Method and system for robot localization and confinement

• US 20060038521A1
• Filed: 09/08/2005
• Published: 02/23/2006
• Est. Priority Date: 01/24/2001
• Status: Active Grant

• Current Assignee: iRobot Corporation
• Original Assignee: iRobot Corporation
• Inventors: Mass, Philip R., Jones, Joseph L.
• Granted Patent: US 7,196,487 B2
• Time in Patent Office: Days
• US Class Current: 318/567
• CPC Class Codes: A47L 2201/04 Automatic control of the travelling movement; Automatic obstacle detection
• CPC Class Codes: A47L 9/009 Carrying-vehicles; Arrangements of trollies or wheels; Means for avoiding mechanical obstacles
• CPC Class Codes: G05D 1/0225 involving docking at a fixed facility, e.g. base station or loading bay parking aids B62D15/027
• CPC Class Codes: G05D 1/0227 using mechanical sensing means, e.g. for sensing treated area
• CPC Class Codes: G05D 1/0234 using optical markers or beacons optical beacons per se G01S1/70
• CPC Class Codes: G05D 1/0238 using obstacle or wall sensors G05D1/0246 and G05D1/0289 take precedence; lidar systems designed for anti-collision purposes G01S17/93
• CPC Class Codes: G05D 1/0242 using non-visible light signals, e.g. IR or UV signals
• CPC Class Codes: G05D 1/0272 comprising means for registering the travel distance, e.g. revolutions of wheels measuring distance traversed on the ground by vehicles, e.g. using odometers G01C22/00
• CPC Class Codes: G05D 1/028 using a RF signal

Abstract

The present invention discloses a system and method for confining a robot to a particular space. The system includes a portable barrier signal transmitter that produces a barrier signal primarily along an axis, and a mobile robot capable of avoiding the barrier signal upon detection of the barrier signal. In the preferred embodiment the barrier signal is emitted in an infrared frequency and the robot includes an omni-directional signal detector. Upon detection of the signal, the robot turns in a direction selected by a barrier avoidance algorithm until the barrier signal is no longer detected.

Claims

1. A confinement system for a mobile robot having propulsion elements for moving the robot, the confinement system comprising:

a signal emitter operable to transmit a first beam and a second beam;

a retro-reflector positionable to reflect at least a portion of the first beam back to the emitter;

a first signal detector operable to detect the reflected portion of the first beam, the reflected portion of the first beam between the emitter and the retro-reflector defining a confinement barrier;

the emitter being operable to transmit the second beam when the first signal detector fails to detect the reflected portion of the first beam;

a second signal detector, adapted for mounting in association with the robot, and operable to detect the second beam; and

a controller, operable to control the robot'"'"'s propulsion elements and responsive to detection of the second beam to control the propulsion elements to move the robot to avoid the second beam;

wherein if operation of the robot causes the reflected portion of the first beam to be blocked such that the first signal detector fails to detect the reflected portion of the first beam, then the emitter is operable to transmit the second beam which, if detected by the second signal detector, causes the controller to control the propulsion elements to move the mobile robot to avoid the second beam.

2. A method for confining a mobile robot to a prescribed zone, the robot having propulsion elements for moving the robot, the method comprising:

providing a signal emitter operable to transmit a first beam and a second beam;

providing a retro-reflector positionable to reflect at least a portion of the first beam back to the emitter;

providing a first signal detector operable to detect the reflected portion of the first beam, the reflected portion of the first beam between the emitter and the retro-reflector defining a confinement barrier;

the emitter being operable to transmit the second beam when the first signal detector fails to detect the reflected portion of the first beam;

providing a second signal detector, adapted for mounting in association with the robot, and operable to detect the second beam; and

providing a controller, operable to control the robot'"'"'s propulsion elements and responsive to detection of the second beam to control the propulsion elements to move the robot to avoid the second beam;

wherein if operation of the robot causes the reflected portion of the first beam to be blocked such that the first signal detector fails to detect the reflected portion of the first beam, then the emitter is operable to transmit the second beam which, if detected by the second signal detector, causes the controller to control the propulsion elements to move the mobile robot to avoid the second beam.