Svendsen, Selma (Andover, MA, US)
Ozick, Daniel N. (Newton, MA, US)
Casey, Christopher M. (Lexington, MA, US)
Kapoor, Deepak Ramesh (Cranston, RI, US)
Campbell, Tony L. (Pepperell, MA, US)
Won, Chikyung (Tewksbury, MA, US)
Morse, Christopher John (Malden, MA, US)
Burnett, Scott Thomas (Windham, NH, US)

Plaque It!

11/633885

10/28/2008

12/04/2006

Images are available in PDF form when logged in. To view PDFs, Login  or  Create Account (Free!)

Click for automatic bibliography generation

iRobot Corporation (Bedford, MA, US)

700/245

15/319, 15/339, 15/49.1

A47L5/00; G06F19/00

700/245, 701/41, 701/23, 15/319, 701/300, 342/385, 701/301, 342/417, 15/339, 15/49.1, 701/24

3457575	SWEEPER FOR CARPETED AND SMOOTH FLOORS	July, 1969	Bienek
3550714	LAWN MOWER	December, 1970	Bellinger
3674316	PARTICLE MONITOR	July, 1972	De Brey
3756667	SUSPENSION FOR TRACKED VEHICLES	September, 1973	Bombardier
3809004	ALL TERRAIN VEHICLE	May, 1974	Leonheart
3937174	Sweeper having at least one side brush	February, 1976	Haaga
4099284	Hand sweeper for carpets	July, 1978	Shinozaki et al.
4119900	Method and system for the automatic orientation and control of a robot	October, 1978	Kremnitz
D258901	Wheeled figure toy	April, 1981	Keyworth
4306329	Self-propelled cleaning device with wireless remote-control	December, 1981	Yokoi
4369543	Remote-control radio vacuum cleaner	January, 1983	Chen et al.
4492058	Ultracompact miniature toy vehicle with four-wheel drive and unusual climbing capability	January, 1985	Goldfarb
4513469	Radio controlled vacuum cleaner	April, 1985	Godfrey et al.
D278732	Animal-like figure toy	May, 1985	Ohkado
4556313	Short range optical rangefinder	December, 1985	Miller, Jr. et al.
4618213	Gelatinous elastomeric optical lens, light pipe, comprising a specific block copolymer and an oil plasticizer	October, 1986	Chen
4620285	Sonar ranging/light detection system for use in a robot	October, 1986	Perdue
4626995	Apparatus and method for optical guidance system for automatic guided vehicle	December, 1986	Lofgren et al.
4674048	Multiple robot control system using grid coordinate system for tracking and completing travel over a mapped region containing obstructions	June, 1987	Okumura
4679152	Navigation system and method for a mobile robot	July, 1987	Perdue
4696074	Multi-purpose household appliance particularly for cleaning floors, carpets, laid carpetings, and the like	September, 1987	Cavalli et al.
D292223	Toy robot or the like	October, 1987	Trumbull
4700301	Method of automatically steering agricultural type vehicles	October, 1987	Dyke
4700427	Method of automatically steering self-propelled floor-cleaning machines and floor-cleaning machine for practicing the method	October, 1987	Knepper
4716621	Floor and bounded surface sweeper machine	January, 1988	Zoni
4733430	Vacuum cleaner with operating condition indicator system	March, 1988	Westergren
4733431	Vacuum cleaner with performance monitoring system	March, 1988	Martin
4756049	Self-propelled cleaning truck	July, 1988	Uehara
4777416	Recharge docking system for mobile robot	October, 1988	George, II et al.
D298766	Toy robot	November, 1988	Tanno
4782550	Automatic surface-treating apparatus	November, 1988	Jacobs
4813906	Pivotable running toy	March, 1989	Matsuyama
4815157	Floor cleaner	March, 1989	Tsuchiya
4829626	Method for controlling a vacuum cleaner or a central vacuum cleaner	May, 1989	Harkonen
4832098	Non-pneumatic tire with supporting and cushioning members	May, 1989	Palinkas
4854000	Cleaner of remote-control type	August, 1989	Takimoto
4887415	Automated lawn mower or floor polisher	December, 1989	Martin
4893025	Distributed proximity sensor system having embedded light emitters and detectors	January, 1990	Lee
4901394	Floor nozzle for electric cleaner	February, 1990	Nakamura et al.
4912643	Position sensing apparatus	March, 1990	Beirne
4918441	Non-contact sensing unit for row crop harvester guidance system	April, 1990	Bohman
4919224	Automatic working vehicular system	April, 1990	Shyu et al.
4919489	Cog-augmented wheel for obstacle negotiation	April, 1990	Kopsco
4933864	Mobile robot navigation employing ceiling light fixtures	June, 1990	Evans et al.
4956891	Floor cleaner	September, 1990	Wulff
4962453	Autonomous vehicle for working on a surface and method of controlling same	October, 1990	Pong et al.
4971591	Vehicle with vacuum traction	November, 1990	Raviv
4974283	Hand-guided sweeping machine	December, 1990	Holsten et al.
4977639	Floor detector for vacuum cleaners	December, 1990	Takahashi et al.
5001635	Vehicle	March, 1991	Yasutomi et al.
5002145	Method and apparatus for controlling automated guided vehicle	March, 1991	Waqkaumi et al.
5022812	Small all terrain mobile robot	June, 1991	Coughlan et al.
D318500	Monster toy robot	July, 1991	Malewicki
5033291	Flexible tactile sensor for measuring foot pressure distributions and for gaskets	July, 1991	Podoloff et al.
5062819	Toy vehicle apparatus	November, 1991	Mallory
5086535	Machine and method using graphic data for treating a surface	February, 1992	Grossmeyer et al.
5093955	Combined sweeper and scrubber	March, 1992	Blehert et al.
5094311	Limited mobility transporter	March, 1992	Akeel
5105502	Vacuum cleaner with function to adjust sensitivity of dust sensor	April, 1992	Takashima
5109566	Self-running cleaning apparatus	May, 1992	Kobayashi et al.
5115538	Vacuum cleaners	May, 1992	Cochran et al.
5136750	Vacuum cleaner with device for adjusting sensitivity of dust sensor	August, 1992	Takashima et al.
5142985	Optical detection device	September, 1992	Stearns
5163202	Dust detector for vacuum cleaner	November, 1992	Kawakami et al.
5165064	Mobile robot guidance and navigation system	November, 1992	Mattaboni
5173881	Vehicular proximity sensing system	December, 1992	Sindle
5204814	Autonomous lawn mower	April, 1993	Noonan et al.
5239720	Mobile surface cleaning machine	August, 1993	Wood et al.
5261139	Raised baseboard brush for powered floor sweeper	November, 1993	Lewis
5277064	Thick film accelerometer	January, 1994	Knigga et al.
5279672	Automatic controlled cleaning machine	January, 1994	Belker, Jr. et al.
5284522	Self-running cleaning control method	February, 1994	Kobayashi et al.
5293955	Obstacle sensing apparatus for a self-propelled cleaning robot	March, 1994	Lee
5303448	Hopper and filter chamber for direct forward throw sweeper	April, 1994	Hennessey et al.
5310379	Multiple configuration toy vehicle	May, 1994	Hippely
5319828	Low profile scrubber	June, 1994	Waldhauser et al.
5321614	Navigational control apparatus and method for autonomus vehicles	June, 1994	Ashworth
5324948	Autonomous mobile robot for radiologic surveys	June, 1994	Dudar et al.
5341540	Process and autonomous apparatus for the automatic cleaning of ground areas through the performance of programmed tasks	August, 1994	Soupert et al.
5353224	Method for automatically controlling a travelling and cleaning operation of vacuum cleaners	October, 1994	Lee et al.
5363935	Reconfigurable mobile vehicle with magnetic tracks	November, 1994	Schempf
5369347	Self-driven robotic cleaning apparatus and driving method thereof	November, 1994	Yoo
5369838	Automatic floor scrubber	December, 1994	Wood et al.
5410479	Ultrasonic furrow or crop row following sensor	April, 1995	Coker
5435405	Reconfigurable mobile vehicle with magnetic tracks	July, 1995	Schempf
5440216	Robot cleaner	August, 1995	Kim
5444965	Continuous and autonomous mowing system	August, 1995	Colens
5446356	Mobile robot	August, 1995	Kim
5451135	Collapsible mobile vehicle	September, 1995	Schempf
5454129	Self-powered pool vacuum with remote controlled capabilities	October, 1995	Kell
5455982	Hard and soft floor surface cleaning apparatus	October, 1995	Armstrong et al.
5465525	Intellectual working robot of self controlling and running	November, 1995	Mifune et al.
5467273	Large area movement robot	November, 1995	Faibish et al.
5497529	Electrical apparatus for cleaning surfaces by suction in dwelling premises	March, 1996	Boesi
5505072	Scanning circuit for pressure responsive array	April, 1996	Oreper
5507067	Electronic vacuum cleaner control system	April, 1996	Hoekstra et al.
5515572	Electronic vacuum cleaner control system	May, 1996	Hoekstra et al.
5534762	Self-propelled cleaning robot operable in a cordless mode and a cord mode	July, 1996	Kim
5537017	Self-propelled device and process for exploring an area with the device	July, 1996	Feiten et al.
5539953	Floor nozzle for vacuum cleaners	July, 1996	Kurz
5542146	Electronic vacuum cleaner control system	August, 1996	Hoekstra et al.
5548511	Method for controlling self-running cleaning apparatus	August, 1996	Bancroft
5551525	Climber robot	September, 1996	Pack et al.
5553349	Vacuum cleaner nozzle	September, 1996	Kilstrom et al.
5555587	Floor mopping machine	September, 1996	Guha
5560077	Vacuum dustpan apparatus	October, 1996	Crotchett
5568589	Self-propelled cleaning machine with fuzzy logic control	October, 1996	Hwang
D375592	Vacuum cleaner	November, 1996	Ljunggren
5611106	Carpet maintainer	March, 1997	Wulff
5611108	Floor cleaning apparatus with slidable flap	March, 1997	Knowlton et al.
5613261	Cleaner	March, 1997	Kawakami et al.
5621291	Drive control method of robotic vacuum cleaner	April, 1997	Lee
5622236	Guidance system for self-advancing vehicle	April, 1997	Azumi et al.
5634237	Self-guided, self-propelled, convertible cleaning apparatus	June, 1997	Paranjpe
5634239	Vacuum cleaner nozzle	June, 1997	Tuvin et al.
5650702	Controlling system for self-propelled floor cleaning vehicles	July, 1997	Azumi
5652489	Mobile robot control system	July, 1997	Kawakami
5682313	Method for localization of beacons for an autonomous device	October, 1997	Edlund et al.
5709007	Remote control vacuum cleaner	January, 1998	Chiang
5717169	Method and apparatus for inspecting well bore casing	February, 1998	Liang et al.
5735959	Apparatus spreading fluid on floor while moving	April, 1998	Kubo et al.
5756904	Pressure responsive sensor having controlled scanning speed	May, 1998	Oreper
5761762	Cleaner and bowling maintenance machine using the same	June, 1998	Kubo et al.
5777596	Touch sensitive flat panel display	July, 1998	Herbert
5781960	Nozzle arrangement for a self-guiding vacuum cleaner	July, 1998	Kilstrom et al.
5787545	Automatic machine and device for floor dusting	August, 1998	Colens
5794297	Cleaning members for cleaning areas near walls used in floor cleaner	August, 1998	Muta
5812267	Optically based position location system for an autonomous guided vehicle	September, 1998	Everett, Jr. et al.
5819008	Mobile robot sensor system	October, 1998	Asama et al.
5831597	Computer input device for use in conjunction with a mouse input device	November, 1998	West et al.
5839156	Remote controllable automatic moving vacuum cleaner	November, 1998	Park et al.
5839532	Vacuum wall walking apparatus	November, 1998	Yoshiji
5841259	Vacuum cleaner and control method thereof	November, 1998	Kim et al.
5867800	Method and device for sensing of obstacles for an autonomous device	February, 1999	Leif
5905209	Output circuit for pressure sensor	May, 1999	Oreper
5916008	Wall descending toy with retractable wheel and cover	June, 1999	Wong
5926909	Remote control vacuum cleaner and charging system	July, 1999	McGee
5933102	Capacitive sensitive switch method and system	August, 1999	Miller
5933913	Cordless wet mop and vacuum assembly	August, 1999	Wright et al.
5935179	System and device for a self orienting device	August, 1999	Kleiner et al.	701/23
5940927	Autonomous surface cleaning apparatus	August, 1999	Haegermarck et al.
5940930	Remote controlled vacuum cleaner	August, 1999	Oh et al.
5942869	Mobile robot control device	August, 1999	Katou
5943730	Scrubber vac-fan seal	August, 1999	Boomgaarden
5943733	Sucking and filtering vehicle for dust and trash collecting	August, 1999	Tagliaferri
5959423	Mobile work robot system	September, 1999	Nakanishi et al.
5968281	Method for mopping and drying a floor	October, 1999	Wright et al.
5983448	Cordless wet mop and vacuum assembly	November, 1999	Wright et al.
5984880	Tactile feedback controlled by various medium	November, 1999	Lander
5989700	Pressure sensitive ink means, and methods of use	November, 1999	Krivopal
5991951	Running and working robot not susceptible to damage at a coupling unit between running unit and working unit	November, 1999	Kubo
6000088	Cordless wet mop and vacuum assembly	December, 1999	Wright et al.
6032542	Prepressured force/pressure sensor and method for the fabrication thereof	March, 2000	Warnick
6041471	Mobile walk-behind sweeper	March, 2000	Charky et al.
6049620	Capacitive fingerprint sensor with adjustable gain	April, 2000	Dickinson et al.
6055702	Vacuum cleaner	May, 2000	Imamura
6065182	Cordless wet mop and vacuum assembly	May, 2000	Wright et al.
6076025	Mobile robot steering method and control device	June, 2000	Ueno
6076226	Controlled self operated vacuum cleaning system	June, 2000	Reed
6088020	Haptic device	July, 2000	Mor
6099091	Traction enhanced wheel apparatus	August, 2000	Campbell
6101671	Wet mop and vacuum assembly	August, 2000	Wright et al.
6108269	Method for elimination of passive noise interference in sonar	August, 2000	Kabel
6125498	Handheld extraction cleaner	October, 2000	Roberts et al.
6142252	Autonomous vehicle that runs while recognizing work area configuration, and method of selecting route	November, 2000	Kinto et al.
6167587	Upright extraction cleaning machine	January, 2001	Kasper et al.
6192548	Upright extraction cleaning machine with flow rate indicator	February, 2001	Huffman
6226830	Vacuum cleaner with obstacle avoidance	May, 2001	Hendriks et al.
6230362	Upright extraction cleaning machine	May, 2001	Kasper et al.
6243913	Cleaning device	June, 2001	Frank et al.
6259979	Method and device for association of anonymous reflectors to detected angle positions	July, 2001	Holmquist
6263539	Carpet/floor cleaning wand and machine	July, 2001	Baig
6272936	Pressure sensor	August, 2001	Oreper
6327741	Controlled self operated vacuum cleaning system	December, 2001	Reed
6370453	Service robot for the automatic suction of dust from floor surfaces	April, 2002	Sommer
6400048	Rotary brush device and vacuum cleaner using the same	June, 2002	Nishimura
6401294	Upright extracton cleaning machine with handle mounting	June, 2002	Kasper
6412141	Upright extraction cleaning machine	July, 2002	Kasper et al.
6437227	Method for recognizing and selecting a tone sequence, particularly a piece of music	August, 2002	Theimer
6442476	Method of tracking and sensing position of objects	August, 2002	Poropat
6444003	Filter apparatus for sweeper truck hopper	September, 2002	Sutcliffe
6481515	Autonomous mobile surface treating apparatus	November, 2002	Kirkpatrick et al.
6493612	Sensors arrangement	December, 2002	Bisset
6493613	Method for operating a robot	December, 2002	Peless et al.
6496754	Mobile robot and course adjusting method thereof	December, 2002	Song et al.
6496755	Autonomous multi-platform robot system	December, 2002	Wallach et al.
6504610	Method and system for positioning an autonomous mobile unit for docking	January, 2003	Bauer
6525509	Docking system for a self-propelled working tool	February, 2003	Petersson et al.
6532404	Mobile robots and their control system	March, 2003	Colens
D474312	Robotic vacuum cleaner	May, 2003	Stephens
6571415	Random motion cleaner	June, 2003	Gerber et al.
6571422	Vacuum cleaner with a microprocessor-based dirt detection circuit	June, 2003	Gordon
6574536	Moving apparatus for efficiently moving on floor with obstacle	June, 2003	Kawagoe et al.
6580246	Robot touch shield	June, 2003	Jacobs
6601265	Vacuum cleaner	August, 2003	Burlington
6605156	Robotic floor cleaning device	August, 2003	Clark et al.
6611120	Robot cleaning system using mobile communication network	August, 2003	Song et al.
6611738	Multifunctional mobile appliance	August, 2003	Ruffner
6658693	Hand-held extraction cleaner with turbine-driven brush	December, 2003	Reed, Jr.
6671592	Autonomous vehicular appliance, especially vacuum cleaner	December, 2003	Bisset et al.
6690134	Method and system for robot localization and confinement	February, 2004	Jones et al.
6741054	Autonomous floor mopping apparatus	May, 2004	Koselka et al.
6748297	Robot cleaner system having external charging apparatus and method for docking with the charging apparatus	June, 2004	Song et al.
6756703	Trigger switch module	June, 2004	Chang
6781338	Method and system for robot localization and confinement	August, 2004	Jones et al.
6809490	Method and system for multi-mode coverage for an autonomous robot	October, 2004	Jones et al.
6830120	Floor working machine with a working implement mounted on a self-propelled vehicle for acting on floor	December, 2004	Yashima et al.
6841963	Robot cleaner, system thereof and method for controlling same	January, 2005	Song et al.
6883201	Autonomous floor-cleaning robot	April, 2005	Jones et al.	15/319
6901624	Self-moving cleaner	June, 2005	Mori et al.
D510066	Base station for robot	September, 2005	Hickey et al.
6938298	Mobile cleaning robot for floors	September, 2005	Aasen
6956348	Debris sensor for cleaning apparatus	October, 2005	Landry et al.
6965209	Method and system for robot localization and confinement	November, 2005	Jones et al.
6971140	Brush assembly of cleaner	December, 2005	Kim
6985556	Proximity detector and radiography system	January, 2006	Shanmugavel
6993954	Sensor equilibration and calibration system and method	February, 2006	George
6999850	Sensors for robotic devices	February, 2006	McDonald
7024278	Navigational control system for a robotic device	April, 2006	Chiapetta et al.
7030768	Water softener monitoring device	April, 2006	Wanie
7057120	Shock absorbent roller thumb wheel	June, 2006	Ma et al.
7085624	Autonomous machine	August, 2006	Aldred et al.
7206677	Efficient navigation of autonomous carriers	April, 2007	Hulden
20010020200	Tool actuation and force feedback on robot-assisted microsurgery system	September, 2001	Das et al.
20010025183	Methods and apparatuses for maintaining a trajectory in sterotaxi for tracking a target inside a body	September, 2001	Shahidi
20010047231	Method for operating a robot	November, 2001	Peless et al.
20020011813	Autonomous floor mopping apparatus	January, 2002	Koselka et al.
20020016649	Robot obstacle detection system	February, 2002	Jones
20020120364	Mobile robots and their control system	August, 2002	Colens
20020156556	Multifunctional mobile appliance	October, 2002	Ruffner
20020173877	Mobile robotic with web server and digital radio links	November, 2002	Zweig
20030019071	Cleaner cartridge	January, 2003	Field et al.
20030025472	Method and system for multi-mode coverage for an autonomous robot	February, 2003	Jones et al.
20030060928	ROBOTIC VACUUM CLEANER	March, 2003	Abramson et al.
20030067451	CAPACITIVE TOUCH DETECTORS	April, 2003	Tagg
20030120389	Robotic vacuum cleaner	June, 2003	Abramson et al.
20030137268	Miniature robotic vehicles and methods of controlling same	July, 2003	Papanikolopoulos et al.
20030192144	Robot vacuum cleaner with air agitation	October, 2003	Song et al.
20030216834	Method and system for remote control of mobile robot	November, 2003	Allard
20030233177	Graphical system configuration program for material handling	December, 2003	Johnson et al.
20040020000	Robot obstacle detection system	February, 2004	Jones
20040030448	System, methods and apparatus for managing external computation and sensor resources applied to mobile robotic network	February, 2004	Solomon
20040030449	Methods and apparatus for multi robotic system involving coordination of weaponized unmanned underwater vehicles	February, 2004	Solomon
20040030450	System, methods and apparatus for implementing mobile robotic communication interface	February, 2004	Solomon
20040030571	System, method and apparatus for automated collective mobile robotic vehicles used in remote sensing surveillance	February, 2004	Solomon
20040031113	Robotic surface treating device with non-circular housing	February, 2004	Wosewick et al.
20040049877	Autonomous floor-cleaning robot	March, 2004	Jones et al.
20040068351	System, methods and apparatus for integrating behavior-based approach into hybrid control model for use with mobile robotic vehicles	April, 2004	Solomon
20040068415	System, methods and apparatus for coordination of and targeting for mobile robotic vehicles	April, 2004	Solomon
20040068416	System, method and apparatus for implementing a mobile sensor network	April, 2004	Solomon
20040076324	Systems and methods for the automated sensing of motion in a mobile robot using visual data	April, 2004	Burl et al.
20040088079	Method and device for obstacle detection and distance measurement by infrared radiation	May, 2004	Lavarec et al.
20040111184	Navigational control system for a robotic device	June, 2004	Chiappetta et al.
20040117064	Sensors for robotic devices	June, 2004	McDonald	700/245
20040134336	System, methods and apparatus for aggregating groups of mobile robotic vehicles	July, 2004	Solomon
20040134337	System, methods and apparatus for mobile software agents applied to mobile robotic vehicles	July, 2004	Solomon
20040148731	Powered edge cleaner	August, 2004	Damman et al.
20040156541	Location mark detecting method for robot cleaner and robot cleaner using the method	August, 2004	Jeon et al.
20040158357	Robot cleaner system having external recharging apparatus and method for docking robot cleaner with external recharging apparatus	August, 2004	Lee et al.
20040200505	Robot vac with retractable power cord	October, 2004	Taylor et al.
20040204792	Robotic vacuum with localized cleaning algorithm	October, 2004	Taylor et al.
20040211444	Robot vacuum with particulate detector	October, 2004	Taylor et al.
20040236468	Robot vacuum with remote control mode	November, 2004	Taylor et al.
20040244138	Robot vacuum	December, 2004	Taylor et al.
20050000543	Robot vacuum with internal mapping system	January, 2005	Taylor et al.
20050010331	Robot vacuum with floor type modes	January, 2005	Taylor et al.
20050021181	Robot cleaner	January, 2005	Kim et al.	700/245
20050067994	Method and system for robot localization and confinement	March, 2005	Jones
20050156562	Autonomous robot auto-docking and energy management systems and methods	July, 2005	Cohen et al.
20050166354	Autonomous vacuum cleaner	August, 2005	Uehigashi
20050204717	Device for automatically picking up objects	September, 2005	Colens
20050251292	Obstacle following sensor scheme for a mobile robot	November, 2005	Casey et al.
20060010638	Cleaner	January, 2006	Shimizu
20060060216	System for automatically exchanging cleaning tools of robot cleaner, and method therefor	March, 2006	Woo
20060089765	System and method for behavior based control of an autonomous vehicle	April, 2006	Pack et al.
20060190133	Autonomous surface cleaning robot for wet cleaning	August, 2006	Konandreas et al.	700/245
20070244610	Autonomous coverage robot navigation system	October, 2007	Ozick et al.	701/23

EP0437024	July, 1991			Appliance housings.
EP0861629	September, 1998			Vacuum cleaner
EP0930040	July, 1999			Low noise fan
EP1331537	July, 2003			Method and system for robot localization and confinement of workspace
FR2828589	August, 2001
GB2283838	May, 1995
GB2404330	February, 2005
JP62120510	June, 1987
JP62154008	July, 1987
JP63183032	July, 1988
JP63241610	October, 1988
JP0026312	January, 1990
JP2026312	January, 1990
JP03051023	March, 1991			SELF-PROPELLED CLEANER
JP06327598	November, 1994			INTAKE PORT BODY FOR VACUUM CLEANER
JP7295636	November, 1995
JP08089451	April, 1996			SELF-MOBILE CLEANER
JP08152916	June, 1996			MOBILE WORKING ROBOT
JP9179625	July, 1997
JP9185410	July, 1997
JP9206258	August, 1997
JP11508810	August, 1999
JP11510935	September, 1999
JP2001258807	September, 2001			SELF-TRAVELING VACUUM CLEANER
JP2001275908	October, 2001			CLEANING DEVICE
JP2001525567	December, 2001
JP200278650	March, 2002
JP2002204768	July, 2002			SELF-PROPELLED CLEANER
JP22204768	July, 2002
JP2002532178	October, 2002
JP3356170	October, 2002
JP2002323925	November, 2002			MOVING WORKING ROBOT
JP22323925	November, 2002
JP2002355206	December, 2002			TRAVELING VACUUM CLEANER
JP2002360471	December, 2002			SELF-TRAVELLING VACUUM CLEANER
JP2002360482	December, 2002			SELF-PROPELLED CLEANER
JP22360479	December, 2002
JP200310076	January, 2003
JP20035296	February, 2003
JP2003036116	February, 2003			AUTONOMOUS TRAVEL ROBOT
JP200338401	February, 2003
JP200338402	February, 2003
JP2003505127	February, 2003
JP23052596	February, 2003
JP2003061882	March, 2003			SELF-PROPELLED VACUUM CLEANER
JP2003310489	November, 2003			ROBOT CLEANER
WO/1995/026512	October, 1995			METHOD AND DEVICE FOR SENSING OF OBSTACLES FOR AN AUTONOMOUS DEVICE
WO/1997/015224	May, 1997			VACUUM CLEANER NOZZLE
WO/1997/040734	November, 1997			AUTONOMOUS DEVICE
WO/1997/041451	November, 1997			SYSTEM AND DEVICE FOR A SELF ORIENTING DEVICE
WO/1999/028800	June, 1999			IMPROVEMENTS TO MOBILE ROBOTS AND THEIR CONTROL SYSTEM
WO/1999/038056	July, 1999			ELECTRONIC SEARCH SYSTEM
WO/1999/038237	July, 1999			DOCKING SYSTEM FOR A SELF-PROPELLED WORKING TOOL
WO/1999/043250	September, 1999			VACUUM CLEANER NOZZLE
WO/2000/004430	January, 2000			ROBOTIC SYSTEM
WO/2000/036962	June, 2000			VACUUM CLEANER
WO/2000/038026	June, 2000			SENSORS ARRANGEMENT
WO/2000/038029	June, 2000			AUTONOMOUS VEHICULAR APPLIANCE, ESPECIALLY VACUUM CLEANER
WO/2000/078410	December, 2000			DEVICE FOR AUTOMATICALLY PICKING UP OBJECTS
WO/2001/006904	February, 2001			ROBOTIC FLOOR CLEANING DEVICE
WO/2001/006905	February, 2001			ROBOTIC SYSTEM
WO/2002/039864	May, 2002			MOBILE ROBOT
WO/2002/039868	May, 2002			SENSORS FOR ROBOTIC DEVICES
WO/2002/058527	August, 2002			ROBOT FOR VACUUM CLEANING SURFACES VIA A CYCLOID MOVEMENT
WO/2002/062194	August, 2002			AUTOMATIC FLOOR CLEANING DEVICE
WO/2002/067744	September, 2002			WHEEL SUPPORT ARRANGEMENT FOR AN AUTONOMOUS CLEANING APPARATUS
WO/2002/067745	September, 2002			OBSTACLE SENSING SYSTEM FOR AN AUTONOMOUS CLEANING APPARATUS
WO/2002/074150	September, 2002			AUTONOMOUS MOBILE CANISTER VACUUM CLEANER
WO/2002/075356	September, 2002			SONAR TRANSDUCER
WO/2002/075469	September, 2002			METHOD AND DEVICE FOR DETERMINING POSITION OF AN AUTONOMOUS APPARATUS
WO/2002/075470	September, 2002			ENERGY-EFFICIENT NAVIGATION OF AN AUTONOMOUS SURFACE TREATMENT APPARATUS
WO/2002/101477	December, 2002			METHOD AND SYSTEM FOR MULTI-MODE COVERAGE FOR AN AUTONOMOUS ROBOT
WO/2003/026474	April, 2003			ROBOTIC VACUUM CLEANER
WO/2003/040845	May, 2003			AN AUTONOMOUS MACHINE
WO/2003/040846	May, 2003			AN AUTONOMOUS MACHINE
WO/2003/040546	May, 2003			COMMON-RAMP-INJECTOR
WO/2004/006034	January, 2004			FLOOR TREATMENT SYSTEM
WO/2004/004533	January, 2004			METHOD FOR OPERATING A FLOOR CLEANING SYSTEM, AND FLOOR CLEANING SYSTEM ASSOCIATED WITH SAID METHOD
WO/2004/005956	January, 2004			SENSOR DEVICE, IN ADDITION TO SELF-PROPELLED FLOOR CLEANING EQUIPMENT COMPRISING A SENSOR DEVICE
WO/2004/058028	January, 2004			MOBILE SOIL CULTIVATION APPLIANCE
WO/2005/077244	January, 2004			SURFACE TREATING DEVICE WITH CARTRIDGE-BASED CLEANING SYSTEM
WO/2006/068403	January, 2004			CLEANING ROBOT HAVING DOUBLE SUCTION DEVICE
WO/2004/025947	March, 2004			A NAVIGATIONAL CONTROL SYSTEM FOR A ROBOTIC DEVICE
WO/2005/055795	June, 2005			AUTOMOTIVE OR DRIVABLE SWEEPING DEVICE AND COMBINED SWEEPING DEVICE/ BASE STATION DEVICE
WO/2005/083541	September, 2005			DEBRIS SENSOR FOR CLEANING APPARATUS
WO/2006/046400	May, 2007			FUEL CELL SYSTEM AND METHOD

Cameron Morland, Autonomous Lawn Mower Control, Jul. 24, 2002.
Doty, Keith L et al, “Sweep Strategies for a Sensory-Driven, Behavior-Based Vacuum Cleaning Agent” AAAI 1993 Fall Symposium Series Instantiating Real-World Agents Research Triangle Park, Raleigh, NC, Oct. 22-24, 1993, pp. 1-6.
Electrolux designed for the well-lived home, website: http://www.electroluxusa.com/node57.as[?currentURL=node142.asp%3F, acessed Mar. 18, 2005.
eVac Robotic Vacuum S1727 Instruction Manual, Sharper Image Corp, Copyright 2004.
Everyday Robots, website: http://www.everydayrobots.com/index.php?option=content&task=view&id=9, accessed Apr. 20, 2005.
Facts on the Trilobite webpage: “http://trilobiteelectroluxse/presskit—en/node11335asp?print=yes&pressID=” accessed Dec. 12, 2003.
Friendly Robotics Robotic Vacuum RV400-The Robot Store website: http://www.therobotstore.com/s.nl/sc.9/category,-109/it.A/id.43/.f, accessed Apr. 20, 2005.
Gat, Erann, Robust Low-computation Sensor-driven Control for Task-Directed Navigation, Proceedings of the 1991 IEEE, International Conference on Robotics and Automation, Sacramento, California, Apr. 1991, pp. 2484-2489.
Hitachi: News release: The home cleaning robot of the autonomous movement type (experimental machine) is developed, website: http://www.i4u.com/japanreleases/hitachirobot.htm., accessed Mar. 18, 2005.
Kärcher Product Manual Download webpage: “http://wwwkarchercom/bta/downloadenshtml?ACTION=SELECTTEILENR&ID=rc3000&submitButtonName=Select+Product+Manual” and associated pdf file “5959-915enpdf (47 MB) English/English” accessed Jan. 21, 2004.
Karcher RC 3000 Cleaning Robot—user manual Manufacturer: Alfred-Karcher GmbH & Co, Cleaning Systems, Alfred Karcher-Str 28-40, PO Box 160, D-71349 Winnenden, Germany, Dec. 2002.
Kärcher RoboCleaner RC 3000 Product Details webpages: “http://wwwrobocleanerde/english/screen3html” through “. . . screen6html” accessed Dec. 12, 2003.
Karcher USA, RC3000 Robotic Cleaner, website: http://www.karcher-usa.com/showproducts.php?op=view—prod¶m1=143¶m2=¶m3=, accessed Mar. 18, 2005.
Koolvac Robotic Vacuum Cleaner Owner's Manual, Koolatron, Undated.
NorthStar Low-Cost, Indoor Localization, Evolution robotics, Powering Intelligent Products.
Put Your Roomba . . . On “Automatic” Roomba Timer> Timed Cleaning-Floorvac Robotic Vacuum webpages: http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=43575198387&rd=1, accessed Apr. 20, 2005.
Put Your Roomba . . . On “Automatic” webpages: “http://www.acomputeredge.com/roomba,” accessed Apr. 20, 2005, 5 pgs.
RoboMaid Sweeps Your Floors So You Won't Have To, the Official Site, website: http//www.thereobomaid.com/, acessed Mar. 18, 2005.
Robot Review Samsung Robot Vacuum (VC-RP30W), website: http://www.onrobo.com/reviews/At—Home/Vacuun—Cleaners/on00vcrp30rosam/index.htm, accessed Mar. 18, 2005.
Robotic Vaccum Cleaner-Blue, website: http://www.sharperimage.com/us/en/catalog/productview.jhtml?sku=S1727BLU, accessed Mar. 18, 2005.
Schofield, Monica, “Neither Master nor Slave” A Pratical Study in the Development and Employment of Cleaning Robots, Emerging Technologies and Factory Automation, 1999 Proceedings EFA'99 1999 7th IEEE International Conference on Barcelona, Spain Oct. 18-21, 1999, pp. 1427-1434.
Wired News: Robot Vacs in the House, website: http://www.wired.com/news/print/0,1294,59237,00.html, accessed Mar. 18, 2005.
Zoombot Remote Controlled Vaccum-RV-500 New Roomba 2, website: http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=43526&item=4373497618&rd=1, accessed Apr. 20, 2005.
Shimoga et al., Touch and force reflection for telepresence surgery, 1994, IEEE, pp. 1049-1050.*.
Autonomous Lawn Care Applications, Conference on Robotics, Authors: Micheal Gregg, Dr. Eric M. Schwartz, Dr. Antonio A. Arroyo—future work includes a mechanism for adjusting cutter height, additional motor and blade for edge cutting.
Sweep Strategies for a Sensory Driven Behavior Based Vacuum Cleaning Agent, Keith L. Doty and Reid R. Harrison.

Hail III, Joseph J.

Ojini, Anthony

Fish & Richardson P.C.

This U.S. patent application claims priority under 35 U.S.C. 119(e) to a U.S. provisional patent application filed on Dec. 2, 2005, entitled “ROBOT NETWORKING, THEMING AND COMMUNICATION SYSTEM” and having assigned Ser. No. 60/741,442, the entire contents of which are hereby incorporated by reference.

What is claimed is:

1. An autonomous coverage robot comprising: a chassis; a drive system mounted on the chassis and configured to maneuver the robot; an edge cleaning head carried by the chassis and driven by an edge cleaning head motor to rotate about a non-horizontal axis, the edge cleaning head extending beyond a lateral extent of the chassis to engage a floor surface while the robot is maneuvered across the floor; a controller carried by the chassis; a motor current sensor in communication with the controller and configured to monitor motor current associated with the edge cleaning head; wherein the controller is configured to reverse bias the motor current to the edge cleaning head motor, in response to an elevated motor current, sufficient to provide substantially free reverse rotation of the edge cleaning head motor, while continuing to maneuver the robot across the floor.

2. The robot of claim 1 wherein the controller, in response to an elevated edge cleaning head motor current, moves the robot backwards, alters a drive direction, and then moves the robot forward.

3. The robot of claim 1 wherein the edge cleaning head comprises a brush with bristles.

4. The robot of claim 1 wherein the edge cleaning head rotates about a substantially vertical axis.

5. The robot of claim 1 wherein the edge cleaning head comprises at least one brush element having first and second ends and defining an axis of rotation about the first end normal to the work surface.

6. The robot of claim 5 wherein the edge cleaning head comprises three brush elements, each brush element forming an angle with an adjacent brush element of about 120 degrees.

7. The robot of claim 5 wherein the edge cleaning head comprises six brush elements, each brush element forming an angle with an adjacent brush element of about 60 degrees.

8. The robot of claim 1 wherein the edge cleaning head is disposed on a peripheral edge of the robot.

9. The robot of claim 1 wherein the edge cleaning head comprises a rotatable squeegee that extends beyond a peripheral edge of the chassis.

10. The robot of claim 1 wherein the edge cleaning head comprises a plurality of absorbent fibers that extend beyond a peripheral edge of the chassis upon rotation of the cleaning head.

11. The robot of claim 1 further comprising a main cleaning head carried by the chassis and driven to rotate about a horizontal axis to engage a floor surface while the robot is maneuvered across the floor, wherein the controller is configured to reverse bias the motor current to the main cleaning head in response to an elevated main cleaning head motor current, while continuing to maneuver the robot across the floor.

12. The robot of claim 11 wherein the controller, in response to an elevated main cleaning head motor current, moves the robot backwards, alters a drive direction, and then moves the robot forward.

13. A method of disentangling an autonomous coverage robotic, the method comprising: running the robot to autonomously traverse across a floor surface in a forward direction of the robot while rotating about a non-horizontal axis an edge cleaning head carried by the chassis and driven by an edge cleaning head motor, the edge cleaning head extending beyond a lateral extent of the chassis while engaging the floor surface; monitoring motor current associated with the edge cleaning head; reverse biasing the motor current to the edge cleaning head motor, in response to detecting an elevated edge cleaning head motor current, sufficient to provide substantially free reverse rotation of the edge cleaning head motor, while continuing to maneuver across the floor surface.

14. The method of claim 13 wherein the robot determines movement of the robot in the forward direction before reverse biasing the motor current to the edge cleaning head in response to an elevated cleaning head motor current.

15. The method of claim 13 wherein the robot reverse biases the motor current to the edge cleaning head in response to an elevated edge cleaning head motor current for a period of time.

16. The method of claim 15 wherein the period of time is about 2 seconds.

17. The method of claim 13 wherein the robot, after reverse biasing the motor current to the edge cleaning head, moves in a reverse direction, alters a drive direction, and then moves in the drive direction.

18. The method of claim 13 wherein the edge cleaning head comprises a brush with bristles.

19. The method of claim 13 wherein the robot further comprises a main cleaning head carried by the chassis and driven to rotate about a horizontal axis to engage the floor surface while the robot is maneuvered across the floor, wherein the robot reverse biases the motor current to the main cleaning head in response to an elevated main cleaning head motor current while continuing to maneuver across the floor surface.

20. The method of claim 19 wherein the robot determines movement of the robot in the forward direction before reverse biasing the motor current to the main cleaning head in response to an elevated main cleaning head motor current.

21. The method of claim 19 wherein the robot reverse biases the motor current to the main cleaning head in response to an elevated cleaning head motor current for a period of time.

22. The method of claim 19 wherein the robot, after reverse biasing the motor current to the main cleaning head, moves in a reverse direction, alters a drive direction, and then moves in the drive direction.

23. An autonomous robot comprising: a chassis; a drive system mounted on the chassis and configured to maneuver the robot; a floor proximity sensor carried by the chassis and configured to detect an adjacent floor surface, the sensor comprising: a beam emitter configured to direct a beam toward the floor surface; and a beam receiver responsive to a reflection of the directed beam from the floor surface and mounted in a downwardly-directed receptacle of the chassis; and a beam-transparent cover having a forward and rearward edge disposed across a lower end of the receptacle to prohibit accumulation of sediment in the receptacle, the forward edge elevated above the rearward edge; wherein the cover comprises an anti-static material.

24. The robot of claim 23 wherein the floor proximity sensor comprises at least one infrared emitter and receiver pair.

25. The robot of claim 23 wherein the drive system comprises: at least one driven wheel suspended from the chassis; and at least one wheel-floor proximity sensor carried by the chassis and housed adjacent one of the wheels, the wheel-floor proximity sensor configured to detect the floor surface adjacent said one of the wheels.

26. The robot of claim 25 wherein the wheel-floor proximity sensor comprises at least one infrared emitter and receiver pair.

27. The robot of claim 23 wherein the drive system further comprises a controller configured to maneuver the robot away from a perceived cliff in response a signal received from the floor proximity sensor.

28. The robot of claim 23 wherein the drive system further comprises: a wheel drop sensor housed near one of the wheels and responsive to substantial downward displacement of the wheel with respect to the chassis.

29. The robot of claim 28 wherein the drive system further comprises a validation system that validates the operability of the floor proximity sensors when all wheels drop.

30. The robot of claim 28 wherein the wheel drop sensor comprises at least one infrared emitter and receiver pair.

31. The robot of claim 23 wherein the lower surface of the receptacle is wedge shaped.

32. The robot of claim 23 wherein the cover comprises a lens.

TECHNICAL FIELD

This invention relates to robots, and more particularly to autonomous coverage robots.

BACKGROUND

Autonomous robots are robots which can perform desired tasks in unstructured environments without continuous human guidance. Many kinds of robots are autonomous to some degree. Different robots can be autonomous in different ways. An autonomous coverage robot traverses a work surface without continuous human guidance to perform one or more tasks. In the field of home, office and/or consumer-oriented robotics, mobile robots that perform household functions such as vacuum cleaning, floor washing, patrolling, lawn cutting and other such tasks have been widely adopted.

SUMMARY

An autonomous coverage robot will encounter many obstacles while operating. In order to continue operating, the robot will need to continually avoid obstacles, and in cases where trapped by fabric, string, or other entangling soft media, free itself.

In one aspect, an autonomous coverage robot includes a chassis, a drive system mounted on the chassis and configured to maneuver the robot, an edge cleaning head carried by the chassis, and a controller carried by the chassis. The edge cleaning head is driven by an edge cleaning head motor and may rotate about a non-horizontal axis. The edge cleaning head extends beyond a lateral extent of the chassis to engage a floor surface while the robot is maneuvered across the floor. The edge cleaning head may be disposed on or near a peripheral edge of the robot. A brush control process, independent of drive processes, on a controller that controls robot operation is configured to monitor motor current associated with the edge cleaning head. The brush control process on the controller is also configured to reverse bias the edge cleaning head motor in a direction opposite to the previous cleaning direction after detecting a spike (e.g., transient or rapid increase in motor current) or in general an elevated motor current motor (to substantially neutrally rotate and/or be driven to rotate at the same speed as a an unwinding cord, string, or other tangled medium), while continuing to maneuver the robot across the floor performing uninterrupted coverage or cleaning of the floor or other motion behaviors. In one implementation, the brush control process on the controller, following an elevated edge cleaning head motor current, reverse biases the edge cleaning head motor (to substantially neutrally rotate and/or be driven to rotate at the same speed as a an unwinding cord, string, or other tangled medium) and subsequently or concurrently passes a signal to a drive motor control process, directly or indirectly via a supervising process, so that the unwinding may occur at the same time that the robot drives substantially backwards, alters a drive direction, and moves the robot forward.

In one implementation, the edge cleaning head includes a brush with bristles that extend beyond a peripheral edge of the chassis. In one example, the edge cleaning head includes at least one brush element having first and second ends, the bush element defining an axis of rotation about the first end normal to the work surface. The edge cleaning head may rotate about a substantially vertical axis. In one instance, the edge cleaning head includes three brush elements, where each brush element forms an angle with an adjacent brush element of about 120 degrees. In another instance, the edge cleaning head comprises six brush elements, where each brush element forms an angle with an adjacent brush element of about 60 degrees.

In another implementation, the edge cleaning head comprises a rotatable squeegee that extends beyond a peripheral edge of the chassis. The rotatable squeegee may be used for wet cleaning, surface treatments, etc.

In yet another implementation, the edge cleaning head includes a plurality of absorbent fibers that extend beyond a peripheral edge of the chassis upon rotation of the cleaning head. The plurality of absorbent fibers may be used like a mop to clean up spills, clean floors, apply surface treatments, etc.

The robot may include multiple cleaning heads (e.g., two or three) carried by the chassis. In one example, the robot further includes a main cleaning head carried by the chassis, a cleaning head extending across a swath covered by the robot, which forms the main work width of the robot, and which may be driven to rotate about a horizontal axis to engage a floor surface while the robot is maneuvered across the floor. The main cleaning head may include a cylindrical body defining a longitudinal axis of rotation parallel to the work surface, bristles disposed on the cylindrical body, and flexible flaps disposed longitudinally along the cylindrical body. The brush control process on the controller is configured to reverse bias the rotation of the main cleaning head (to substantially neutrally rotate and/or be driven to rotate at the same speed as a an unwinding cord, string, or other tangled medium), in response to an elevated main cleaning head motor current, while a motion control process independently continues to maneuver the robot across the floor. In another example, the robot includes two main cleaning brushes carried by the chassis and driven to rotate about a horizontal axis to engage a floor surface while the robot is maneuvered across the floor. The two main cleaning brushes may be driven to rotate in the same or opposite directions.

In another aspect, a method of disentangling an autonomous coverage robot includes placing the robot on a floor surface, the robot autonomously traversing across the floor surface in a forward direction of the robot while rotating about a non-horizontal axis an edge cleaning head carried by the chassis and driven by an edge cleaning head motor. The edge cleaning head extends beyond a lateral extent of the chassis while engaging the floor surface. The robot independently provides a reverse bias for the edge cleaning head motor (to substantially neutrally rotate and/or be driven to rotate at the same speed as a an unwinding cord, string, or other tangled medium), in response to an elevated edge cleaning head motor current while continuing to maneuver across the floor surface.

In one implementation, the brush control process on the controller of the robot determines movement of the robot in the forward direction before (independently of robot motion control) reversing the rotation of the edge cleaning head in response to an elevated cleaning head motor current. The brush control process of the robot may (independently of robot motion control) reverses the rotation of the edge cleaning head in response to an elevated edge cleaning head motor current for a period of time. In one example, after the brush control process reverses the rotation of the edge cleaning head, the brush control process may directly or through a supervising process pass a signal to the motion control process of the robot to move in a reverse direction, alter a drive direction, and moves in the drive direction.

In another implementation, the robot also includes a main cleaning brush carried by the chassis, which may be driven to rotate about a horizontal axis to engage the floor surface while the robot is maneuvered across the floor. The robot independently reverses the rotation of the main cleaning brush in response to an elevated main cleaning head motor current while continuing to maneuver across the floor surface. The brush cleaning process of the robot may also determine movement of the robot in the forward direction before independently reversing the rotation of the main cleaning brush in response to an elevated main cleaning brush motor current. Furthermore, the brush cleaning process of the robot may also reverse the rotation of the main cleaning brush for a certain period of time or in intervals.

In another aspect, an autonomous coverage robot includes a drive system, a bump sensor, and a proximity sensor. The drive system is configured to maneuver the robot according to a heading (turn) setting and a speed setting. The bump sensor is responsive to a collision of the robot with an obstacle in a forward direction. The proximity sensor is responsive to an obstacle forward of the robot at a proximate distance but not contacting the robot, e.g., 1-10 inches, preferably 1-4 inches. The motion control processes of the drive system may also be configured to reduce the speed setting in response to a signal from the proximity sensor indicating detection of a potential obstacle, while continuing a cleaning or coverage process, including advancing the robot according to the heading setting. Furthermore, the motion control processes of the drive system may also be configured to alter the heading (turn) setting in response to a signal received from the bump sensor indicating contact with an obstacle.

In some instances, the motion control processes of the drive system may be configured to alter the heading setting in response to the signals received from the bump sensor and one or more side proximity sensors to follow a perimeter of the obstacle. In other instances, the drive system may be configured to alter the heading (turn) setting in response to the signals received from the bump sensor and the proximity sensor to direct the robot away from the obstacle. In one example, the drive system is configured to maneuver the robot at a torque (e.g., motor current or motor resistance) setting and the drive system is configured to alter the motor current or motor resistance setting in response to a signal received from the bump sensor indicating contact with an obstacle. The drive system may increase the motor current or motor resistance setting in response to a signal received from the bump sensor indicating contact with an obstacle.

The proximity sensor may include a plurality of sets of at least one infrared emitter and receive pair, directed toward one another to converge at a fixed distance from one another, substantially as disclosed in “Robot obstacle detection system”, U.S. Pat. No. 6,594,844, herein incorporated by reference in its entirety. Alternatively, the proximity sensor may include a sonar device. The bump sensor may include a switch, a capacitive sensor, or other contact sensitive device.

The robot may be placed on the floor. In yet another aspect, a method of navigating an autonomous coverage robot with respect to an object on a floor includes the robot autonomously traversing the floor in a cleaning mode at a full cleaning speed. Upon sensing a proximity of the object forward of the robot, the robot reduces the cleaning speed to a reduced cleaning speed while continuing towards the object until the robot detects a contact with the object. Upon sensing contact with the object, the robot turns with respect to the object and cleans next to the object, optionally substantially at the reduced cleaning speed. The robot may follow a perimeter of the object while cleaning next to the object. Upon leaving the perimeter of the robot, the robot may increase speed to a full cleaning speed. The robot may maintain a substantially constant following distance from the object, may maintain a following distance smaller than the extent of extension of an edge cleaning head or brush beyond a following side of the robot body, or may substantially contact the object while cleaning next to the object in response to the initial, reduced cleaning speed contact with the object. In one example, the following distance from the object is substantially a distance between the robot and the object substantially immediately after the contact with the object. In another example, the following distance from the object is between about 0 and 2 inches.

In one instance, the robot performs a maneuver to move around the object in response to the contact with the object. The maneuver may include the robot moving in a substantially semi-circular path, or a succession of alternating partial spirals (e.g., arcs with progressively decreasing radius) around the object. Alternatively, the maneuver may include the robot moving away from the object and then moving in a direction substantially tangential to the object.

Upon sensing a proximity of the object forward of the robot, the robot may decrease the full cleaning speed to a reduced cleaning speed at a constant rate, an exponential rate, a non-linear rate, or some other rate. In addition, upon sensing contact with the object, the robot may increase a torque (e.g., motor current) setting of the drive, main brush, or side brush motors.

In yet another aspect, an autonomous robot includes a chassis, a drive system mounted on the chassis and configured to maneuver the robot, and a floor proximity sensor carried by the chassis and configured to detect a floor surface below the robot. The floor proximity sensor includes a beam emitter configured to direct a beam toward the floor surface and a beam receiver responsive to a reflection of the directed beam from the floor surface and mounted in a downwardly-directed receptacle of the chassis. The floor proximity sensor may be a substantially sealed unit (e.g., in the downward direction) and may also include a beam-transparent cover having a forward and rearward edge disposed across a lower end of the receptacle to prohibit accumulation of sediment, “carpet fuzz”, hair, or household dust within the receptacle. The cover may include a lens made of an anti-static material. The forward edge of the cover, i.e., the edge of the cover in the direction of robot motion, at the leading edge of the robot, is elevated above the rearward edge. The lower surface of the receptacle may be wedge shaped. In one example, the floor proximity sensor includes at least one infrared emitter and receiver pair, substantially as disclosed in “Robot obstacle detection system”, U.S. Pat. No. 6,594,844.

In one implementation, the drive system of the robot includes at least one driven wheel suspended from the chassis and at least one wheel-floor proximity sensor carried by the chassis and housed adjacent one of the wheels, the wheel-floor proximity sensor configured to detect the floor surface adjacent the wheel. The drive system may also include a controller configured to maneuver the robot away from a perceived cliff in response a signal received from the floor proximity sensor. In some instances, the drive system includes a wheel drop sensor housed near one of the wheels and responsive to substantial downward displacement of the wheel with respect to the chassis. The drive system may include a validation system that validates the operability of the floor proximity sensors when all wheels drop. The validation is based on the inference that all wheels dropped are likely the result of a robot being lifted off the floor by a person, and checks to see that all floor proximity sensors do not register a floor surface (either no reflection measured, or a reflection that is too strong). Any sensor that registers a floor surface or a too strong reflection (e.g., indicating a blocked sensor) is considered blocked. In response to this detection, the robot may initiate a maintenance reporting session in which indicia or lights indicate that the floor proximity sensors are to be cleaned. In response to this detection, the robot will prohibit forward motion until a validation procedure determines that all floor proximity sensors are clear and are functional. Each wheel-floor and wheel drop proximity sensors may include at least one infrared emitter and receiver pair.

DESCRIPTION OF DRAWINGS

FIG. 1 shows an above-perspective view of an example autonomous coverage robot.

FIG. 2 shows a below-perspective view of an example autonomous coverage robot.

FIG. 3 shows an exploded view of an example autonomous coverage robot.

FIG. 4 shows a front-perspective view of an example main cleaning head which may be incorporated in an autonomous coverage robot.

FIG. 5 shows an exploded view of an example main cleaning head which may be used with an autonomous coverage robot.

FIG. 6A shows an above-perspective view of an example edge cleaning head which uses a rotatable brush.

FIG. 6B shows an exploded view of an example edge cleaning head.

FIG. 6C shows schematic views of a tilt of an example edge cleaning head.

FIG. 7 shows an example of an edge cleaning head with a rotatable squeegee.

FIG. 8A shows a bumper which may be used with autonomous coverage robot.

FIG. 8B shows kinetic bump sensors and proximity sensors.

FIG. 9A shows a block diagram of an exemplary robot; FIGS. 9B and 9C show flow charts describing motion control and brush operation.

FIG. 10 shows floor proximity sensors and an attachment brace which may be used for detecting an adjacent floor.

FIGS. 11 and 12 show side and exploded views of a floor proximity sensor.

FIG. 13 shows an exploded view of a cover used with the floor proximity sensor shown in FIGS. 11 and 12.

FIG. 14 is an exploded view showing an example of a caster wheel assembly.

FIG. 15 is an exploded view showing an example of a wheel-drop sensor.

FIG. 16 is a cross-sectional view showing an example of a caster wheel assembly.

FIGS. 17 A-H illustrate examples of methods for disentangling coverage robots with various configurations of cleaning heads.

FIG. 17A illustrates a method of disentangling which may be used with a coverage robot having an agitating roller

FIG. 17B illustrates a method of disentangling which may be used with a coverage robot having an agitating roller and a brush roller.

FIG. 17C has a side view and a bottom view that illustrates a method for disentangling a coverage robot with dual agitating rollers.

FIG. 17D illustrates an alternate method of disentangling with the robot shown in FIG. 17C.

FIG. 17E illustrates a method of disentangling a coverage robot with two agitation rollers and a brush roller.

FIG. 17F illustrates another method of disentangling the coverage robot.

FIG. 17G has a side view and a bottom view illustrating a disentanglement method with a coverage robot 300 with two agitation rollers and two air ducts.

FIG. 17H has a side view and a bottom view illustrating a disentanglement method with a coverage robot 300 with two agitation rollers, a brush roller and two air ducts.

Like reference symbols in the various drawings indicate like elements.

DETAILED DESCRIPTION

FIGS. 1-3 show above-perspective, below-perspective, and exploded views of an example autonomous coverage robot 100 . Robot 100 has a chassis 102 , a drive system 104 , an edge cleaning head 106 a , and a controller 108 . Drive system 104 is mounted on the chassis 102 , and is a differential drive (left and right wheels near to or on the center diameter of the robot and independently speed controllable) configured to maneuver robot 100 . Edge cleaning head 106 a is mounted to extend past the side edge of chassis 102 for removing dirt and debris below and immediately adjacent to robot 100 , and more particularly to sweep dirt and debris into the cleaning path of the main cleaning head 106 b as the robot cleans in a forward direction. In some implementations, the main or edge cleaning heads 106 b , 106 a may also be used to apply surface treatments. A controller 108 (also depicted in FIG. 9A) is carried by chassis 102 and is controlled by behavior based robotics to provide commands to the components of robot 100 based on sensor readings or directives, as described below, to clean or treat floors in an autonomous fashion. A battery 109 may provide a source of power for robot 100 and its subsystems. A bottom cover 110 may protect internal portions of robot 100 and keep out dust and debris.

Drive system 104 includes a left drive wheel assembly 112 , a right drive wheel assembly 114 and a castor wheel assembly 116 . Drive wheel assemblies 112 , 114 and castor wheel assembly 116 are connected to chassis 102 and provide support to robot 106 . Controller 108 may provide commands to the drive system to drive wheels 112 and 114 forward or backwards to maneuver robot 100 . For instance, a command may be issued by controller 108 to engage both wheel assemblies in a forward direction, resulting in forward motion of robot 100 . In another instance, a command may be issued for a left turn that causes left wheel assembly 112 to be engaged in the forward direction while right wheel assembly 114 is driven in the rear direction, resulting in robot 100 making a clockwise turn when viewed from above.

FIGS. 4 and 5 show front perspective and exploded views of a main cleaning brush 111 which may be incorporated in the main cleaning head 106 b of the robot 100 via attachment to chassis 102 . General structure of a robot and cleaning heads as disclosed herein is similar to that disclosed in U.S. Pat. No. 6,883,201, herein incorporated by reference in its entirety, except when so noted. In general, when a robot brush becomes entangled with cords, strings, hair, fringes or tassels, the brush motor may encounter overcurrent or temperature rise, and may cause increased energy consumption, poor cleaning, slowing or jamming of the brush. If the robot is so controlled or the entangling item is heavy or secured, the robot may be held in place, and if sensors are available to detect stasis, may stop moving and thereby fail to clean. A robot that gets stuck during its working routine must be “rescued” and cleaned in order to continue autonomous function. Theoretically, there may be additional expenditure of energy to combat static or dynamic friction in the drive wheels, caster, bin squeegee and cleaning head drive train (reverse-drive). The fringes/tassels/cords may wind tightly around a smallest wind diameter of the cleaning brush (e.g., usually the core of a brush 111 , if the brush 111 includes only bristles). If the smallest diameter of the cleaning brush 111 is solid (no elasticity), additional energy may be required to overcome static or dynamic friction in a gear train of the cleaning head and the brushes in contact with the floor, e.g., when the brush is rotated in the opposite within the cleaning head in order to unwind the fringes/tassels/cords. If the tassel or string is permitted to continue winding about the brush, it may be necessary to remove the brush 111 from the cleaning head 106 b in order to remove the entanglement. Main cleaning head 111 has baffles or soft flaps 113 and bristles 115 arranged along a cleaning head body 117 . Soft flaps 113 disposed along the length of cleaning head body 117 may minimize static friction. Cleaning head body 117 may be rotated about its horizontal axis so that it engages the floor surface while robot 100 is moving across a floor, causing baffles 113 and bristles 115 to agitate dirt and debris which may be on the floor's surface. Controller 108 may be configured to reverse bias the rotation of main cleaning head 111 (i.e., provide sufficient reverse current to permit the cleaning brush to freely rotate when the robot draws out and unwinds an entanglement as it moves away in a forward direction) following a sharp rise in or an elevated main cleaning head motor current, while continuing to conduct a cleaning cycle or other cycle as the controller 108 executes individual motion control behaviors to move the robot 100 across the floor. A rim 116 of soft flaps 113 in this case can become the smallest diameter of cleaning head 111 . Rim 116 is flexible (pliable, soft), so as to require little energy to deform, potentially diverting energy away from that required to initiate robot 100 movement. A momentary delay in a brush gear train encountering static friction provides an opportunity for robot 100 to resume movement, thereby enabling easier disentanglement of brushes. Similarly, a cord or tassel may become less entangled about the larger diameter of the rim 116 (in comparison to a core such as core 117 or even smaller core) simply because the brush 111 does not complete as many turns per unit length of entangled cord or tassel. Furthermore, a length-wise scooped (curved) nature of the flaps 13 further acts as a spring forcing the tassels/fringes to unravel/open during the momentary lag between the robot being set in motion and a reverse bias to bias back-driving of the entangled cleaning head 111 . Bristles 115 may be used primarily used to clean, while flaps 113 may be used primarily for disentanglement purposes. This allows robot 100 to continue to clean (agitate the carpet) if an entangled string snaps off and gets retained by flaps 113 in cleaning head 111 . Other robot details and features combinable with those described herein may be found in the following U.S. Provisional Patent Application No. 60/747,791, the entire contents of which are hereby incorporated by reference.

FIGS. 6A and 6B show above-perspective and exploded views of edge cleaning head 106 . Edge cleaning head 106 a is carried by chassis 102 and driven by an edge cleaning head motor 118 and drive transmission 119 to rotate a brush 120 about a non-horizontal axis. Brush 120 has brush elements 122 A-F that extend beyond a peripheral edge of chassis 102 . Each brush element 122 A-F forms an angle of about 60 degrees with adjacent brush elements and is tipped with bristles extending along the axis of the elements. Brush 120 may be rotated about a vertical axis, such that the ends of bush elements 122 A-F move normal to the work surface. Edge cleaning head 106 may be located near the edge of robot 100 so that brush 120 is capable of sweeping dirt and debris beyond the edge of chassis 102 . In some implementations, the edge cleaning head 106 operates about an axis offset (tilted) from a vertical axis of the robot. As shown in schematic form in FIG. 6C the brush 106 may be tilted, in both forward and side to side directions (i.e., tilted downward with respect to the plane of wheel contact about a line about 45 degrees from the direction of travel within that plane), in order to collect debris from outside the robot's periphery toward the main work width, but not disturb such collected debris once it is there or otherwise eject debris from the work width of the robot. The axis offset is optionally adjustable to customize the tilt of the cleaning head 106 to suit various carpet types, such as shag.

Other configurations of edge cleaning heads may also be used with robot 100 . For example, an edge cleaning head may have three evenly-spaced brush elements separated by 120 degrees. FIG. 7 shows another example of an edge cleaning head 124 in which a rotatable squeegee 126 is used in place of a brush. In other configurations, an edge cleaning head may have one or more absorbent fibers that extend beyond a peripheral edge of chassis 102 .

FIG. 8A shows a bumper 130 which may be used with the autonomous coverage robot 100 . FIG. 8B shows proximity sensors 134 which may be housed within bumper 130 . Drive system 104 may be configured to maneuver robot 100 according to a heading setting and a speed setting. Proximity sensors 134 may sense a potential obstacle in front of the robot.

FIG. 9A shows a schematic view of electronics of the robot 100 . The robot 100 includes a controller 103 which communicates with a bumper micro-controller 107 A, that together control an omni-directional receiver, directional receiver, the wall proximity sensors 134 , and the bumper switches 132 . The controller 103 monitors all other sensor inputs, including the cliff sensors 140 and motor current sensors for each of the motors.

Control of the direction and speed of the robot 100 may be handled by motion control behaviors selected by an arbiter according to the principles of behavior based robotics for coverage and confinement, generally disclosed in U.S. Pat. Nos. 6,809,490 and 6,781,338, herein incorporated by reference in their entireties (and executed by controller 108 ), to reduce the speed magnitude of robot 100 when proximity sensor 134 detects a potential obstacle. The motion behaviors executed by the controller 108 may also alter the velocity of robot 100 when kinetic bump sensors 132 detect a collision of robot 100 with an obstacle. Accordingly, referring to FIG. 9A, robot 100 traverses a floor surface by executing a cruising or STRAIGHT behavior 900 . When robot 100 detects a proximate, but not yet contacting obstacle via proximity sensors 134 , robot 100 executes a gentle touch routine 902 (which may be a behavior, a part of a behavior, or formed by more than one behavior), in which robot 100 does not proceed at full cleaning speed into the obstacle; but instead reduces its approach speed from a full cleaning speed of about 300 mm/sec to a reduced cleaning speed of about 100 mm/sec via controller 108 toward the potential obstacle, such that when a collision does occur, the collision is less noisy, and less likely to mar surfaces. The overall noise, the potential damage to the robot 100 or the object being collided thereby is reduced. When robot 100 detects contact with the object via kinetic bump sensors 132 , robot 100 executes one of the following routines: bounce 910 , follow obstacle perimeter 912 , alter drive direction and move away from object 914 , or alter drive direction to curve to approach the object and follow along it (e.g., a wall). Bounce 910 entails robot 100 moving so as to bounce along the object. Follow obstacle perimeter 912 entails robot 100 using proximity sensors 134 to follow along a perimeter of the object at a predefined distance to, for example, clean up close to the object and/or clean to the very edge of a wall. The robot 100 continuously cleans the room, and when it detects a proximate object (which may be a wall, table, chair, sofa, or other obstacle) in the forward direction, it continues cleaning in the same direction without interruption, albeit at a reduced speed. In predetermined and/or random instances, the robot 100 will bump the object, turn in place so that the edge of the main cleaning head 106 b is as close to the wall as possible, and closely follow the object on the side of the robot, essentially at the reduced cleaning speed, such that the side/edge brush 106 a collects debris or dirt from the corner between the floor and the wall or obstacle. Once the robot 100 leaves the wall, after a predetermined and/or randomized distance within predetermined limits, the robot 100 increases its speed up to full cleaning speed. On other occasions, it will bump the object, turn in place until facing away from the object or wall, and immediately proceed away from the object or wall at full cleaning speed.

The robot 100 employs a behavioral software architecture within the controller 103 . While embodiments of the robot 100 discussed herein may use behavioral based control only in part or not at all, behavior based control is effective at controlling the robot to be robust (i.e. not getting stuck or failing) as well as safe. The robot 100 employs a control and software architecture that has a number of behaviors that are executed by an arbiter in controller 103 . A behavior is entered into the arbiter in response to a sensor event. In one embodiment, all behaviors have a fixed relative priority with respect to one another. The arbiter (in this case) recognizes enabling conditions, which behaviors have a full set of enabling conditions, and selects the behavior having the highest priority among those that have fulfilled enabling conditions. In order of decreasing priority, the behaviors are generally categorized as escape and/or avoidance behaviors (such as avoiding a cliff or escaping a corner), and working behaviors (e.g., wall following, bouncing, or driving in a straight line). The behaviors may include: different escape (including escaping corners, anti-canyoning, stuck situations, “ballistic” temporary fire-and-forget movement that suppress some avoid behaviors, e.g., as disclosed in U.S. Pat. No. 6,809,490) cliff avoiding, virtual wall avoiding (a virtual wall may be a beacon with a gateway beam), spot coverage (covering in a confined pattern such as a spiral or boustrophedon patch), align (turning in place, using side proximity sensors to align with a forward obstacle encountered while obstacle following, e.g., an inside corner), following (representing either or both of substantially parallel or bump following along an obstacle using a side proximity sensor or bumper that extends to the side of the robot), responding to a bump in order to “bounce” (a behavior that occurs after the robot bumps an object), and drive (cruising). Movement of the robot, if any, occurs while a behavior is arbitrated. If more than one behavior is in the arbiter, the behavior with a higher priority is executed, as long as any corresponding required conditions are met. For example, the cliff avoiding behavior will not be executed unless a cliff has been detected by a cliff detection sensor, but execution of the cliff avoiding behavior always takes precedence over the execution of other behaviors that also have satisfied enabling conditions.

The reactive behaviors have, as their enabling conditions or triggers, various sensors and detections of phenomena. These include sensors for obstacle avoidance and detection, such as forward proximity detection (multiple), forward bump detection (multiple), cliff sensors (multiple), detection of a virtual wall signal (which may instead be considered a coverage trigger). Sensors of these types are be monitored and conditioned by filters, conditioning, and their drivers, which can generate the enabling conditions as well as record data that helps the behavior act predictably and on all available information (e.g., conversion to one-bit “true/false” signals, recording of likely angle of impact or incidence based on strength or time differences from a group of sensors, or historical, averaging, frequency, or variance information).

Actual physical sensors may be represented in the architecture by “virtual” sensors synthesized from the conditioning and drivers. Additional “virtual” sensors that are synthesized from detectable or interpreted physical properties, proprioceptive or interpreted upon the robot 100 , such as over-current of a motor, stasis or stuck condition of the robot 100 (by monitoring a lack of odometry reading from a wheel encoder or counter), battery charge state via coulometry, and other virtual sensors.

In addition, reactive behaviors can act according to enabling conditions that represent detected phenomena to be sought or followed. A beam or wireless (RF, acoustic) signal can be detected without direction; or in some cases with direction. A remote beam or marker (bar code, retro-reflective, distinctive, fiducial, or natural recognized by vision landmark) giving a direction can permit homing or relative movement; without direction the robot 100 can nonetheless move to servo on the presence, absence, and/or relative strength of a detected signal. The reflection of a beam from the robot 100 , edge, or line can be similarly detected, and following behaviors (such as obstacle following by the robot 100 ) conducted by servoing on such signal. A debris or artifact signal can be collected by monitoring debris or objects collected by or traversed by the robot, and that signal can be an enabling condition for a reactive behavior controlling a spot coverage pattern.

The robot 100 maintains concurrent processes, “parallel” processes that are not generally considered reactive behaviors. A scheduler may be necessary to allocate processor time to most other processes, e.g., including the arbiter and behaviors, in a co-operative or other multitasking manner. If more threading is available, less processes may be managed by the scheduler. As noted, filters and conditioning and drivers, can interpret and translate raw signals. These processes are not considered reactive behaviors, and exercise no direct control over the motor drives or other actuators. In addition, in the present embodiment, brush motor controller(s) control the main and side brushes, although these may alternatively be controlled by dedicated brush behaviors and a brush control arbiter.

In accordance with another example, the gentle touch routine 902 may employ an infrared proximity detector 134 that should go off (i.e., when a receiver receives from a reflection originating in the overlapping space of an emitter and receiver angled toward one another) from about 1 to 10 inches (preferably, from 1 to 4 inches. This distance is selected in order to be within the effective range of the IR proximity or cross-beam sensor 134 , yet with sufficient time to slow the mobile robot 100 before a collision with a detected obstacle). Conventional proximity sensors return a signal strength depending on obstacle albedo; cross-beam sensors 134 can be thresholded for various albedos intruding in the specific distance from the sensor where the receiver and emitter's beam/field cross. Additionally, slowing down based on a proximately detected wall may be suppressed in or turned off by the user, independently of the bump sensor 132 . Controller 108 may slow the robot's descent substantially in a steady reduction then cruise slowly. Controller 108 may execute an S-curve slowly over about 3 inches, can slow down steadily but at an accelerating or decelerating rate over about 3 inches. During escape behaviors, for example, panic, stasis, stuck, anti-canyoning, the robot may essentially can be turn off the proximity sensors 134 —usually by not using the proximity sensors 134 as an enabling condition for any escape behavior or some avoidance behaviors

Drive system 104 may be configured to reduce the speed setting in response to a signal from proximity sensor 134 which indicating detection of a forward obstacle, while continuing to advance the robot 100 and work the floor or surface according to the existing heading setting. Drive system 104 may be configured to alter the heading setting in response to a signal received from bump sensor 132 that indicates contact with an obstacle. For example, drive system 104 may be configured to alter the heading setting in response to the signals received from the bump sensor 132 and the proximity sensor 134 such that robot 100 follows a perimeter of the obstacle. In another example, drive system 104 may be configured to change heading to direct robot 104 away from the obstacle.

Proximity sensors 134 may include one or more pairs of infrared emitters and receivers. For instance, a modulated emitter and a standard receiver may be used. A light pipe (not shown), collimating or diffusing optics, Fresnel or diffractive optics, may be used in some implementations to eliminate blind spots by providing a more uniform light pattern or a light pattern more concentrated or more likely to be detected in high probability/high impact areas, such as the immediate forward direction. Alternatively, some implementations may make use of sonar or other types of proximity sensors.

In some implementations, kinetic bump sensor 132 may include a mechanical switch 130 . In some implementations, bump sensor 132 may include a capacitive sensor. Other types of contact sensors may also be used as well.

Drive system 104 may be configured to maneuver robot 100 at a torque (or motor current) setting in response to a signal received from bump sensor 132 which indicates contact with an obstacle. For instance, drive system 104 may increase the torque (or motor current) setting in response to a signal received from the bump sensor indicating contact with an obstacle.

In another example method of navigating an autonomous coverage robot with respect to an object on a floor, robot 100 may be initially placed on the floor (or may already be on the floor, e.g., if the robot starts itself from a charging dock) with robot 100 autonomously traversing the floor in a cleaning mode at a full cleaning speed. If robot 100 senses a nearby object in front of robot 100 , it reduces the cleaning speed (e.g., to a reduced cleaning speed) and continues moving toward the object and working/cleaning the floor until detecting impact, which is likely to be with the object but may be another object. Upon sensing impact with an object, robot 100 turns with respect to the object that it bumped and cleans next to, i.e., along, the object. Robot 100 may, for instance, follow the object's perimeter while cleaning along or next to the object. In another instance, robot 100 may maintain a somewhat constant following distance from the object while cleaning next to the object in response to the contact with the object. The following distance from the object may be a distance between robot 100 and the object immediately after the contact with the object, for instance, 0 to 2 inches. The distance is optionally less than the distance that the side or edge brush unit 106 a extends beyond the side of the robot.

Robot 100 may, in some instances, perform a maneuver to move around the object in response to the contact with the object. For example, robot 100 may move in a somewhat semi-circular path around the object, or a succession of alternating partial spirals (e.g., arcs with progressively decreasing radius). In another instance, robot 100 may move away from the object and then move in a direction that is somewhat tangential to the object.

Robot 100 may decrease the cleaning speed to a reduced speed at a constant rate, for instance, at a non-linear or exponential rate. The full cleaning speed of robot 100 may be about 300 mm/s and the reduced cleaning speed of robot 100 may be about 100 mm/s.

FIG. 10 shows kinetic bump sensors 132 , floor proximity sensors 140 and an attachment brace 142 which may be used with robot 100 for detecting an adjacent floor. Kinetic bump sensors 132 may sense collisions between robot 100 and objects in the robot's forward path. Floor proximity sensors may be carried by chassis 102 and be used to sense when robot 100 is near a “cliff”, such as a set of stairs. Floor proximity sensors 140 may send signals to controller 108 indicating whether or not a cliff is detected. Based on signals from the floor proximity sensors 140 , controller 108 may direct drive system 104 to change speed or velocity to avoid the cliff.

FIGS. 11 and 12 show side and exploded views of a floor proximity sensor 140 . Floor proximity sensor 140 has a body with a forward section 144 , a rear section 146 , an emitter 148 , a receiver 150 , and a cover 152 . Emitter 148 and receiver 150 may be capable of emitting and receiving infrared light. Emitter 148 and receiver 150 are arranged within the forward and rear body sections 144 , 146 at an angle so that their axes line up at a point beneath robot 100 at the approximate floor distance.

FIG. 13 shows an exploded view of cover 152 . Cover 152 consists of a lens 154 and a cover body 156 . Lens 152 may be transparent to infrared light and cover body 156 may be opaque to facilitate focusing emissions sent from emitter 148 . The forward edge 158 of cover 152 is elevated above its rearward edge 159 to aid in reducing dust build up and to ensure that light is received by receiver 150 primarily when sensor 140 is positioned correctly over a floor and a reduced amount is received when sensor 140 is over a “cliff”. In some implementations, cover 152 is constructed using a material with anti-static (dissipative or conductive) properties,