a2, United States Patent
`US 6,493,612 B1
`(10) Patent No.:
`Dec. 10, 2002
`(45) Date of Patent:
`Bisset et al.
`
`US006493612B1
`
`(54) SENSORS ARRANGEMENT
`
`(75)
`
`Inventors: David Lindsey Bisset, Wiltshire (GB);
`Alan Gerard Clark, Wiltshire (GB)
`
`(73)
`
`Assignee: Dyson Limited, Malmesbury (GB)
`
`(*)
`
`Notice:
`
`Subject to any disclaimer, the term of this
`patent is extended or adjusted under 35
`US.C. 154(b) by 0 days.
`
`(21)
`
`(22)
`
`(86)
`
`Appl. No.:
`PCT Filed:
`
`PCT No::
`
`09/868,492
`
`Dec.6, 1999
`
`PCT/GB99/04090
`
`§ 371 (c)(1),
`(2), (4) Date:
`
`Jun. 18, 2001
`
`(87)
`
`PCT Pub. No.: W0O00/38026
`
`PCT Pub. Date: Jun. 29, 2000
`
`Foreign Application Priority Data
`(30)
`Dec. 18, 1998
`
`(GB) cocesecssstesssssstesssecsseessecsseesseesnes 9827758
`
`(52)
`
`(S21) Unt. CW? oecceecccsccsssssseeeeee G01C 22/00; GOSD 1/00;
`A4TL 11/00; A47L 13/00
`UWS. Cle cesccssssssssssseseeseeeee 701/23; 701/22; 180/167;
`180/168; 180/169; 180/180; 318/580; 318/587;
`318/868.16; 340/943; 340/435; 15/319;
`15/323; 15/339; 15/340.1; 706/905
`(58) Field of Search .......00....... 701/23.1, 22; 180/167,
`180/168, 169, 280; 706/905; 318/580, 587,
`568.16; 340/943, 435; 15/319, 323, 339,
`340.1; 134/18, 21, 6
`
`(56)
`
`References Cited
`U.S. PATENT DOCUMENTS
`
`6/1994 Ashworth oe. 180/167
`5,321,614 A
`8/1994 Soupert et al. wo. 15/319
`5,341,540 A
`
`.....
`... 180/169
`5,377,106 A * 12/1994 Drunk et al.
`
`... 180/167
`5,548,512 A *
`8/1996 Quraishi
`.......
`....
`5,682,313 A * 10/1997 Edlund et al.
`. 342/127
`
`......
`5,913,919 A *
`6/1999 Baueret al.
`.. 180/169
`.......
`5,995,884 A * 11/1999 Allen et al.
`... 180/167
`4/2000 Sarangapani......
`.. 180/167
`6,055,042 A *
`6/2000 Ueno et al. we. 701/23
`6,076,025 A *
`
`eeeeee 15/319
`6,076,226 A *
`6/2000 Reed oe
`
`
`9/2000 Kawagoe ......ceeee 15/319
`6,119,057 A *
`6,338,013 B1 *
`1/2002 Ruffner
`.....
`.... 180/167
`2001/0004719 Al *
`6/2001 Sommer ......... eee 701/23
`
`FOREIGN PATENT DOCUMENTS
`
`FR
`WO
`WO
`
`2 695 342 Al
`WO 93/03399
`WO 97/41451
`
`3/1994
`2/1993
`11/1997
`
`* cited by examiner
`
`Primary Examiner—William A. Cuchlinski, Jr.
`Assistant Examiner—Ronnie Mancho
`(74) Attorney, Agent, or Firm—Morrison & Foerster LLP
`
`(57)
`
`ABSTRACT
`
`An autonomous vehicle, such as a robotic cleaning device,
`includes wheels which support the vehicle and allow the
`vehicle to traverse a surface. Downward looking wheel
`sensors sense the presence of a surfacein front of the wheels.
`Another sensor is provided at or near a leading edge of the
`vehicle for sensing the presence beneath the leading edge of
`the vehicle. The vehicle is arranged so that movementof the
`vehicle is possible if the leading edge sensor senses that
`there is no surface beneath the leading edge of the vehicle,
`provided that the wheel sensors indicate that there is a
`surface adjacent to the wheel. Whenthe leading edge sensor
`senses that there is no surface beneath the leading edge of
`the vehicle, the vehicle performs an edge following routine.
`
`5,279,672 A *
`
`1/1994 Betker et al. oo... 134/18
`
`13 Claims, 11 Drawing Sheets
`
`FOLLOW WALL
`
`
`
`
`
`LEADING EDGE SENSOR DETECTS
`ABSENCE OF SURFACE;
`ENTER EDGE FOLLOW MODE
`
`
`
`
`
`
`REVERSE FROM EDGE
`USE SIDE DOWNLOOKING
`WITH AN ACUTE TURN
`SENSOR TO FOLLOW EDGE
`
`556
`
`
`MOVE FORWARD UNTIL
`
`LEADING EDGE SENSOR
`DETECTS ABSENCE OF SURFACE
`
`
`
`DO SENSORSINDICATE
`PRESENCE OF WALL ?
`
`
`ENTER WALL FOLLOW
`MODE
`
`
`
`Silver Star Exhibit 1026
`
`Silver Star Exhibit 1026
`
`

`

`U.S. Patent
`
`Dec.10, 2002
`
`Sheet 1 of 11
`
`US 6,493,612 B1
`
`2808 0
`
`
` 04a
`
`
`230220230210b204b23
`
`226202a
`
`226230b
`
`250
`
`Silver Star Exhibit 1026
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`Silver Star Exhibit 1026
`
`

`

`U.S. Patent
`
`Dec.10, 2002
`
`Sheet 2 of 11
`
`US 6,493,612 B1
`
`204b230b
`
`202a220b
`
`
`
`
`
`<=SSS a
`
`todaokJakokI
` enoaES=eeneEe
` i)
`OE
`breyten a
`aSESS
`eeey_in
`3
`i
`122
`
`206b
`
`FIG.2.
`
`230b
`
`202b
`
`Silver Star Exhibit 1026
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`Silver Star Exhibit 1026
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`

`

`U.S. Patent
`
`Dec.10, 2002
`
`Sheet 3 of 11
`
`US 6,493,612 B1
`
`FIG.3.
`
`Silver Star Exhibit 1026
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`Silver Star Exhibit 1026
`
`

`

`U.S. Patent
`
`Sheet 4 of 11
`
`US 6,493,612 B1
`
`Dec.10, 2002
`
`
`
`208a|290
`230a=.208b
`106
`FIG.4b.
`
`Silver Star Exhibit 1026
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`Silver Star Exhibit 1026
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`

`

`Sheet 5 of 11
`
`Dec.10, 2002
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`US 6,493,612 B1
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`U.S. Patent
`
`222a 224a’
`
`Silver Star Exhibit 1026
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`Silver Star Exhibit 1026
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`

`

`U.S. Patent
`
`Dec.10, 2002
`
`Sheet 6 of 11
`
`US 6,493,612 B1
`
`FIG.6.
`
`220b
`
`220c
`
`FIG.7.
`
`220a
`
`
`224b
`
`sb
`
`220b
`
`> 99h
`|
`
`224b
`
`Silver Star Exhibit 1026
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`Silver Star Exhibit 1026
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`

`

`U.S. Patent
`
`Sheet 7 of 11
`
`US 6,493,612 B1
`
`Dec.10, 2002
`
`FIG.9.
`
`FIG.8.
`
`Silver Star Exhibit 1026
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`Silver Star Exhibit 1026
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`

`

`U.S. Patent
`
`Dec.10, 2002
`
`Sheet 8 of 11
`
`US 6,493,612 B1
`
`TX
`
`Rx(2) FIG.10.
`OIP
`
`RX(1)
`412 OP
`408 St
`
`420
`
`FOLLOW WALL
`
`
`
`
`LEADING EDGE SENSOR DETECTS
`ABSENCE OF SURFACE;
`ENTER EDGE FOLLOW MODE
`
`
`MOVE FORWARDUNTIL
`LEADING EDGE SENSOR
`
`DETECTS ABSENCE OF SURFACE
`
`
`DO SENSORSINDICATE
`PRESENCE OF WALL ?
`
`
`
`ENTER WALL FOLLOW
`MODE
`
`FIG.16.
`
`Silver Star Exhibit 1026
`
`Silver Star Exhibit 1026
`
`

`

`D/LOOKER CONTROL
`
`
`CIRCUIT
`
`WHEEL
`
`RIGHT
`
`WHEEL
`
`D/LOOKER
`
`LEADING
`
`EDGE
`
`U.S. Patent
`
`Dec.10, 2002
`
`Sheet 9 of 11
`
`US 6,493,612 B1
`
`LEFT
`
`D/LOOKER
` DECISION
`
`MOTOR
`
`272
`
`
`
`
`SIDE
`
`DILOOKER
`
`278,280
`
`OTHER SENSOR
`
`SOFTWARE
`
`305
`
`FIG.11.
`
`DRIVER
`
`HARDWARE
`
`MOTORS.
`
`Silver Star Exhibit 1026
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`Silver Star Exhibit 1026
`
`

`

`U.S. Patent
`
`022'012
`
`‘02'2028¢
`
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`16AYOWAW96
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`
`
`Dec. 10, 2002
`
`Sheet 10 of 11
`
`US 6,493,612 B1
`
`
`
`UZPZ'2L2ONISSIIONdev
`
`
`
`S6SYOSNASGIOHSAYHLSYOLOW
`
`NOILOVYL
`
`duvOd
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`ONISSSOONd
`
`
`
`ZOL'LOL
`
`Silver Star Exhibit 1026
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`Silver Star Exhibit 1026
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`
`
`
`
`
`

`

`U.S. Patent
`
`Dec.10, 2002
`
`Sheet 11 of 11
`
`US 6,493,612 B1
`
`FIG.13.
`
` SECTION ALONG X- X'
`
`
`FIG.15.
`
`Silver Star Exhibit 1026
`
`Silver Star Exhibit 1026
`
`

`

`US 6,493,612 B1
`
`1
`SENSORS ARRANGEMENT
`
`2
`and a control apparatus for controlling operation of an
`autonomousvehicle.
`
`This application claims priority to International Appli-
`cation No. PCT/GB99/04090 which was published on Jun.
`29, 2000.
`
`An embodiment of the present invention will now be
`described, by way of example only, with reference to the
`accompanying drawings, wherein:
`
`FIELD OF THE INVENTION
`
`BRIEF DESCRIPTION OF THE DRAWINGS
`
`The invention relates to an arrangementof sensors for an
`autonomousvehicle, particularly but not exclusively for an
`autonomous vacuum cleaner.
`
`10
`
`BACKGROUND OF THE INVENTION
`
`An autonomous vehicle generally has a plurality of sen-
`sors for detecting obstacles in the path of the vehicle to
`prevent collision or accidents. While some autonomous
`vehicles can cope with undulating surfaces, they usually
`need to avoid any areas where there is a significant change
`in height, such as stairs where there is a danger that the
`machine can becomestuck or fall, causing damage to the
`vehicle and to others. It is know to provide an autonomous
`vehicle with sensors that monitor the presence of a surface;
`these are often called “downlooking”or “drop-off” sensors.
`Arobotic cleaning device described in Patent Application
`WO 93/03399 has drop-off sensors at a forward edge of the
`cleaning device and is arranged to stop the drive motors
`when one of the dropoff sensors senses the absence of a
`surface beneath the cleaning device. U.S. Pat. No. 5,377,106
`describes an unmanned cleaning vehicle with four drop-off
`sensors mounted on a bumperand side walls of the vehicle.
`The vehicle stops if any of the sensors senses an excessive
`distance between the sensor and the floor.
`
`Safety regulations require that downlooking sensors
`should cause the vehicle to stop wheneverthe sensors detect
`the absence of a surface. This places severe constraints on
`flexibility of controlling the vehicle near to any places where
`these is a significant change in height. The present invention
`seeks to provide moreflexibility in operating an autonomous
`vehicle under these conditions.
`
`SUMMARYOF THE INVENTION
`
`there is
`According to a first aspect of the invention,
`provided an autonomous vehicle comprising wheels for
`supporting the vehicle and for allowing the vehicle to
`traverse a surface, downward looking wheel sensors for
`sensing the presence of a surface in front of the whells, a
`further sensor at or near a leading edge of the vehicle for
`sensing the presence of a surface beneath the leading edge
`of the vehicle and a control apparatus for controlling move-
`mentof the vehicle, the control apparatus being arranged to
`permit movement of the vehicle when the leading edge
`sensor detects the absence of a surface beneath the leading
`edge of the vehicle, providing the wheel sensors indicate the
`presence of a surface adjacent
`the wheel. This has the
`advantage of allowing more flexibility in controlling move-
`ment of the cleaning device.
`Preferably, the vehicle is arranged to operate so that when
`the leading edge sensor detects the absence of a surface
`beneath the leading edge of the vehicle, the vehicle performs
`an edge following routine. The edge following routine can
`be a zig-zag movementalongthe edge, or it can use a further
`downloading sensor which senses the presence of a surface
`adjacent a side edge of the vehicle.
`Further aspects of the invention provide a method of
`operating an autonomousvehicle, software for performing a
`method of controlling operation of an autonomousvehicle
`
`15
`
`20
`
`25
`
`30
`
`40
`
`45
`
`50
`
`55
`
`60
`
`65
`
`FIG. 1 is a perspective view of an autonomous vehicle,
`specifically a vacuum cleaner, according to an embodiment
`of the invention;
`FIG. 2 is a front view of the autonomousvehicle of FIG.
`
`FIG. 3 is a rear view of the autonomous vehicle of FIG.
`
`1;
`
`1;
`
`FIGS. 4a and 4b are side views, taken from the right and
`left sides respectively, of the autonomousvehicle of FIG. 1;
`FIGS. 5a and 5b are underneath and plan viewsrespec-
`tively of the autonomousvehicle of FIG. 1;
`FIG. 6 is a schematic view illustrating the positioning of
`infrared sensors on the autonomousvehicle of FIG. 1;
`FIG. 7 is a schematic view illustrating the grouping of
`infra-red sensors on the autonomous vehicle of FIG. 1;
`FIG. 8 is a schematic view illustrating the positioning of
`ultra-sonic sensors on the autonomousvehicle of FIG. 1; and
`FIG. 9 is a schematic view illustrating the positioning of
`further infra-red sensors on the autonomousvehicle of FIG.
`1;
`
`FIG. 10 shows the form of a downlooking sensor;
`FIG. 11 schematically shows how the downlooking sen-
`sors are used by the control system for the vehicle;
`FIG. 12 showsa control system for the cleaner;
`FIG. 13 shows one example of a sideways downlooking
`sensor;
`
`FIGS. 14 and 15 show two ways in whichthe cleaner can
`operate when the cleaner reaches an edge of a surface that
`it is cleaning; and
`FIG. 16 is a flow diagram of a method for operating the
`cleaner.
`
`DETAILED DESCRIPTION OF THE
`INVENTION
`
`The embodiment illustrated takes the form of an autono-
`mous vacuum cleaner. The vacuum cleaner 100 shownin the
`
`said drawings has a supporting chassis 102 which is gener-
`ally circular in shape and is supported on two driven wheels
`104 and a castor wheel 106. The chassis 102 is preferably
`manufactured from high-strength moulded plastics material,
`such as ABS, but can equally be made from metal such as
`aluminium orsteel. The chassis 102 provides support for the
`components of the cleaner 100 which will be described
`below. The driven wheels 104 are arranged at either end of
`a diameter of the chassis 102, the diameter lying perpen-
`dicular to the longitudinal axis of the cleaner 100. Each
`driven wheel 104 is moulded from a high-strength plastics
`material and carries a comparatively soft,
`ridged band
`around its circumference to enhance the grip of the wheel
`104 when the cleaner 100 is traversing a smooth floor. The
`soft, ridged band also enhancesthe ability of the wheels 104
`to mount and climb over small obstacles. The driven wheels
`
`104 are mounted independently of one another via support
`bearings (not shown) and each driven wheel 104 is con-
`nected directly to a motor 105 which is capable of driving
`the respective wheel 104 in either a forward direction or a
`
`Silver Star Exhibit 1026
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`

`

`US 6,493,612 B1
`
`3
`reverse direction. By driving both wheels 104 forward at the
`same speed,
`the cleaner 100 can be driven in a forward
`direction. By driving both wheels 104 in a reverse direction
`at
`the same speed,
`the cleaner 100 can be driven in a
`backward direction. By driving the wheels 104 in opposite
`directions, the cleaner 100 can be madeto rotate about its
`own central axis so as to effect a turning manoeuvre. The
`aforementioned method of driving a vehicle is well known
`and will not therefore be described any further here.
`The castor wheel 106 is significantly smaller in diameter
`than the driven wheels 104 as can be seen from, for example,
`FIGS. 4a and 4b. The castor wheel 106 is not driven and
`merely serves to support the chassis 102 at the rear of the
`cleaner 100. The location of the castor wheel 106 at the
`trailing edge of the chassis 102, and the fact that the castor
`wheel 106 is swivellingly mounted on the chassis by means
`of a swivel joint 110, allows the castor wheel 106 to trail
`behind the cleaner 100 in a manner which does not hinder
`
`the manoeuvrability of the cleaner 100 whilst it is being
`driven by way of the driven wheels 104. The castor wheel
`106 can be made from a mouldedplastics material or can be
`formed from another synthetic material such as Nylon.
`Mounted on the underside of the chassis 102 is a cleaner
`
`head 122 which includes a suction opening 124 facing the
`surface on which the cleaner 100 is supported. The suction
`opening 124is essentially rectangular and extends across the
`majority of the width of the cleaner head 122. A brush bar
`125 is rotatably mounted in the suction opening 124 and a
`motor (not shown) is mounted on the upper surface of the
`cleaner head 122 for driving the brush bar 125 by wayof a
`drive belt (not shown) extending between a shaft of the
`motor and the brush bar 125. The cleaner head 122 is
`
`mounted on the chassis 102 in such a waythat the cleaner
`head 122 is able to float on the surface to be cleaned. This
`is achieved in this embodimentin that the cleaner head 122
`is pivotally connected to an arm (not shown) which in turn
`is pivotally connected to the underside of the chassis 102.
`The double articulation of the connection between the
`cleaner head 122 andthe chassis 102 allows the cleaner head
`
`to move freely in a vertical direction with respect to the
`chassis 102. This enables the cleaner head to climb over
`
`small obstacles such as books, magazines, rug edges,etc.
`Obstacles of up to approximately 25 mm in height can be
`traversed in this way. A flexible or telescopic conduit is
`located between a rear portion of the cleaner head 122 and
`an inlet port located in the chassis 102.
`As can be seen from FIGS. 5a and 55, the cleaner head
`122 is asymmetrically mounted on the chassis 102 so that
`one side of the cleaner head 122 protrudes beyond the
`general circumference of the chassis 102. This allows the
`cleaner 100 to clean up to the edge of a room onthe side of
`the cleaner 100 on which the cleaner head 122 protrudes.
`The chassis 102 carries a plurality of sensors which are
`designed and arranged to detect obstacles in the path of the
`cleaner 100 andits proximity to, for example, a wall or other
`boundary such as a piece of furniture. The sensors comprise
`several ultra-sonic sensors and several infrared sensors. The
`
`array of sensors will be described in more detail below.
`Control software, comprising navigation controls and steer-
`ing devices for navigating and manoeuvringthe cleaner 100
`around a defined area in order to clean the carpet or other
`surface within the area,
`is housed within a housing 142
`located beneath a control panel 144 or elsewhere within the
`cleaner 100. The specific design of the control software does
`not form part of the present invention. In the manner of
`known autonomousvehicles, the control software is able to
`receive the outputs of the sensors and to drive the motors
`
`10
`
`15
`
`20
`
`25
`
`30
`
`35
`
`40
`
`45
`
`50
`
`55
`
`60
`
`4
`105 so that obstacles are avoided whilst following a path
`specified by algorithms appropriate to the nature of the
`vehicle. Any appropriate software can be used in this way to
`navigate the cleaner 100 around a room to be cleaned.
`The vacuum cleaner 100 also includes a motor and fan
`
`unit 150 supported on the chassis 102 for drawing dirty air
`into the vacuum cleaner 100 via the suction opening 124 in
`the cleaner head 122. The chassis 102 also carries a cyclonic
`separator 152 for separating dirt and dust from the air drawn
`into the cleaner 100. The inlet port which communicates
`with the rear portion of the cleaner head 122 via the conduit
`mentioned above forms the inlet to the cyclonic separator
`152. The cyclonic separator, which preferably comprises
`two cyclones in series, need not be described any further
`here, being known technology and described adequately
`elsewhere.
`
`The cyclonic separator 152 is releasable from the chassis
`102 in order to allow emptying of the cyclonic separator
`152. A hooked catch (not shown) is provided by means of
`which the cyclonic separator 152 is held in position when the
`cleaner 100 is in use. When the hookedcatch is released (by
`manualpressing of a button 134 located in the control panel
`144), the cyclonic separator 152 can belifted away from the
`chassis 102 by meansof gripper portions 170. The cyclonic
`separator 152 can then be emptied.
`Twobattery packs 160 are located on the chassis 102 on
`either side of the cyclonic separator 152. The battery packs
`160 are identical and are spaced from the central axis of the
`vacuum cleaner 100 by a significant distance, say between
`50 and 150 mm.
`
`The vacuum cleaner 100 described above operates in the
`following manner. In orderfor the cleaner 100 to traverse the
`area to be cleaned, the wheels 104 are driven by the motors
`105 which, in turn, are powered by the batteries 160. The
`direction of movementof the cleaner 100 is determined by
`the control software which communicates with the sensors
`
`which are designed to detect any obstacles in the path of the
`cleaner 100 so as to navigate the cleaner 100 around the area
`to be cleaned. The normal forward direction of the cleaner
`100 is such that the cleaner head 122trails behind the driven
`
`wheels 104. The battery packs 160 also power the motor and
`fan unit 150 which draws air into the cleaner 100 via the
`
`cleaner head 122 and passesit to the cyclonic separator 152
`where the dirt and dust is separated from the airflow. The
`battery packs 160 are also used to power the motor which
`drives the brush bar 125 which,in turn assists with pick-up,
`particularly on carpets. The air which exits the cyclonic
`separator 152 is passed across the motor and fan unit 150 by
`appropriate ducting, as is common in many appliances,
`including vacuum cleaners.
`The sensor array forming part of the vacuum cleaner 100
`will now be described in more detail. The array comprises a
`plurality of ultra-sonic sensors and a plurality of infra-red
`sensors. The majority of the sensors are located in a forward
`surface 180 of the vacuum cleaner 100. The forward surface
`
`180 is substantially semi-circular in plan view, as can be
`seen from FIGS. 5a and 5b. However, further sensors are
`located at the uppermost extremity of the cleaner 100, at the
`rear of the cleaner 100, immediately over the brush bar 122,
`and on the underside of the cleaner 100. Details are given
`below.
`
`Three ultra-sonic sensors 202, 204 and 206, each consist-
`ing of an ultra-sonic emitter and an ultra-sonic receiver, are
`positioned in the forward surface 180. A first of the said
`ultra-sonic sensors 202, comprising an emitter 202a@ and a
`receiver 2025,is directed in a forward direction so that the
`
`Silver Star Exhibit 1026
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`Silver Star Exhibit 1026
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`

`US 6,493,612 B1
`
`5
`emitted signals are transmitted in the normal forward direc-
`tion oftravel of the cleaner 100. A second ultra-sonic sensor
`204, comprising an emitter 204a and a receiver 2045,is
`directed such that the emitted signals are transmitted out-
`wardly to the left of the cleaner 100 in a direction which is
`perpendicular to the direction of transmission by the ultra-
`sonic sensor 202. A third ultra-sonic sensor 206, comprising
`an emitter 206a and a receiver 206),is directed such that the
`emitted signals are transmitted outwardly to the right of the
`cleaner 100 in a direction which is perpendicular to the
`direction of transmission by the ultra-sonic sensor 202 and
`opposite to the direction of transmission by the ultra-sonic
`sensor 204. A fourth ultra-sonic sensor 208, comprising an
`emitter 208a and a receiver 208),is located in the rear of the
`cleaner 100 (see FIG. 3) and is directed rearwardly so that
`the emitted signals are transmitted parallel to the normal
`forward direction of travel of the cleaner 100 but in the
`
`opposite direction. These four sensors 202, 204, 206, 208
`detect the presence of walls and obstacles to the front, left,
`right and rear of the cleaner 100.
`A fifth ultra-sonic sensor 210 is located in the forward
`surface 180. The fifth ultra-sonic sensor 210 comprises an
`emitter 210a@ and a receiver 210b. The fifth ultra-sonic
`
`sensor 210 is positioned so that the emitter 210a transmits at
`an angle which is substantially midway between the direc-
`tions in which the forward- and left-looking sensors 202,
`204 transmit. In the embodiment, the sensor 210 transmits in
`a direction of 45° to the normal forward direction of travel
`of the vacuum cleaner 100. As can be seen from FIG. 1, the
`sensor 210 transmits to the side of the cleaner 100 on which
`
`the cleaner head 122 protrudes.
`FIG. 8 shows schematically the arrangement of ultra-
`sonic sensors 202, 204, 206, 208 and 210 on the vacuum
`cleaner 100 if the normal direction of forward travel is along
`the arrow F. In the arrangement shown,the angle a is 45°,
`although variations to this arrangement are possible.
`The inclusion of the sensor 210 provides the vehicle 100
`with greater angular control as it moves along a wall or other
`obstacle with the cleaner head 122 close to the wall. The
`
`sensor 210 is able to detect the presence of a wall or similar
`large obstacle and, if the wall or other obstacle alongside
`which the vehicle is moving disappears (for example, when
`a comeris encountered), then the vehicle 100 is made aware
`of the change earlier than it would have been if the sensor
`210 had not been present. This allows the vehicle to take
`account of comers and other changesin its environment with
`greater accuracy and manoeuvrablity.
`A plurality of infra-red sensors are also included in the
`forward surface 180. The infra-red sensors comprise emit-
`ters 220 and receivers 230. Most of the emitters 220 are
`
`arranged in four groups of three which are spaced substan-
`tially evenly around the forward surface 180. A first emitter
`group 220a comprises a central emitter 222a and two side
`emitters 224a. A second emitter group 220b comprises a
`central emitter 222b and two side emitters 224b. A third
`emitter group 220c comprises a central emitter 222c and two
`side emitters 224c and a fourth emitter group 220d com-
`prises a central emitter 222d and two side emitters 224d.
`Oneof the emitter groups 2206is illustrated in FIG. 7. Each
`side emitter 224b is arranged at an angle b of approximately
`60° to the central emitter 222). Each emitter 222b, 224b has
`a beam angle c of approximately 50°. This arrangement
`creates a field of relatively even emitted signals covering an
`angle of substantially 170° to 180°. It will be appreciated
`that a similar field can be created by providing a larger
`number of emitters, each having a smaller beam angle than
`the arrangementillustrated in FIG. 7.
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`FIG. 6 illustrates the arrangement of the emitter groups
`220a, 220b, 220c, 220d on the cleaner 100. As will be seen
`from the figure, the first emitter group 220cis located at the
`end of a radial line extending at an angle d of 30° to the
`transverse axis 190 of the cleaner 100 on the left side
`thereof. The fourth emitter group 220d is located at the end
`of a radial line also extending at an angle d of 30° to the
`transverse axis 190 but on the right side of the cleaner 100.
`The second and third emitter groups 2206, 220c are located
`at the ends of radial lines extending at an angle e of 60° to
`the transverse axis 190 on the left and nght sides of the
`cleaner 100 respectively. The third emitter group 220c is
`identical to the second emitter group 220b asillustrated in
`FIG. 7. However, the first and fourth emitter groups 220a,
`220d each have one side emitter 224a, 224d which is
`specifically directioned so that the signal emitted is parallel
`to the transverse axis 190. This is achieved, in this specific
`case, by varying the angle b between the relevant central
`emitter 222a, 222d and the respective side emitter 224a,
`224d from 60° to 30°. It will be appreciated that, if either of
`the angles b and d differ from the values given above, then
`the extent of the variation in angle b between the relevant
`central emitter 222a, 222d and the respective side emitter
`224a, 224d will need to be adjusted so that the side emitter
`224a, 224d remains directed outwardly in a direction par-
`allel to the transverse axis 190. Two additional emitters 226
`are positioned close to the central axis of the cleaner 100 and
`are directioned so that they emit signals in a substantially
`forward direction with respect to the normal direction of
`travel.
`
`Thefirst and fourth emitter groups 220a, 220d are located
`in a horizontal plane which is vertically spaced from the
`horizontal plane in which the second and third emitter
`groups 220b, 220c are located. The first and fourth emitter
`groups 220a, 220d are located at a higher level than the
`second and third emitter groups 220b, 220c. The additional
`emitters 226 are also spaced vertically from the two afore-
`mentioned horizontal planes. The arrangement is symmetri-
`cal about the longitudinal axis of the cleaner 100. The whole
`of the array of emitters is designed so that at least two of the
`emitters will send signals directly to any point in the path of
`the cleaner (in the forward direction). (This will not apply,
`of course, to points which are extremely close to the cleaner
`itself.)
`The receivers 230 are spaced substantially evenly around
`the forward surface 180. A first receiver 230a is located
`adjacent each of the emitters 224a, 224d which are direc-
`tioned parallel to the transverse axis 190 so as to receive
`signals therefrom. These receivers 230a are specifically
`paired with the emitters 224a, 224d. The remaining receiv-
`ers 230b are spaced substantially evenly around the forward
`surface 180 and are not paired with any of the emittersatall.
`The receivers 230 areall located in a single horizontal plane
`with the exception of two central receivers 230b which are
`located adjacent the forward-looking emitters 226. The lack
`of pairing of the receivers with the emitters gives the cleaner
`100 an enhanced ability to detect its position within an
`environment and with respect to objects and obstacles.
`Two passive infra-red detectors 240 are located in the
`forward surface 180 for
`the purpose of detecting heat
`sources such as humans, animals and fires. The passive
`infra-red detector 240 is directioned so that it looks in a
`forward direction to detect heat sources in its path. Two
`forward-looking ultra-sonic sensors 250, each comprising an
`emitter 250a and a receiver 250b, are positioned at an
`uppermost extremity of the cleaner 100 so that they are able
`to sense obstacles immediately in front of the cleaner and at
`
`Silver Star Exhibit 1026
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`Silver Star Exhibit 1026
`
`

`

`US 6,493,612 B1
`
`7
`or near an uppermost extremity thereof. In this case, the
`sensors 250 are positioned in the casing of the fan and motor
`unit 150 so that they both look along the uppermost edge of
`the cyclonic separator 152. The direction of each sensor 250
`is parallel to the direction of the other sensor 250. The
`sensors 250 are able to detect any obstacles which are at a
`sufficiently high level not to be detected by the sensors
`arranged in the forward surface 180 but which would
`constitute an obstruction to the forward movement of the
`
`cleaner 100. Rearward-looking sensors could also be pro-
`vided at a high level if required, but none is shown in the
`embodimentillustrated in the drawings. It will be appreci-
`ated that a similar effect can be achieved using sensors
`(preferably ultra-sonic sensors) positioned lower on the
`cleaner than the uppermost extremity but directioned so as
`to look towards the appropriate area adjacent the uppermost
`extremity in front of the cleaner 100.
`Further infra-red sensors 260, 262 are positioned on the
`chassis 102 immediately above the protruding end of the
`cleaner head 122. Each sensor 260, 262 comprises an emitter
`260a, 262a and a receiver 260b, 262b. The first of these
`sensors 260 is directioned so that the emitter 260a emits a
`signal in a direction parallel to the longitudinal axis of the
`cleaner head 122 or of the brush bar 125. Thedirection of the
`signal from the sensor 260 is therefore perpendicular to the
`forward direction of travel and parallel to the direction of the
`signal emitted by emitter 224a. The sensor 260 is thus able
`to detect the distance of a wall or other obstacle along which
`the cleaner 100 is intended to travel. In combination with the
`emitter 224a and the receiver 230a, the sensor 260 is also
`able to maintain the direction of travel of the cleaner 100
`parallel with the wall or other obstacle along which the
`cleaner 100 is intendedto travel. This is achieved by way of
`the parallel signals being maintained essentially identical.
`Any variation between the two signals can be easily recog-
`nised and the path of the cleaner 100 can then be adjusted to
`compensate for the discrepancy. The arrangement is illus-
`trated in FIG. 9. As will be seen from the figure, the distance
`between the directions of the two signals is approximately
`one half of the length of the cleaner 100, although this can
`be varied to a considerable extent. Preferably, the distance
`will not be less than a quarter of the length of the vehicle nor
`more than three quarters thereof.
`The second of the further infra-red sensors 262 is direc-
`
`tioned so that the emitter 262a sends a signal rearwardly in
`a direction parallel to the direction of travel of the cleaner
`100. The sensor 262 is able to detect the presence of an
`obstacle on which the cleaner head 122 may become lodged
`if the cleaner 100 were traveling in a rearward direction or
`turning or rotating about a vertical axis.
`Infra-red sensors 272, 274, 276 are provided on the
`underside of the cleaner 100. Each sensor 272, 274, 276 is
`directioned so that it looks downwardly towards the surface
`across which the cleaner 100 travels and which the cleaner
`
`100 is intended to clean. Two downward-looking sensors
`274, 276 are provided in the chassis 102 immediately in
`front of each of the driven wheels 104. A further downward-
`
`the front edge of the
`looking sensor 272 is provided at
`chassis 102 and on or close to the longitudinal axis of the
`cleaner 100. Each sensor 272, 274, 276 comprises an emitter
`and a receiver. In the embodimentillustrated, the outermost
`component of each sensor 274, 276 is a receiver and the
`innermost componentis an emitter. Each of the sensors 272,
`274, 276 is capable of detecting the presence or absence of
`the surface across which the cleaner 100 travels. A signalis
`sent to the control software to bring the cleaner 100to a halt,
`or to turn, immediately one of the sensors 274, 276 detects
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`that the surface is absent. This is likely to be due to the
`presence of a stairway or other edge of the surface. The
`cleaner 100 is thus prevented from falling from a height in
`the event that a stairway or other edge is encountered. For
`safety reasons, each of the sensors located in front of each
`wheel is connected to the control software via different
`circuits so that, should one circuit fail, the other sensor will
`still be functional in order to avoid an accident occurring.
`Further downlooking sensors 278, 280 are provided on the
`underside of the cleaner 100 adjacent the periphery of the
`cleaner. Side downlooking sensors 278, 280 are arranged to
`detect the presence of a surface adjacent a side edge of the
`vehicle outside of the path of the wheel and forward of the
`wheel, in the normal direction of movement of the vehicle.
`The normal, forward, direction of movement of the vehicle
`is shownas arrow 290.