicle. For example, a user may select an
option on a remote controller to start a motor of the aerial
vehicle. In some instances, the remote controller may be a
smartphone, tablet, joystick, wearable object (e.g., glasses,
gloves, helmet, wristband), or any other type of terminal as
described in greater detail elsewhere herein. Alternatively, the
command may be received from a terminal local to the aerial vehicle
or built into the aerial vehicle. For example, a user may turn on a
power switch or select an `on` button to turn on the aerial vehicle
and start a motor. In some instances, the command may be generated
by a user remote to the aerial vehicle. Alternatively, the command
may be provided by a user on-board the aerial vehicle.
[0059] The aerial vehicle may determine whether it has received a
command to start a motor 214. If it has not yet received a command,
the vehicle may remain stationary on the surface. If it has
received a command, a flight controller may output an idle motor
value 216. In some embodiments, an aerial vehicle motor may be in
idle mode so that the motor is running without causing any
actuation of a propulsion unit. The motor may be running in idle
mode without any loads except engine accessories.
[0060] The integral output (I) may be set to zero 218. The integral
output may be set to zero once the flight control outputs an idle
motor value 216. In some instances, the integral output may be set
to zero when it has been determined that a command has been
received to start a motor 214. The integral output may be set to
zero while the aerial vehicle is still on the surface (e.g., prior
to taking off). The integral output may be set to zero in all
directions (e.g., vertical, left/right, forward/backward, heading
angle). The I value may be cleared in all directions. In some other
instances, the I value may be set to a default value, such as a
constant numerical value.
[0061] A flight control command may be provided 222. In some
instances, the flight control may be generated by a user. The user
may use a remote terminal, such as that described elsewhere herein.
The same remote terminal may be used to provide a command to start
a motor 212 and provide flight controls 222. Alternatively, the
user may control the flight via one or more controls local to the
aerial vehicle or built-into the aerial vehicle. The flight control
commands may be used to control position of the aerial vehicle. The
flight control commands received may be provided to a flight
controller on-board the aircraft, which may generate one or more
signals for the operation of the motor. The motor may in turn drive
one or more propulsion units, such as a rotor blade, of the aerial
vehicle.
[0062] If the flight control command 222 is greater than a
predetermined value 220, output to the motor may be increased. The
output to the motor may be increased by a constant value 226. If
the flight control command is less than a predetermined value, then
the output to the motor may be reduced. In some instances, the
output to the motor may be reduced by a constant value 224 until
the motor is running in idle mode 216. In some instances, it may be
determined whether the vertical speed of the aerial vehicle is
greater than a predetermined value 220, in which case the output to
the motor is increased, for example by a constant value 226. If the
vertical speed of the aerial vehicle is less than a predetermined
value 220, the output to the motor may be decreased, for example at
a constant value 224, until the motor is running in idle mode
216.
[0063] While the predetermined value 220 is exceeded (e.g., for
vertical speed of the aerial vehicle) and the output to the motor
is being increased, the aerial vehicle may be increasing its
altitude relative to the surface. Thus the aerial vehicle may be
rising from the surface. In some instances, the aerial vehicle may
be accelerating or decelerating while rising. Alternatively, the
aerial vehicle may be rising at a constant velocity.
[0064] An output to a motor of the aerial vehicle may be determined
while the aerial vehicle is rising. In some instances, the output
to the motor may be known based on command signals from a flight
controller that may dictate the output to the motor. In another
example, the output to the motor may be measured using one or more
sensor. The output to the motor may be indicative of the output to
the motor to provide a particular altitude. For instance, in some
embodiments, it may be known what output needs to be provided to a
motor for that type of aerial vehicle to reach a particular
altitude. The output to the motor may be provided as a power output
to the motor. The degree, intensity, or level of the output to the
motor may be calculated or measured. In some embodiments, an aerial
vehicle may have multiple motors. Output to the motor may refer to
output to a single motor, average output to multiple motors, or
total aggregated output to the multiple motors.
[0065] The system may detect whether the output to the motor
exceeds a predefined output value. In some instances, the system
may also detect the upward acceleration of the aerial vehicle. The
system may detect whether the upward acceleration is greater than a
predefined acceleration value. In one example, the system may
detect whether the output to the motor is greater than a first
predefined output value (Output1) and whether the upward
acceleration of the aerial vehicle is greater than the predefined
acceleration value (Acc1). If both these conditions are met 232
then it may be determined that a takeoff threshold has been met and
the aircraft has taken off 234.
[0066] The system may detect whether the motor is greater than a
second predefined output value (Output 2). If this condition is met
232 then it may be determined that a takeoff threshold has been met
and the aircraft has taken off 234.
[0067] It may be determined whether either of the takeoff
conditions has been met. For example, it may be determined whether
at least one of the conditions have been met (1) output is greater
than Output1 and upward acceleration is greater than Acc1, or (2)
output is greater than Output2. If at least one of (1) or (2) has
been met 232 then it may be determined that a takeoff threshold has
been met and the aircraft has taken off 234. In some embodiments, a
second predefined output value Output2 may have a different value
than a first predefined output value Output 1. For example, a
second predefined output value Output2 may be greater than a first
predefined output value Output1. The second condition (2) may be
provided to make sure that the aerial vehicle has taken off, even
if detection of the first condition (1) has failed. For example,
even if detection of Output1 has failed, or Acc1 has failed,
detection of Output2 may be provided to detect if the aircraft has
taken off. In some embodiments, condition (1) will typically be met
before condition (2). Alternatively, in some instances, condition
(2) may be met prior to detection of condition (1) being met.
[0068] After it is determined that an aircraft has taken off 234,
the integral control I may be calculated. Thus, normal integral
control may be permitted after it is determined that an aircraft
has taken off. A PID control scheme may be used. The integral
control may be calculated in the vertical direction. The integral
may also be calculated for other directions (e.g., right/left,
forwards/backwards, heading angle). The aerial vehicle may then be
operating in a normal flight state 238 which includes integral
control.
[0069] The process may include controlling flight of an aircraft
under a first control scheme prior to detecting whether a takeoff
threshold is met, and controlling flight of the aircraft under a
second control scheme after detecting the takeoff threshold is met.
The first control scheme may use an integral control scheme where
an integral output is zero (or other default value), while the
second control scheme may use a normal integral control scheme,
where the integral output may be calculated. The first control
scheme may be in effect up to step 226. In some instances, a first
control scheme is in effect once the command is received to start
the motor, up to when it is determined that a takeoff threshold is
met (e.g., which may occur at steps 232, 234). The second control
scheme may be in effect after 234 (e.g., from 236 onwards). In some
instances, the second control scheme is in effect once it is
determined that the aircraft has taken off 236.
[0070] In some instances, one or more of the steps described 228,
230, 232 may be used to determine whether a takeoff threshold is
met. It may be determined whether a takeoff threshold is met based
on an output value to one or motors of the aerial vehicle. For
instance, based on an amount of power output to one or more motors,
whether a takeoff threshold is met may be determined. In some
instances, it may be determined whether a takeoff threshold is met
based on an acceleration of the aerial vehicle. In alternate
embodiments, other information about the aerial vehicle, such as
velocity or positional information may be used to determine whether
a threshold has been met.
[0071] The systems and methods described herein may advantageously
permit the aerial vehicle to determine whether a takeoff threshold
has been met without requiring any signals received from a source
external to the aerial vehicle. For example, the aerial vehicle
need not receive any signals from external devices, such as global
positioning system (GPS) satellites, towers, other aerial vehicles,
remote terminals, in determining whether a takeoff threshold has
been met. The aerial vehicles also need not receive any signals
from objects (e.g., signals that are pinged back from ultrasonic
sensors on-board the aerial vehicle, or any other type of sensor
that requires a signal back). Any sensors used in the determination
of whether the takeoff threshold has been met may be provided
on-board the aerial vehicle and use information that is detectable
on-board the aerial vehicle. Thus, signals used to determine
whether a takeoff threshold has been met may be generated from
sensors that are self-contained within the aerial vehicle and need
not interact with an environment around the aerial vehicle.
[0072] The aerial vehicle may determine whether a takeoff threshold
has been met based on one or more signals from an inertial
measurement unit (IMU). An IMU can include one or more
accelerometers, one or more gyroscopes, one or more magnetometers,
or suitable combinations thereof. For example, the IMU can include
up to three orthogonal accelerometers to measure linear
acceleration of the movable object along up to three axes of
translation, and up to three orthogonal gyroscopes to measure the
angular acceleration about up to three axes of rotation. The IMU
can be rigidly coupled to the aerial vehicle such that the motion
of the aerial vehicle corresponds to motion of the IMU.
Alternatively the IMU can be permitted to move relative to the
aerial vehicle with respect to up to six degrees of freedom. The
IMU can be directly mounted onto the aerial vehicle, or coupled to
a support structure mounted onto the aerial vehicle. The IMU may be
provided exterior to or within a housing of the movable object. The
IMU may be permanently or removably attached to the movable object.
In some embodiments, the IMU can be an element of a payload of the
aerial vehicle. The IMU can provide a signal indicative of the
motion of the aerial vehicle, such as a position, orientation,
velocity, and/or acceleration of the aerial vehicle (e.g., with
respect to one, two, or three axes of translation, and/or one, two,
or three axes of rotation). For example, the IMU can sense a signal
representative of the acceleration of the aerial vehicle, and the
signal can be integrated once to provide velocity information, and
twice to provide location and/or orientation information. The IMU
may be able to determine the acceleration, velocity, and/or
location/orientation of the aerial vehicle without interacting with
any external environmental factors or receiving any signals from
outside the aerial vehicle.
[0073] An IMU may provide a signal about acceleration of the aerial
vehicle that may be used to determine whether a takeoff threshold
has been met. The signal about the acceleration of the aerial
vehicle may be compared to a threshold acceleration value Acc1. In
alternative embodiments, information comparing velocity information
to a velocity threshold and/or position information to a position
threshold may be used.
[0074] An aerial vehicle may also be able to determine whether a
takeoff threshold is met based on an output value to one or motors
of the aerial vehicle. For instance, based on an amount of power
output to one or more motors, whether a takeoff threshold is met
may be determined. In some instances, a sensor may be provided to
measure the amount of output to one or more motors. The sensor may
be provided on-board the aerial vehicle and/or within an aerial
vehicle housing. Alternatively, the amount of output to one or more
motors may be determined based on a command signal generated by a
flight controller. The output to one or more motors may be
calculated based on a desired degree of output that is calculated
by the flight controller and used to generate the command signal
that drives the motors. In some embodiments, a measured output from
the motors may be used to calculate an output to the motors or to
determine a takeoff threshold of the aerial vehicle.
[0075] In some embodiments, the output to the motors may be
combined with the acceleration of the aerial vehicle or any other
positional information of the aerial vehicle to determine whether a
takeoff threshold has been met. The takeoff threshold may be when
the aerial vehicle switches between control schemes. Thus, the
output to a motor may be combined with acceleration of the aerial
vehicle or considered on its own to determine when to switch from a
first control scheme to a second control scheme.
[0076] FIG. 3 provides a high level schematic of an aerial vehicle,
in accordance with an embodiment of the invention. An aerial
vehicle 300 may be in communication with a control apparatus 310.
In some instances, the control apparatus may be remote terminal,
examples of which are provided in greater detail elsewhere herein.
The aerial vehicle may include a flight controller 320, inertial
sensor 330, motor 340, command receiver 350 which may include an
antenna 355.
[0077] The aerial vehicle 300 may be a UAV. The aerial vehicle may
be configured to take off and land without a human on-board. The
aerial vehicle may communicate with a control apparatus 310. In
some embodiments, wireless communications may be used. Any form of
communication, such as those described in greater detail elsewhere
herein, may be used. In some embodiments, a control apparatus may
send a signal to the aerial vehicle to control operation of the
aerial vehicle. The control apparatus may send a signal to control
flight of the aerial vehicle, such as takeoff, landing, and/or
flight maneuvering. The control apparatus may send a signal that
controls the position of the aerial vehicle (e.g., location (along
one, two, or three axes), orientation (along one, two, or three
axes)). The control apparatus may send a flight control signal
which may result in control of one or more motors of the aerial
vehicle that controls propulsion units of the aerial vehicle, and
results in control of the flight position of the aerial vehicle.
The control apparatus may send a signal to control other aspects of
operation of the aerial vehicle. For example, the control apparatus
may send a signal that controls positioning of a payload on an
aerial vehicle, or operation of the payload. The control apparatus
may also send signals that control the type of information sensed
by the aerial vehicle. The control apparatus may optionally send a
signal that instructs the aerial vehicle to turn on (e.g., power
up) or turn off (e.g., power down).
[0078] The control apparatus 310 may have an antenna that may
communicate with an antenna 355 of a command receiver 350 on the
aerial vehicle 300. Any form of transceivers may be used between
the control apparatus and the aerial vehicle. For example, the
control apparatus may include a transceiver that may be capable of
communicating with a transceiver of the aerial vehicle. The
transceivers may permit wireless communications between the aerial
vehicle and the control apparatus. In some instances, the
communications may include radiofrequency (RF) communications,
infrared (IR) communications, WiFi communications, or 3G/4G or
other types of telecommunications. The communications may be
two-way communications between the control apparatus and the aerial
vehicle. For instance, the control apparatus may provide a signal
that is sent to the aerial vehicle and controls operation of the
aerial vehicle. The aerial vehicle may provide information to the
control apparatus, such as information captured by a sensor or
payload of the aerial vehicle, or positional information relating
to the aerial vehicle. Alternatively, the communications may be a
one-way communication from the control apparatus to the aerial
vehicle to control the aerial vehicle.
[0079] The aerial vehicle 300 may have a flight controller 320. The
flight controller may have one or more processors and/or one or
more memory units. The processors may be capable of performing one
or more step or calculation described herein. The processors may
perform the one or more steps in accordance with non-transitory
computer readable medium, which include code, logic, or
instructions for performing the steps. The memory units may include
the non-transitory computer readable medium.
[0080] The flight controller 320 may receive a signal from the
command receiver 350. This may include a flight control signal. A
user using a flight control apparatus 310 may input a flight
command, which may be received by the command receiver, which may
provide a signal indicative of the flight command to the flight
controller. The flight controller may provide instructions to one
or more motors 340 (or any other type of actuator) of the aerial
vehicle. The instructions to the motors may include output power to
drive the motors. The instructions may be generated based on the
flight command from the command receiver. The motors may be used to
drive one or more propulsion units, such as rotor blades, of the
aerial vehicle. The motors may drive the rotor blades of the aerial
vehicle to provide lift and/or control flight of the aerial
vehicle. In some instances, the power output to the motors may be
used to determine whether the aerial vehicle has reached a takeoff
threshold.
[0081] The aerial vehicle may include one or more inertial sensors
330. An inertial sensor may include an accelerometer, gyroscope,
magnetometer, or other type of sensor that may be used to determine
a state of the aerial vehicle. The inertial sensor need not receive
signals from outside the aerial vehicle. The inertial sensor may
generate a signal in response to a detected force on the aerial
vehicle. The inertial sensor may provide a signal indicative of an
acceleration of the aerial vehicle (e.g., in one, two, or three
directions), or angular acceleration of the aerial vehicle (e.g.,
about one, two, or three axes of rotation). In some instances, the
acceleration of the aerial vehicle in a vertical direction may be
measured. Measurements from the inertial sensors may be used to
determine acceleration (e.g., linear and/or angular) of the aerial
vehicle, velocity (e.g., linear and/or angular) or the aerial
vehicle, or position (e.g., location and/or orientation) of the
aerial vehicle. The inertial sensors may be part of an IMU, or may
be provided individually. The inertial sensors may include a
three-axis accelerometer and/or a three-axis gyroscope.
Alternatively, multiple single or double-axis accelerometers and/or
gyroscopes may be used.
[0082] Information from the one or more inertial sensors 330 may be
sent to the flight controller 320. The flight controller may
provide instructions to one or more motors 340 of the aerial
vehicle. The instructions may be generated based on the signals
from the inertial sensors. In some instances, the information from
the inertial sensors may be used to determine whether the aerial
vehicle has reached a takeoff threshold. For example, a vertical
acceleration of the aerial vehicle measured by the inertial
sensors, may be used to determine whether the aerial vehicle has
reached a takeoff threshold. The flight controller may consider
both the flight command received through the command receiver, and
a measurement from an inertial sensor in determining whether a
takeoff threshold has been met.
[0083] In some instances, information may be provided by a
barometer. The barometer may be used to measure ambient pressure
around the aerial vehicle. Information from a barometer may
optionally be sent to a flight controller. The flight controller
may generate one or more signals to a motor based on input from the
barometer. The information from the barometer may or may not be
used to determine whether the aerial vehicle has reached a takeoff
threshold. In some instances, a lower pressure may be indicative of
a higher altitude. The barometer may or may not need to be
calibrated to the current environmental conditions of the aerial
vehicle. In some instances, a change in pressure may be used to
determine whether a takeoff threshold has been met, or as part of
the information used to determine whether a takeoff threshold has
been met. Pressure information may be used in combination or in
place of output to motor and/or acceleration of the aerial
vehicle.
[0084] In one embodiment, a control apparatus 310 may provide a
takeoff command to the aerial vehicle 300. The takeoff command may
include input from a user of the control apparatus that is
indicative of motor speed or power provided to the motor 340. In
one example, a user may push a joystick in a direction to
correspond to increased or decreased rotational speed of the motor,
which may correspond to how quickly the aerial vehicle may ascend
or descend. The takeoff command may be received by a command
receiver 350 of the aerial vehicle, which may provide information
about the takeoff command to a flight controller 320. The flight
controller may also receive information from one or more sensors of
the aerial vehicle. In some instances, the one or more sensors may
include inertial sensors 330. Based on the information received,
the flight controller may generate and provide a signal to drive
one or more motors of the aerial vehicle.
[0085] The flight controller may generate a signal to drive motors
of the aerial vehicle in accordance with a first control scheme
when a takeoff threshold has not been met, and in accordance with a
second control scheme when the takeoff threshold has been met. One
or more processors of the flight controller may be used to
determine whether the takeoff threshold has been met. The
processors of the flight controller may calculate an output to
provide to the motors in accordance with the various control
schemes. For instance, the flight controller may calculate an
output to provide to the motors in response to the command receiver
and the inertial sensor in accordance with a first control scheme
when the takeoff threshold value has not been reached. The flight
controller may calculate an output to provide to the motors in
response to the command receiver and the inertial sensor in
accordance with a second control scheme when the takeoff threshold
value has been reached. In some embodiments, the first control
scheme may not include an integral output of zero, while the second
control scheme may include a calculated integral output. The flight
controller may directly output analog takeoff control values
(optionally, without using integral control or having an integral
output of zero), and after successful takeoff switch to PID
control.
[0086] The flight controller may determine, with aid of one or more
processors, that a takeoff threshold has been met, based on an
output to be provided to the motor. If the output to the motor
exceeds an output threshold value, it may be determined that the
takeoff threshold has been met. The flight controller may determine
that a takeoff threshold has been met based on a signal received by
an inertial sensor. For instance, if the vertical acceleration of
the aerial vehicle exceeds a threshold acceleration value, it may
be determined that the takeoff threshold has been met. In some
instances, the flight controller may determine that a takeoff
threshold has been met based on a combination of the output to the
motor and a signal from an inertial sensor. For instance, the
flight controller may determine that a threshold has been met when
at least one of the following conditions is true: (1) the vertical
acceleration of the aerial vehicle exceeds a threshold acceleration
value and the output to the motor exceeds a first threshold output
value, or (2) the output to the motor exceeds a second threshold
output value. The flight controller may be able to make the
determination of whether the takeoff threshold has been met without
relying on any information other than the output to the motor and
input from the inertial sensor. The flight controller may be able
to determine whether the takeoff threshold has been met without
relying on any information other than the output to the motor and
acceleration (e.g., vertical acceleration) of the aerial
vehicle.
[0087] The threshold acceleration value and/or threshold output
values may be predetermined. In some instances, the threshold
values may differ, based on the type of aerial vehicle. For
example, a larger or heavier aerial vehicle may have a different
threshold output value than a smaller or lighter aerial vehicle. In
another example, different aerial vehicles may have different
numbers of propulsion units and/or motors with different
characteristics. The different aerial vehicles may have different
threshold output values from one another. In some instances,
threshold acceleration values may remain the same for different
types of aerial vehicles, or may differ. The various threshold
values may be pre-assigned for different models or types of aerial
vehicles. Such threshold values may be pre-programmed on-board the
flight controller of the aerial vehicle. Alternatively, the flight
controller of the aerial vehicle may access the threshold values
from off-board the aerial vehicle. In some instances, the threshold
values may be updated. The threshold values may be updated by being
sent to the flight controller and being replaced on-board the
aerial vehicle. Alternatively, the threshold values may be updated
off-board the aerial vehicle and the most recent threshold values
may be accessed by the aerial vehicle at the time of use. In some
instances, various threshold values for various types of aerial
vehicles may be stored in a look-up table or other format.
Information about the aerial vehicle type may be used to access the
desired threshold values for determining whether a takeoff
threshold has been met.
[0088] In some instances, an aerial vehicle may have a single motor
driving one or more propulsion units. The flight controller may
determine the output to the motor and/or use the output to the
motor to determine whether a takeoff threshold has been met. In
alternate embodiments, multiple motors may be provided, each
driving a single propulsion unit or multiple propulsion units. The
flight controller may determine output to the multiple motors
and/or use the output to the multiple motors to determine whether a
takeoff threshold has been met. The flight controller may use the
acceleration of the aerial vehicle to determine whether the takeoff
threshold has been met.
[0089] The flight controller may be able to determine whether the
takeoff threshold has been met without requiring any information or
signal from a source external to the aerial vehicle. For example,
the flight controller may be able to determine whether the takeoff
threshold has been met without relying on a GPS signal. The flight
controller may also be able to determine whether a takeoff
threshold has been met without relying on sensors that require
feedback from outside the aerial vehicle (e.g., ultrasonic sensors,
ultrawideband (UWB) or other sensors that receive echo waves from
outside the vehicle).
[0090] Being able to determine whether a takeoff threshold has been
met without requiring any external signals may be advantageously
permit the aerial vehicle to operate independently of many
environmental factors. For example, not requiring a GPS input may
permit the aerial vehicle to operate in indoor or outdoor
conditions where GPS signals may otherwise be blocked or
unreliable. In another example, not requiring feedback from outside
the vehicle (e.g., sensors that may require an echo to determine
altitude of the aerial vehicle), may diminish risks of interfering
signals occurring, or having environmental factors such as moving
parts (e.g., leaves blowing in the wind) reducing the reliability
of the echoed signal. The systems and methods described herein are
also simple and do not require very many complicated calculations
that can take more time or processing power. The systems and
methods provided herein may provide conditions that may be easily
evaluated without performing complex calculations that may be used
in systems that look at various relative position and movement
information compared to an outside reference.
[0091] The systems and methods described herein may permit an
aerial vehicle to operate under a first control scheme when taking
off, which will reduce likelihood of instability that may occur
under traditional control schemes during takeoff. Once it has been
determined that the aerial vehicle has sufficiently taken off by
meeting a takeoff threshold, the aerial vehicle may switch to a
second control scheme for normal flight operations. The aerial
vehicle may determine when to switch to the second control scheme
based on information that is provided on-board the aerial vehicle
without requiring external signals. This may provide a smooth,
assisted takeoff for the aerial vehicle in a wide variety of
environmental conditions. This may allow more novice users to
easily take off by pushing the throttle on a control apparatus. The
users may not need to perform more complicated maneuvers during
takeoff, which are suited to more experienced users, and which
would be more likely required if a typical PID control scheme is
used.
[0092] The systems, devices, and methods described herein can be
applied to a wide variety of movable objects. As previously
mentioned, any description herein of an aerial vehicle may apply to
and be used for any movable object. Any description herein of an
aerial vehicle may apply specifically to UAVs. A movable object of
the present invention can be configured to move within any suitable
environment, such as in air (e.g., a fixed-wing aircraft, a
rotary-wing aircraft, or an aircraft having neither fixed wings nor
rotary wings), in water (e.g., a ship or a submarine), on ground
(e.g., a motor vehicle, such as a car, truck, bus, van, motorcycle,
bicycle; a movable structure or frame such as a stick, fishing
pole; or a train), under the ground (e.g., a subway), in space
(e.g., a spaceplane, a satellite, or a probe), or any combination
of these environments. The movable object can be a vehicle, such as
a vehicle described elsewhere herein. In some embodiments, the
movable object can be carried by a living subject, or take off from
a living subject, such as a human or an animal. Suitable animals
can include avines, canines, felines, equines, bovines, ovines,
porcines, delphines, rodents, or insects.
[0093] The movable object may be capable of moving freely within
the environment with respect to six degrees of freedom (e.g., three
degrees of freedom in translation and three degrees of freedom in
rotation). Alternatively, the movement of the movable object can be
constrained with respect to one or more degrees of freedom, such as
by a predetermined path, track, or orientation. The movement can be
actuated by any suitable actuation mechanism, such as an engine or
a motor. The actuation mechanism of the movable object can be
powered by any suitable energy source, such as electrical energy,
magnetic energy, solar energy, wind energy, gravitational energy,
chemical energy, nuclear energy, or any suitable combination
thereof. The movable object may be self-propelled via a propulsion
system, as described elsewhere herein. The propulsion system may
optionally run on an energy source, such as electrical energy,
magnetic energy, solar energy, wind energy, gravitational energy,
chemical energy, nuclear energy, or any suitable combination
thereof. Alternatively, the movable object may be carried by a
living being.
[0094] In some instances, the movable object can be a vehicle.
Suitable vehicles may include water vehicles, aerial vehicles,
space vehicles, or ground vehicles. For example, aerial vehicles
may be fixed-wing aircraft (e.g., airplane, gliders), rotary-wing
aircraft (e.g., helicopters, rotorcraft), aircraft having both
fixed wings and rotary wings, or aircraft having neither (e.g.,
blimps, hot air balloons). A vehicle can be self-propelled, such as
self-propelled through the air, on or in water, in space, or on or
under the ground. A self-propelled vehicle can utilize a propulsion
system, such as a propulsion system including one or more engines,
motors, wheels, axles, magnets, rotors, propellers, blades,
nozzles, or any suitable combination thereof. In some instances,
the propulsion system can be used to enable the movable object to
take off from a surface, land on a surface, maintain its current
position and/or orientation (e.g., hover), change orientation,
and/or change position.
[0095] The movable object can be controlled remotely by a user or
controlled locally by an occupant within or on the movable object.
In some embodiments, the movable object is an unmanned movable
object, such as a UAV. An unmanned movable object, such as a UAV,
may not have an occupant onboard the movable object. The movable
object can be controlled by a human or an autonomous control system
(e.g., a computer control system), or any suitable combination
thereof. The movable object can be an autonomous or semi-autonomous
robot, such as a robot configured with an artificial
intelligence.
[0096] The movable object can have any suitable size and/or
dimensions. In some embodiments, the movable object may be of a
size and/or dimensions to have a human occupant within or on the
vehicle. Alternatively, the movable object may be of size and/or
dimensions smaller than that capable of having a human occupant
within or on the vehicle. The movable object may be of a size
and/or dimensions suitable for being lifted or carried by a human.
Alternatively, the movable object may be larger than a size and/or
dimensions suitable for being lifted or carried by a human. In some
instances, the movable object may have a maximum dimension (e.g.,
length, width, height, diameter, diagonal) of less than or equal to
about: 2 cm, 5 cm, 10 cm, 50 cm, 1 m, 2 m, 5 m, or 10 m. The
maximum dimension may be greater than or equal to about: 2 cm, 5
cm, 10 cm, 50 cm, 1 m, 2 m, 5 m, or 10 m. For example, the distance
between shafts of opposite rotors of the movable object may be less
than or equal to about: 2 cm, 5 cm, 10 cm, 50 cm, 1 m, 2 m, 5 m, or
10 m. Alternatively, the distance between shafts of opposite rotors
may be greater than or equal to about: 2 cm, 5 cm, 10 cm, 50 cm, 1
m, 2 m, 5 m, or 10 m.
[0097] In some embodiments, the movable object may have a volume of
less than 100 cm.times.100 cm.times.100 cm, less than 50
cm.times.50 cm.times.30 cm, or less than 5 cm.times.5 cm.times.3
cm. The total volume of the movable object may be less than or
equal to about: 1 cm.sup.3, 2 cm.sup.3, 5 cm.sup.3, 10 cm.sup.3, 20
cm.sup.3, 30 cm.sup.3, 40 cm.sup.3, 50 cm.sup.3, 60 cm.sup.3, 70
cm.sup.3, 80 cm.sup.3, 90 cm.sup.3, 100 cm.sup.3, 150 cm.sup.3, 200
cm.sup.3, 300 cm.sup.3, 500 cm.sup.3, 750 cm.sup.3, 1000 cm.sup.3,
5000 cm.sup.3, 10,000 cm.sup.3, 100,000 cm.sup.3, 1 m.sup.3, or 10
m.sup.3. Conversely, the total volume of the movable object may be
greater than or equal to about: 1 cm.sup.3, 2 cm.sup.3, 5 cm.sup.3,
10 cm.sup.3, 20 cm.sup.3, 30 cm.sup.3, 40 cm.sup.3, 50 cm.sup.3, 60
cm.sup.3, 70 cm.sup.3, 80 cm.sup.3, 90 cm.sup.3, 100 cm.sup.3, 150
cm.sup.3, 200 cm.sup.3, 300 cm.sup.3, 500 cm.sup.3, 750 cm.sup.3,
1000 cm.sup.3, 5000 cm.sup.3, 10,000 cm.sup.3, 100,000 cm.sup.3, 1
m.sup.3, or 10 m.sup.3.
[0098] In some embodiments, the movable object may have a footprint
(which may refer to the lateral cross-sectional area encompassed by
the movable object) less than or equal to about: 32,000 cm.sup.2,
20,000 cm.sup.2, 10,000 cm.sup.2, 1,000 cm.sup.2, 500 cm.sup.2, 100
cm.sup.2, 50 cm.sup.2, 10 cm.sup.2, or 5 cm.sup.2. Conversely, the
footprint may be greater than or equal to about: 32,000 cm.sup.2,
20,000 cm.sup.2, 10,000 cm.sup.2, 1,000 cm.sup.2, 500 cm.sup.2, 100
cm.sup.2, 50 cm.sup.2, 10 cm.sup.2, or 5 cm.sup.2.
[0099] In some instances, the movable object may weigh no more than
1000 kg. The weight of the movable object may be less than or equal
to about: 1000 kg, 750 kg, 500 kg, 200 kg, 150 kg, 100 kg, 80 kg,
70 kg, 60 kg, 50 kg, 45 kg, 40 kg, 35 kg, 30 kg, 25 kg, 20 kg, 15
kg, 12 kg, 10 kg, 9 kg, 8 kg, 7 kg, 6 kg, 5 kg, 4 kg, 3 kg, 2 kg, 1
kg, 0.5 kg, 0.1 kg, 0.05 kg, or 0.01 kg. Conversely, the weight may
be greater than or equal to about: 1000 kg, 750 kg, 500 kg, 200 kg,
150 kg, 100 kg, 80 kg, 70 kg, 60 kg, 50 kg, 45 kg, 40 kg, 35 kg, 30
kg, 25 kg, 20 kg, 15 kg, 12 kg, 10 kg, 9 kg, 8 kg, 7 kg, 6 kg, 5
kg, 4 kg, 3 kg, 2 kg, 1 kg, 0.5 kg, 0.1 kg, 0.05 kg, or 0.01
kg.
[0100] In some embodiments, a movable object may be small relative
to a load carried by the movable object. The load may include a
payload and/or a carrier, as described in further detail elsewhere
herein. In some examples, a ratio of a movable object weight to a
load weight may be greater than, less than, or equal to about 1:1.
In some instances, a ratio of a movable object weight to a load
weight may be greater than, less than, or equal to about 1:1.
Optionally, a ratio of a carrier weight to a load weight may be
greater than, less than, or equal to about 1:1. When desired, the
ratio of an movable object weight to a load weight may be less than
or equal to: 1:2, 1:3, 1:4, 1:5, 1:10, or even less. Conversely,
the ratio of a movable object weight to a load weight can also be
greater than or equal to: 2:1, 3:1, 4:1, 5:1, 10:1, or even
greater.
[0101] In some embodiments, the movable object may have low energy
consumption. For example, the movable object may use less than
about: 5 W/h, 4 W/h, 3 W/h, 2 W/h, 1 W/h, or less. In some
instances, a carrier of the movable object may have low energy
consumption. For example, the carrier may use less than about: 5
W/h, 4 W/h, 3 W/h, 2 W/h, 1 W/h, or less. Optionally, a payload of
the movable object may have low energy consumption, such as less
than about: 5 W/h, 4 W/h, 3 W/h, 2 W/h, 1 W/h, or less.
[0102] FIG. 4 illustrates an unmanned aerial vehicle (UAV) 400, in
accordance with embodiments of the present invention. The UAV may
be an example of a movable object as described herein. The UAV 400
can include a propulsion system having four rotors 402, 404, 406,
and 408. Any number of rotors may be provided (e.g., one, two,
three, four, five, six, or more). The rotors, rotor assemblies, or
other propulsion systems of the unmanned aerial vehicle may enable
the unmanned aerial vehicle to hover/maintain position, change
orientation, and/or change location. The distance between shafts of
opposite rotors can be any suitable length 410. For example, the
length 410 can be less than or equal to 2 m, or less than equal to
11 m. In some embodiments, the length 410 can be within a range
from 40 cm to 7 m, from 70 cm to 2 m, or from 11 cm to 11 m. Any
description herein of a UAV may apply to a movable object, such as
a movable object of a different type, and vice versa. The UAV may
use an assisted takeoff system or method as described herein.
[0103] In some embodiments, the movable object can be configured to
carry a load. The load can include one or more of passengers,
cargo, equipment, instruments, and the like. The load can be
provided within a housing. The housing may be separate from a
housing of the movable object, or be part of a housing for a
movable object. Alternatively, the load can be provided with a
housing while the movable object does not have a housing.
Alternatively, portions of the load or the entire load can be
provided without a housing. The load can be rigidly fixed relative
to the movable object. Optionally, the load can be movable relative
to the movable object (e.g., translatable or rotatable relative to
the movable object). The load can include a payload and/or a
carrier, as described elsewhere herein.
[0104] In some embodiments, the movement of the movable object,
carrier, and payload relative to a fixed reference frame (e.g., the
surrounding environment) and/or to each other, can be controlled by
a terminal. The terminal can be a remote control device at a
location distant from the movable object, carrier, and/or payload.
The terminal can be disposed on or affixed to a support platform.
Alternatively, the terminal can be a handheld or wearable device.
For example, the terminal can include a smartphone, tablet, laptop,
computer, glasses, gloves, helmet, microphone, or suitable
combinations thereof. The terminal can include a user interface,
such as a keyboard, mouse, joystick, touchscreen, or display. Any
suitable user input can be used to interact with the terminal, such
as manually entered commands, voice control, gesture control, or
position control (e.g., via a movement, location or tilt of the
terminal).
[0105] The terminal can be used to control any suitable state of
the movable object, carrier, and/or payload. For example, the
terminal can be used to control the position and/or orientation of
the movable object, carrier, and/or payload relative to a fixed
reference from and/or to each other. In some embodiments, the
terminal can be used to control individual elements of the movable
object, carrier, and/or payload, such as the actuation assembly of
the carrier, a sensor of the payload, or an emitter of the payload.
The terminal can include a wireless communication device adapted to
communicate with one or more of the movable object, carrier, or
payload.
[0106] The terminal can include a suitable display unit for viewing
information of the movable object, carrier, and/or payload. For
example, the terminal can be configured to display information of
the movable object, carrier, and/or payload with respect to
position, translational velocity, translational acceleration,
orientation, angular velocity, angular acceleration, or any
suitable combinations thereof. In some embodiments, the terminal
can display information provided by the payload, such as data
provided by a functional payload (e.g., images recorded by a camera
or other image capturing device).
[0107] Optionally, the same terminal may both control the movable
object, carrier, and/or payload, or a state of the movable object,
carrier and/or payload, as well as receive and/or display
information from the movable object, carrier and/or payload. For
example, a terminal may control the positioning of the payload
relative to an environment, while displaying image data captured by
the payload, or information about the position of the payload.
Alternatively, different terminals may be used for different
functions. For example, a first terminal may control movement or a
state of the movable object, carrier, and/or payload while a second
terminal may receive and/or display information from the movable
object, carrier, and/or payload. For example, a first terminal may
be used to control the positioning of the payload relative to an
environment while a second terminal displays image data captured by
the payload. Various communication modes may be utilized between a
movable object and an integrated terminal that both controls the
movable object and receives data, or between the movable object and
multiple terminals that both control the movable object and
receives data. For example, at least two different communication
modes may be formed between the movable object and the terminal
that both controls the movable object and receives data from the
movable object.
[0108] FIG. 5 illustrates a movable object 500 including a carrier
502 and a payload 504, in accordance with embodiments. Although the
movable object 500 is depicted as an aircraft, this depiction is
not intended to be limiting, and any suitable type of movable
object can be used, as previously described herein. One of skill in
the art would appreciate that any of the embodiments described
herein in the context of aircraft systems can be applied to any
suitable movable object (e.g., an UAV). In some instances, the
payload 504 may be provided on the movable object 500 without
requiring the carrier 502. The movable object 500 may include
propulsion mechanisms 506, a sensing system 508, and a
communication system 510.
[0109] The propulsion mechanisms 506 can include one or more of
rotors, propellers, blades, engines, motors, wheels, axles,
magnets, or nozzles, as previously described. The movable object
may have one or more, two or more, three or more, or four or more
propulsion mechanisms. The propulsion mechanisms may all be of the
same type. Alternatively, one or more propulsion mechanisms can be
different types of propulsion mechanisms. The propulsion mechanisms
506 can be mounted on the movable object 500 using any suitable
means, such as a support element (e.g., a drive shaft) as described
elsewhere herein. The propulsion mechanisms 506 can be mounted on
any suitable portion of the movable object 500, such on the top,
bottom, front, back, sides, or suitable combinations thereof.
[0110] In some embodiments, the propulsion mechanisms 506 can
enable the movable object 500 to take off vertically from a surface
or land vertically on a surface without requiring any horizontal
movement of the movable object 500 (e.g., without traveling down a
runway). Optionally, the propulsion mechanisms 506 can be operable
to permit the movable object 500 to hover in the air at a specified
position and/or orientation. One or more of the propulsion
mechanisms 500 may be controlled independently of the other
propulsion mechanisms. Alternatively, the propulsion mechanisms 500
can be configured to be controlled simultaneously. For example, the
movable object 500 can have multiple horizontally oriented rotors
that can provide lift and/or thrust to the movable object. The
multiple horizontally oriented rotors can be actuated to provide
vertical takeoff, vertical landing, and hovering capabilities to
the movable object 500. In some embodiments, one or more of the
horizontally oriented rotors may spin in a clockwise direction,
while one or more of the horizontally rotors may spin in a
counterclockwise direction. For example, the number of clockwise
rotors may be equal to the number of counterclockwise rotors. The
rotation rate of each of the horizontally oriented rotors can be
varied independently in order to control the lift and/or thrust
produced by each rotor, and thereby adjust the spatial disposition,
velocity, and/or acceleration of the movable object 500 (e.g., with
respect to up to three degrees of translation and up to three
degrees of rotation).
[0111] The sensing system 508 can include one or more sensors that
may sense the spatial disposition, velocity, and/or acceleration of
the movable object 500 (e.g., with respect to up to three degrees
of translation and up to three degrees of rotation). The one or
more sensors can include global positioning system (GPS) sensors,
motion sensors, inertial sensors, proximity sensors, or image
sensors. The sensing data provided by the sensing system 508 can be
used to control the spatial disposition, velocity, and/or
orientation of the movable object 500 (e.g., using a suitable
processing unit and/or control module, as described below).
Alternatively, the sensing system 508 can be used to provide data
regarding the environment surrounding the movable object, such as
weather conditions, proximity to potential obstacles, location of
geographical features, location of manmade structures, and the
like.
[0112] The communication system 510 enables communication with
terminal 512 having a communication system 514 via wireless signals
516. The communication systems 510, 514 may include any number of
transmitters, receivers, and/or transceivers suitable for wireless
communication. The communication may be one-way communication, such
that data can be transmitted in only one direction. For example,
one-way communication may involve only the movable object 500
transmitting data to the terminal 512, or vice-versa. The data may
be transmitted from one or more transmitters of the communication
system 510 to one or more receivers of the communication system
512, or vice-versa. Alternatively, the communication may be two-way
communication, such that data can be transmitted in both directions
between the movable object 500 and the terminal 512. The two-way
communication can involve transmitting data from one or more
transmitters of the communication system 510 to one or more
receivers of the communication system 514, and vice-versa.
[0113] In some embodiments, the terminal 512 can provide control
data to one or more of the movable object 500, carrier 502, and
payload 504 and receive information from one or more of the movable
object 500, carrier 502, and payload 504 (e.g., position and/or
motion information of the movable object, carrier or payload; data
sensed by the payload such as image data captured by a payload
camera). In some instances, control data from the terminal may
include instructions for relative positions, movements, actuations,
or controls of the movable object, carrier and/or payload. For
example, the control data may result in a modification of the
location and/or orientation of the movable object (e.g., via
control of the propulsion mechanisms 506), or a movement of the
payload with respect to the movable object (e.g., via control of
the carrier 502). The control data from the terminal may result in
control of the payload, such as control of the operation of a
camera or other image capturing device (e.g., taking still or
moving pictures, zooming in or out, turning on or off, switching
imaging modes, change image resolution, changing focus, changing
depth of field, changing exposure time, changing viewing angle or
field of view). In some instances, the communications from the
movable object, carrier and/or payload may include information from
one or more sensors (e.g., of the sensing system 508 or of the
payload 504). The communications may include sensed information
from one or more different types of sensors (e.g., GPS sensors,
motion sensors, inertial sensor, proximity sensors, or image
sensors). Such information may pertain to the position (e.g.,
location, orientation), movement, or acceleration of the movable
object, carrier and/or payload. Such information from a payload may
include data captured by the payload or a sensed state of the
payload. The control data provided transmitted by the terminal 512
can be configured to control a state of one or more of the movable
object 1200, carrier 1202, or payload 504. Alternatively or in
combination, the carrier 502 and payload 504 can also each include
a communication module configured to communicate with terminal 512,
such that the terminal can communicate with and control each of the
movable object 500, carrier 502, and payload 504 independently.
[0114] In some embodiments, the movable object 500 can be
configured to communicate with another remote device in addition to
the terminal 512, or instead of the terminal 512. The terminal 512
may also be configured to communicate with another remote device as
well as the movable object 500. For example, the movable object 500
and/or terminal 512 may communicate with another movable object, or
a carrier or payload of another movable object. When desired, the
remote device may be a second terminal or other computing device
(e.g., computer, laptop, tablet, smartphone, or other mobile
device). The remote device can be configured to transmit data to
the movable object 500, receive data from the movable object 500,
transmit data to the terminal 512, and/or receive data from the
terminal 512. Optionally, the remote device can be connected to the
Internet or other telecommunications network, such that data
received from the movable object 500 and/or terminal 512 can be
uploaded to a website or server.
[0115] FIG. 6 is a schematic illustration by way of block diagram
of a system 600 for controlling a movable object, in accordance
with embodiments. The system 600 can be used in combination with
any suitable embodiment of the systems, devices, and methods
disclosed herein. The system 600 can include a sensing module 602,
processing unit 604, non-transitory computer readable medium 606,
control module 608, and communication module 610.
[0116] The sensing module 602 can utilize different types of
sensors that collect information relating to the movable objects in
different ways. Different types of sensors may sense different
types of signals or signals from different sources. For example,
the sensors can include inertial sensors, GPS sensors, proximity
sensors (e.g., lidar), or vision/image sensors (e.g., a camera).
The sensing module 602 can be operatively coupled to a processing
unit 604 having a plurality of processors. In some embodiments, the
sensing module can be operatively coupled to a transmission module
612 (e.g., a Wi-Fi image transmission module) configured to
directly transmit sensing data to a suitable external device or
system. For example, the transmission module 612 can be used to
transmit images captured by a camera of the sensing module 602 to a
remote terminal.
[0117] The processing unit 604 can have one or more processors,
such as a programmable processor (e.g., a central processing unit
(CPU)). The processing unit 604 can be operatively coupled to a
non-transitory computer readable medium 606. The non-transitory
computer readable medium 606 can store logic, code, and/or program
instructions executable by the processing unit 604 for performing
one or more steps. The non-transitory computer readable medium can
include one or more memory units (e.g., removable media or external
storage such as an SD card or random access memory (RAM)). In some
embodiments, data from the sensing module 602 can be directly
conveyed to and stored within the memory units of the
non-transitory computer readable medium 606. The memory units of
the non-transitory computer readable medium 606 can store logic,
code and/or program instructions executable by the processing unit
604 to perform any suitable embodiment of the methods described
herein. For example, the processing unit 604 can be configured to
execute instructions causing one or more processors of the
processing unit 604 to analyze sensing data produced by the sensing
module. The memory units can store sensing data from the sensing
module to be processed by the processing unit 604. In some
embodiments, the memory units of the non-transitory computer
readable medium 606 can be used to store the processing results
produced by the processing unit 604.
[0118] In some embodiments, the processing unit 604 can be
operatively coupled to a control module 608 configured to control a
state of the movable object. For example, the control module 608
can be configured to control the propulsion mechanisms of the
movable object to adjust the spatial disposition, velocity, and/or
acceleration of the movable object with respect to six degrees of
freedom. Alternatively or in combination, the control module 608
can control one or more of a state of a carrier, payload, or
sensing module.
[0119] The processing unit 604 can be operatively coupled to a
communication module 610 configured to transmit and/or receive data
from one or more external devices (e.g., a terminal, display
device, or other remote controller). Any suitable means of
communication can be used, such as wired communication or wireless
communication. For example, the communication module 610 can
utilize one or more of local area networks (LAN), wide area
networks (WAN), infrared, radio, WiFi, point-to-point (P2P)
networks, telecommunication networks, cloud communication, and the
like. Optionally, relay stations, such as towers, satellites, or
mobile stations, can be used. Wireless communications can be
proximity dependent or proximity independent. In some embodiments,
line-of-sight may or may not be required for communications. The
communication module 610 can transmit and/or receive one or more of
sensing data from the sensing module 602, processing results
produced by the processing unit 604, predetermined control data,
user commands from a terminal or remote controller, and the
like.
[0120] The components of the system 600 can be arranged in any
suitable configuration. For example, one or more of the components
of the system 600 can be located on the movable object, carrier,
payload, terminal, sensing system, or an additional external device
in communication with one or more of the above. Additionally,
although FIG. 6 depicts a single processing unit 604 and a single
non-transitory computer readable medium 606, one of skill in the
art would appreciate that this is not intended to be limiting, and
that the system 600 can include a plurality of processing units
and/or non-transitory computer readable media. In some embodiments,
one or more of the plurality of processing units and/or
non-transitory computer readable media can be situated at different
locations, such as on the movable object, carrier, payload,
terminal, sensing module, additional external device in
communication with one or more of the above, or suitable
combinations thereof, such that any suitable aspect of the
processing and/or memory functions performed by the system 600 can
occur at one or more of the aforementioned locations.
[0121] While preferred embodiments of the present invention have
been shown and described herein, it will be obvious to those
skilled in the art that such embodiments are provided by way of
example only. Numerous variations, changes, and substitutions will
now occur to those skilled in the art without departing from the
invention. It should be understood that various alternatives to the
embodiments of the invention described herein may be employed in
practicing the invention. It is intended that the following claims
define the scope of the invention and that methods and structures
within the scope of these claims and their equivalents be covered
thereby.
* * * * *