U.S. patent application number 17/052989 was filed with the patent office on 2021-07-29 for robotic cleaning device with retractable side brush.
This patent application is currently assigned to Aktiebolaget Electrolux. The applicant listed for this patent is Aktiebolaget Electrolux. Invention is credited to Andreas Klintemyr.
Application Number | 20210228035 17/052989 |
Document ID | / |
Family ID | 1000005565727 |
Filed Date | 2021-07-29 |
United States Patent
Application |
20210228035 |
Kind Code |
A1 |
Klintemyr; Andreas |
July 29, 2021 |
ROBOTIC CLEANING DEVICE WITH RETRACTABLE SIDE BRUSH
Abstract
A robotic cleaning device having a main body, a propulsion
system configured to move the robotic cleaning device over a
surface to be cleaned, a controller configured to control the
propulsion system to move the robotic cleaning device over the
surface to be cleaned, at least one rotatable side brush arranged
to sweep debris from the surface to be cleaned, and a mechanism
configured to at least partly retract the at least one rotatable
side brush into a space arranged inside the main body upon
receiving a control signal from the controller, such that the
rotatable side brush is moved out of contact with the surface to be
cleaned.
Inventors: |
Klintemyr; Andreas;
(Stockholm, SE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Aktiebolaget Electrolux |
Stockholm |
|
SE |
|
|
Assignee: |
Aktiebolaget Electrolux
Stockholm
SE
|
Family ID: |
1000005565727 |
Appl. No.: |
17/052989 |
Filed: |
May 18, 2018 |
PCT Filed: |
May 18, 2018 |
PCT NO: |
PCT/EP2018/063177 |
371 Date: |
November 4, 2020 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A46B 13/008 20130101;
A47L 9/0472 20130101; A47L 9/2847 20130101; A46B 15/0095 20130101;
A47L 2201/04 20130101; A47L 2201/06 20130101; A46B 2200/3033
20130101; A46B 13/02 20130101; A47L 9/0411 20130101; A47L 9/2852
20130101; A47L 9/0494 20130101 |
International
Class: |
A47L 9/04 20060101
A47L009/04; A47L 9/28 20060101 A47L009/28; A46B 13/00 20060101
A46B013/00; A46B 13/02 20060101 A46B013/02; A46B 15/00 20060101
A46B015/00 |
Claims
1. A robotic cleaning device comprising: a main body; a propulsion
system configured to move the robotic cleaning device over a
surface to be cleaned; a controller configured to control the
propulsion system to move the robotic cleaning device over the
surface to be cleaned; at least one rotatable side brush arranged
to sweep debris from the surface to be cleaned; and a mechanism
configured to at least partly retract the at least one rotatable
side brush into a space arranged inside the main body upon
receiving a control signal from the controller, such that the
rotatable side brush is moved out of contact with the surface to be
cleaned.
2. The robotic cleaning device of claim 1, wherein the mechanism
comprises: a retractable member coupled to the at least one
rotatable side brush and arranged to retract the at least one
rotatable side brush into the space; and an actuator arranged to
move the retractable member into, or out of, the space upon
receiving a control signal from the controller.
3. The robotic cleaning device of claim 1, wherein the at least one
rotatable side brush is configured to be retractable into the space
inside the main body in an axial direction with respect to a
rotational axis of the side brush.
4. The robotic cleaning device of claim 3, wherein the space is
cylindrically shaped and the mechanism comprises: a threaded rod
located in the cylindrically shaped space; an annular threaded
member to which the at least one rotatable side brush is attached,
the annular threaded member being arranged to engage with the
threaded rod; and an actuator configured to rotate the threaded
rod; wherein a diameter of the cylindrically shaped space is
adapted to a dimension of the at least one rotatable side brush
such that friction is created between the side brush and an
interior of the cylindrically shaped space, thereby at least partly
preventing the at least one rotatable side brush from rotating when
in contact with the interior; wherein said friction causes the
annular threaded member to move along the threaded rod to extend
out from the space in order to have the at least one rotatable side
brush rotate and sweep the debris from the surface to be cleaned
upon the threaded rod rotating in a first direction, the threaded
annular member moving along the threaded rod until it reaches an
end member of the threaded rod preventing the annular threaded
member to move out of threaded engagement with the threaded rod;
and friction between the at least one rotating side brush and the
surface to be cleaned causes the annular threaded member to move
along the threaded rod to retract into the space upon the threaded
rod rotating in a second direction.
5. The robotic cleaning device of claim 4, wherein the mechanism
further comprises: a spring arranged between the annular threaded
member and the end member.
6. The robotic cleaning device of claim 4, further comprising: an
opening in a bottom side of the main body via which debris is
removed from the surface, wherein the at least one rotatable side
brush is arranged adjacent to the opening.
7. The robotic cleaning device of claim 2, wherein the actuator
comprises a motor.
8. The robotic cleaning device of claim 1, wherein the robotic
cleaning device comprises a robotic vacuum cleaner, a robotic
sweeper or a robotic floor washer.
Description
TECHNICAL FIELD
[0001] The invention relates to a robotic cleaning device being
equipped with at least one retractable side brush.
BACKGROUND
[0002] Robotic vacuum cleaners are known in the art, which are
equipped with drive means in the form of motors for moving the
cleaner across a surface to be cleaned. The robotic vacuum cleaners
are further equipped with intelligence in the form of
microprocessor(s) and navigation means for enabling an autonomous
behaviour such that the robotic vacuum cleaners freely can move
around and clean a space in the form of e.g. a room.
[0003] Traditionally, robotic vacuum cleaners have been arranged
with circular-shaped main bodies. Such a robot having co-axial
drive wheels at the centre of its body has the advantage that it is
easy to control and cannot easily get stuck since it always can
rotate 180.degree. and go back the same way it came.
[0004] However, the circular-shaped main body makes them unsuitable
for cleaning corners or edges where a floor meets a wall since
these circular vacuum cleaners due to their shape cannot move into
a corner or close enough to a wall, or other objects around which
cleaning is required such as e.g. chair legs.
[0005] An example of a robotic vacuum cleaner aiming at solving
this problem is disclosed in US 2013/0086760, the main body of
which is circular-shaped, and which robotic vacuum cleaner is
equipped with rotatable side brushes which are arranged at a bottom
side of the main body in a front section of the robotic vacuum
cleaner for sweeping debris out of corners where the robotic vacuum
cleaner cannot reach. Further, each rotatable side brush is mounted
on a respective pivotable arm which can be pivoted to have the side
brushes extend in front of the main body to reach even further.
Side brushes have also been used for robotic vacuum cleaner having
other shapes, such as triangular shapes.
[0006] Now, a problem with side brushes is that they have a
tendency of performing poorly on certain types of surfaces, such as
for instance carpets where carpet fibres can get entangled with the
rotating brushes. Further, carpets also wear the side brushes down
thereby impacting their durability and may even cause unintentional
lift of the robot, not letting it sink into the carpet to clean it
thoroughly. Another disadvantage is that the side brushes hamper
the capability of the robot to climb over objects such as
thresholds, cables and carpet edges.
SUMMARY
[0007] An object of the invention is to solve, or at least mitigate
this problem in the art, and thus to provide a robotic vacuum
cleaner which is not hampered by its side brushes.
[0008] This object is attained in a first aspect of the invention
by a robotic cleaning device comprising, a main body, a propulsion
system configured to move the robotic cleaning device over a
surface to be cleaned, a controller configured to control the
propulsion system to move the robotic cleaning device over the
surface to be cleaned, at least one rotatable side brush arranged
to sweep debris from the surface to be cleaned. The robotic
cleaning device further comprises a mechanism configured to at
least partly retract said at least one rotatable side brush into a
space arranged inside the main body upon receiving a control signal
from the controller, such that the rotatable side brush is moved
out of contact with the surface to be cleaned.
[0009] Advantageously, by being capable of retracting the side
brush(es), the robotic cleaning device can avoid a situation where
the side brush entangles with fibres of a carpet, or to improve the
capability of the robot to climb over objects such as thresholds,
cables and carpet edges, or simply enable to not permanently have
the side brush contacting the surface over which the robotic
cleaning device moves.
[0010] In an embodiment, the mechanism further comprises a
retractable member coupled to the at least one rotatable side brush
arranged to retract the at least one rotatable side brush into said
space, and an actuator (e.g. a motor) arranged to move the
retractable member into, or out of, said space upon receiving a
control signal from the controller.
[0011] In an embodiment, said at least one rotatable side brush is
arranged to be retractable into the space inside the main body in
an axial direction with respect to the rotational axis of the side
brush.
[0012] In an embodiment, said space is cylindrically shaped and the
mechanism configured to retract said at least one rotatable side
brush comprises a threaded rod located in the cylindrically shaped
space, an annular threaded member to which the at least one
rotatable side brush is attached, the annular threaded member being
arranged to engage with the threaded rod, and an actuator (e.g. a
motor) configured to rotate the threaded rod. Further, a diameter
of the cylindrically shaped space is adapted to a dimension of the
at least one rotatable side brush such that friction is created
between the side brush and an interior of the cylindrically shaped
space, thereby at least partly preventing the at least one
rotatable side brush (114) to rotate when in contact with said
interior, wherein said friction causes the annular threaded member
to move along the threaded rod to extend out from the space in
order to have the at least one rotatable side brush rotate and
sweep the debris from the surface to be cleaned upon the threaded
rod rotating in a first direction, the threaded annular member
moving along the threaded rod until it reaches an end member of the
threaded rod preventing the annular threaded member to move out of
threaded engagement with the threaded rod, and friction between the
at least one rotating side brush and the surface to be cleaned
causes the annular threaded member to move along the threaded rod
to retract into the space upon the threaded rod rotating in a
second direction. Advantageously, the same actuator is used for
retracting the side brush and for rotating the side brush.
[0013] In a further embodiment, the mechanism further comprises a
spring arranged between the annular threaded member and the end
member.
[0014] In still an embodiment, the robotic cleaning device further
comprises an opening in a bottom side of the main body via which
debris is removed from the surface, wherein the at least one
rotatable side brush is arranged adjacent to the opening.
[0015] Generally, all terms used in the claims are to be
interpreted according to their ordinary meaning in the technical
field, unless explicitly defined otherwise herein. All references
to "a/an/the element, apparatus, component, means, step, etc." are
to be interpreted openly as referring to at least one instance of
the element, apparatus, component, means, step, etc., unless
explicitly stated otherwise. The steps of any method disclosed
herein do not have to be performed in the exact order disclosed,
unless explicitly stated.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] The invention is now described, by way of example, with
reference to the accompanying drawings, in which:
[0017] FIG. 1 shows a robotic cleaning device according to an
exemplifying embodiment of the present invention;
[0018] FIG. 2 shows the robotic cleaning device of FIG. 1 in a
front view;
[0019] FIG. 3 shows retraction of a rotatable side brush in an
embodiment;
[0020] FIG. 4 shows retraction of a rotatable side brush in another
embodiment;
[0021] FIGS. 5a and b shows retraction/extension of a rotatable
side brush in an embodiment;
[0022] FIGS. 6a and b shows extension of a rotatable side brush in
an embodiment; and
[0023] FIG. 7 shows a spring-biased side brush in an
embodiment.
DETAILED DESCRIPTION
[0024] The invention will now be described more fully hereinafter
with reference to the accompanying drawings, in which certain
embodiments of the invention are shown. This invention may,
however, be embodied in many different forms and should not be
construed as limited to the embodiments set forth herein;
[0025] rather, these embodiments are provided by way of example so
that this disclosure will be thorough and complete, and will fully
convey the scope of the invention to those skilled in the art. Like
numbers refer to like elements throughout the description.
[0026] The invention relates to robotic cleaning devices, or in
other words, to automatic, self-propelled machines for cleaning a
surface, e.g. a robotic vacuum cleaner, a robotic sweeper or a
robotic floor washer. The robotic cleaning device according to the
invention can be mains-operated and have a cord, be
battery-operated or use any other kind of suitable energy source,
for example solar energy.
[0027] Even though it is envisaged that the invention may be
performed by a variety of appropriate robotic cleaning devices
being equipped with sufficient processing intelligence, FIG. 1
shows a robotic cleaning device 100 according to an embodiment of
the present invention in a bottom view, i.e. the bottom side of the
robotic cleaning device is shown. The arrow indicates the forward
direction of the robotic cleaning device 100 being illustrated in
the form of a robotic vacuum cleaner.
[0028] The robotic cleaning device 100 comprises a main body in
housing components such as a propulsion system comprising driving
means in the form of two electric wheel motors 115a, 115b for
enabling movement of the driving wheels 112, 113 such that the
cleaning device can be moved over a surface to be cleaned. Each
wheel motor 115a, 115b is capable of controlling the respective
driving wheel 112, 113 to rotate independently of each other in
order to move the robotic cleaning device 100 across the surface to
be cleaned. A number of different driving wheel arrangements, as
well as various wheel motor arrangements, can be envisaged. It
should be noted that the robotic cleaning device may have any
appropriate shape, such as a device having a more traditional
circular-shaped main body, or a triangular-shaped main body. As an
alternative, a track propulsion system may be used or even a
hovercraft propulsion system. The propulsion system may further be
arranged to cause the robotic cleaning device 100 to perform any
one or more of a yaw, pitch, translation or roll movement.
[0029] A controller 116 such as a microprocessor controls the wheel
motors 115a, 115b to rotate the driving wheels 112, 113 as required
in view of information received from an obstacle detecting device
(not shown in FIG. 1) for detecting obstacles in the form of walls,
floor lamps, table legs, around which the robotic cleaning device
must navigate. The obstacle detecting device may be embodied in the
form of a 3D sensor system registering its surroundings,
implemented by means of e.g. a 3D camera, a camera in combination
with lasers, a laser scanner, etc. for detecting obstacles and
communicating information about any detected obstacle to the
microprocessor 116. The microprocessor 116 communicates with the
wheel motors 115a, 115b to control movement of the wheels 112, 113
in accordance with information provided by the obstacle detecting
device such that the robotic cleaning device 100 can move as
desired across the surface to be cleaned.
[0030] Further, the robotic cleaning device 100 is equipped with
one or more batteries 117 for powering the different components
included in the cleaning device 100. The one or more batteries 117
are charged via a charging station into which the robotic cleaning
device 100 docks.
[0031] Moreover, the main body in of the robotic cleaner 100
comprises a suction fan 120 creating an air flow for transporting
debris to a dust bag or cyclone arrangement (not shown) housed in
the main body via the opening 118 in the bottom side of the main
body in. The suction fan 120 is driven by a fan motor 121
communicatively connected to the controller 116 from which the fan
motor 121 receives instructions for controlling the suction fan
120. The main body 111 is further arranged with one or more
rotatable side brushes 114 adjacent to the opening 118. The
rotation of the side brush 114 is typically accomplished by a
separate motor (not shown in FIG. 1), or a brush roll motor.
[0032] With further reference to FIG. 1, the controller/processing
unit 116 embodied in the form of one or more microprocessors is
arranged to execute a computer program 125 downloaded to a suitable
storage medium 126 associated with the microprocessor, such as a
Random Access Memory (RAM), a Flash memory or a hard disk drive.
The controller 116 is arranged to carry out a method according to
embodiments of the present invention when the appropriate computer
program 125 comprising computer-executable instructions is
downloaded to the storage medium 126 and executed by the controller
116. The storage medium 126 may also be a computer program product
comprising the computer program 125. Alternatively, the computer
program 125 may be transferred to the storage medium 126 by means
of a suitable computer program product, such as a digital versatile
disc (DVD), compact disc (CD) or a memory stick. As a further
alternative, the computer program 125 may be downloaded to the
storage medium 126 over a wired or wireless network. The controller
116 may alternatively be embodied in the form of a digital signal
processor (DSP), an application specific integrated circuit (ASIC),
a field-programmable gate array (FPGA), a complex programmable
logic device (CPLD), etc.
[0033] FIG. 2 shows a front view of the robotic cleaning device 100
of FIG. 1 in an embodiment of the present invention illustrating
the previously mentioned obstacle detecting device in the form of a
3D sensor system comprising at least a camera 123 and a first and a
second line laser 127, 128, which may be horizontally or vertically
oriented line lasers. Further shown is the controller 116, the main
body 111, the driving wheels 112, 113, and the rotatable side brush
114. The controller 116 is operatively coupled to the camera 123
for recording images of a vicinity of the robotic cleaning device
100. The first and second line lasers 127, 128 may preferably be
vertical line lasers and are arranged lateral of the camera 123.
The camera 123 is controlled by the controller 116 to capture and
record a plurality of images per second. Data from the images is
extracted by the controller 116 and the data is typically saved in
the memory 126 along with the computer program 125.
[0034] The first and second line laser 127, 128 are configured to
scan, preferably in a vertical orientation, the vicinity of the
robotic cleaning device 100, normally in the direction of movement
of the robotic cleaning device 100. The first and second line
lasers 127, 128 are configured to send out laser beams, which
illuminate furniture, walls and other objects of e.g. a room to be
cleaned. The camera 123 is controlled by the controller 116 to
capture and record images from which the controller 116 creates a
representation or layout of the surroundings that the robotic
cleaning device 100 is operating in, by extracting features from
the images and by measuring the distance covered by the robotic
cleaning device 100, while the robotic cleaning device 100 is
moving across the surface 129 to be cleaned.
[0035] It is noted that the side brush 114 may be arranged on a
robotic cleaning device 100 which is less complex than that
exemplified for illustrative purposes in FIGS. 1 and 2.
[0036] Now, in an embodiment, in order to avoid the side brush 114
entangling with fibres of a carpet, or to avoid hampering the
capability of the robot 100 to climb over objects such as
thresholds, cables and carpet edges, or simply to not permanently
have the side brush 114 contacting the surface over which the
robotic cleaning device 100 moves, the robotic cleaning device 100
is equipped with a mechanism for retracting the side brush 114 into
a space in the main body 111.
[0037] FIG. 3 illustrates the robotic cleaning device 100 being
equipped with such a mechanism comprising a retractable member 119,
such as a rod or a piston, on which the side brush 114 is arranged,
and an actuator exemplified by motor 124 for retracting the rod 122
into the space 119 in the main body 111.
[0038] Thus, if it no longer is desirable to have the side brush
114 contact the surface 129 to be cleaned, the controller 116 will
control the motor 124 to retract the rod 122 into the space 119
such that the side brush 114 advantageously is partly or fully
retracted into the space 119 having as a result that the side brush
114 no longer contacts the surface 129. Conversely, should it again
be desirable to have the side brush 114 contact the surface 129,
the controller 116 will control the motor 124 to extend the rod 122
out from the space 119, whereby the side brush 124 will extend out
from the space 119 and finally contact the surface 129 as shown in
FIG. 2.
[0039] FIG. 4 illustrates the robotic cleaning device 100 being
equipped with a mechanism for extracting the rotatable side brush
114 into a space 119 in the main body 111 according to a further
embodiment.
[0040] In this embodiment, the rotatable side brush 114 is
retracted into the space 119 in a direction being axial to the
rotational axis of the rotatable side brush 114. Again, the
retracting member 122 may be embodied by a rod or piston being
retracted into--or extended out of--the space by means of a motor
124 such that the side brush 114 advantageously is partly or fully
retracted into/extended out of the space 119 in order to move the
side brush 114 in and out of contact with the surface 129.
[0041] In the embodiments described with reference to FIGS. 3 and
4, the motor 124 is utilized for causing the retracting member 122
to retract into/extend out of the space 119 in the main body 111,
and it may be necessary to equip the robotic cleaning device 100
with a further motor (not shown) for actually rotating the side
brush 114.
[0042] FIG. 5a illustrates a further embodiment of the mechanism
for retracting the rotatable side brush 114 into the space 119 in a
direction being axial to the rotational axis of the rotatable side
brush 114.
[0043] In this embodiment the retracting member is embodied in the
form of a threaded rod 122a located in the space 119, which
threaded rod 122a the motor 124 is arranged to rotate. Further in
this embodiment, the space 119 is cylindrically shaped (which may
also be the case in the previously illustrated embodiments).
[0044] Moreover, the mechanism comprises an annular threaded member
130 to which the side brush 114 is attached, which annular threaded
member 130 is arranged to engage with the threaded rod 122a.
[0045] Now, in this embodiment, a diameter of the cylindrically
shaped space 119 is adapted to the dimensions of the side brush 114
such that friction is created between the side brush 114 and an
interior of the cylindrically shaped space. As can be seen in FIG.
5a, the retracted side brush 114 is in close contact with the
interior of the space 119.
[0046] Upon the motor 124 starts rotating the threaded rod 122a in
a first direction (i.e. the rotational direction of the rotating
side brush 114 when the brush in cleaning mode), the friction
between the side brush 114 and the interior of the space 119 will
prevent the side brush 114 from rotating--or at least from freely
rotating--which has as an effect that the annular member 130 and
thus the side brush 114 will move downwards along the threaded rod
122a and extend out of the space 119 until it reaches an end
section 131 of the threaded rod 122a preventing the annular
threaded member 130 to move out of threaded engagement with the
threaded rod 122a.
[0047] Conversely, with reference to FIG. 5b, upon the motor 124
starts rotating the threaded rod 122a in a second direction (i.e.
opposite to the rotational direction of the rotating side brush 114
being in cleaning mode), the friction between the side brush 114
and the interior of the space 119 will prevent the side brush 114
from rotating which has as an effect that the annular member 130
and thus the side brush 114 will move upwards along the threaded
rod 122a and retract into the space 119 until it reaches an end
position in the form of e.g. a position as measured by a sensor or
a timer, or a mechanical end stop or simply an interior end wall of
the space 119.
[0048] Assuming that the retracted side brush 114 of FIG. 5a is to
be extended out of the space 119 and set into cleaning mode, the
motor 124 will rotate the threaded rod 122a in the indicated first
direction while the friction between the interior of the space 119
and the side brush 114 will prevent the side brush 114 from
rotating.
[0049] With reference to FIG. 6a, as a result of the friction, the
annular threaded member 130 and thus the side brush 114 will move
in downwards direction along the threaded rod 122a.
[0050] Subsequently, as can be seen in FIG. 6b, the annular
threaded member 130 and thus the side brush 114 will exit the space
119 and extend out from the main body in and move in a downward
direction until the annular threaded member 130 abuts against the
end section 131 which prevents the annular threaded member 130 to
move out of engagement with the threaded rod 122a. As can be
concluded form FIG. 6b, the rotating side brush 114 is now in
cleaning mode.
[0051] In this position, if it is desirable that the annular
threaded member 130 and thus the rotating side brush 114 is to be
retracted into the main body iii of the robotic cleaning device
100, the controller 116 will control the motor 124 to alter the
rotational direction of the threaded rod 122a, in which case
friction between the rotating side brush 114 and the surface 129 to
be cleaned causes the annular threaded member 130 to move in an
upward direction along the threaded rod 122a to retract into the
space 119.
[0052] Advantageously, with the embodiment illustrated in FIGS.
5a-b and 6a-b, the motor 124 used for causing the side brush 114 to
retract into/extend out of the space 119 is also used for rotating
the side brush 114. Hence, a single motor 124 can be used for
handling both the retraction/extension as well as the rotation of
the side brush 114.
[0053] FIG. 7 illustrates a further embodiment, where a spring 132
is arranged between the end member 131 and the annular threaded
member 130, the spring being attached to either one of the end
member 131 and the annular threaded member 130. Advantageously, by
arranging the end member 131 and the annular threaded member 130 to
be spring-biased with respect to each other, the friction between
the rotating side brush (not shown in FIG. 7) and the surface to be
cleaned may be controlled based on degree of stiffness of the
selected spring 132.
[0054] The invention has mainly been described above with reference
to a few embodiments. However, as is readily appreciated by a
person skilled in the art, other embodiments than the ones
disclosed above are equally possible within the scope of the
invention, as defined by the appended patent claims.
* * * * *