U.S. patent application number 17/265613 was filed with the patent office on 2021-06-03 for moving robot and controlling method thereof.
This patent application is currently assigned to LG ELECTRONICS INC.. The applicant listed for this patent is LG ELECTRONICS INC.. Invention is credited to KOH CHOI, BYUNGJIN KIM, KYOUNGSUK KO, HYUNGSUB LEE, SUNGWOOK LEE.
Application Number | 20210165421 17/265613 |
Document ID | / |
Family ID | 1000005431201 |
Filed Date | 2021-06-03 |
United States Patent
Application |
20210165421 |
Kind Code |
A1 |
KO; KYOUNGSUK ; et
al. |
June 3, 2021 |
MOVING ROBOT AND CONTROLLING METHOD THEREOF
Abstract
A moving robot includes a traveling unit, a power supply unit, a
communication unit, and a memory to store therein coordinates
information regarding a point to which the main body has moved by a
reference distance in a state of being in contact with the charging
station, and a control unit to output a control command to return
to the charging station based on a state of the power supply unit
while the main body travels in the one area, to determine a
position of the charging station from a current position of the
main body based on a first signal transmitted from the charging
station and a second signal transmitted by the communication unit,
in response to the output of the control command, and to controls
the traveling unit so that the main body moves to a position
corresponding to the stored coordinates information.
Inventors: |
KO; KYOUNGSUK; (Seoul,
KR) ; KIM; BYUNGJIN; (Seoul, KR) ; LEE;
SUNGWOOK; (Seoul, KR) ; LEE; HYUNGSUB; (Seoul,
KR) ; CHOI; KOH; (Seoul, KR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
LG ELECTRONICS INC. |
Seoul |
|
KR |
|
|
Assignee: |
LG ELECTRONICS INC.
Seoul
KR
|
Family ID: |
1000005431201 |
Appl. No.: |
17/265613 |
Filed: |
July 25, 2019 |
PCT Filed: |
July 25, 2019 |
PCT NO: |
PCT/KR2019/009257 |
371 Date: |
February 3, 2021 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
62714088 |
Aug 3, 2018 |
|
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
G05D 2201/0208 20130101;
G05D 1/0276 20130101; G05D 1/0225 20130101; B60L 53/36 20190201;
G05D 1/0094 20130101 |
International
Class: |
G05D 1/02 20060101
G05D001/02; B60L 53/36 20060101 B60L053/36; G05D 1/00 20060101
G05D001/00 |
Foreign Application Data
Date |
Code |
Application Number |
Apr 30, 2019 |
KR |
10-2019-0050966 |
Claims
1. A moving robot that travels within one area where a charging
station is installed, the moving robot comprising: a traveling unit
to rotate or move a main body; a power supply unit to supply power
to the main body; a communication unit to transmit and receive
signals to and from the charging station; a memory to store therein
coordinates information regarding a point to which the main body
has moved by a reference distance in a state of being in contact
with the charging station; and a control unit to output a control
command to return to the charging station based on a state of the
power supply unit while the main body travels in the one area,
wherein the control unit determines a position of the charging
station from a current position of the main body based on a first
signal transmitted from the charging station and a second signal
transmitted by the communication unit, in response to the output of
the control command, and controls the traveling unit so that the
main body moves to a position corresponding to the stored
coordinates information, and wherein the control unit calculates a
rotation angle for docking to the charging station based on the
first signal and the second signal when the main body reaches the
position corresponding to the stored coordinates information, and
controls the traveling unit so that a head of the main body is
rotated according to the calculated rotation angle.
2. The moving robot of claim 1, wherein the charging station is
provided with a pair of Ultra-wideband (UWB) modules to transmit
the first signal and receive the second signal, and wherein the
communication unit of the main body is provided with a pair of UWB
modules to receive the first signal and transmit the second
signal.
3. The moving robot of claim 2, wherein the pair of UWB modules
provided in the communication unit is disposed to be symmetric in
right and left directions with respect to the front of the main
body, and determines the position of the charging station with
respect to the current position of the main body by receiving the
first signal from the charging station, respectively.
4. The moving robot of claim 3, wherein the control unit, while the
main body moves to the position corresponding to the stored
coordinates information, determines one intersection close to a
head direction of the main body as the position of the charging
station, of two intersections between a first circle that a
distance between a first UWB anchor provided in the communication
unit and a first UWB tag of the charging station is a radius and
the first UWB anchor is a center, and a second circle that a
distance between a second UWB anchor provided in the communication
unit and a second UWB tag of the charging station is a radius and
the second UWB anchor is a center.
5. The moving robot of claim 1, wherein coordinates information of
a point to which the main body has moved backward by a reference
distance in a state of being in contact with the charging station
includes angle information calculated based on the first signal and
the second signal.
6. The moving robot of claim 1, wherein the control unit calculates
distance information and angle information between the current
position of the main body and the charging station based on the
first signal received from the charging station and the second
signal transmitted by the communication unit, in response to the
output of the control command, and controls the traveling unit so
that the head of the main body is rotated toward the position
corresponding to the stored coordinates information.
7. The moving robot of claim 6, wherein the control unit checks the
position of the charging station in real time based on the first
signal received through a plurality of UWB modules while the main
body moves to the position corresponding to the stored coordinates
information after the head of the main body is rotated toward the
point corresponding to the stored coordinates information.
8. The moving robot of claim 7, wherein the control unit, after the
main body moves to the position corresponding to the stored
coordinates information, determines a head direction of the main
body on the basis of the angle information calculated based on the
first signal received from the charging station and the second
signal transmitted by the communication unit, and then controls the
traveling unit so that the head is rotated according to the
determined head direction.
9. The moving robot of claim 8, wherein the control unit, after the
head is rotated according to the determined head direction, checks
whether or not to correct the determined head direction, based on a
difference between distances at which the first signal transmitted
from the charging station is received by a first UWB module and a
second UWB module disposed in the main body, respectively.
10. The moving robot of claim 9, wherein a current head direction
is determined as a docking direction when it is determined that the
distance at which the first signal is received by the first UWB
module is the same as the distance at which the first signal is
received by the second UWB module.
11. The moving robot of claim 1, wherein the control unit controls
the traveling unit so that the main body docks to the charging
station by moving straightly by the reference distance, after the
main body rotates the head according to the calculated rotation
angle at the position corresponding to the stored coordinates
information.
12. The moving robot of claim 1, wherein the control unit
determines the position of the charging station in real time based
on the first signal and the second signal while the main body moves
to the position corresponding to the stored coordinates
information, and sets a docking path by avoiding the charging
station when the position of the charging station is included in a
path along which the main body moves to the stored coordinates
information.
13. The moving robot of claim 1, wherein the control unit stores
position information regarding the main body at a time point when
the control command has been output, and controls the traveling
unit so that the main body moves to the stored position information
when the main body docks to the charging station and charging of
the power supply unit is completed.
14. A method for controlling a moving robot that travels within one
area where a charging station is installed, the method comprising:
storing in advance coordinates information regarding a point, to
which a main body of the moving robot has moved by a reference
distance in a state of being in contact with the charging station;
outputting a control command to return to the charging station
based on a state of a power supply unit that supplies power to the
main body while the main body travels in the one area; determining
a position of the charging station with respect to the main body
based on a first signal transmitted from the charging station and a
second signal transmitted by the main body, in response to the
output of the control command, and controlling the main body to
move to a position corresponding to the stored coordinates
information; and calculating a rotation angle for docking to the
charging station based on the first signal and the second signal
when the main body reaches the position corresponding to the stored
coordinates information, and controlling a head of the main body to
be rotated according to the calculated rotation angle.
15. The method of claim 14, wherein the controlling the main body
to move to the position corresponding to the stored coordinates
information comprises: calculating distance information and angle
information between a current position of the main body and the
charging station based on the first signal received from the
charging station and the second signal transmitted by the main
body, in response to the output of the control command; and
controlling the head of the main body to be rotated toward the
position corresponding to the stored coordinates information.
16. The method of claim 15, further comprising: checking the
position of the charging station in real time based on the first
signal received through a plurality of UWB modules provided in the
main body while the main body moves to the position corresponding
to the stored coordinates information after the head of the main
body is rotated toward the position corresponding to the stored
coordinates information.
17. The method of claim 16, further comprising, after the main body
moves to the position corresponding to the stored coordinates
information: determining a head direction of the main body on the
basis of the angle information calculated based on the first signal
received from the charging station and the second signal
transmitted by the main body; and rotating the head according to
the determined head direction and docking to the charging station.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is the National Stage filing under 35
U.S.C. 371 of International Application No. PCT/KR2019/009257,
filed on Jul. 25, 2019, which claims the benefit of earlier filing
date and rights of priority to U.S Provisional application No.
62/714,088 filed on Aug. 3, 2018 and Korean Application No.
10-2019-0050966 filed on Apr. 30, 2019, the contents of which are
all hereby incorporated by reference herein in their entirety.
BACKGROUND
Technical Field
[0002] The present disclosure relates to a moving robot that
autonomously travels in a designated area, and a method for
controlling the same.
Background Art
[0003] Generally, a moving robot is a device that automatically
performs a predetermined operation while traveling by itself in a
predetermined range without a user's operation. The moving robot
senses obstacles located in the area and performs its operations by
moving close to or away from such obstacles.
[0004] Such a moving robot may include a cleaning robot that
carries out cleaning while traveling in an area, as well as a lawn
mower robot that mows the grass on a bottom of the area.
[0005] Generally, lawn mowers include a passenger type which a user
boards and controls to mow the lawn or cut the grass during
movement, and a work-behind type or hand-operating type that is
pulled or pushed manually by a user to cut the grass. Such lawn
mowers are moved by a direct control of the user to mow the lawn,
which causes user's inconvenience in that the device is operated
only directly by the user.
[0006] Accordingly, a moving robot type lawn mower that an element
for mowing the lawn is provided on a moving robot, namely, a lawn
mower robot has been studied. However, since the lawn mower robot
operates outdoors other than indoors, it is necessary to set an
area to be moved in advance. Specifically, since the outdoors is an
open space unlike the indoors, an area designation should first be
carried out, and an area to be driven by the robot should be
limited to a space where grass is growing.
[0007] For this purpose, in Korean Patent Laid-Open Publication No.
2015-0125508, wires are laid under the ground where grass is
planted, in order to set an area to be moved by a lawn mower robot
or a moving robot, and the moving robot is controlled to move in an
inner area of the wires. Then, a boundary for the moving robot is
set based on a voltage value induced by the wires.
[0008] However, this method has a problem that the wires must be
laid under the ground every time of setting the boundary. In
addition, in order to change the boundary once set, new wires must
be laid after the previously laid wires are removed, which causes
much time and efforts for the boundary setting.
[0009] The US Patent laid-open Publication No. US 2017/0026818
discloses a method in which a distance between Beacon and the
mobile lawn mower robot is determined by pairing the mobile lawn
mower robot and the Beacon, whether the Beacon is located within a
pairing distance is determined by comparing the determined distance
with the pairing distance, and the result of the determination is
used for a navigator.
[0010] Recently, a method of controlling the travel of a moving
robot by using a low-cost Ultra-wideband (UWB) communication
technology known to have precision of about 30 cm or shorter has
been studied. UWB is suitable for real-time location tracking
because it is hardly affected by multipath problems by virtue of
its properties of precise region estimation and material
penetration.
[0011] By using such UWB communication technology, a relative
location of another device, for example, UWB tag, existing in a UWB
positioning range may be calculated. In the case of determining the
relative location of the UWB tag using the UWB communication
technology, Angle of Arrival (AoA) positioning may be used.
[0012] On the other hand, since the moving robot travels using a
rechargeable battery, recharging must be performed according to the
remaining power level of the battery. Accordingly, researches and
commercialization are carried out for charging a moving robot by
making the moving robot go to a charging station, which is
installed in advance for the moving robot, by itself according to
its battery state. However, in outdoor environments, it is not easy
for the moving robot to accurately return to the charging station
due to a widely open space and various terrain characteristics.
[0013] Even if the moving robot reaches the position of the
charging station, it is necessary to set an accurate docking path
in order to correctly connect its connector to a connector of the
charging station. When wires are laid in a boundary of an area
where the moving robot travels, the moving robot moves to the
charging station along the laid wires, but laying the wires in the
boundary causes various other problems.
[0014] Korean Patent Registration No. 10-0902115 proposes a method
of precisely guiding a moving robot to a charging station using a
camera and infrared sensors. However, in the case of the camera and
the infrared sensors, the docking position can be precisely guided
only when the moving robot approaches the charging station to some
extent. Therefore, there are various problems in guiding a docking
path to the charging station for the moving robot in a widely open
space such as outdoor environments. Also, as in the case where the
moving robot is moving toward the charging station from the rear
with respect to a docking direction of the charging station, if the
moving robot is located in a blind spot of signals (or an angle of
view), a docking position is less likely to be induced.
SUMMARY
Technical Problem
[0015] Therefore, one aspect of the present disclosure is to
provide a moving robot, capable of carrying out docking for
charging by accurately returning to a charging station from a
current position even without installing wires in a travel boundary
of the moving robot, and a method of controlling the same.
[0016] Another aspect of the present disclosure is to provide a
moving robot, capable of efficiently setting a docking path for
charging using UWB signals without having to lay even a guide wire
around a charging station, and a method of controlling the
same.
[0017] Still another aspect of the present disclosure is to provide
a moving robot, capable of accurately carrying out docking even
without using a magnetic field SLAM while minimizing a signal blind
spot by covering all the 360-degree directions when the moving
robot attempts to dock to a charging station, and a method of
controlling the same.
Technical Solution
[0018] To achieve those aspects and other advantages of the present
disclosure, there is provided a moving robot that travels within
one area where a charging station is installed, the moving robot
including a traveling unit to rotate or move a main body, a power
supply unit to supply power to the main body, a communication unit
to transmit and receive signals to and from the charging station, a
memory to store therein coordinates information regarding a point
to which the main body has moved by a reference distance in a state
of being in contact with the charging station, and a control unit
to output a control command to return to the charging station based
on a state of the power supply unit while the main body travels in
the one area. In addition, the control unit may determine a
position of the charging station from a current position of the
main body based on a first signal transmitted from the charging
station and a second signal transmitted by the communication unit,
in response to the output of the control command, control the
traveling unit so that the main body moves to a position
corresponding to the stored coordinates information, calculate a
rotation angle for docking to the charging station based on the
first signal and the second signal when the main body reaches the
position corresponding to the stored coordinates information, and
control the traveling unit so that a head of the main body is
rotated according to the calculated rotation angle.
[0019] In one embodiment, the charging station may be provided with
a pair of Ultra-wideband (UWB) modules to transmit the first signal
and receive the second signal, and the communication unit of the
main body may be provided with a pair of UWB modules to receive the
first signal and transmit the second signal.
[0020] In one embodiment, the pair of UWB modules provided in the
communication unit may be disposed to be symmetric in right and
left directions with respect to the front of the main body, and
determine the position of the charging station with respect to the
current position of the main body by receiving the first signal
from the charging station, respectively.
[0021] In one embodiment, while the main body moves to the position
corresponding to the stored coordinates information, the control
unit may determine one intersection close to a head direction of
the main body as the position of the charging station, of two
intersections between a first circle that a distance between a
first UWB anchor provided in the communication unit and a first UWB
tag of the charging station is a radius and the first UWB anchor is
a center, and a second circle that a distance between a second UWB
anchor provided in the communication unit and a second UWB tag of
the charging station is a radius and the second UWB anchor is a
center.
[0022] In one embodiment, coordinates information of a point to
which the main body has moved backward by a reference distance in a
state of being in contact with the charging station may include
angle information calculated based on the first signal and the
second signal.
[0023] In one embodiment, the control unit may calculate distance
information and angle information between the current position of
the main body and the charging station based on the first signal
received from the charging station and the second signal
transmitted by the communication unit, in response to the output of
the control command, and control the traveling unit so that the
head of the main body is rotated toward the position corresponding
to the stored coordinates information.
[0024] In one embodiment, the control unit may check the position
of the charging station in real time based on the first signal
received through a plurality of UWB modules while the main body
moves to the position corresponding to the stored coordinates
information after the head of the main body is rotated toward the
point corresponding to the stored coordinates information.
[0025] In one embodiment, after the main body moves to the position
corresponding to the stored coordinates information, the control
unit may determine a head direction of the main body on the basis
of the angle information calculated based on the first signal
received from the charging station and the second signal
transmitted by the communication unit, and then control the
traveling unit so that the head is rotated according to the
determined head direction.
[0026] In one embodiment, after the head is rotated according to
the determined head direction, the control unit may check whether
or not to correct the determined head direction, based on a
difference between distances at which the first signal transmitted
from the charging station is received by a first UWB module and a
second UWB module disposed in the main body, respectively.
[0027] In one embodiment, a current head direction may be
determined as a docking direction when it is determined that the
distance at which the first signal is received by the first UWB
module is the same as the distance at which the first signal is
received by the second UWB module.
[0028] In one embodiment, the control unit may control the
traveling unit so that the main body docks to the charging station
by moving straightly by the reference distance, after the main body
rotates the head according to the calculated rotation angle at the
position corresponding to the stored coordinates information.
[0029] In one embodiment, the control unit may determine the
position of the charging station in real time based on the first
signal and the second signal while the main body moves to the
position corresponding to the stored coordinates information, and
set a docking path by avoiding the charging station when the
position of the charging station is included in a path along which
the main body moves to the stored coordinates information.
[0030] In one embodiment, the control unit may store position
information regarding the main body at a time point when the
control command has been output, and control the traveling unit so
that the main body moves to the stored position information when
the main body docks to the charging station and charging of the
power supply unit is completed.
[0031] To achieve these aspects and other advantages according to
the present disclosure, there is provided a method for controlling
a moving robot that travels within one area where a charging
station is installed, the method including storing in advance
coordinates information regarding a point, to which a main body of
the moving robot has moved by a reference distance in a state of
being in contact with the charging station, outputting a control
command to return to the charging station based on a state of a
power supply unit that supplies power to the main body while the
main body travels in the one area, determining a position of the
charging station with respect to the main body based on a first
signal transmitted from the charging station and a second signal
transmitted by the main body, in response to the output of the
control command, and controlling the main body to move to a
position corresponding to the stored coordinates information, and
calculating a rotation angle for docking to the charging station
based on the first signal and the second signal when the main body
reaches the position corresponding to the stored coordinates
information, and controlling a head of the main body to be rotated
according to the calculated rotation angle.
[0032] In one embodiment, the controlling the main body to move to
the position corresponding to the stored coordinates information
may include calculating distance information and angle information
between a current position of the main body and the charging
station based on the first signal received from the charging
station and the second signal transmitted by the main body, in
response to the output of the control command, and controlling the
head of the main body to be rotated toward the position
corresponding to the stored coordinates information.
[0033] In one embodiment, the method may further include checking
the position of the charging station in real time based on the
first signal received through a plurality of UWB modules provided
in the main body while the main body moves to the position
corresponding to the stored coordinates information after the head
of the main body is rotated toward the position corresponding to
the stored coordinates information.
[0034] In one embodiment, the method may further include, after the
main body moves to the position corresponding to the stored
coordinates information, determining a head direction of the main
body on the basis of angle information calculated based on the
first signal received from the charging station and the second
signal transmitted by the main body, and rotating the head
according to the determined head direction and docking to the
charging station.
Advantageous Effects
[0035] As described above, in a moving robot and a control method
thereof in accordance with an embodiment of the present disclosure,
a docking path for charging can be set without having to set wires
in a boundary along which the moving robot travels or to lay a
guide wire under the ground around a charging station. In addition,
since the moving robot can cover all the 360-degree directions when
docking to the charging station even if it is located at anywhere
within a boundary, a signal blind spot can be minimized and
accurate docking can be carried out without using a magnetic field
SLAM.
BRIEF DESCRIPTION OF THE DRAWINGS
[0036] FIG. 1 is a perspective view illustrating an example of a
moving robot according to the present disclosure.
[0037] FIG. 2A is a conceptual view illustrating a state where the
moving robot according to the present disclosure performs
communications with a terminal, a charging station, and a
server.
[0038] FIG. 2B is a block diagram illustrating an exemplary
configuration of a moving robot according to the present
disclosure, FIG. 2C is a block diagram illustrating an exemplary
configuration of a terminal communicating with the moving robot
according to the present disclosure, FIG. 2D is a block diagram
illustrating an exemplary configuration of a charging station
communicating with the moving robot according to the present
disclosure.
[0039] FIG. 3 is a conceptual view illustrating a signal flow
generated during communication among a moving robot, a terminal, a
charging station, a location information transmitter, and GPS, in
accordance with an embodiment of the present disclosure.
[0040] FIGS. 4A, 4B and 4C are conceptual views related to setting
a virtual boundary for the moving robot without laying wires under
the ground, in accordance with an embodiment of the present
disclosure.
[0041] FIG. 5 is a view illustrating the concept of Angle of
Arrival (AoA) positioning technology.
[0042] FIG. 6A is a view illustrating a concept of recognizing a
position of a charging station according to the positioning
technology of FIG. 5, and FIGS. 6B and 6C are exemplary views
illustrating that the moving robot docks to the charging station
using a guide wire.
[0043] FIG. 7 is a flowchart illustrating a method of controlling a
moving robot in accordance with an embodiment of the present
disclosure.
[0044] FIGS. 8A, 8B, 8C, 8D, 8E and 8F are conceptual views
illustrating operations of FIG. 7 in detail.
[0045] FIG. 9 is a conceptual view illustrating a method of docking
to the charging station when the moving robot is located in the
existing blind spot in accordance with an embodiment of the present
disclosure.
DETAILED DESCRIPTION
[0046] Hereinafter, a moving robot according to the present
disclosure will be described in detail with reference to the
accompanying drawings.
[0047] Hereinafter, description will be given in detail of
embodiments disclosed herein. Technical terms used in this
specification are merely used for explaining specific embodiments,
and should not be constructed to limit the scope of the technology
disclosed herein.
[0048] First, the term "moving robot" disclosed herein may be used
as the same meaning as "robot" which can autonomously travel, "lawn
mower moving robot," "lawn mower robot," "lawn mower," and "moving
robot for mowing lawn," and those terms will be used equally.
[0049] FIG. 1 is a block diagram of a moving robot for mowing lawn
according to the present disclosure.
[0050] A moving robot according to the present disclosure may
include an outer cover 101, an inner body (not shown), and wheels
1092.
[0051] The outer cover 101 may define appearance of the moving
robot. The appearance of the moving robot may be formed in a shape
similar to an automobile, for example. The outer cover 101 may be
formed to cover an outside of the inner body (not shown).
[0052] The outer cover 101 may be mounted on an upper portion of
the inner body so as to cover the upper portion of the inner body.
A receiving portion may be formed inside the outer cover 101, and
the inner body may be received in the receiving portion.
[0053] A bumper 102 may be provided on a front portion of the outer
cover 101 in preparation for collision with an obstacle. The bumper
102 may be formed of a rubber material that can mitigate
impact.
[0054] A plurality of ultrasonic sensor modules 103 may be mounted
on a front upper portion of the outer cover 101. The plurality of
ultrasonic sensor modules 103 is configured to emit ultrasonic
waves toward the front of the robot while the robot travels, and
receive reflected waves reflected from the obstacle, so as to
detect the front obstacle.
[0055] The plurality of ultrasonic sensor modules 103 may be spaced
apart from one another in a vehicle width direction. The plurality
of ultrasonic sensor modules 103 may be spaced apart from the
bumper 102 rearward by a designated distance. In addition, the
plurality of ultrasonic sensor modules 103 may be replaced with
other signal-based sensors, such as UWB sensors, other than the
ultrasonic sensors.
[0056] The moving robot may include a control unit. The control
unit may stop the operation of the moving robot when an obstacle is
detected by receiving a detection signal from the ultrasonic sensor
modules 103.
[0057] A first top cover 105 and a second top cover 106 may be
provided on the top of the outer cover 101. A stop switch 107 may
be provided between the first top cover 105 and the second top
cover 106. The stop switch 107 may be mounted on the outer cover
101 to be pressed. When the user presses the stop switch 107 one
time in an emergency state, the stop switch 107 may be switched on
so that the operation of the moving robot is stopped. When the stop
switch 107 is pressed once more, the operation of the moving robot
may be restarted.
[0058] The plurality of wheels 1092 may be connected respectively
to driving motors provided in the inner body, and rotatably mounted
on both side surfaces of the inner body 160 in a widthwise
direction of the inner body 160. Each of the plurality of wheels
1092 may be connected to the driving motors by a driving shaft, so
as to be rotatable by receiving power from the driving motors.
[0059] The plurality of wheels 1092 may supply power for the travel
of the robot, and each of the plurality of wheels 1092 may be
controlled by the control unit independently to be rotated by
different RPM.
[0060] In addition, a handle 120 (which may also be referred to as
a `carrying handle`) may be installed on the outer cover 101 so
that the user can grip it with a hand while carrying the moving
robot.
[0061] FIG. 2A illustrates a state in which the moving robot 100,
the charging station 300, the terminal 200, and the server 500
perform communication, in accordance with the present
disclosure.
[0062] The moving robot 100 according to the present disclosure may
exchange data with the charging station 300 or the terminal 200
through network communication.
[0063] In addition, the moving robot 100 may perform a
weeding-related operation or a corresponding operation according to
a control command received from the charging station 300 or the
terminal 200 through network communication or other communication.
The charging station 300 according to the present disclosure may
exchange data with the terminal 200 through network
communication.
[0064] Here, the network communication may refer to at least one of
wireless communication technologies, such as a wireless LAN (WLAN),
a wireless personal area network (WPAN), a wireless fidelity
(Wi-Fi) Wi-Fi direct, Digital Living Network Alliance (DLNA),
Wireless Broadband (WiBro), World Interoperability for Microwave
Access (WiMAX), Zigbee, Z-wave, Blue-Tooth, Radio Frequency
Identification (RFID), Infrared Data Association (IrDA),
Ultrawide-Band (UWB), Wireless Universal Serial Bus (USB), and the
like.
[0065] Here, other communications may refer to wireless
communication technologies by which communications are performed
directly without moving communication networks between the moving
robot 100 and the charging station 300, between the moving robot
100 and the terminal 200, and between the charging station 300 and
the terminal 200.
[0066] The illustrated network communication may vary depending on
a communication method of the moving robot 100.
[0067] In FIG. 2A, the moving robot 100 may provide information
sensed through each sensing unit to the charging station 300 or the
terminal 200 through network communication. In addition, the
terminal 200 may transmit a control command generated based on the
received information to the moving robot 100 through the network
communication.
[0068] On the other hand, the terminal 200 may be named as a
controller, a remote controller, or the like, which is operated by
a user to control operations related to the travel of the moving
robot 100. To this end, the terminal 200 may be provided with an
application installed therein for controlling operations related to
the traveling of the moving robot 100, and the corresponding
application may be executed through a user operation.
[0069] In FIG. 2A, a communication unit of the moving robot 100 and
a communication unit of the terminal 200 may also directly
communicate with each other or indirectly communicate with each
other via another router (not shown), to recognize information
related to a traveling operation of the moving robot and locations
of the moving robot and the terminal.
[0070] Also, the moving robot 100, the charging station 300, the
terminal 200 and the server 500 may be connected via a network and
exchange data with one another.
[0071] For example, the server 500 may exchange data with the
moving robot 100 and/or the terminal 200, to register information
related to a boundary set for the moving robot 100, map information
based on the set boundary, obstacle information on the map. In
addition, the server 500 may provide the registered information to
the moving robot 100, the charging station 300, and/or the terminal
200 according to a request.
[0072] The server 500 may be wirelessly connected to the moving
robot 100 through the terminal 200. Alternatively, the server 500
may be connected to the moving robot 100 without passing through
the terminal 200.
[0073] The server 500 may include a programmable processor and may
include various algorithms. By way of example, the server 500 may
be provided with algorithms related to performing machine learning
and/or data mining. As an example, the server 500 may include a
speech recognition algorithm. In this case, when receiving voice
data, the received voice data may be output by being converted into
data in a text format.
[0074] Meanwhile, the server 500 may store firmware information and
driving information (course information, and the like) for the
moving robot 100, and register product information related to the
moving robot 100. For example, the server 300 may be a server
managed by a moving robot manufacturer or a server managed by an
open application store operator.
[0075] Hereinafter, FIG. 2B is a block diagram illustrating an
exemplary configuration of the moving robot 100 according to the
present disclosure, and FIG. 2C is a block diagram illustrating an
exemplary configuration of the terminal 200 communicating with the
moving robot 100.
[0076] First, the configuration of the moving robot 100 will be
described in detail with reference to FIG. 2B.
[0077] As illustrated in FIG. 2B, the moving robot 100 may include
a communication unit 1100, an input unit 1200, a traveling unit
1300, a sensing unit 1400 provided with a location detector 1401
and an obstacle detector 1402, an output unit 1500, a memory 1600,
a weeding unit 1700, a control unit 1800, and a power supply unit
1900.
[0078] The communication unit 1100 may perform communication with
the terminal 200 through a wireless communication scheme. Also, the
communication unit 1100 may perform communication with the terminal
which is connected to a predetermined network to control an
external server or the moving robot.
[0079] The communication unit 1100 may transmit information related
to a generated map to the terminal 200. The communication unit 1100
may receive a command from the terminal 200 and transmit data
regarding an operation state of the moving robot 100 to the
terminal 200.
[0080] The communication unit 1100 transmits and receives data by
being equipped with a communication module such as Wi-Fi, WiBro,
and the like, as well as through short-range wireless
communications such as Zigbee and Bluetooth. In addition, the
communication unit 1100 may include a UWB module for transmitting
an UWB signal.
[0081] The input unit 1200 may include an input element such as at
least one button, a switch, and a touch pad. The output unit 1500
may include an output element such as a display unit and a speaker.
When the output unit 1500 is used simultaneously as the input
element and the output element, a user command can be input and the
operation state of the moving robot can be output through the
display unit or the speaker.
[0082] The memory 1600 may store therein an input detection signal,
reference data for determining an obstacle, and obstacle
information regarding a detected obstacle. The memory 1600 may also
store therein control data for controlling the operation of the
moving robot and data according to a cleaning mode of the moving
robot.
[0083] The memory 1600 may store therein collected location
information, and information related to a travel area and its
boundary. For example, the memory 1600 may store data that is
readable by a microprocessor, and may be one of a hard disk drive
(HDD), a solid state disk (SSD), a silicon disk drive (SDD), ROM,
RAM, CD-ROM, a magnetic tape, a floppy disk, or an optical data
storage device.
[0084] The traveling unit 1300 may include at least one driving
motor, and may allow the moving robot to move according to a
control command of the control unit 1800. The traveling unit 1300
may include a left wheel driving motor for rotating the left wheel
and a right wheel driving motor for rotating the right wheel. In
addition, the traveling unit 1300 may further include one or more
auxiliary wheels for stable support.
[0085] For example, while the moving robot main body travels, the
left wheel driving motor and the right wheel driving motor may be
rotated in the same direction. A traveling direction of the moving
robot main body (or moving robot) 100 may be switched when the left
wheel driving motor and the right wheel driving motor are rotated
at different speeds or in opposite directions.
[0086] The weeding unit 1700 cuts the lawn on a bottom surface
while the moving robot is traveling. The weeding unit 1700 is
provided with a brush or blade for cutting the lawn, and cuts the
lawn on the bottom surface in a rotating manner.
[0087] The obstacle detector 1402 may include a plurality of
sensors for detecting obstacles existing in front of the moving
robot. The obstacle detector 1402 may detect obstacles in front of
the main body, namely, in the traveling direction of the moving
robot, using at least one of a laser, ultrasonic waves, infrared
rays, and a 3D sensor.
[0088] In addition, the obstacle detector 1402 may include a camera
for capturing the front of the moving robot so as to detect an
obstacle. The camera is a digital camera, which may include an
image sensor (not shown) and an image processor (not shown). An
image sensor is an apparatus for converting an optical image into
an electrical signal. The image sensor is configured as a chip on
which a plurality of photo diodes is integrated, and the photodiode
may be a pixel, for example. Electric charges are accumulated in
the respective pixels by an image, which is formed on the chip by
light passing through a lens, and the electric charges accumulated
in the pixels are converted into an electrical signal (for example,
voltage). Charge Coupled Device (CCD), Complementary Metal Oxide
Semiconductor (CMOS), and the like are well known as image sensors.
In addition, a DSP or the like may be provided as the image
processor.
[0089] The location detector 1401 includes a plurality of sensor
modules for transmitting and receiving location information. The
location detector 1401 includes a GPS module that transmits and
receives GPS signals or a location sensor module that transmits and
receives location information to and from a location information
transmitter 50 (see FIG. 3). For example, the location detector 140
is provided with a sensor module that transmits and receives an
ultrasonic, UWB, or infrared signal when the location information
transmitter transmits a signal through one of ultrasonic wave,
ultra-wideband (UWB), and infrared ray.
[0090] When the location sensor module is implemented as a UWB
sensor module, even if an obstacle exists between the location
information transmitter 50 and the moving robot 100, signals can be
transmitted and received through such an obstacle or the like.
Therefore, transmission and reception of the UWB signals are
smoothly carried out.
[0091] Unless otherwise mentioned, it may be premised that the
location information transmitter 50 and the moving robot 100, the
location information transmitter 50 and the terminal 200, and the
moving robot 100 and the terminal 200 are provided with at least
one UWB sensor module so as to transmit and receive the UWB signals
to and from each other.
[0092] Also, even when the moving robot 100 moves while following
the terminal 200, the location may be determined using the sensor
module.
[0093] For example, when the moving robot 100 travels while
following the terminal 200, the terminal and the moving robot each
include a UWB sensor and perform wireless communication with each
other. The terminal may transmit a signal from its UWB sensor. The
moving robot may receive the signal of the terminal through its UWB
sensor and determine the location of the terminal based on the
signal of the terminal so as to follow the terminal.
[0094] As described above, since the UWB signal transmitted by the
UWB sensor can pass through an obstacle, the signal transmission is
not affected even if the user moves while holding the terminal.
However, in the case of an obstacle having a designated size or
more, the signal transmission may be failed or a signal
transmission distance may be reduced even if the signal is
transmitted through the obstacle.
[0095] In addition, the UWB sensors provided in the terminal and
the moving robot, respectively, may estimate or measure a distance
between them. When the moving robot follows the terminal, the
travel of the moving robot is controlled according to a distance
from the terminal, so that the moving robot does not move away from
the terminal by a predetermined distance. That is, the moving robot
may follow the terminal while maintaining a proper distance so that
the distance from the terminal is not too close or too far
away.
[0096] The location detector 1401 may include one UWB sensor or a
plurality of UWB sensors. For example, when the location detector
1401 includes two UWB sensors, for example, the two UWB sensors may
be provided on left and right sides of the main body of the moving
robot, respectively, to receive signals. Accordingly, the location
detector 1401 may detect the location by comparing the received
signals.
[0097] For example, when the distances measured respectively by the
left sensor and the right sensor are different according to the
locations of the moving robot and the terminal, relative locations
of the moving robot and the terminal and a direction of the moving
robot may be determined based on the distances.
[0098] Meanwhile, in addition to the obstacle detector 1402 and the
location detector 1401, the sensing unit 1400 may include various
sensors, such as a cliff detection sensor installed on a rear
surface of the main body to detect a cliff, a rain sensor to detect
a humid or rainy weather condition, a proximity sensor, a touch
sensor, an RGB sensor, a fuel gauge sensor, an acceleration sensor,
a geomagnetic sensor, a gravity sensor, a gyroscope sensor, an
illuminance sensor, an environmental sensor (a thermometer, a
radiation detection sensor, a heat detection sensor, a gas
detection sensor, etc.), a plurality of 360-degree sensors, a floor
state detection sensor, and the like.
[0099] In addition, the sensing unit 1400 may include at least one
tilt sensor (not shown) for detecting movement of the main body.
The tilt sensor calculates a tilted direction and a tilted angle of
the main body when the main body is tilted in a front, rear, left,
or right direction. The tilt sensor may be an acceleration sensor,
or the like. In the case of the acceleration sensor, any of a gyro
type, an inertial type, and a silicon semiconductor type is
applicable. In addition, various sensors or devices capable of
detecting the movement of the main body may be used.
[0100] The control unit 1800 controls data input/output, and
controls the traveling unit 1300 so that the moving robot travels
according to settings. The control unit 1800 controls the traveling
unit 1300 to independently control the operations of the left wheel
driving motor and the right wheel driving motor, so that the main
body of the moving robot 100 travels straight or rotate.
[0101] The control unit 1800 determines a traveling direction
corresponding to a signal received through the sensing unit 1400
and controls the traveling unit 1300. In addition, the control unit
1800 controls the traveling unit 1300 to vary a traveling speed, so
that the moving robot travels or stops according to the distance
from the terminal. Accordingly, the moving robot can move while
following locations of the terminal corresponding to the changes in
location of the terminal.
[0102] In addition, the control unit 1800 may control the moving
robot to move, following the terminal 200, according to a set
mode.
[0103] The control unit 1800 may set a virtual boundary for an area
based on location information received from the terminal 200 or
location information calculated through the location detector 1401.
Also, the control unit 1800 may set any one of areas formed by set
boundaries as a travel area. The control unit 1800 sets a boundary
in a shape of a closed loop by connecting discontinuous location
information with lines or curves, and sets an inner area of the set
boundary as the travel area. Also, when a plurality of boundaries
is set, the control unit 1800 may set any of areas formed by the
plurality of boundaries as a travel area.
[0104] When the boundary and the travel area are set, the control
unit 1800 controls the traveling unit 1300 so that the moving robot
travels within the travel area without moving over the set
boundary. The control unit 1800 calculates a current location based
on received location information, and controls the traveling unit
1300 so that the calculated current location is located within the
travel area set by the boundary.
[0105] In addition, the control unit 1800 may determine obstacle
information input by the obstacle detector 1402 and travel avoiding
obstacles. Also, the control unit 1800 may modify a preset travel
area, if necessary, based on the obstacle information.
[0106] For example, the control unit 1800 may control the traveling
unit 1300 to travel by passing through an obstacle or avoiding the
obstacle, by way of changing a moving direction or a travel path in
correspondence with obstacle information input from the obstacle
detector.
[0107] The control unit 1800 may set the moving robot so as not to
approach a cliff by a predetermined distance or closer when the
cliff is detected. In addition, the control unit 1800 may change a
traveling direction according to a user selection, which is input
through the terminal 200, by way of transmitting traveling
information regarding a detected obstacle to the terminal 200 and
displaying such information on the terminal.
[0108] The power supply unit 1900 includes a rechargeable battery
(or battery module) (not shown). The battery may be detachably
mounted to the moving robot 100. When it is detected through the
sensing unit 1400 that the battery gauge is insufficient, the
control unit 1800 may control the traveling unit 1300 to move the
moving robot to the location of a charging station for recharging
the battery. When presence of the charging station is detected by
the sensing unit 1400, recharging of the battery is performed.
[0109] Hereinafter, the main configuration of the terminal 200 that
performs communication with the moving robot 100 according to the
present disclosure will be described, with reference to FIG.
2C.
[0110] Referring to FIG. 2C, the terminal 200 may include a mobile
terminal that can be carried by a user and may include a
communication unit 210, an input unit 220, a UWB module 230, a
sensing unit 240, a display unit 251, a memory 260, and a control
unit 280.
[0111] The communication unit 210 may perform communication with an
external server or the moving robot 100 through wireless
communication. The communication unit 210 transmits and receives
data by being equipped with a communication module such as Wi-Fi,
WiBro, and the like, as well as through short-range wireless
communications such as Zigbee and Bluetooth. In addition, the
communication unit 210 may include a UWB module for transmitting a
UWB signal.
[0112] The input unit 220 may include an input element such as at
least one button, a switch, and a touch pad.
[0113] Also, the input unit 220 is configured to permit various
types of inputs to the wearable device 100. Examples of such inputs
include image information (or signal), audio information (or
signal), data or various information input by a user, and may be
provided with one or a plurality of cameras 221.
[0114] Such cameras 221 may process image frames of still pictures
or videos obtained by image sensors in an image capture mode. The
processed image frames may be displayed on the display unit 251 or
stored in memory 170. Meanwhile, the cameras 221 provided in the
terminal 200 may be arranged in a matrix configuration to permit a
plurality of images having various angles or focal points to be
input to the terminal 200. Also, the cameras 221 may be located in
a stereoscopic arrangement to acquire left and right images for
implementing a stereoscopic image.
[0115] The camera 221 typically includes at least one a camera
sensor (CCD, CMOS, etc.), a photo sensor (or image sensors), and a
laser sensor.
[0116] Implementing the camera 221 with a laser sensor may allow
detection of a touch of a physical object with respect to a 3D
stereoscopic image. The photo sensor may be laminated on, or
overlapped with, the display device. The photo sensor may be
configured to scan movement of the physical object in proximity to
the touch screen. In more detail, the photo sensor may include
photo diodes and transistors (TRs) at rows and columns to scan
content received at the photo sensor using an electrical signal
which changes according to the quantity of applied light. Namely,
the photo sensor may calculate the coordinates of the physical
object according to variation of light to thus obtain location
information of the physical object.
[0117] The display unit 251 may include a touch sensor to receive a
control command through a touch input. In addition, the display
unit 251 may be configured to output a control screen for
controlling the moving robot 100, and a map screen on which a set
boundary and the location of the moving robot 100 are
displayed.
[0118] The memory 260 may store therein data related to the travel
of the moving robot 100. In addition, the memory 260 may store
therein location information regarding the moving robot 100 and the
terminal 200, and information regarding a travel area of the moving
robot and a boundary of the travel area. For example, the memory
1600 may store data that is readable by a microprocessor, and may
be one of a hard disk drive (HDD), a solid state disk (SSD), a
silicon disk drive (SDD), ROM, RAM, CD-ROM, a magnetic tape, a
floppy disk, or an optical data storage device.
[0119] The sensing unit 240 includes a location detector (not
shown) for transmitting and receiving location information, and at
least some of a gyro sensor and an acceleration sensor for sensing
a change in spatial motion of the terminal 200, a geomagnetic
sensor, and an IMU (Inertia Measurement Unit) sensor. At this time,
the gyro sensor and the acceleration sensor may be implemented as
any one of 3-axis, 6-axis, or 9-axis gyro sensor and acceleration
sensor.
[0120] The location detector includes a plurality of sensor modules
for transmitting and receiving location information. For example,
the location detector may include a GPS module, an Ultra-Wideband
(UWB) module, a geomagnetic sensor, an acceleration sensor, a gyro
sensor, and the like, to recognize coordinates of a point which is
indicated by a posture change such as a tilt or the like, as well
as a current location of the terminal 200.
[0121] The UWB module 230 which is included in the location
detector or separately provided may exchange UWB signals with the
moving robot 100 and/or the location information transmitter 50.
Accordingly, not only the location of the terminal 200 but also the
location of the moving robot 100 with respect to the terminal 200,
the location of the location information transmitter 50 with
respect to the terminal 200, the location of the location
information transmitter 50 with respect to the moving robot 100,
and the like can be recognized.
[0122] The acceleration sensor is a sensor that measures how much
force an object is receiving based on gravitational acceleration of
the earth. A three-axis acceleration sensor refers to a sensor
capable of measuring magnitude of acceleration in x, y, and z-axial
directions. Such an acceleration sensor may be used as one
three-axis acceleration sensor, a six-axis acceleration sensor with
two three-axis acceleration sensors applied, or a nine-axis
acceleration sensor with three three-axis acceleration sensors
applied.
[0123] By using a sensing value of the three-axis acceleration
sensor, roll (rotation with respect to the x axis) and pitch
(rotation with respect to the y axis) may be calculated. A unit
used is [g]. On the other hand, rotation with respect to the z axis
coinciding with the direction of gravitational acceleration, that
is, a yaw (rotation with respect to the z axis) value may be
calculated only by additionally applying a three-axis gyro sensor
or a magnetometer. Also, in a motion state in which an object is
not stopped, a tilt value cannot be detected by only the three-axis
acceleration sensor.
[0124] The three-axis gyro sensor is a sensor for controlling
posture of an object, namely, a sensor capable of measuring angular
velocity in the x, y, and z-axial directions. Here, the angular
velocity refers to an angle of rotation per hour. A unit used is
[degree/sec].
[0125] The IMU sensor is a combined sensor of a three-axis
acceleration sensor and a three-axis gyro sensor. Alternatively,
the IMU sensor is a nine-axis sensor with a three-axis acceleration
sensor, a three-axis gyro sensor, and a three-axis geomagnetic
sensor. By using such an IMU sensor, the roll, the pitch and the
yaw can all be calculated.
[0126] The UWB module 230 may transmit or receive a UWB signal
through a UWB module provided in the moving robot 100. The terminal
200 may play a role of `remote control device` in that it can
control the travel or weeding operation of the moving robot 100
through communication with the moving robot 100.
[0127] In addition to the UWB module 210, the terminal 200 may
further include a distance measuring sensor.
[0128] The distance measuring sensor may emit at least one of a
laser light signal, an IR signal, an ultrasonic signal, a carrier
frequency, and an impulse signal, and may calculate a distance from
the terminal 200 to the corresponding signal based on a reflected
signal.
[0129] To this end, the distance measuring sensor may include, for
example, a time of flight (ToF) sensor. For example, the ToF sensor
may include a transmitter that emits an optical signal transformed
to a specific frequency, and a receiver that receives and measures
a reflected signal. When the ToF sensor is installed on the
terminal 200, the transmitter and the receiver may be spaced apart
from each other to avoid signal affection therebetween.
[0130] Hereinafter, the laser light signal, the IR signal, the
ultrasonic signal, the carrier frequency, the impulse signal, and
the UWB signal described above may collectively be referred to as
`signal`. In this specification, `UWB signal` which is rarely
affected by an obstacle will be exemplarily described. Therefore,
it can be said that the distance measuring sensor plays a role of
calculating a distance from the terminal 200 to a point where a
signal is emitted. In addition, the distance measuring sensor may
include a transmitter that emits signals and one receiver or a
plurality of receivers for receiving reflected signals.
[0131] Hereinafter, an exemplary configuration of the charging
station 300 for charging a power supply unit (battery) included in
the moving robot according to the present disclosure will be
described with reference to FIG. 2D.
[0132] Referring to FIG. 2D, the charging station 300 may include a
charging contact unit 320, a sensing unit 330, a communication unit
340, and a control unit (or processor).
[0133] The charging station 300 may include a charge contact unit
320 configured to transmit and receive electric signals with the
moving robot 100 and to charge the battery included in the moving
robot 100. When a connector provided in the moving robot 100 and
the charging contact unit 320 are in contact with each other, the
battery provided in the moving robot 100 may be charged.
[0134] The sensing unit 330 may sense a position, a traveling path,
and a posture (a direction which the moving robot faces) of the
moving robot 100 which is approaching the charging station 300.
[0135] Thereafter, the control unit (processor) may transmit
information sensed by the sensing unit 330 to the moving robot 100
through the communication unit 340, so that the moving robot
properly docks to the charging station (or the connector of the
moving robot and the charging contact unit of the charging station
are properly in contact with each other).
[0136] In addition, the sensing unit 330 may be configured to sense
surrounding information of the charging station 300. For example,
the sensing unit 330 may sense an event occurring in a space where
the charging station 300 is installed.
[0137] The sensing unit 330 may also sense information related to
the moving robot 100 or information related to the terminal
300.
[0138] For example, the sensing unit 330 may sense a distance
between the moving robot 100 and the charging station 300, the
position of the moving robot 100, a direction (or angle) that the
moving robot 100 is located, a traveling path (or traveling
trajectory) of the moving robot 100, and whether or not the moving
robot 100 is approaching the charging station 300.
[0139] Also, the sensing unit 330 may sense location information
(position information) regarding the terminal 200 with respect to
the charging station 300.
[0140] For this, the sensing unit 330 may include a UWB module
configured to transmit and receive UWB signals to and from a UWB
module provided in the terminal 200 or the moving robot 100.
[0141] That is, the sensing unit 330 may include a distance
measuring sensor.
[0142] The distance measuring sensor may emit at least one of a
laser light signal, an IR signal, an ultrasonic signal, a carrier
frequency, and an impulse signal, and may calculate a distance to
the corresponding signal based on a reflected signal.
[0143] To this end, the distance measuring sensor may include, for
example, a time of flight (ToF) sensor. For example, the ToF sensor
may include a transmitter that emits an optical signal transformed
to a specific frequency, and a receiver that receives and measures
a reflected signal. The transmitter and the receiver may be spaced
apart from each other to avoid signal affection therebetween.
[0144] The communication unit 340 may perform communication with an
external server 500, the terminal 200, or the moving robot 100
through wireless communication. The communication unit 340
transmits and receives data by being equipped with a communication
module such as Wi-Fi, WiBro, and the like, as well as through
short-range wireless communications such as
[0145] Zigbee and Bluetooth. In addition, the communication unit
340 may include a UWB module for transmitting a UWB signal.
[0146] Also, the communication unit 340 may perform communication
with the server 400, the terminal 200, or the moving robot 100
through the network communication described above. To this end, the
communication unit 340 may be wirelessly connected to the mobile
communication network and may communicate with the server 500, the
terminal 200, or the moving robot 100 through the mobile
communication network.
[0147] However, the present disclosure is not limited to this, and
the communication unit 340 may be configured to directly
communicate with the moving robot 100 or the terminal 200.
[0148] Hereinafter, FIG. 3 is a conceptual view illustrating a
signal flow of devices for setting a boundary with respect to a
moving robot, for example, a signal flow of the moving robot 100,
the terminal 200, a GPS 60, the location information transmitter
50, and the charging station 300.
[0149] The signal transmitted from the charging station 300 may be
an Ultra-wideband (UWB) signal. To this end, the charging station
300 may comprise at least one UWB module (UWB sensor). In this
case, the moving robot 100 may receive the UWB signal transmitted
from the charging station 300, and determine the current position
based on the UWB signal.
[0150] In addition, the charging station 300 may include a GPS
module to transmit GPS signals. In this case, the GPS signals
transmitted from the charging station 300 may be received by the
GPS satellite. The GPS satellite may transmit a reception result of
the GPS signals received from the charging station 300 to the
moving robot 100.
[0151] When the location information transmitter 50 transmits a
signal by its UWB sensor, the terminal 200 may receive a signal
related to location information from the location information
transmitter 50 through a UWB module provided in the terminal 200
itself. At this time, a signaling method of the location
information transmitter 50 and a signaling method between the
moving robot 100 and the terminal 200 may be the same or different
from each other.
[0152] For example, the terminal 200 may transmit ultrasonic waves
and the moving robot 100 may receive the ultrasonic waves of the
terminal 200 to follow the terminal 200. As another example, a
marker may be attached on the terminal 200. The moving robot 100
may recognize the marker attached on the terminal 200 by capturing
a moving direction of the terminal, so as to follow the terminal
200.
[0153] In FIG. 3, location information may be received from the
location information transmitter 50 or the GPS 60. A GPS signal, an
ultrasonic signal, an infrared signal, an electromagnetic signal,
or a UWB signal may be used as a signal corresponding to the
location information.
[0154] The moving robot needs to collect location information for
setting a travel area and a boundary. The moving robot 100 may
collect location information by setting any one point of an area as
a reference location. At this time, a location of any one of an
initial start point, the charging station, and the location
information transmitter 50 may be set as the reference location.
The moving robot 100 may generate coordinates and a map for the
area on the basis of the set reference location and store the
generated coordinates and map. When the map is generated and
stored, the moving robot 100 may move based on the map.
[0155] In addition, the moving robot 100 may set a new reference
location at every operation, and determine a location within the
area based on the newly-set reference location.
[0156] Also, the moving robot 100 may receive location information
collected from the terminal 200 which is moving along a
predetermined path.
[0157] The terminal 200 may move arbitrarily and its moving path
may change according to a subject which moves the terminal.
However, in order to set a travel area of the moving robot, the
terminal 200 may preferably move along an outer side of the travel
area.
[0158] The terminal 200 calculates coordinates of a location within
an area based on a reference location. In addition, the moving
robot 100 may collect location information while moving with
following the terminal 200.
[0159] When the terminal 200 or the moving robot 100 travels along
a predetermined path alone, the terminal 200 or the moving robot
100 may calculate a current location based on a signal transmitted
from the GPS 60 or the location information transmitter 50.
[0160] The moving robot 100 and the terminal 200 may move by
setting the same reference location with respect to a predetermined
area. When the reference location is changed at every operation,
the reference location set with respect to the terminal 200 and
location information collected from the reference location may be
transmitted to the moving robot 100. The moving robot 100 may set a
boundary based on the received location information.
[0161] Meanwhile, the moving robot 100 and the terminal 200 may
determine their relative locations using Ultra-wide Band (UWB)
technology. To this end, one of UWB modules may be a UWB anchor and
the other one may be a UWB tag.
[0162] For example, the UWB module 230 of the terminal 200 may
operate as `UWB tag` that emits an UWB signal, and the UWB module
of the moving robot 100 may operates as `UWB anchor` that receives
a UWB signal.
[0163] However, it should be noted that the present disclosure is
not limited to this. For example, the UWB module 230 of the
terminal 200 may operate as an UWB anchor, and the UWB module of
the moving robot 100 may operate as a UWB tag. In addition, the UWB
module may include one UWB anchor and a plurality of UWB tags.
[0164] Hereinafter, description will be given of a method in which
the moving robot 100 and the terminal 200 determine (recognize)
their relative locations through a UWB communication technology.
First, a distance between the moving robot 100 and the terminal 200
is calculated using a distance measurement technology such as a ToF
(Time of Flight) scheme.
[0165] Specifically, a first impulse signal, which is a UWB signal
radiated (emitted) from the terminal 200, is transmitted to the
moving robot 100. To this end, the UWB module of the terminal 200
may operate as `UWB tag` for transmission and the UWB module of the
moving robot 100 may operate as `UWB anchor` for reception.
[0166] Here, the UWB signal (or the impulse signal) can be smoothly
transmitted and received even if an obstacle exists in a specific
space, and the specific space may have a radius of several tens of
meters (m).
[0167] The first impulse signal may be received through the UWB
anchor of the moving robot 100. The moving robot 100 which has
received the first impulse signal transmits a response signal to
the terminal 200. Then, the terminal 200 may transmit a second
impulse signal, which is an UWB signal with respect to the response
signal, to the moving robot 100. Here, the second impulse signal
may include delay time information which is calculated based on a
time at which the response signal has been received and a time at
which the second impulse signal has been transmitted responsive to
the response signal.
[0168] The control unit of the moving robot 100 may calculate a
distance between the moving robot 100 and the terminal 200, based
on a time at which the response signal has been transmitted, a time
at which the second impulse signal has been arrived at the UWB
anchor of the moving robot 100, and the delay time information
included in the second impulse signal.
Distance ? c * t 2 - t 1 - t ? 2 ##EQU00001## ? indicates text
missing or illegible when filed ##EQU00001.2##
[0169] Here, t2 denotes an arrival time of the second impulse
signal, t1 denotes a transmission time of the response signal,
treply denotes a delay time, and c denotes a constant value
indicating a speed of light.
[0170] As such, the distance between the moving robot 100 and the
terminal 200 can be determined by measuring a time difference
between signals transmitted and received between the UWB tag and
the UWB anchor included in the moving robot 100 and the terminal
200, respectively.
[0171] A distance between the moving robot 100 and the location
information transmitter 50 and a distance between the terminal 200
and the location information transmitter 50 can also be determined
in the same or similar manner.
[0172] Hereinafter, an operation of setting a boundary with respect
to the moving robot 100 using the location information transmitter
50 and the terminal 200 without laying wires under the ground will
be described, with reference to FIGS. 4A to 4C.
[0173] In this manner, a boundary which is a reference of a travel
area may be set using the location information transmitter 50, the
terminal 200, and the moving robot 100, or using only the location
information transmitter 50 and the moving robot 100, without
embedding wires. A travel area which is distinguished by the
boundary may be referred as to `wireless area.`
[0174] The `wireless area` may be one or plural. In addition, one
wireless area may include a plurality of spot areas additionally
set in the corresponding area, so that a mowing function performed
by the moving robot 100 can be performed more efficiently.
[0175] A boundary must be set so that the moving robot 100 can
perform mowing while moving in a travel area set outdoors. Then, a
travel area, namely, a wireless area in which the moving robot 100
is to travel is designated inside the set boundary.
[0176] Referring to FIG. 4A, there may be various obstacles 10a,
10b, and 10c at the outdoors in addition to a house illustrated in
the drawing. Here, the obstacles 10a, 10b, and 10c may include, for
example, fixed obstacles such as a building, a rock, a tree, a
swimming pool, a pond, a statue, a garden, and the like, which
exist at the outdoors, and obstacles that move. Also, size and
shape of the obstacles 10a, 10b, and 10c may be very various.
[0177] If the obstacles are present close to the set boundary, the
boundary must be set, from the beginning, to avoid these various
obstacles 10a, 10b, 10c.
[0178] However, as illustrated in FIG. 4A, when the obstacles 10a,
10b, and 10c exist within a travel area set based on a boundary R,
additional boundaries for the respective obstacles 10a, 10b, and
10c should be set or the previously-set boundary should be changed
through the same or similar process to the method of setting the
travel area inside the boundary R.
[0179] Also, in the present disclosure, a plurality of location
information transmitters 50M, 51, 52, 53, 54, and 55 may be
installed in advance in a predetermined area, in order to set a
boundary without laying wires.
[0180] The plurality of location information transmitters 50M, 51,
52, 53, 54, and 55 may transmit signals. Specifically, the
plurality of location information transmitters 50M, 51, 52, 53, 54,
and 55 may transmit signals to one another or may transmit signals
to the moving robot 100 and/or the terminal 200.
[0181] Here, the signals may include, for example, UWB signals,
ultrasonic signals, infrared signals, Bluetooth signals, Zigbee
signals, or the like.
[0182] At least three of the plurality of location information
transmitters 50M, 51, 52, 53, 54, and 55 may be installed in a
spaced manner. Also, the plurality of location information
transmitters 50M, 51, 52, 53, 54, and 55 may be installed at high
points higher than a reference height, in order to minimize signal
interference when the UWB sensor is not included.
[0183] The plurality of location information transmitters 50M, 51,
52, 53, 54, and 55 is preferably installed at locations adjacent to
a boundary to be set. The plurality of location information
transmitters 50M, 51, 52, 53, 54, and 55 may be installed outside
or inside a boundary to be set.
[0184] For example, FIG. 4A illustrates a plurality of location
information transmitters 50M, 51, 52, 53, 54, and 55 installed
inside the boundary R, but the present disclosure is not limited
thereto. For example, the plurality of location information
transmitters 50M, 51, 52, 53, 54 and 55 may be installed outside
the boundary R, or some may be installed inside the boundary R and
the others outside the boundary R.
[0185] When the location information transmitter 50M, 51, 52, 53,
54, 55 includes a UWB sensor, the UWB sensor may transmit and
receive UWB signals to and from the moving robot 100 and/or the
terminal 200 located in a predetermined area, so as to calculate
location information regarding the moving robot 100 and/or the
terminal 200.
[0186] For example, the moving robot 100 may calculate the location
of the moving robot 100 by comparing amounts/intensities of signals
of the plurality of location information transmitters 50M, 51, 52,
53, 54, and 55 and determining a spaced distance and direction from
each location information transmitter. A method of calculating
location information regarding the terminal 200 may be similarly
performed.
[0187] At least one of the plurality of location information
transmitters 50M, 51, 52, 53, 54, and 55 may be a reference
location information transmitter 50M for setting a boundary. The
reference location information transmitter 50M may be installed at
a place where a charging station 70 is located, for example, as
illustrated in FIG. 4A.
[0188] coordinates values of the plurality of location information
transmitters 50M, 51, 52, 53, 54, and 55 may be set based on the
reference location information transmitter 50M. More specifically,
the location information transmitter 50M may transmit and receive
signals to and from the remaining location information transmitters
51, 52, 53, 54, and 55, to calculate x and y coordinate values
corresponding to the locations of the remaining location
information transmitters, with respect to the reference location
information transmitter as a zero point. Accordingly, the location
information regarding the plurality of location information
transmitters 50M, 51, 52, 53, 54, and 55 can be set.
[0189] When the moving robot 100 sets the charging station 70 where
the reference location information transmitter 50M is located as an
operation start point, it may be easier to determine (recognize)
the location of the moving robot 100 at every operation. Also, when
a battery gauge is insufficient during the travel of the moving
robot 100, the moving robot 100 may move to the reference location
information transmitter 50M where the charging station 70 is
located and charge the battery.
[0190] When the reference location information transmitter 50M is
installed at a place where the charging station 70 is located, it
is not necessary to set the location of the charging station 70
separately.
[0191] On the other hand, when the moving robot 100 becomes
significantly far away from the reference location information
transmitter 50M as it keeps traveling, the reference location
information transmitter may be changed to another location
information transmitter which is located close to a current
location of the moving robot, based on amounts/intensities of
signals transmitted from the plurality of location information
transmitters 50M, 51, 52, 53, 54, and 55.
[0192] On the other hand, unlike FIG. 4A, when the charging station
70 is located outside the boundary R, that is, the boundary has
been set at an inner side than the charging station 70, the moving
robot 100 may return to the charging station over the boundary for
recharging the battery.
[0193] However, when the charging station 70 is located outside the
boundary, a moving area (not shown) may be additionally set between
the charging station 70 and the travel area set within the
boundary, so as to guide the moving robot 100 to return to the
charging station 70 located outside the boundary.
[0194] Hereinafter, FIG. 4B exemplarily illustrates a method of
setting a boundary for the moving robot 100 and a travel area with
respect to the boundary, by using the plurality of location
information transmitters 50M, 51, 52, 53, 54, and 55 and the
terminal 200.
[0195] First, the terminal 200 moves from the location information
transmitter 55 along a first path 401 at an outer side of an area,
in which lawn is planted. At this time, the terminal 200 may be
moved by a person, but may also be moved by another transportation
device such as a drone.
[0196] The terminal 200 may determine a current location through
the location information transmitter 55 or a GPS. As the mobile
terminal 200 moves, a distance and direction to each location
information transmitter may be calculated based on signals
transmitted from the other location information transmitters 51 to
54. Accordingly, coordinates of the plurality of points
corresponding to the change of the location of the terminal 200 may
be recognized and stored as location information.
[0197] In this regard, each of the plurality of location
information transmitters 50M, 51, 52, 53, 54, and 55 may transmit a
UWB including unique information for identifying a signal.
Accordingly, the terminal 200 can individually analyze and process
a first signal 411 transmitted from the first location information
transmitter 51, a second signal 412 transmitted from the second
location information transmitter 52, a third signal 413 transmitted
from the third location information transmitter 53, and a fourth
signal 414 transmitted from the fourth location information
transmitter 54.
[0198] In addition to this, the first to third location information
transmitters 51 to 53 may transmit and receive signals 421 to 423
to the fourth location information transmitter 54, which is located
close to the current location of the terminal 200, receive a
response signal to the transmitted signals, and transmit a signal
424 corresponding to the response signal to the terminal. The
terminal can check whether or not there is an error between the
current location of the corresponding location information
transmitter 54 and the predefined location (initially-installed
point) based on the signal 424.
[0199] According to this, the location error of the location
information transmitter can be checked together when the moving
robot 100 moves for setting the travel area or the wireless
area.
[0200] When the movement corresponding to the first path 401 is
completed, for example, when the first path 401 forms a shape of a
closed curve or reaches a designated end point, the terminal 200
transmits location information, which has been stored while moving
along the first path 401, to the moving robot 100.
[0201] Then, the moving robot 100 may set a line, which
sequentially connects the location information stored while the
terminal 200 moves along the first path 401, or an outer line of
the line, as a boundary R. In addition, the moving robot 100 may
set an inner area of the first path 401 with respect to the set
boundary R as a travel area or a wireless area.
[0202] The moving robot 100 may perform test traveling in the set
travel area or wireless area. At this time, the boundary and/or the
travel area may be partially modified by the moving robot 100. For
example, the boundary and/or the travel area for the moving robot
100 may be partially modified in consideration of situation
information, collected when a new obstacle is detected, when an
existing obstacle is removed, when an uneven surface or a pothole
is detected, or when a non-travelable spot due to the traveling
function of the moving robot 100 is detected.
[0203] Or, as illustrated in FIG. 4B, the moving robot 100 follows
the location of the terminal 200 at a predetermined distance while
the terminal 200 moves along the first path 401, and accordingly
the boundary and/or the travel area for the moving robot 100 can be
set without additional test traveling.
[0204] At this time, there may be a difference between the first
path 401 along which the terminal 200 has moved and the moving path
of the moving robot 100 following the terminal 200. That is, the
moving robot 100 can move, following the terminal 200, in a manner
of ignoring or removing a location which the moving robot 100
cannot follow on the track of the first path 401, along which the
terminal 200 has moved. In this case, the moving robot 100 may
store the corresponding location change and may keep following the
current location of the terminal 200 based on points corresponding
to the location change.
[0205] When the distance between the terminal 200 and the moving
robot 100 exceeds a predetermined distance as the traveling speed
of the moving robot 100 is slowed due to obstacle avoidance or the
like, a designated warning sound (`first warning sound`) may be
output from the moving robot 100 to notify the excess so that a
user or the like moving the terminal 200 can stop the movement of
the terminal 200.
[0206] Thereafter, when the moving robot 100 restarts to travel by
avoiding obstacles and the like in a designated manner and
accordingly the distance to the terminal 200 in the stopped state
is reduced to be in a designated range again, a corresponding
warning sound (`second warning sound`) may be output from the
moving robot 100 to notify it so that the user or the like moving
the terminal 200 can perform the movement.
[0207] Meanwhile, FIG. 4B exemplarily illustrates that the location
information regarding the moving robot 100 and/or the terminal 200
is calculated by the plurality of location information transmitters
50M, 51, 52, 53, 54, and 55 upon movement for setting the travel
area or wireless area, but such location information may, of
course, be calculated through GPS.
[0208] FIG. 4C exemplarily illustrates that additional boundaries
for a plurality of obstacles 10a, 10b, and 10c existing in a travel
area (or wireless area) 410 in a state where a boundary R and the
travel area inside the boundary R have been set.
[0209] In FIG. 4C, if there are obstacles 10a, 10b, and 10c having
a predetermined size or greater inside the set travel area 410,
additional boundaries for the detected obstacles 10a, 10b, and 10c
may be set.
[0210] The moving robot 100 (or the terminal 200 and the moving
robot 100 or the terminal 200) may set additional boundaries and a
travel area with respect to the additional boundaries by moving
along outer peripheries of the obstacles 10a, 10b, and 10c in the
same or similar manner as described above with reference to FIG.
4B.
[0211] In FIG. 4C, dashed lines formed at the outside of the
obstacles 10a, 10b, 10c may indicate the additional boundaries.
Unlike the boundary set in FIG. 4B, an inner side is set as a
non-travelable area and an outer side as a travelable area, with
respect to the set additional boundary.
[0212] Thus, the change of the travel area due to the setting of
the additional boundary can be reflected in the modification of the
existing boundary and travel area. A map corresponding to the
existing boundary and travel area can also be modified
accordingly.
[0213] The moving robot 100 may perform operations such as weeding
and the like while moving in the travelable area within the travel
area. While the moving robot 100 moves in the travelable area
within the travel area, the plurality of location information
transmitters 50M, 51, 52, 53, 54 and 55 transmit signals, for
example, UWB signals {circle around (1)} to one another, thereby
determining their locations. Also, the plurality of location
information transmitters 50M, 51, 52, 53, 54 and 55 transmit
signals, for example, UWB signals {circle around (2)} to the moving
robot 100, so that the moving robot 100 can recognize its current
location within the travel area.
[0214] Meanwhile, the moving robot 100 according to the present
disclosure may determine (recognize) the relative location of a
location information transmitter or a charging station based on a
UWB signal transmitted from the location information transmitter or
the charging station.
[0215] Here, the location information transmitter or the charging
station that transmits the UWB signal may be referred to as "UWB
tag". The moving robot 100 that recognizes the position by
receiving the UWB signal transmitted from the location information
transmitter or the charging station may be referred to as "UWB
anchor". An Angle of Arrival (AoA) positioning technology may be
used as one of positioning technologies by which a UWB anchor
recognizes the position of a UWB tag.
[0216] The moving robot 100 uses the AoA (Angle of Arrival)
positioning technique to determine the relative location of the
location information transmitter. Hereinafter, an AoA (Angle of
Arrival) positioning technique will be described with reference to
FIG. 5A.
[0217] Referring to FIG. 5A, the UWB anchor includes antennas A1
and A2 in a first transceiver and a second transceiver,
respectively, for receiving UWB signals. The UWB tag T1 transmits
the UWB signals through an antenna of a third transceiver (Transmit
Signal). Then, the first antenna A1 and the second antenna A2 of
the UWB anchor receive the UWB signals.
[0218] At this time, if a distance I between the UWB anchor and the
UWB tag T1 is longer than a spaced distance d between the first
antenna A1 and the second antenna A2 provided in the UWB anchor, an
incident shape as shown in FIG. 5A is shown if the transmitted UWB
signals are in the form of a plane wave.
[0219] Therefore, a distance difference is caused between the UWB
signals incident on the first antenna A1 and the second antenna A2.
The distance difference corresponds to p in FIG. 5A. An angle
formed by a first line connecting the first antenna A1 and the
second antenna A2 and a second line orthogonal to the first line is
.theta.. Therefore, the angle .theta. may be calculated through the
following Equation 1.
p = d sin .theta. [ Equation 1 ] sin .theta. = p d ##EQU00002##
[0220] Meanwhile, the distance between the first antenna A1 or the
second antenna A2 and the UWB tag T1 may be measured using two-way
ranging. Two-way ranging is a method in which a transmitter and a
receiver share their own time information while exchanging signals
several times so as to eliminate a time error and thus measure a
distance.
[0221] When the spaced distance 1 between the first antenna A1 or
the second antenna A2 and the UWB tag T1 is known and the angle
.theta. described above is obtained, a relative location of the UWB
tag T1 with respect to the first antenna A1 and the second antenna
A2 may be determined through the following Equation 2.
.alpha. 2 .pi. = p .lamda. [ Equation 2 ] .theta. = sin - 1 .alpha.
.lamda. 2 .pi. d ##EQU00003##
[0222] Here, .alpha. denotes a phase difference between UWB signals
received by the first transceiver and the second transceiver
provided in the UWB anchor.
[0223] As described above, the UWB anchor may transmit and receive
signals to and from the UWB tag, thereby determining the relative
position of the UWB tag.
[0224] Referring to FIG. 6A, the charging station 300 for charging
the moving robot 100 may be installed within the boundary R of the
aforementioned wireless area. The charging station 300 may also
include a communication unit 340 to transmit signals, for example,
UWB signals, indicating a location.
[0225] When it is determined that the moving robot 100 located
within the area is required to be recharged, the moving robot 100
should determine a relative position by transmitting and receiving
signals, for example, UWB signals, to and from the charging station
300, in order to approach a point (or position) where the charging
station is installed. More specifically, the moving robot 100
should recognize distance information d from its current position
to the charging station 300 and angle information .theta. formed by
its current position and the charging contact unit of the charging
station.
[0226] On the other hand, if the moving robot 100 approaches the
charging station 300 without a plan, it is difficult to expect that
the charging connector located on the front of the moving robot 100
is accurately connected to the charging contact unit of the
charging station 300. Therefore, it is necessary to set a planned
docking path in consideration of accurate connection, i.e.,
docking.
[0227] In the case where the boundary of the area is set by wires,
the moving robot can approach the charging station along the wires
of the boundary. However, when the boundary of the area is set
using the wires, various problems occur in view of costs,
management, re-installation and the like.
[0228] Thus, as illustrated in FIGS. 6B and 6C, it may be
considered that a guide wire with a predetermined length may be
buried near the charging station.
[0229] A docking method using a guide wire 610 will be described in
detail as follows. First, the moving robot 100 rotates (R) its head
by recognizing a heading direction P1 toward the charging station
300 at its current position based on a magnetic value of a
geomagnetic sensor (compass sensor) and signals transmitted from
signal transmission modules 341 and 342 of the charging station
300.
[0230] A distance I from the current position of the moving robot
100 to the charging station 300 may be recognized based on the
signals transmitted from the signal transmission modules 341 and
342. At this time, an angle .theta. of a point where a line
connecting the distance 1 and a line orthogonal to an installed
position of the charging station 300 may be calculated.
[0231] Subsequently, as illustrated in FIG. 6C, the moving robot
100 is controlled to move to a point spaced apart from the charging
station 300 by a distance d, for example, to a point spaced by 2 m
from the charging station 300, considering the installation of the
guide wire connected to the charging station 300.
[0232] However, the docking method requires for laying the guide
wire and has a coverage up to only 180 degrees with respect to the
installed position of the charging station 300. This causes a
problem when the moving robot 100 attempts docking in a signal
blind spot. In addition, a magnetic field SLAM or the like must be
utilized for accurate docking.
[0233] Accordingly, the present disclosure has implemented a moving
robot, capable of setting a docking path without having to install
a wire along a boundary or laying a guide wire under the ground
around a charging station, and a method of controlling the same.
The present disclosure also has implemented a moving robot, capable
of performing accurate docking with covering all the 360-degree
directions and without using a magnetic field SLAM, and a method of
controlling the same.
[0234] Hereinafter, a method of controlling a moving robot
according to an embodiment of the present disclosure will be
described in detail with reference to FIGS. 7, 8A, 8B, 8C, 8D, 8E
and 8F. The moving robot 100 according to the present disclosure is
implemented to travel in one area where a charging station is
installed, and the travel area of the moving robot may be replaced
with the aforementioned wireless area.
[0235] In FIG. 7, coordinates information regarding a point, to
which the moving robot 100 has moved by a reference distance from
the charging station 300, in a state where the main body of the
moving robot 100 is in contact with the charging station 300
(S10).
[0236] Specifically, in a state where a charging connector of the
moving robot 100 is in contact with a charging contact unit of the
charging station 300, the moving robot 100 moves backward by a
predetermined distance r1. At this time, the predetermined distance
r1 may be referred to as a reference distance, and may be a length
(about 30 cm) as long as a radius of the main body of the moving
robot. Then, the moving robot 100 moves backward to a point which
is spaced apart from the charging station by the reference
distance, stops at the point, and then stores coordinates
information regarding the point.
[0237] For this purpose, the moving robot 100 may transmit and
receive signals (e.g., UWB signals) to and from the charging
station 300 from when the main body is released from the charging
contact unit of the charging station 300, check in real time a
point to which it moves, and determine coordinates information
regarding the corresponding point (hereinafter, referred to as
`return reference point`).
[0238] Specifically, two UWB modules (or UWB sensors) provided in
the main body of the moving robot receive UWB signals (hereinafter,
referred to as `first signal`) transmitted from the charging
station 300, respectively. In addition, two UWB modules (or UWB
sensors) provided in the charging station 300 receive UWB signals
(hereinafter, referred to as `second signal`) transmitted from the
moving robot 100, respectively. The charging station 300 and the
moving robot 100 each may include a plurality of antennas
electrically connected to the UWB modules.
[0239] The plurality of UWB modules provided in the moving robot
100 may be disposed symmetrically in right and left directions with
respect to the front of the moving robot main body, and each may
receive the first signal from the charging station 300 so as to
determine the position of the charging station based on the current
position of the main body.
[0240] At this time, the UWB modules of the moving robot 100 and
the charging station 300 may be electrically connected with a
plurality of antennas. In this case, it may be immediately
determined whether the charging station 300 is located at the front
or at the rear with respect to a head direction of the main body of
the moving robot 100. As a result, a rotating direction of the head
to be described later can be easily determined.
[0241] In one embodiment, coordinates information regarding the
point to which the main body of the moving robot 100 has moved
backward by the reference distance r1 in the state of being in
contact with the charging station 300, namely, `return reference
point` may include angle information calculated based on the second
signal.
[0242] Referring to FIG. 8A, the moving robot 100 located at the
return reference point includes a plurality of UWB modules (or UWB
sensors) 111 and 112 for transmitting and receiving UWB signals to
and from the charging station 300. The plurality of UWB modules (or
UWB sensors) 111 and 112 of the moving robot may be disposed on the
front of the head of the moving robot in a spaced manner in right
and left directions. However, those components may not be limited
to the arrangement.
[0243] As illustrated in FIG. 8A, the charging station 300 facing
the moving robot also includes a plurality of UWB modules (or UWB
sensors) 341 and 342 for transmitting and receiving UWB signals to
and from the moving robot 100.
[0244] The UWB signals transmitted from the first UWB module 111 of
the moving robot 100 are received by the antennas of the first UWB
module 341 and the second UWB module 342 of the charging station
300. The UWB signals transmitted from the first UWB module 341 of
the charging station 300 are received by the antennas of the first
UWB module 111 and the second UWB module 112 of the moving robot
100.
[0245] Accordingly, the control unit of the moving robot 100 may
acquire first angle information .theta.2 formed by the first UWB
module 111 of the moving robot 100 and the first UWB module 341 and
the second UWB module 342 of the charging station 300. The control
unit of the moving robot 100 may acquire second angle information
.theta.3 formed by the second UWB module 112 of the moving robot
100 and the first UWB module 341 and the second UWB module 342 of
the charging station 300.
[0246] At this time, since the moving robot 100 which has been in
contact with the charging station 300 is moved backward so as to be
located at the return reference point, the moving robot 100
maintains a state/posture parallel to the charging station 300.
Therefore, the first angle information .theta.2 and the second
angle information .theta.3 become the same value. However, the same
value includes a range having tolerable error/difference even if
the first angle information .theta.2 and the second angle
information .theta.3 are not completely equal, and is limited to a
value belonging to a docking allowable range.
[0247] Along with this, the control unit of the moving robot 100
senses a value (i.e., heading value) P1 of the head direction of
the moving robot 100 with respect to the magnetic north direction,
at the return reference point, through a compass sensor or an IMU
sensor provided in the moving robot 100. The control unit of the
moving robot may acquire an angle .theta.1 between a heading value
at the time when the main body is located at the return reference
point and a heading value in the magnetic north direction. This
information may be stored as third angle information.
[0248] As such, after the moving robot 100 stops at the return
reference point for a predetermined time from the charging station
300, the moving robot 100 travels in one area along a designated
(set) travel path.
[0249] While the main body of the moving robot 100 travels in the
one area, the control unit of the moving robot may output a control
command to return to the charging station 300 based on the state of
the power supply unit that supplies power to the main body
(S20).
[0250] Specifically, the control unit of the moving robot may
output a control command to return to the charging station when a
remaining battery level of the power supply unit reaches a
reference range. Here, the reference range means a degree that
travel and docking for returning to the charging station can be
carried out by the remaining battery level of the moving robot.
[0251] Meanwhile, in one example, the control command output by the
control unit of the moving robot may also be transmitted to the
charging station. In this case, the charging station 300 which has
received the control command may transmit to the moving robot 100 a
signal for searching for the current position of the moving robot
100, a signal indicating whether the moving robot 100 can be
recharged, and/or a signal for guiding the return of the moving
robot 100.
[0252] Next, in response to the output of the control command, the
control unit of the moving robot 100 checks the position of the
charging station 300 at the current position of the moving robot
100, based on the first signal transmitted from the charging
station 300 and the second signal transmitted from the main body of
the moving robot 100. At the same time, the control unit of the
moving robot 100 may control the moving robot 100 to travel to the
position corresponding to the stored coordinates information,
namely, the return reference point (S30).
[0253] In detail, referring to FIG. 8B, when the control command to
return to the charging station 300 is output during traveling in
the one area, the moving robot 100 may transmit a signal (i.e.,
`first signal`) to the charging station 300 through the first UWB
module 111 and the second UWB module 112. The charging station 300
may also transmit a signal (i.e., `second signal`) to the moving
robot 100 through the first UWB module 341 and the second UWB
module 342.
[0254] As for the moving robot 100, since the position of the
charging station 300 is determined based on the first signal and
the second signal, it can be said that the moving robot 100
operates as a UWB anchor and the charging station 300 operates as a
UWB tag. Also, as for the charging station 300, since the position
of the moving robot 100 is determined based on the first signal and
the second signal, it can be said that the moving robot 100
operates on a UWB tag and the charging station 300 operates as a
UWB anchor.
[0255] In this manner, since the moving robot 100 and the charging
station 300 can determine their relative positions, the moving
robot 100 can rotate the head from its current position toward the
point where the charging station is located (P2).
[0256] Specifically, the control unit of the moving robot 100 may
calculate distance information and angle information between the
current position of the main body of the moving robot and the
charging station 300 based on the first signal transmitted from the
charging station 300 and the second signal transmitted through the
communication unit according to the output of the control command,
and control the traveling unit to rotate the head of the main body
toward the point corresponding to the stored coordinates
information, namely, the return reference point.
[0257] The control unit may acquire distance information 11 from
the current position of the moving robot 100 to the charging
station 300 after the rotation of the head of the main body.
[0258] The control unit of the moving robot may also acquire the
position of the return reference point G and distance information
12 from the current position of the moving robot 100 to the return
reference point G, based on an angle .theta.5 of a point where a
signal distance between the second UWB module 112 of the moving
robot 100 and the first UWB module 341 of the charging station 300
meets a virtual line connecting the return reference point and the
charging station 300, and an angle .theta.6 of a point where a
signal distance between the first UWB module 111 of the moving
robot 100 and the second UWB module 342 of the charging station 300
meets the virtual line connecting the return reference point and
the charging station 300.
[0259] Thereafter, as illustrated in FIG. 8C, the control unit of
the moving robot 100 rotates the head toward the return reference
point G, and control the main body of the moving robot 100 to move
to the return reference point G.
[0260] At this time, in one embodiment, the control unit of the
moving robot 100 may check in real time the position of the
charging station 300 and the distance 11 from the current position
of the moving robot 100 to the charging station 300, while moving
to the return reference point G. At the same time, the control unit
may control the moving robot to travel while checking even the
distance 12 from the current position of the moving robot 100 to
the return reference point G in real time.
[0261] Also, although not shown, when the distance I1 up to the
charging station 300 is reduced to be within the reference range,
that is, when the moving robot 100 approaches the charging station
300, an LED blinking signal or the like may be output to the
charging station 300 and a signal corresponding to this may be
transmitted to the moving robot 100.
[0262] As such, since the moving robot 100 can search for the
return reference point G and move with respect to the searched
point, instead of performing a return movement with respect to the
position of the charging station, it may be similarly applied even
to the case where the moving robot 100 approaches the charging
station from the rear of the charging station, unlike the example
illustrated in FIGS. 8A to 8C.
[0263] FIG. 8D illustrates an example in which the moving robot 100
confirms the position of the charging station 300 in real time
while moving toward the return reference point G.
[0264] Specifically, while the main body of the moving robot is
moving to the position corresponding to the stored coordinates
information, namely, the return reference point, the control unit
of the moving robot 100 determines an intersection C2 close to the
head direction of the moving robot main body as the position of the
charging station 300, of two intersections Cl and C2 between a
first circle that a distance between the first UWB anchor provided
in the communication unit and the first UWB tag 341 of the charging
station 300 is a radius and the first UWB anchor is a center, and a
second circle that a distance between the second UWB anchor
provided in the communication unit and the second UWB tag 342 of
the charging station 300 is a radius and the second UWB anchor is a
center.
[0265] Also, in order for the moving robot 100 to accurately reach
the return reference point, the control unit may control the main
body of the moving robot 100 to travel while modifying (correcting)
the head direction of the main body, using the position of the
charging station 300, angle information, for example, angles
.theta.1, .theta.2, .theta.3, included in the stored coordinates
information, and angle information .theta.5, .theta.6 acquired
after rotating the head direction toward the charging station. This
modification (or correction) may be performed at a time point when
the moving robot 100 reaches or approaches a virtual circle 820
with a radius corresponding to the distance from the current
position of the moving robot 100 to the charging station 300.
[0266] When the main body reaches the return reference point, the
control unit of the moving robot 100 calculates a rotation angle
for docking to the charging station 300, based on the first signal
transmitted from the charging station 300 and the second signal
transmitted by the main body of the moving robot 100.
[0267] Specifically, the control unit determines the head direction
of the moving robot main body, based on the first signal
transmitted from the charging station 300 and the second signal
transmitted by the communication unit, after the moving robot main
body moves to the position corresponding to the stored coordinates
information. The control unit then controls the traveling unit so
that the head rotates according to the determined head
direction.
[0268] Referring to FIG. 8E, when the moving robot 100 reaches the
return reference point, the control unit may acquire an angle
.theta.8 of the head direction to be rotated from a current heading
value for docking, based on a heading value .theta.1 with respect
to the magnetic north direction measured through the compass sensor
at the time of storing the coordinates information, and a current
heading value .theta.7 relative to the magnetic north
direction.
[0269] In the present disclosure, it may also be possible to
calculate the angle .theta.8 of the head direction to be rotated
from the current heading value without using the compass
sensor.
[0270] In detail, when the head direction of the moving robot 100
does not coincide with the docking direction, a difference occurs
in signal reception distances of UWB signals which are received by
the antennas of the first UWB module 111 of the moving robot 100
from the first and second UWB modules 341 and 342 of the charging
station 300 and signal reception distances of UWB signals which are
received by the antennas of the second UWB module 112 of the moving
robot 100 from the first and second UWB modules 341 and 342 of the
charging station 300. This difference in the signal reception
distances causes an angle difference at a point where a virtual
line indicating the same signal reception distance meets a line
according to a current arrangement direction of the first and
second UWB modules 111 and 112 of the moving robot 100. The angle
difference is an angle value .theta.8 by which the another UWB
module 112 is to be rotated with respect to the one UWB module 111
(a UWB module/antenna with a shorter signal reception
distance).
[0271] Also, in one embodiment, even after the head of the moving
robot 100 located at the return reference point is rotated
according to the determined head direction, the control unit may
determine whether or not to correct or modify the determined head
direction, based on a difference between distances at which the
first signal transmitted from the charging station 300 is received
in the first and second UWB modules 111 and 112 of the moving robot
100, respectively.
[0272] Specifically, after the head of the moving robot is rotated
according to the determined head direction, when a signal distance
of the UWB signal received by the antenna of the first UWB module
111 of the moving robot and a signal distance of the UWB signal
received by the antenna of the second UWB module 112 of the moving
robot are different from each other, the head is rotated to modify
the heading value by an angle corresponding to the difference. When
it is determined that the two signal reception distances are not
different from each other (or if the difference is ignorable), it
is determined that an additional modification is not carried
out.
[0273] For example, referring to FIG. 8F, when the determined head
direction is a correct docking direction, the control unit
determines that the angle information .theta.1, .theta.2 included
in the stored coordinates information and the angle values
calculated based on the first signal and the second signal with
respect to the current head direction have no difference, and
controls the moving robot 100 to go straight toward the charging
station 300 by a distance r1.
[0274] At this time, although not shown, in one embodiment, even
the charging station 300 may receive the signals transmitted from
the moving robot 100 through the antennas of the plurality of UWB
modules, and then transmit a docking initiation signal to the
moving robot 100 when there is no difference between signal
reception distances.
[0275] On the other hand, the moving robot may temporarily deviate
from the return reference point upon modifying the determined head
direction. That is, before correcting the head direction of the
moving robot 100, backward/forward/leftward/rightward travel by a
predetermined distance from the current position may be performed.
In this case, the control unit may control the moving robot 100 to
move from a changed position to the return reference point
again.
[0276] As such, when it is determined that the reception distance
of the first signal transmitted from the charging station 300 and
received by the first UWB module 111 of the moving robot 100 is the
same as the reception distance of the first signal received by the
second UWB module 112, the current head direction is determined as
a docking direction. Accordingly, the moving robot 100 moves
straightly until the charging connector of the moving robot 100 is
connected to the charging contact unit of the charging station
300.
[0277] Then, the control unit rotates the head of the moving robot
according to the calculated rotation angle, and then performs
docking to the charging station 300 (S40).
[0278] When the charging of the battery is completed after the
docking, the control unit controls the moving robot to return to
the position where the moving robot has been located when the
control command is output. To this end, the control unit may store
position information of the moving robot main body at the time
point when the control command is output, and control the traveling
unit so that the main body moves to the stored position
information.
[0279] As described above, according to the present disclosure, the
moving robot can return to the charging station even if it is
located at anywhere in all the 360-degree directions with reference
to the charging station, by using a plurality of UWB modules (or
UWB sensors) provided in the moving robot and a plurality of UWB
modules provided in the charging station.
[0280] As such, the moving robot can return to the charging station
even if it is located at anywhere in all the 360-degree directions
with respect to the charging station, thereby minimizing a UWB
signal blind spot.
[0281] In detail, referring to FIG. 9, there is a case where the
moving robot 100 comes close for docking from the rear side with
respect to the charging contact unit of the charging station 300
along the travel path of the moving robot 100, depending on the
terrain of the area where the charging station 300 is installed. At
this time, the return reference point G is not located between the
moving robot 100 and the charging station 300, and is blocked by
the charging station. If a guide wire is not installed, points BP1
and BP shown correspond to signal blind spots.
[0282] Setting a docking path at these points BP1 and BP2 may be
realized in two ways.
[0283] One is that the moving robot 100 sets a docking path in a
manner of moving along a virtual circle 920 having a radius
corresponding to a distance from the charging station 300 to the
moving robot 100, while recognizing its current position and the
position of the charging station 300 in real time based on the
first signal and the second signal transmitted and received through
the plurality of UWB modules. At this time, since the return
reference point G should be included in the virtual circle 920, the
distance should be at least equal to or longer than a distance,
namely, r1 from the charging station 300 to the return reference
point G.
[0284] The other is to accurately determine coordinates of the
return reference point based on the first signal and the second
signal, and then to set a docking path in a manner that the moving
robot moves directly toward the coordinates. In this way, while
moving to the point G corresponding to the stored coordinates
information, the position of the charging station can be determined
in real time based on the first signal and the second signal. Also,
when the position of the charging station is included in a path
along which the moving robot main body moves to the stored
coordinates information, the docking path may be reset by avoiding
the charging station 300.
[0285] As described above, in a moving robot and a control method
thereof in accordance with an embodiment of the present disclosure,
a docking path for charging can be set without having to set wires
in a boundary along which the moving robot travels or to lay a
guide wire under the ground around a charging station. In addition,
since the moving robot can cover all the 360-degree directions when
docking to the charging station even if it is located at anywhere
within a boundary, a signal blind spot can be minimized and
accurate docking can be carried out without using a magnetic field
SLAM.
[0286] The present disclosure described above can be implemented as
computer-readable codes on a program-recorded medium. The
computer-readable medium may include all types of recording devices
each storing data readable by a computer system. Examples of the
computer-readable medium include a hard disk drive (HDD), a solid
state disk (SSD), a silicon disk drive (SDD), a ROM, a RAM, a
CD-ROM, a magnetic tape, a floppy disk, an optical data storage
device and the like, and may also be implemented in the form of a
carrier wave (e.g., transmission over the Internet). In addition,
the computer may also include the control unit 1800 of the moving
robot. The above detailed description should not be limitedly
construed in all aspects and should be considered as illustrative.
The scope of the present disclosure should be determined by
rational interpretation of the appended claims, and all changes
within the scope of equivalents of the present disclosure are
included in the scope of the present disclosure.
* * * * *