Method and system for robot localization and confinement

• US 20040085037A1
• Filed: 10/29/2003
• Published: 05/06/2004
• 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 6,781,338 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 robot confinement system, comprising:

(a) a transmitter that includes a signal emitter and a signal detector, the signal emitter being operative to broadcast a first beam and a second beam;

(b) a retroreflector positioned and operative to reflect at least a portion of the first beam back to the transmitter;

(c) the signal detector being operative to detect the reflected portion of the first beam, the reflected portion of the first beam between the signal emitter and the retroreflector defining a barrier for the robot confinement system;

(d) the signal emitter being operative to broadcast the second beam when the signal detector fails to detect the reflected portion of the first beam; and

(e) a mobile robot including

(e1) means for moving the mobile robot to avoid the second beam,

(e2) a detector operative to detect the second beam, and

(e3) a control unit, operative in response to detection of the second beam, to run an algorithm for moving the mobile robot to avoid the second beam broadcast by the signal emitter;

(f) wherein if operation of the mobile robot causes the reflected portion of the first beam to be blocked such that the signal detector fails to detect the reflected portion of the first beam, the transmitter signal emitter is operative to broadcast the second beam, which is detected by the mobile robot detector, causing the control unit to run the algorithm to move the mobile robot to avoid the second beam.

2. The robot confinement system of claim 1 wherein the algorithm implemented by the control unit of the mobile robot moves the mobile robot to turn in a chosen direction until the second beam is no longer detected by the mobile robot detector.

3. The robot confinement system of claim 1 wherein the algorithm implemented by the control unit of the mobile robot moves the mobile robot in a direction opposite to the most recently traveled direction until the second beam is no longer detected by the mobile robot detector.