U.S. patent application number 11/574290 was filed with the patent office on 2008-08-07 for robot cleaner with improved vacuum unit.
This patent application is currently assigned to Sharper Image Corporation. Invention is credited to Eric C. Blair, Andrew Heninger, Shek Fai Lau, Eric Ng, Charles E. Taylor.
Application Number | 20080184518 11/574290 |
Document ID | / |
Family ID | 36000610 |
Filed Date | 2008-08-07 |
United States Patent
Application |
20080184518 |
Kind Code |
A1 |
Taylor; Charles E. ; et
al. |
August 7, 2008 |
Robot Cleaner With Improved Vacuum Unit
Abstract
A robot cleaner includes a vacuum air path including an inlet, a
particulate collection dustbin, a fan, and an air exit.
Inventors: |
Taylor; Charles E.; (Punta
Gorda, FL) ; Lau; Shek Fai; (Foster City, CA)
; Blair; Eric C.; (San Rafael, CA) ; Heninger;
Andrew; (Palo Alto, CA) ; Ng; Eric; (San
Leandro, CA) |
Correspondence
Address: |
BELL, BOYD & LLOYD LLP
P.O. BOX 1135
CHICAGO
IL
60690
US
|
Assignee: |
Sharper Image Corporation
San Francisco
CA
|
Family ID: |
36000610 |
Appl. No.: |
11/574290 |
Filed: |
August 26, 2005 |
PCT Filed: |
August 26, 2005 |
PCT NO: |
PCT/US2005/030422 |
371 Date: |
March 25, 2008 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60605066 |
Aug 27, 2004 |
|
|
|
60605181 |
Aug 27, 2004 |
|
|
|
Current U.S.
Class: |
15/319 ;
901/1 |
Current CPC
Class: |
A47L 9/009 20130101;
A47L 9/2852 20130101; A47L 2201/04 20130101; A47L 2201/00 20130101;
A47L 9/2805 20130101; A47L 9/2884 20130101; A47L 9/2894 20130101;
A47L 9/2889 20130101; A47L 9/2826 20130101; A47L 9/2857
20130101 |
Class at
Publication: |
15/319 ;
901/1 |
International
Class: |
A47L 9/00 20060101
A47L009/00; A47L 9/28 20060101 A47L009/28; A47L 5/22 20060101
A47L005/22 |
Claims
1. A robot cleaner comprising: a housing: a processor in the
housing for controlling the robot cleaner; and a vacuum air path in
the housing, the vacuum air path including vacuum inlet at the
bottom of the robot cleaner, a filter for filtering particulates
from the air flow, a fan drawing air through the filter and
exhausting the air out of the robot cleaner.
2. The robot cleaner of claim 1, further comprising a dustbin in
the vacuum air path for collecting particulates.
3. The robot cleaner of claim 2, wherein the dustbin includes an
opening allowing air and particulates into the dustbin and includes
a trap portion below the opening for collecting particulates.
4. The robot cleaner of claim 2, wherein the dustbin includes an
air baffle.
5. The robot cleaner of claim 1, further comprising wheels wherein
a portion of the inlet of the vacuum air path is positioned in
front of the wheels.
6. The robot cleaner of claim 1, wherein the inlet of the vacuum
air path is positioned at least partially inside a region defined
by a bumper.
7. The robot cleaner of claim 1, wherein the axis of rotation of
the fan is parallel with the bottom of the robot cleaner.
8. The robot cleaner of claim 1, wherein the axis of rotation of
the fan is perpendicular with the bottom of the robot cleaner.
9. The robot cleaner of claim 1, wherein the axis of rotation of
the fan is not perpendicular of parallel with the bottom of the
robot cleaner.
10. The robot cleaner of claim 1, further comprising a brush
located adjacent to the inlet so that the brush can agitate
particulates into the vacuum air path.
11. The robot cleaner of claim 1, wherein the top of the robot
cleaner has an air exit with protective fins.
12. The robot cleaner of claim 1, further comprising a cowl that
directs the air to the top of the robot cleaner.
13. A robot cleaner comprising: a substantially flat housing; a
processor in the housing for controlling the robot cleaner; and a
vacuum air path in the housing, the vacuum air path including
vacuum inlet at the bottom of the robot cleaner, a dustbin for
receiving particulate from the air path; a filter for filtering
particulate from the air flow, a fan drawing air through the filter
and exhausting the air out the top of the robot cleaner.
14. A robot cleaner comprising: a housing a processor in the
housing for controlling the robot cleaner; a vacuum air path in the
housing, the vacuum air path including vacuum inlet at the bottom
of the robot cleaner, a filter for filtering particulate from the
air flow, a fan drawing air through the filter and exhausting the
air out of the robot cleaner; and wheels connected to a motor to
move the robot cleaner; wherein the inlet of the vacuum air path is
positioned in front of the wheels.
15. The robot cleaner of claim 14, further comprising a brush,
wherein the brush is located adjacent to the inlet so that the
brush can agitate particulate into the vacuum air path.
16. The robot cleaner of claim 14, wherein air is exhausted out the
top of the robot cleaner.
17. The robot cleaner of claim 14, further comprising a dustbin in
the vacuum air path for collecting particulate.
18. The robot cleaner of claim 14, wherein the top of the robot
cleaner has an air exit with protective fins that are angled from
the vertical to reduce the air resistance of the exhausted air.
19. The robot cleaner of claim 18, wherein a cowl partially
surrounds the fan.
20. A robot cleaner comprising: a substantially circular housing; a
processor in the housing for controlling the robot cleaner; and a
fan in the housing drawing air and particulate from the bottom of
the robot cleaner and exhausting the air out the top of the robot
cleaner, the top of the robot cleaner having an air exit with
protective fins that are angled from the vertical to reduce the air
resistance of the exhausted air.
21. The robot cleaner of claim 20, wherein an air flow
straightening portion is located before the fan.
Description
FIELD OF THE INVENTION
[0001] The present invention relates generally to robotic
cleaners.
BACKGROUND
[0002] Robot cleaners, such as robot vacuums, have been proposed to
clean rooms. One robot vacuum is the Roomba.TM. vacuum from iRobot.
The Roomba.TM. vacuum makes multiple passes through a room in a
random fashion. The Roomba.TM. vacuum starts in a spiral pattern
until it contacts a wall, follows the wall for a period of time and
then crisscrosses the room in straight lines. After it covers the
room multiple times, the Roomba.TM. stops and turns itself off.
[0003] There remains a need for improved robotic vacuum cleaners
that clean more effectively.
BRIEF DESCRIPTION OF THE DRAWINGS
[0004] FIG. 1A is a diagram that illustrates a functional view of a
robot cleaner of one embodiment.
[0005] FIG. 1B is a diagram that illustrates a top view of a robot
cleaner of one embodiment.
[0006] FIG. 1C is a diagram that illustrates a bottom view of a
robot cleaner of one embodiment.
[0007] FIG. 1D is a diagram that illustrates a side view of a robot
cleaner of one embodiment.
[0008] FIG. 1E is a diagram that illustrates a remote control of
one embodiment of the present invention.
[0009] FIG. 1F is a cross-sectional diagram of a robot cleaner of
one embodiment of the present invention.
[0010] FIG. 1G is an exposed view of an exemplary robot
cleaner,
[0011] FIG. 2 is a diagram illustrating software modules of one
embodiment of the present invention.
[0012] FIGS. 3A-3E are diagrams that illustrate a star clean of
embodiments of the present invention.
[0013] FIG. 3F is a diagram that illustrates a fan clean of one
embodiment of the present invention.
[0014] FIG. 4 is a diagram that illustrates a "move to new region"
mode of one embodiment of the present invention.
[0015] FIG. 5 is a diagram that illustrates a robot cleaner using a
short term memory map.
[0016] FIG. 6 is a diagram that illustrates an wall cleaning mode
of an embodiment of the present invention.
[0017] FIG. 7 is a diagram that illustrates an entanglement
recovery mode of one embodiment of the present invention.
[0018] FIGS. 8A and 8B are diagrams that illustrate the operation
of an entanglement sensor of one embodiment of the present
invention.
[0019] FIGS. 9A-9B illustrate direction control embodiments of the
robot cleaner.
[0020] FIG. 10 illustrate the positioning of a brush of a robot
cleaner of one embodiment.
[0021] FIG. 11 is a diagram illustrating a V-shaped clean of one
embodiment of the present invention.
[0022] FIG. 12 is a diagram illustrating operating modes of one
embodiment of the present invention.
[0023] FIGS. 13A-13B are diagrams illustrating the operation of a
bumper sensor of one embodiment of the present invention.
[0024] FIG. 14 is a diagram that illustrates the operation of a
robot cleaner with barrier cones.
[0025] FIG. 15 is a diagram that illustrates protective fins on an
air exit that are angled from the vertical.
[0026] FIG. 16 is a diagram that illustrates an air baffle for use
in a dustbin of one embodiment.
[0027] FIG. 17A-17B shows exemplary orientation of a fan for the
vacuum unit of a robot cleaner of one embodiment of the present
invention.
[0028] FIG. 18 shows exemplary fan designed for a vacuum unit of a
robot cleaner of one embodiment of the present invention.
DETAILED DESCRIPTION
[0029] FIG. 1 is a functional diagram of a robot cleaner 100 of an
exemplary embodiment of the present invention. In this example, the
robot cleaner 100 includes a cleaning unit 102. The cleaning unit
102 can be of a type to clean any object including a cleaning unit
to clean carpeted or uncarpeted floors. One cleaning unit comprises
a vacuum, with or without a sweeping brush. Alternately, the
cleaning unit can comprise a sweeper, duster, cleaning pad or any
other type of cleaning unit.
[0030] The robot cleaner 100 can include a processor 104 for
receiving information from sensors and producing control commands
for the robot cleaner 100. For the purposes of this application,
the term "processor" includes one or more processor. Any type of
processor can be used. The processor 104 can be associated with a
memory 105 which can store program code, internal maps and other
state data for the robot cleaner 100. The processor 104, in one
embodiment, is mounted to a circuit board that connects the
processor 104 to wires for the sensors, power and motor
controllers. The processor 104 can use software code to implement
the modes and behaviors described below.
[0031] In the example of FIG. 1, sensors for the robot cleaner 100
include front bumper sensors 106 and 108. In one embodiment, the
front sensors use an optical emitter and detector rather than a
mechanical switch. The use of more than one front bumper sensor
allows the robot cleaner 100 to differentiate between different
types of obstacles that the robot encounters. For example, the
triggering of a single front sensor may indicate that the robot
cleaner 100 has run into a small obstacle. When both front sensors
indicate an obstacle, the robot cleaner 100 may have run into a
wall or other large obstacle. In one embodiment, the robot cleaner
100 may begin a new operating mode, such as an object following
mode, after contacting the wall.
[0032] In one embodiment, the cleaning unit 102 includes a sweeping
brush 114 that sweeps up dirt and other particulate off of a
carpeted or uncarpeted floor. The vacuum 116 can use a fan to draw
up dirt and other particulate up to particulate storage 118. The
cleaning unit 102 can also include a motor or motors 120 for the
sweeper 114 and for the fan used with the vacuum 116.
[0033] Other sensors 112 can also be used for obstacle detection.
These other sensors 112 can include ultrasonic sensors, infrared
(IR) sensors, laser ranging sensors and/or camera-based sensors.
The other sensors can be used instead of, or as a complement to,
the front bumper sensors.
[0034] In one embodiment, sensors are used to detect the position
of the robot cleaner. In the example of FIG. 1, sensors associated
with wheels 120 and 122 can be used to determine the position of
the robot. The wheel sensors can track the turning of the wheels.
Each unit of revolution corresponds to a linear distance that the
treads of wheels 120 and 122 have traveled. This information can be
used to determine the location and orientation of the robot
cleaner. In an alternate embodiment, separate encoder wheels can be
used.
[0035] In one embodiment, optical quadrature encoders can be used
to track the position and rotation of the wheels 120 and 122 and
thus give information related to the position of the robot cleaner
100.
[0036] In one embodiment, a particulate sensor 135 is used to
detect the level of particulate cleaned or encountered by the robot
cleaner 100. The operation of the robot cleaner 100 can be modified
in response to a detected level of particulate. For example, in
response to a high detected level of particulate, the robot cleaner
can more thoroughly clean the current location. For example, the
robot cleaner can slow down, back up or cause more overlap with
previously cleaned regions or do a localized clean. When a low
level of particulate is sensed, the current location may be cleaned
less thoroughly. For example, the robot can be sped up or the
overlap reduced.
[0037] In one example, the particulate sensor can be optical
detector, such as photoelectric detector or a nephelometer, which
detects the scattering of light off of particulate. In a
photoelectric detector, such as those used in some smoke detectors,
the light source and light sensor are positioned at 90-degree
angles to one another. The light sensor may also be positioned in a
chamber to reduce the ambient light. The detected level of
scattered light is roughly proportional to the amount of
particulate.
[0038] Alternately, a sound or vibration detector can sense the
level of particulate cleaned by the robot cleaner. In one example,
dirt contacts the sides of the vacuum as it is being acquired. More
dirt causes greater noise and vibrations.
[0039] In one embodiment, a remote control unit is used. Signals
from the remote control (not shown) received by remote control
sensor 138 are decoded by processor 104 and used to control the
operation of the robot cleaner 100.
[0040] The remote control can provide an indication concerning a
room state to the robot cleaner. In an automatic cleaning mode, the
processor can be used to direct the robot cleaner to clean the
room. The processor uses the indication to set a cleaning pattern
for the automatic cleaning mode. The room state indication can be
an indication of cleaning time, on/off state, hard/soft surface
clean, room size, room dirtiness or other indications. In one
example, the cleaning time can be selected from the values: 15
minutes, 30 minutes and max life. The hard/soft surface clean
indicates whether the surface is carpeted or uncarpeted, for
example a hard surface clean can use a reduced speed sweeper
operation. In one embodiment, a clean/dirty indication is used to
set an overlap in the cleaning pattern. For example, it may be
useful to have more overlap for a dirty room.
[0041] In one example, the remote control is used to select between
an automatic control mode and a user control mode. In the automatic
control mode, the processor of the robot directs the robot cleaner
while the robot cleaner cleans. In the user control mode, commands
from the remote control are used to direct the robot cleaner. The
robot cleaner can keep track of its position so that when the robot
cleaner returns to the automatic control mode the robot cleaner is
able to resume cleaning.
[0042] In the example of FIG. 1, the robot cleaner 100 includes a
battery 141, which is used to power the operation of the cleaning
unit 110, the motors 124 and 126, the processor 104 and any other
element that requires power. Battery management unit 142 under
control of the processor 104 controls the supply of power to the
elements of the robot cleaner 100. In one embodiment, the robot
cleaner 100 can be put into a reduced power mode. In one example,
the reduced power mode involves turning all or parts of the
cleaning unit 102 off. For example, the vacuum and/or the sweeper
can be turned off in the reduced power mode. Alternately, the
cleaning unit can be put into a mode that uses less power. The
processor 104 can automatically put the robot cleaner in a reduced
power mode when the processor 104 determines that the robot cleaner
104 is in a region that has been cleaned.
[0043] In one embodiment, the robot cleaner 100 has a user input
element 140 on its case. The user input element 140 allows for the
user to input the size of the room, room clutter, the dirt level,
or other indications concerning the room. As discussed above, the
size of the room can affect the operation of the robot cleaner.
[0044] In one embodiment, additional positioning sensors (not
shown) are used as an alternate or supplement to the wheel encoders
for determining the position of the robot cleaner 100. These
additional positioning sensors can include gyroscopes, compasses
and global positioning system (GPS) based units.
[0045] The object following sensors 150 and 152 of FIG. 1 can be
sonar, infrared or another type of sensor. Object following can use
a sensor, such as a Sonar or IR sensor to follow along the side of
an object. The signal from the sensor will typically be smaller the
further the robot cleaner is from the object. The sensor signal can
be used as feedback in a control algorithm to ensure that the robot
cleaner keeps a fixed distance from the wall. In one embodiment,
the object following sensors are on multiple sides of the robot
cleaner. Sensors in the front of the robot cleaner can be used to
avoid collisions. Sensors of the side of the robot cleaner can be
used to produce a feedback signal while the robot cleaner is moving
parallel to the object.
[0046] FIG. 1B illustrates an illustration of a top view of a robot
cleaner of one embodiment. Shown in this embodiment are the housing
164, wheels 165 and 166, front bumper 167 which contains the bumper
sensors, removable particulate section 168, a handle 169, and input
buttons 170 with indicator lights. The particulate section 168 can
be removable so that the particulate can be thrown away without
requiring vacuum bags. The housing 164 can be made of plastic or
some other material.
[0047] FIG. 1C illustrates the bottom of an exemplary robot
cleaner. Shown in this view is sweeper 171, vacuum inlet 172,
battery compartment 175, bottom roller 176, bumper sensors 173 and
174, and edge detection sensors 176 and 178.
[0048] FIG. 1D illustrates a side view of a robot cleaner. This
side view shows an embodiment where the bumper 167 includes an
extension 167a to protect the wheel 165 from becoming entangled and
to allow for obstacles above the main bumper portion to be detected
by the robot cleaner.
[0049] FIG. 1E illustrates an exemplary remote control including a
number of control buttons 180, a remote control joystick 181 and
stop button 182 for remotely steering the robot cleaner. In one
embodiment, the signals from the remote control are sent to the
robot cleaner to provide state information that the robot cleaner
can use during its operations.
[0050] FIG. 1F is a diagram that shows a cross-sectional view of a
robot cleaner of one embodiment. A vacuum air path 183 is shown.
The vacuum air path can include a vacuum inlet 184 at the bottom of
the robot cleaner, a filter 185 for filtering particulate from the
air flow; and a fan 186 drawing air through the filter 185 and
exhausting the air out of the robot cleaner.
[0051] In one embodiment, the air is exhausted out the top of the
robot cleaner out of vents 187. As shown in FIG. 15, the top of the
robot cleaner can have an air exit 187 with protective fins that
are angled from the vertical to reduce the air resistance of the
exhausted air. In one embodiment, the air is forced by the fins
186a of the fan 186 out of the air exit 187. In one embodiment,
since the fan blades 186a are tilted, the air from the fan 186
moves at an angle from the vertical. By tilting the protective fins
from the vertical, this can reduce the air resistance that the air
from the fan sees and thus increase the airflow cause by the fan
186.
[0052] A dustbin 188 can be in the vacuum air path 183 for
collecting particulate. The dustbin 188 can include an opening 188a
allowing air and particulate into the dustbin 188 and include a
trap portion 188b below the opening for collecting particulate. The
dustbin 188 can be removable to allow the collected particulate
material to be discarded. The opening 188a can include a trap door
that by the airflow through the vacuum air pack 183. Once the fan
186 stops, the cover can automatically lower to prevent particulate
from moving back out through the opening. The filter 184 can be
part of the dustbin 188 and prevents the particulate from moving
out of the dustbin 188. The filter 184 can be made of polyester or
other material.
[0053] FIG. 16 shows exemplary air baffles 1602 and 1604 that can
be used to slow air in the dustbin and thus make it more likely
that the particulate will settle in the trap 188b. The air baffle
can be adjacent to an opening 188a of the dustbin. The air baffles
1602 and 1604 can be positioned over the entrance to the dustbin
188. The air baffle can include a number of projections, such as a
cow catcher shape. The baffles should be designed so that they do
not overly block the airflow to the fan.
[0054] In one embodiment, wheels are connected to a motor to move
the robot cleaner. The inlet 184 of the vacuum air path can be
positioned in front of the wheels. The inlet 184 of the vacuum air
path can be positioned at least partially inside a region defined
by a bumper. Positioning the air inlet forward on the robot cleaner
helps the robot cleaner to clean areas close to walls.
[0055] FIG. 1F shows the case where the axis of rotation of the fan
is parallel with the bottom of the robot cleaner. FIG. 17A shows
the case where the axis of rotation of the fan is perpendicular
with the bottom of the robot cleaner. Alternately, as shown in FIG.
17B, the axis of rotation of the fan can be neither perpendicular
nor parallel with the bottom of the robot cleaner. A selection of
axis rotation and not perpendicular or parallel to the bottom of
the cleaner can be done to reduce the thickness of the robot
cleaner.
[0056] A brush 189 can be located adjacent to the inlet so that the
brush can agitate particulate such that it can be entrained in the
vacuum air path. The arrangement shown in FIG. 1F illustrates a
case which the brush 189 can lift particles off the floor and then
the particles can be swept up into the airflow path 183. A rubber
element 192 can be used to isolate the brush area 189 from the back
of the robot cleaner and increase the suction towards the front of
the robot cleaner. The rubber element 192 can be made such that it
can tilt when it contacts something.
[0057] A cowl 190 can at least partially surround the fan. The cowl
190 can direct the air to the top of the robot cleaner. The cowl
190 can include an airflow straightening portion located before the
fan. Straightening the airflow can help insure that the airflow
going towards the fan 186 is non turbulent. This can increase the
effectiveness of the fan 186 and thus increase the suction of the
robot cleaner.
[0058] The fan 186 can exhaust the air substantially perpendicular
to the axis of rotation of the fan. The fan can include blades 186a
at the fan perimeter that exhaust the air directly out of an air
exit outside the robot cleaner. The fan 186 can includes a center
portion without blades. FIG. 18 shows exemplary fan designs. It is
desirable to have the efficiency of the robot fan be as large as
possible which increases the efficiency of the suction. Other fan
designs can also be used.
[0059] In one embodiment, the robot cleaner can have a brush for
removing the patterns made into the carpet. This brush can be
positioned anywhere on the robot cleaner behind the rotating brush.
The brush can fluff up the carpet to avoid conspicuous patterns in
the carpet made by the wheels or other parts of the robot
cleaner.
[0060] Placing the particulate collection before the fan 186 has
the advantage that the fan does not contact the particulate.
[0061] FIG. 1G is an exposed view of an exemplary robot
cleaner.
[0062] FIG. 2 illustrates control operations of one embodiment the
robot cleaner. A user input device 202 such as remote control 204
or push button input 206 on the top of the robot cleaner can be
used to provide user state information 204. The user state
information 204 can be stored along with other memory used by the
robot cleaner, such as mapping information. In this example, the
state information includes a hard/soft floor indication 206, an
on/off indication 208, a localized clean room indication 210, a
cleaning time indication 212 and remote control directions
indication, 214. The hard/soft floor indication 206 can be used by
cleaning unit control 218 to adjust the operation of sweep floor
hard or soft floor. The cleaning unit control controls the
operation of the sweeper and the vacuum. In one example, for a hard
floor, the sweeper can be turned off or can be caused to revolve
slower. The on/off indication 208 can be used to turn on or off the
robot cleaner. Additionally, the on/off indication 208 can be used
to pause the robot cleaner when the supplemental cleaning elements
are used. The localized clean button 210 is used to select between
the localized clean control 220 and the area clean control 222. The
clean time information 210 is used to select the clean time, such
as to select between a 15 minute clean, 30 minute clean or max life
clean. The remote control direction indications 214 are provided to
the position control 230. The position control 230 can be also
controlled by the automatic control unit 216. The position control
can also interact with the position tracking unit 232 which can
include mapping functions. Position tracking can track the current
position of the robot cleaner. In an alternate embodiment, limited
or no position tracking is used for some or all of the cleaning
functions. In one embodiment, the information for the position
tracking unit 232 can be provided by the automatic control 216.
[0063] A number of sensors 234 can be used. The bumper detector
sensors 238, stairway detector sensors 240 and object following
sensor 242 can provide input into the object detection module 224.
The object detection module can provide information to the area
clean module 322 and localized clean module 220. The object
following sensors 242 can also provide a signal to the object
following mode control unit 226 for operating the robot cleaner in
an object falling mode.
[0064] A connection port detector 216 which can be used in one
embodiment to detect whether a supplemental cleaning element is
attached. In one embodiment, when the detector 216 detects that the
supplemental cleaning element is attached, the sweeper can be
automatically turned off.
[0065] Wheel sensors 244 can also be used to provide information
for the position tracking 232. In one embodiment, this information
is used for the internal map.
[0066] The modules of FIG. 2 can be mm on a processor or
processors. In one embodiment, conventional operating systems are
used due to the speed of a contemporary processors. An alternate
embodiment, a real time operating system (RTOS) can be used. Real
time operating system are operating systems that guarantees a
certain capability within a specified time constraint. Real time
operating systems are available from vendors such as Wind River
Systems, Inc., of Alameda Calif.
[0067] One embodiment of the present invention is a robot cleaner
including a cleaning unit 102, wheels to move the robot cleaner and
a processor to control the robot cleaner. In a localized cleaning
mode, the robot cleaner can repeatedly clean with the cleaning unit
through the center of a localized cleaning region at different
orientations.
[0068] The robot cleaner can do a star-shaped or other type of
clean in the localized cleaning region. FIGS. 3A-3E illustrate one
example of a star cleaning embodiment. FIG. 3A shows a portion of a
star clean with a forward segment 302 and a backward segment 304.
In the example of FIG. 3A, the forward segment is straight with a
curved backward segment but this need not be the case. FIG. 3B
shows an example of a full star pattern 306. In this example, the
cleaning repeatedly goes thought the center 308. This can improve
the cleaning in the center of the location clean region. The
localized clean, such as the star clean, need not require that the
robot cleaner end up at the location that the robot cleaner started
the localized clean.
[0069] The localized clean can focus on a small region for a short
period of time using a star pattern. This focus can maximize the
number of passes through a central point and minimize the number of
gross robot movements. In one embodiment, the robot cleaner does
not need to turn around during the star clean procedure. This
decreases the time to completion and increases the amount of time
that the robot is actually cleaning the required area.
[0070] In one embodiment, the robot cleaner moves backward during
the star cleaning. When the robot cleaner does not have sensors in
the back, the robot cleaner can be controlled to substantially only
back over regions that the robot has already occupied. This is
especially important if the robot cleaner does not have sensors to
detect descending stairways in the back. FIGS. 3D and 3E illustrate
an embodiment where the robot cleaner has sensors in the back and
can thus move backward into new territory.
[0071] The pattern of driving straight and moving backwards along
an arc can be repeated until the robot has made a full 360 degree
arc. Should the robot contact an obstacle during this time there
are several routines which can be initiated depending on the time
and location of the bump.
[0072] In one embodiment, if the robot detects an obstacle at the
very beginning of a first pass and if this obstacle is within the
area where the robot is planning to place the center of the spot,
the robot will select a `fan pattern` in place of the standard star
pattern. This is due to the close proximity of the obstacle and the
inability to successfully traverse the standard spot cleaning
trajectory. The `fan pattern` can consist of moving back and forth
in ever decreasing radii or curvature. This attempts to maximize
the coverage of the small available region presented by the user.
FIG. 3F illustrates an exemplary fan pattern 320 with passes 322,
324, 326, 328, 330, 332, and 334.
[0073] If the robot cleaner detects a bump that is outside the
`major` or center portion of the region to be cleaned, the robot
cleaner can merely adjusts the center of the spot and continue to
clean in the localized clean mode.
[0074] At the end of the localized clean, the robot cleaner can do
a perimeter clean 310 shown in FIG. 3C. In one example, the
perimeter clean picks up dust that has been pushed to the edge of
the localized clean region. If there is a disturbance (bumps,
stairs, etc.) that has caused a change in trajectory or if the
robot cleaner is on a soft surface, such as carpeted floor, the
perimeter clean can be skipped. The perimeter clean may work better
and be more necessary for a hard surface and in one embodiment the
perimeter clean is only done when the hard floor state is
selected.
[0075] In one embodiment, a robot cleaner determines an estimate of
room size based on distances between obstacle detections. The
estimate of room size can be used to determine the distance that
the robot cleaner goes in a wall following mode when the robot
cleaner attempts to move to a new area.
[0076] In one embodiment, the robot cleaner can be in one of two
operating modes: (i) cleaning and (ii) move to new area. While in a
cleaning mode, the robot cleaner can chose to clean near walls
(wall cleaning) mode or it can choose to clean an area away from
the walls (area clean mode). The probability of picking area clean
vs. wall clean can be function of the estimated room size. The room
size estimate can be computed as a function of the running average
of a number of the last distances the robot cleaner was able to
travel in between bump events. In larger rooms, the probability of
area clean can be increased to account for the fact that area grows
with the square of the room radius while perimeter only grows
linearly.
[0077] The probability of picking a cleaning mode rather than a
"moving to a new area" mode can be a function of the ratio between
area covered while in cleaning mode and the estimated area size
(computed using the estimated room size). As the amount of cleaned
area approaches the estimated area size, the probability of picking
"move to a new area" approaches one. When the "move to new area"
mode is picked, the robot cleaner can goes into a wall (object)
following mode and continue wall following for a distance related
to the estimate room size. In one embodiment, the wall following
distance is greater than twice the estimated room radius. In one
embodiment, the wall following distance is equal to about four
times the estimated room radius.
[0078] FIG. 4 illustrates an example where the estimated room size
is less than the total room size. The robot cleaner determines the
estimated room size based on the distance between obstacle
detections. Since obstacles 402, 404, and 406 keep the robot
cleaner in a small section of the room 400, the estimated room size
is based on this small section of the room. The wall following path
410 of the move-to-new-area mode gets the robot cleaner out of this
small section of the room.
[0079] An indication of an area covered in a cleaning mode can be
maintained. The indication of area covered in the cleaning mode and
the estimated room size can be used to determine when to move to a
new area. The determination of whether to move to a new area can be
done when the robot cleaner contacts an obstacle. The determination
of whether to move to a new area can be done probabilistically. A
predetermined probability curve can be stored as a look-up table in
memory. The probability of moving to a new area can depend on the
estimated room size and the area covered in a cleaning mode. The
robot cleaner can have multiple cleaning modes. The robot cleaner
can use the room size estimate to select between cleaning modes,
such as between a wall cleaning mode and an area cleaning mode.
[0080] In one embodiment, a robot cleaner maintains an internal
map, the internal map indicating the orientation of any detected
obstacles. The robot cleaner can use the internal map to determine
a new direction to go if the robot cleaner detects an obstacle and
can clear the internal map after the robot cleaner is out of a
local region.
[0081] In one embodiment, the robot cleaner employs a short-term
memory mechanism to remember the angular location (orientation) of
obstacles when it tries to find a straight path it can freely
traverse. In one embodiment, the angular location (orientation) of
obstacles is maintained with respect to a center location. The
first time a bump is detected, the robot cleaner can initialize a
linear array of bits, each bit representing a specific direction of
motion from a center location and mark the direction the first bump
came from as occupied. The robot cleaner can then randomly or
systematically pick a new direction among the list of unoccupied
directions, rotate to face this new direction and attempt to go
forward. If the robot cleaner travels for more than a predetermined
distance without bumping into anything, the map can be cleared and
the process reinitialized when a new bump occurs. In one
embodiment, the predetermined distance is 50 cm. If the robot
cleaner bumps into an obstacle before it has traveled the
predetermined distance, the obstacle location is registered in the
array as an occupied direction and anew direction is picked among
all un-occupied directions. The new direction can be picked
randomly.
[0082] FIG. 5 illustrates an example of this operation. In step 1,
an obstacle, the wall 502, is found. The short term map 504 is
updated. The robot cleaner 500 moves back to the center and selects
a new direction. In step 2, the robot cleaner moves forward and
contacts the obstacle 508. The robot cleaner 506 can then move back
to the center point and select a new direction. The short term map
504 continues to be updated until the robot cleaner 506 finds a
direction from which the robot cleaner 506 can escape.
[0083] In one embodiment, the internal map does not store distance
information. This means that the internal map is small and easy to
work with. For example, the array can be shifted when the robot
cleaner turns at the center location. Alternately, a pointer can be
stored to indicate the robot cleaner's orientation with respect to
the internal map.
[0084] The robot cleaner can have a bumper with left and right
contact sensors. The triggering of the contact sensors can affect
the update of the internal map. In one embodiment, the indicated
obstacle in the internal map is greater when both the left and
right contact sensors trigger than if only one of the left and
right contact sensors trigger. The size of the area indicated for
the obstacle in the internal map can also depend on the distance of
the obstacle from the center location.
[0085] In one embodiment, if the internal map indicates obstacles
in a predetermined percentage of directions the robot cleaner goes
into an escape mode. For example, if the internal map indicates
obstacles in substantially all directions, the robot cleaner can go
into the escape mode.
[0086] In the escape mode, the robot cleaner can contact the
obstacles, physically probing for an opening so the robot cleaner
can escape. The robot cleaner can do short curves after each bump
that moves away from then back towards the perimeter of the
trapping region. The robot cleaner bumps against the obstacles
until it can escape from the local area. This mode can be
considered to be a bump wall (obstacle) following mode. In one
embodiment, if no escape is found after a predetermined time, the
robot cleaner signals that it needs assistance.
[0087] In one embodiment, a robot cleaner cleans a first floor
region next to a wall such that the bumper of the robot cleaner
contacts the wall. The robot cleaner can back up, then clean a
second floor region next to the wall with the robot cleaner such
that the bumper of the robot cleaner contacts the wall. The second
floor region can be adjacent to the first floor region.
[0088] In one embodiment, the brush and dust intake of the robot
cleaner are located in the front of the unit. This allows the robot
cleaner to clean very close to the obstacles that it bumps against.
In one embodiment, the brush of the cleaning unit is positioned in
front of wheels that move the robot cleaner. The brush of the
cleaning unit can be positioned partially or completely inside a
region defined by the bumper.
[0089] A procedure has been devised that allows the robot cleaner
to systematically clean segments near walls or furniture. The
procedure is illustrated in the FIG. 6A. During phase (1) the robot
cleaner uses wall (object) following behavior to travel at a set
distance from the obstacle.
[0090] After the robot cleaner has traveled a predetermined
distance, such as 1 m, if the edge it has been following was
straight, it enters the wall clean procedure. In phase (2) the
robot cleaner drives along a curved trajectory while going forward
that positions it as parallel as possible to the wall. At this
point it enters a "Squaring to wall mode" during which the wheels
push the robot cleaner to align the front bumper to the edge of the
wall. The robot cleaner can know it has completed the squaring
phase when both bumper switches have triggered. The robot cleaner
then backs up along the same path it drove forward on until the
unit is positioned parallel to the wall. The robot cleaner moves
forward for a distance equal to or less than the intake width and
repeats the same procedure again. In one embodiment, the distance
moved is less than the intake width, for example 2/3 of the intake
width, so there is overlap in the wall clean regions. The routine
ends when the desired number of passes has been executed or
"squaring to wall" procedure has detected the end of the straight
segment.
[0091] The bumper can have a substantially flat section that is at
least one-third, or one-half, as long as the width of the robot
cleaner. The wall cleaning can be done for a predetermined distance
along a wall. The wall cleaning can be one of multiple cleaning
modes. Other cleaning modes can include an area cleaning mode. A
serpentine clean can be done in the area cleaning mode. An estimate
of the room size can be determined by the robot cleaner. In one
embodiment, the robot cleaner is more likely to go into the wall
cleaning mode for smaller estimated room sizes. The cleaning modes
can be selected probabilistically. The cleaning mode can be
selected when an obstacle is contacted. In one embodiment, the
backing up of the robot cleaner can stay within an area that the
robot cleaner has already moved forward through.
[0092] In one embodiment, the robot cleaner detects an entanglement
of a brush on the robot cleaner, turns off the brush, moves forward
with the brush off, then turns on the brush to detect whether the
entanglement is removed.
[0093] In one embodiment, upon initially detecting that the robot
cleaner brush has been entangled, the unit turns off the brush
motor. The entanglement can be detected by determining that the
brush is not moving by using the system of FIGS. 8A and 8B or by
using another type of detector. The brush motor can be turned of in
the hope that by continuing to move without no power to the brush,
the obstruction may be pulled out naturally. The robot cleaner then
moves forward. In FIG. 7, the robot cleaner 702 moves from spot 704
to spot 706. After a short time, the brush is tried again. If the
brush is still not able to operate, the vacuum fan is turned off,
an indicator light is flashed, and the main brush disentangle
procedure is entered.
[0094] In the main procedure (cycle of steps), the robot cleaner
turns 90 degrees, and moves forward a predetermined distance, such
as 50 cm. In FIG. 7, the robot cleaner 702 moves from spot 706 to
spot 708. This is done to remove the robot cleaner from the
previous area in the hope that the obstruction has been partially
pulled out and a change in trajectory will aid this removal. At the
end of this move, the robot cleaner rotates the brush in the
opposite direction then moves backward over its path. This is done
to manually try to push the obstruction out of the brush. The brush
is then pulsed in a forward direction. If the brush is still not
functional after repeating the cycle of steps a number of time,
such as eight times, the robot cleaner gives up.
[0095] In one embodiment shown in FIGS. 8A and 8B, the brush has a
central rod 802 including a hole 804. An emitter 806 and detector
808 are arranged such that in one orientation 810 of the rod 802,
light from the emitter passes through the hole 804 to the detector.
The emitter 806 and detector 808 can be used to determine if the
brush is entangled.
[0096] In orientation 810, a signal from emitter 806 is detected by
detector 808. In orientation 812, a signal from emitter 806 is not
detected by detector 808. The signal at the detector 808 can be
used to determine whether the brush is operating normally or is
stuck.
[0097] In one embodiment, the robot cleaner 100 is able to detect
an entangled condition. The processor can monitor the robot cleaner
to detect the entangled condition and then adjust the operation of
the robot cleaner to remove the entangled condition. Robot cleaners
can become entangled at the sweeper or drive wheels 120 and 122.
The entangled condition may be caused by a rug, string or other
objects in a room. In the example of FIG. 1, motor 120 drives the
sweeper 114 and motors 124 and 126 drive the wheels 120 and 122. In
one embodiment, when an entangled condition is sensed, the
processor adjusts the operation of the robot cleaner to remove the
entangled condition.
[0098] In an alternate embodiment, the back EMF at a motor can be
used to detect an entanglement. The motors driving the wheels and
sweeper will tend to draw a larger amount or spike in the current
when the motor shaft is stalled or stopped. A back electromotive
force (EMF) is created when the motor is turned by an applied
voltage. The back EMF reduces the voltage seen by the motor and
thus reduces the current drawn. When a rise or spike in the current
is sensed at the motor, the stall in the drive wheel, and thus the
entanglement condition, can be determined.
[0099] The entangled condition can be determined in other ways, as
well. In one embodiment, a lack of forward progress of the robot
cleaner can be used to detect the entangled condition. For example,
when the robot cleaner is being driven forward but the detected
position does not change and there are no obstacles detected by the
sensors, an entangled condition may be assumed. The detection of
the entangled condition can use the position tracking software
module described below.
[0100] In one embodiment, a robot cleaner system includes a robot
cleaner including a cleaning unit and a processor, and a remote
control including a directional control. A directional command from
the remote control can cause the robot cleaner to shift the
cleaning in one direction without requiring a user to hold down the
directional control until a spot is reached.
[0101] FIG. 9B shows a path of the robot cleaner in an area clean
mode in region 910. When the user indicates with the remote control
to move to an adjacent region the robot cleaner can shift the area
clean to region 912. The shift does not require the user to hold
down a directional control until the desired spot is reached. In
one embodiment, the robot cleaner stays in the area clean mode.
FIG. 9C shows an alternate embodiment where the robot cleaner
shifts from cleaning region 914 to cleaning region 916.
[0102] FIG. 9A shows a remote control 902 with outer directional
control 904 surrounding an inner stop button 906. In one embodiment
in an automatic cleaning mode, the processor directs the robot
cleaner to clean the room. In a user control mode, a user can
direct the robot cleaner using the outer directional control.
[0103] In one embodiment, when the robot cleaner is in an area
clean mode and the directional command is received, the robot
cleaner shifts into cleaning an area in the direction indicated by
the direction command. The area clean mode can be a serpentine
clean. In one embodiment, if a directional control is pressed for a
short period of time, the cleaning shifts into another
direction.
[0104] In one embodiment, robot cleaner can follow the commands of
the directional control for an extended period of time. FIG. 9D
shows an example of this type of system. The robot cleaner cleans
in an area clean mode in region 920, follows path 922 under the
control of the user, and returns into an area clean in region 924.
In one embodiment, if directional control is pressed for a longer
period of time, the robot cleaner follows the commands of the
directional control. Alternately, when the stop button 906 is
pressed, the joystick, such as an outer directional controller, is
enabled for the remote control of the robot cleaner.
[0105] The area clean can be a serpentine clean. In this mode, the
robot cleaner cleans a region with cleaning segments up to a
predetermined distance. Incremental right (or left) cleaning
segments can be done so that the next segment touches or overlaps
the last north/south cleaning segment. The width of the cleaning
area produced by the cleaning unit of the robot cleaner is related
to the level of overlap. The serpentine clean can be done with
sharp transitions between horizontal and vertical segments by
stopping the robot cleaner at the end of a segment and rotating the
robot cleaner to the direction of the next segment. Alternately,
the serpentine clean can have curved angles by turning the robot
cleaner while the robot cleaner is still moving for a gradual
transition from one segment to the next.
[0106] The robot cleaner can return to the original location after
cleaning the spot or not. In an automatic cleaning mode, a
processor can direct the robot cleaner to clean the room. In a user
control mode, a user can direct the robot cleaner using an outer
directional control. The remote control can include a region with
an outer directional control surrounding an inner stop button.
[0107] The outer directional control can include four directional
projections. The stop button can stop the current mode of the robot
cleaner. When the stop button is pressed, the outer directional
control can be used for controlling the direction of the robot
cleaner.
[0108] In one embodiment of the present invention as shown in the
example of FIG. 10, a robot cleaner 1002 includes a cleaning unit
1004 with a brush 1006 at the bottom of the robot cleaner 1002 and
wheels 1008 and 1010 connected to a motor to move the robot
cleaner; in wherein the brush 1006 of the cleaning unit is
positioned in front of the wheels 1008 and 1010. The robot cleaner
can include a bumper 1012. The brush 1006 of the cleaning unit 1004
can be positioned partially, mostly, or completely inside a region
defined by the bumper 1012. Having a brush positioned in this
location allows for cleaning close to a wall.
[0109] In one embodiment, the bumper 1012 has a substantially flat
section (length 1014) that is at least one-third, or at least one
half as long as the width 1016 of the robot cleaner. Having a
bumper with a flat section allows the cleaning unit to be
positioned closer to a wall.
[0110] FIG. 11, shows a robot cleaner with an obstacle backaway
mode. In one embodiment, the robot cleaner contacts an object, such
as wall 1102, and does a serpentine clean 1004 having segments,
such as segments 1106, 1108, 1110 and 1112, 1114, that lengthen as
the robot cleaner moves away from the object. Such a clean can help
avoid other obstacles near the object. This mode can work well
along with a wall cleaning mode.
[0111] In one embodiment, the cleaned region 1104 includes a
V-shaped area 1116. The segments can reach a maximum length after a
predetermined distance from the wall. In one embodiment, the
serpentine clean is an area clean mode. The robot cleaner has
additional cleaning modes, such as a wall cleaning mode and a
move-to-new-area mode.
[0112] FIG. 12 illustrates an example of some of the modes for the
robot cleaner. In this example, the cleaning modes 1202 include a
wall cleaning mode 1204 and an area cleaning mode 1206. The wall
cleaning mode 1204 can be selected less often for larger rooms. The
move-to-new-area mode 1208 can be selected probabilistically based
on the estimated room size. The entangle recovery mode 1210 can be
entered when an entanglement is detected.
[0113] FIG. 14A illustrates a robot cleaning system of one
embodiment. The robot cleaning system 1410 can include a robot
cleaner 1412 and barrier units 1414 and 1416. The robot cleaner
1412 can include a tactile sensor, such as bumper sensors 1412a and
1412b. The barrier units 1414 and 1416 can be used to prevent the
robot cleaner 1412 from passing through a region 1418, such as the
doorway defined by wall 1419. When the barrier units are contacted
by the robot cleaner 1412, a tactile sensor 1412a and/or 1412b
triggers and the robot cleaner redirects itself to avoid the
barrier unit. The barrier units can thus be placed to prevent the
robot cleaner from leaving a room or falling down stairs. The
barrier unit can be such that the tactile sensor on the robot
cleaner is triggered by contact with the barrier unit, the
triggering of the tactile sensor of the robot cleaner resulting in
the robot cleaner changing direction. An anti-slide element and/or
weights can be used on the barrier unit to prevent the barrier unit
from being moved backwards by the robot cleaner.
[0114] The barrier units 1414 and 1416 can be weighted at a bottom
portion. In one embodiment, a weight is encased in plastic in the
bottom region. The weight lowers the center of gravity of the
barrier unit and increases the friction if the barrier unit on the
floor surface. The barrier units can also include an anti-slide
element to increase the friction with the floor surface. The
anti-slide element can include the rubber grommets. In one
embodiment, the anti-slide element includes projections on the
bottom of the barrier unit. The projections can stick into a carpet
surface to help prevent the barrier units from sliding. The
projections can be sized such that they are above the lowest part
of the barrier unit, such as the rubber grommets, so that the
projections would not contact a hard wood floor but can still
extend into a carpet. Projections can be put at the bottom of an
anti-slide element, such as the rubber grommets. The anti-slide
element can include hooks on the bottom of the barrier unit. The
hooks can be a strip of the hook portion of a hook and loop
fastener, such as Velcro.TM.. These hooks can contact a carpet
surface.
[0115] The barrier unit can be relatively short. In one embodiment,
the barrier unit is less than 6 inches high. In one embodiment, the
barrier unit is less than 4 inches high. In one embodiment, the
barrier unit is about 3 inches high.
[0116] The barrier unit can be a cone. The cone can define a hollow
center. This allows the barrier units to be stacked to aid in easy
storage and packaging.
[0117] FIGS. 13A and 13B illustrate an example of an optical bump
sensor. In FIG. 8A, the element 1300 is biased in a first position
where energy from the emitter 1302 reaches the detector 1304. In
FIG. 13B, after the bumper contacts an object, the element 1300 is
moved to a second position where energy from the emitter 1302 is
blocked from reaching the detector 1304. The element 1300 can be a
bumper sensor, such as bumper sensors 106 and 108 of the robot
cleaner of FIG. 1. The element 1300 can be biased in the first
position by a spring (not shown).
[0118] A room cleaning mode can be selected by a button on the
input 140 of FIG. 1 or by using a remote control. In one
embodiment, a particulate detector on the robot cleaner can be used
to determine when to switch to a localized cleaning mode. In one
embodiment, the processor 104 can be used to control the robot
cleaner in the selected cleaning mode.
[0119] In one embodiment, a descending stairway can be detected
with an edge sensor 154 or 156. The edge sensor unit can include an
emitter and a detector. The detector can detect less reflected
energy when the sensor is positioned over the descending stairway.
The descending stairway is avoided and the cleaning continued.
[0120] In one embodiment, a convergent mode sensor can be aimed at
the floor. In a convergent mode sensor, only energy reflected from
a finite intersection region will be detected. The finite
intersection region can be positioned at the floor (focused on the
floor). When the convergent mode sensor is over the descending
stairway, substantially no reflected energy is detected.
[0121] As shown in FIG. 1, the edge sensors 154 and 156 can be
positioned at the periphery of the robot cleaner. The edge sensors
can be infrared or other types of sensors. In one embodiment,
processor 104 can cause the robot cleaner to resume the clean once
a descending stairway is avoided.
[0122] One embodiment of the present invention includes selecting a
floor type mode. The floor type modes including a hard surface mode
and a soft surface mode. Operation in the soft surface mode
includes rotating a sweeper, such as sweeper 104 of FIG. 1, more
than in the hard surface mode. The robot cleaner cleans in the
selected floor type mode. The hard surface mode avoids excessive
noise that can be associated with a sweeper contacting a wood or
other hard surface.
[0123] In the hard surface mode, the sweeper can be off or operate
at a reduced speed. The soft surface mode can be a carpet cleaning
mode. The selection of the floor type mode can be done by pressing
a button on the robot cleaner or on a remote control. Alternately,
a floor sensor such as a vibration sensor, a mechanical sensor, or
an optical sensor, can be used to select between the floor type
modes. Processor 104 can be used to control the robot cleaner in
the selected floor type mode.
[0124] In one embodiment, a supplemental cleaning element can be
attached to the robot cleaner. The attachment of the supplemental
cleaning element can pause the robot cleaner or the robot cleaner
can be paused by pressing a button on the robot cleaner or a remote
control. The robot cleaner can be carried and the supplemental
cleaning element used to clean to clean an object. In this way, the
robot cleaner can be used as a portable vacuum.
[0125] The supplemental cleaning element can connect to a
connection port on the top or bottom of the robot cleaner.
Connecting the supplemental cleaning element to the connection port
can result in the normal mode vacuum inlet being mechanically or
electromechanically closed. A part of the supplemental cleaning
element or connection port can close off the normal mode vacuum
inlet. Alternately, the supplemental cleaning element can cover the
normal mode vacuum inlet on the bottom of the robot cleaner.
[0126] As shown in FIG. 1, the robot cleaner can have a handle,
such as handle 160 of FIG. 1, for holding the robot cleaner while
cleaning with the supplemental cleaning unit. In the example of
FIG. 1, the handle 160 is part of the edge of the robot
cleaner.
[0127] The supplemental cleaning element can include a hose
attachment, a tube, a brush, a nozzle, a crevice tool and other
elements. The use of both the robot cleaning mode increases the
flexibility and usability of the device.
[0128] In one embodiment, indications of cleaned regions can be
stored in a long-term internal map. The long-term internal map can
be used to determine the cleaned regions for setting the reduced
power mode. Power management using the reduced power mode can save
battery life.
[0129] Using indications of the cleaned regions within a room, such
as using a long-term internal map, can also allow the robot cleaner
100 to avoid randomly re-cleaning regions of a room. This also
reduces the cleaning time. If the power consumption is kept low
using such techniques, an inexpensive battery or a more effective
but energy-hungry cleaning unit can be used.
[0130] In one embodiment, no internal map is stored. The operations
of the cleaning can be done without storing the position
information. This can simplify the software and potentially cost of
the robot cleaner.
[0131] In one embodiment, such as the embodiment shown in FIG. 5,
the robot cleaner can store an internal map of less than a full
room. In one embodiment, a map of a relatively small area around
the robot cleaner is done. The internal map can keep track of
objects, such as walls, in the area of the robot cleaner. The
position of the robot cleaner can be maintained in the map so that
objects can be avoided. In one embodiment, a short time period of
data is stored. Old data can be removed from the internal map.
Storing the map data for a short period ensures that the data does
not become too stale. In one embodiment, data for a period of less
than five minutes is stored. In one embodiment, data is stored for
about 90 seconds. Alternately, data can be maintained for a
specific distance from the robot cleaner. Data for regions outside
this distance can be removed. Both of these internal mapping
techniques, reduce the memory and processing requirements of the
internal mapping.
[0132] The robot sensors 112 can include a camera. In one
embodiment, the robot vacuum uses computer vision type image
recognition. The camera can use a detector which produces a two
dimensional array of image information. The camera can be a visible
light camera, a thermal camera, an ultraviolet light camera, laser
range finder, synthetic aperture radar or any other type of camera.
Information from the camera can be processed using an image
recognition system. Such a system can include algorithms for
filtering out noise, compensating for illumination problems,
enhancing images, defining lines, matching lines to models,
extracting shapes and building 3D representation.
[0133] One example of a camera for use with the Robot Cleaner is a
charge coupled device (CCD) camera to detect visible light. A video
camera, such as a camcorder, is arranged so that light falls on an
array of metal oxide silicon (MOS) capacitors. Typically, the
output of the video signal is an analog signal that is digitized
for use by a computer processor. A computer card framegrabber can
be used to take analog camera signals and produce a digitized
output. Framegrabbers can produce gray scale or color digital
images.
[0134] An example of a gray scale image uses an 8 bit number to
store 256 discreet values of gray. Color can be represented using
indications of the color components. For example, by using a red,
green, blue (RGB) representation. The cameras can be used to
produce orientation information for the robot computer as well as
to create a map of the room.
[0135] Imaging technology can be used to identify a region in an
image with a particular color. On way to do this is to identify all
pixels in an image which have a certain color. Pixels which share
the same color can be group together. This can be used to identify
an object such as a recharge base, which has a specific color.
[0136] One use of vision for the robot cleaner can be to determine
range information. The range information can be obtained by using
two or more cameras. A stereo camera pair can be centered on the
same point in an image. The angles of the two cameras can give
range information.
[0137] In one embodiment, a light striper is used. Light stripers
project lines, stripes, grids or a pattern of dots on an
environment and then a vision camera observes how a pattern is
distorted on an image. Vision algorithms can scan the rows on the
image to see whether the projected lines or dot array is
continuous. The location of breaks of the line or the array of dots
gives information about the size of an obstacle. Relative placement
of the lines or array indicate whether the obstacles are above
ground or below ground. For example, such a system can be used to
determine a descending stairway which should be avoided by the
robot cleaner.
[0138] In one embodiment, the software used for the robot cleaner
can include a software module for vision. The vision software
module can interact with other modules such as those for optical
avoidance and behavior. In one embodiment, the robotic vacuum uses
navigation functionality such as the ERSP navigation tool available
from Evolution Robotics. The ERSP navigation tool controls visual
location mapping, path planning, obstacle and cliff avoidance
exploration and occupancy grid functionality. The localization and
mapping system uses images and other sensors to do visual
localization as well as to construct a map that includes landmarks
generated by the robot as it explores an environment. The
localization and mapping compensates for the changes in lighting
moving people and moving objects. The robot uses an existing map of
an area or creates a map by determining landmarks in a camera
image. When the robot cleaner moves from a known location, the
robot cleaner can re-orient itself using the landmarks. Path
planning modules can use the map with the landmarks to orient the
robot within a path. The landmark map can be used to produce a map
of clean or unclean regions within a room. The clean/unclean region
map can be separate from or integrated with the landmark map. The
robot can use the clean/unclean region map to clean the room.
[0139] Any number of sensors can be used with the robot. The
sensors can include dead reckoning sensors such as odometry
sensors, potentiometers, synchros and resolvers, optical encoders
and the like. Doppler or internal navigation sensors can also be
used. The robot cleaner can also use internal position error
correction.
[0140] The sensors can also use tactical and proximity sensors
including tactile feelers, tactile bumpers, distributed surface
arrays. Proximity sensors such as magnetic proximity sensors,
inductive proximity sensors, capacitive proximity sensors,
ultrasonic proximity sensors, microwave proximity sensors and
optical proximity sensors can also be used.
[0141] Sensors can include triangulation ranging sensors such as a
stereo disparity sensors and active triangulation units. The
sensors can include the time of flight (TOF) sensors such as
ultrasonic TOF systems and laser-based TOF sensors. The sensors can
include phase-shift measurement and frequency modulation sensors.
The sensors can include other ranging techniques such as
interferometry range from focus, and return signal intensity
sensors. The sensors can also include acoustical energy sensors and
electromagnetic energy sensors.
[0142] The sensors can include collision avoidance sensors that use
navigational control strategies such as reactive control,
representational world modeling and combined approach. The sensors
can also use navigational re-referencing.
[0143] The sensors can include guide path following sensors such as
wire guided and optical stripe sensors. The sensors can include a
magnetic compass. The sensors can also include gyroscopes including
mechanical gyroscopes and optical gyroscopes. The sensors can
include RF position-location systems including ground based and
satellite bases systems.
[0144] The sensors can include ultrasonic and optical
position-location sensors. Sensors can include wall, doorway, and
ceiling reference sensors.
[0145] The sensors can include acoustical sensors, vibration
sensors, ultrasonic presence sensors, optical motion detection,
passive infrared motion detection, microwave motion detection,
video motion detection, intrusion detection on the move and
verification and assessment.
[0146] In one example, the robot cleaner uses a sensor that
produces multiple indications of the distances to an object. An
example of such a sensor is an infrared sensor available from
Canesta, Inc. of San Jose, Calif. Details of such infrared sensors
are described in the U.S. Pat. No. 6,323,932 and published patent
applications US 2002/0140633 A1, US 2002/0063775 A1, US
2003/0076484 A1 each of which are incorporated herein by
reference.
[0147] In one embodiment of the present invention is a robot that
includes a sensor producing multiple indications of distances to
the closest object in an associated portion of the environment. The
processor receives indications from the sensor, determines a
feature in the environment and controls a motion unit of the robot
to avoid the feature.
[0148] The sensor indications can be produced by measuring a period
of time to receive a reflected pulse. Alternately, the indications
can be produced by measuring an energy of a reflected pulse up to a
cutoff time. A determined feature can be indicated in an internal
map of the robot. The determined feature can be a step, an object
in a room, or other element. The robot can be a robot cleaner.
[0149] In one example, an infrared sensor includes an infrared
light source to produce pulses of infrared light, optics to focus
reflections from the infrared light pulses from different portions
of the environment of the robot to different detectors in a 2D
array of detectors. The detectors can produce indications of
distances to the closest object in an associated portion of the
environment.
[0150] The optics can include a single or multiple optical
elements. In one embodiment, the optics focus light reflected from
different regions of the environment to detectors in a 2D array.
The detectors produce indications of the distances to the closest
objects in associated portions of the environment. The 2D array can
includes pixel detectors and associated detector logic. In one
embodiment, the 2D array of detectors is constructed of CMOS
technology on a semiconductor substrate. The pixel detectors can be
photodiodes. The detector logic can include counters. In one
embodiment, a counter for a pixel detector runs until a reflected
pulse is received. The counter value thus indicates the time for
the pulse to be sent from the IR sensor and reflected back from an
object in the environment to the pixel detector. Different portions
of environment with different objects will have different pulse
transit times.
[0151] In one embodiment, each detector produces an indication of
the distance to the closest object in the associated portion of the
environment. Such indications can be sent from the 2D detector
array to a memory such as a Frame Buffer RAM that stores frames of
the indications. A frame can contain distance indication data of
the pixel detectors for a single pulse. A controller can be used to
initiate the operation of the IR pulse source as well as to control
the counters in the 2D detector array.
[0152] The processor in one embodiment is adapted to receive the
indications from the IR sensor. In one embodiment, the indications
are stored in the frame buffer Random Access Memory (RAM). The
indications are used by the processor to determine a feature in the
environment and to control the motion of the unit to avoid the
feature. Examples of features include steps, walls and objects such
as a chair legs. The advantage of the above described IR sensor
with a two-dimensional array of detectors is that a full frame of
distance indications can be created. Full frames of distance
indications simplify feature detection. The burden on the processor
is also reduced. In one embodiment, feature detection software
receives frames of indications and uses the frames to detect
features. Once the features are determined, the features can be
added to an internal environment map with feature mapping software.
The motion control software can be used to track the position of
the robot. Alternately, other elements can be used for positioning
the robot. In one embodiment, the robot uses the indications from
the detector to determine how to move the robot so that the robot
avoids falling down stairs, and bumping into walls and other
objects.
[0153] In one embodiment, the robot cleaner shuts down when the
vacuum becomes tangled in its own cord. Sensors can be located at
the sweeper, wheels or cord payout. When the sensor detects an
entanglement, signals can be sent to the processor to cause the
robot cleaner to shut down.
[0154] The robot cleaners can be powered by batteries or power
cords. When a power cord is used, the cord can be connected to a
wall socket or a unit, such as a central unit connected to a wall
socket. The robot cleaner can maneuver to avoid the power cord. A
payout can be used to keep the power cord tight. In one embodiment,
the robot cleaner keeps the cord on one or the other side of the
robot cleaner.
[0155] In one embodiment, a robot system includes a robot cleaner
including a cleaning unit, and a motion unit, and a unit connected
to the robot cleaner by an electrical cord to provide power to the
robot cleaner. The robot cleaner can clean the room while connected
to the unit and the power cord is wound in as the robot cleaner
gets closer to the unit. The unit can be a central unit, wherein
the robot cleaner moves around the central unit to clean the room.
The unit can be connected to a power socket by another power cord.
A payout can be located at the robot cleaner or the unit. The robot
cleaner can prevent the power cord from completely wrapping around
an object on the floor. The robot cleaner can keep track of its
motion to determine motion changes caused by the power cord
contacting objects on the floor. The robot cleaner can clean back
and forth in region behind the object.
[0156] A number of different types of batteries can be used. The
batteries can include lithium ion (Li-ion), NiMH, NiCd batteries,
and fuel cell batteries. Fuel cell batteries extract energy from
hydrogen. When the hydrogen is joined to oxygen forming water
energy, is produced. The energy takes the form of electricity and
some waste heat. The hydrogen can be obtained from a compound, such
as methanol. Fuel cell batteries can provide relatively high energy
supply which will be used for powering the vacuum fans and the like
on a robot vacuum.
[0157] One embodiment of the present invention is a robot cleaner
that includes a germicidal ultraviolet lamp. The germicidal
ultraviolet lamp can emit radiation when it is energized.
[0158] In one embodiment, the cleaning unit includes an
electrostatic filter. The germicidal ultraviolet lamp can be
positioned to irradiate an airflow before the electrostatic filter.
A mechanical filter can also be used. The mechanical filter can be
a vacuum cleaner bag. In one embodiment, the robot cleaner is
configured to preclude human viewing of UV light emitted directly
from the germicidal ultraviolet lamp. When the germicidal
ultraviolet lamp is directed towards the floor, the lamp can be
placed in a recessed cavity so that the lamp light does not leak
out the side of the robot cleaner, but goes directly towards the
floor surface. A protective covering for the lamp can be used in
this embodiment to prevent the lamp from contacting a thick rug or
other raised surface.
[0159] The vacuum of this example includes an inlet (not shown). A
fan (not shown) can be placed before or after the mechanical
filter. In one embodiment, the mechanical filter is a vacuum
cleaner bag, which provides for particulate storage. The vacuum
cleaner can also includes an electrostatic filter (electrostatic
precipitator) to filter additional particulate from an airflow. The
airflow goes out the outlet (not shown). In one embodiment, the
electrostatic filter includes an emitter which creates ions and a
collector which attracts particulate matter.
[0160] The robot cleaner can have a reservoir that contains a
cleaner, disinfectant, carpet freshener, insecticide, perfume or
other substance. For example, a carpet cleaning solution can be
sprayed onto a carpet which then can be swept up by the robot
cleaner. Additionally, an ozone generator can be used to produce
ozone to kill bacteria or other germs.
[0161] The foregoing description of the preferred embodiments of
the present invention has been provided for the purposes of
illustration and description. It is not intended to be exhaustive
or to limit the invention to the precise forms disclosed. Many
modifications and variations will be apparent to practitioners
skilled in the art. The embodiments were chosen and described in
order to best explain the principles of the invention and its
practical application, thereby enabling others skilled in the art
to understand the invention for various embodiments and with the
various modifications as are suited to the particular use
contemplated. It is intended that the scope of the invention be
defined by the following claims and their equivalents.
* * * * *