Method and system for robot localization and confinement

• US 6,690,134 B1
• Filed: 01/24/2002
• Issued: 02/10/2004
• Est. Priority Date: 01/24/2001
• Status: Expired due to Term

• Current Assignee: iRobot Corporation
• Original Assignee: iRobot Corporation
• Inventors: Mass, Philip R., Jones, Joseph L.
• Primary Examiner(s): Nappi, Robert
• Assistant Examiner(s): MILLER, PATRICK L
• Application Number:
  US10/056,804
• Time in Patent Office: 747 Days
• Field of Search: 318/567, 318/568.16, 318/580, 318/587, 318/568.12, 153/19, 153/39, 701/22, 701/23, 701/200, 701/210, 701/300, 701/301, 701/28, 901/1, 901/46, 901/47, 180/167-169
• 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 portable barrier signal transmitting device that includes at least a primary emitter, said primary emitter being operative to emit a confinement beam primarily along an axis, said axis of said emitted confinement beam defining a directed barrier;

b. a mobile robot;

c. said mobile robot comprising;

means for turning in at least one direction;

a detector operative to detect said directed barrier formed by said emitted confinement beam; and

a control unit controlling said means for turning;

d. whereby the control unit runs an algorithm for avoiding said directed barrier formed by said emitted confinement beam upon detection of said directed barrier formed by said emitted confinement beam, said algorithm being operative to turn the robot in a chosen direction until said directed barrier formed by said emitted confinement beam is no longer detected.

2. The robot confinement system of claim 1, wherein said algorithm is further operative to continue to turn the robot in the chosen direction at least a predetermined amount after said directed barrier formed by said emitted confinement beam is no longer detected.

3. The robot confinement system of claim 2, wherein said chosen direction of turning implemented by said algorithm is a generally clockwise or counterclockwise direction.

4. The robot confinement system of claim 3, wherein said chosen direction of turning implemented by said algorithm is a random direction selection function.

5. The robot confinement system of claim 4, wherein said chosen direction of turning implemented by said algorithm further comprises turning in the same direction at least twice before a final turning direction is chosen randomly.

6. The robot confinement system of claim 3, wherein the generally clockwise or counterclockwise direction comprising the chosen direction of turning implemented by said algorithm is based upon detecting gradient levels of the directed barrier formed by said emitted confinement beam at a plurality of orientations.

7. The robot confinement system of claim 6 wherein the chosen direction of turning implemented by said algorithm is the orientation of the detected directed barrier formed by said emitted confinement beam with the smallest gradient level.

8. The robot confinement system of claim 1, wherein said portable barrier signal transmitting device further comprises a secondary emitter, wherein the primary emitter is operative to transmit a collimated confinement beam to form said directed barrier and the secondary emitter is operative to transmit a substantially omni-directional beam.

9. The robot confinement system of claim 1, wherein the directed barrier formed by said emitted confinement beam emitted by said primary emitter is a modulated signal in an infrared frequency.

10. The robot confinement system of claim 9, wherein operation of said signal directed barrier detector is substantially omni-directional.

11. The robot confinement system of claim 10, wherein said mobile robot includes a shell and wherein said directed barrier detector is located on top of the shell of said robot such that operation of said directed barrier detector is not substantially affected by the shell of said robot.

12. The robot confinement system of claim 1, where said robot further comprises a plurality of directed barrier detectors.

13. The robot confinement system of claim 1 wherein said portable barrier signal transmitting device further comprises a reflection detector, wherein said primary emitter is operative to emit at least first and second confinement beams, said primary emitter being operative to emit the second confinement beam upon failure of said reflection detector to detect the first emitted confinement beam.

14. The robot confinement system of claim 1, wherein the robot has a predetermined turning radius, and wherein said directed barrier formed by said emitted confinement beam has a width as least as wide as the turning radius of the robot.

15. A robot confinement system, comprising:

a. a portable barrier signal transmitting device that includes at least a primary emitter, said primary emitter being operative to emit a confinement beam primarily along an axis, said axis of said emitted confinement beam defining a directed barrier;

b. a mobile robot;

c. said mobile robot comprising;

means for turning in at least one direction;

a detector operative to detect said directed barrier formed by said emitted confinement beam; and

a control unit controlling said means for turning;

d. whereby the control unit runs an algorithm for avoiding said directed barrier formed by said emitted confinement beam upon detection of said directed barrier formed by said emitted confinement beam, said algorithm being operative to reverse direction at which the robot most recently traveled until said directed barrier formed by said emitted confinement beam is no longer detected.

16. A method of confining a robot using a directed barrier, comprising the steps of:

a. providing a portable barrier signal transmitting device that includes a primary emitter that is operative to emit a confinement beam to provide said directed barrier that is primarily linear;

b. providing a sensor positioned on the robot, said sensor being operative to detect said directed barrier formed by said emitted confinement beam;

c. providing mobility means on the robot, such that the robot can turn in at least one direction;

d. avoiding said directed barrier formed by said emitted confinement beam upon detection of said said directed barrier formed by said emitted confinement beam by said sensor by implementing an algorithm to move the robot in a chosen direction.

17. The method according to claim 16, wherein said directed barrier formed by said emitted confinement beam emitted by said primary emitter is a modulated signal in an infrared frequency.

18. The method according to claim 17, wherein operation of said directed barrier sensor is substantially omni-directional.

19. The method according to claim 18, wherein the robot has a predetermined turning radius and wherein said directed barrier formed by said emitted confinement beam has a width at least as wide as the turning radius of the robot.