Robot Confinement

• US 20080084174A1
• Filed: 10/30/2007
• Published: 04/10/2008
• Est. Priority Date: 01/24/2001
• Status: Active Grant

• Current Assignee: iRobot Corporation
• Original Assignee: iRobot Corporation
• Inventors: Jones, Joseph, Mass, Philip
• Granted Patent: US 7,579,803 B2
• Time in Patent Office: Days
• US Class Current: 318/568.12
• 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

A method of confining a robot in a work space includes providing a portable barrier signal transmitting device including a primary emitter emitting a confinement beam primarily along an axis defining a directed barrier. A mobile robot including a detector, a drive motor and a control unit controlling the drive motor is caused to avoid the directed barrier upon detection by the detector on the robot. The detector on the robot has an omnidirectional field of view parallel to the plane of movement of the robot. The detector receives confinement light beams substantially in a plane at the height of the field of view while blocking or rejecting confinement light beams substantially above or substantially below the plane at the height of the field of view.

Claims

1. A method of confining a robot comprising:

providing a portable barrier signal transmitting device that includes at least a primary emitter;

emitting from the primary emitter a confinement beam primarily along an axis defining a directed barrier;

providing a mobile robot comprising a detector, a drive motor and a control unit controlling the drive motor;

detecting by the detector the directed barrier formed by the emitted confinement beam;

controlling the drive motor, based on the detecting, to cause the robot to avoid the directed barrier.

2. The method of claim 1, wherein the drive motors are controlled to reverse the direction of travel of the robot.

3. The method of claim 1, wherein the drive motors are controlled to turn the robot away from the directed barrier.

4. The method of claim 1, wherein the drive motors are controlled to alternately approach and avoid the directed barrier.

5. The method of claim 1, wherein the detector is a light beam receiver system oriented in a manner to have an omnidirectional field of view such that the detecting is performed regardless of orientation of the robot.

6. The method of claim 1, wherein the controlling includes turning the robot in one of a random direction and a predetermined direction until the directed barrier formed by the emitted confinement beam is no longer detected.

7. The method of claim 1, wherein controlling includes turning the robot in a chosen direction at least a predetermined amount after the directed barrier formed by the emitted confinement beam is no longer detected.

8. The method of claim 1, wherein the controlling includes turning in the same direction at least twice before a final turning direction is chosen randomly.

9. The method of claim 1, wherein the controlling is based upon detecting gradient levels of the directed barrier formed by the emitted confinement beam at a plurality of orientations.

10. The method of claim 9, wherein a chosen direction of turning corresponds to the orientation of the smallest gradient level.

11. The method of claim 1, wherein the portable barrier signal transmitting device further comprises a secondary emitter, the method further comprising transmitting a collimated confinement beam from the primary emitter to form the directed barrier and transmitting a substantially omnidirectional beam from the secondary emitter.

12. The method of claim 11, wherein the directed barrier formed by the emitted confinement beam emitted by the primary emitter is a modulated signal in an infrared frequency.

13. The method of claim 1, wherein the portable barrier signal transmitting device further comprises a reflection detector, the method further comprising emitting a second confinement beam from the primary emitter upon failure of the reflection detector to detect the first emitted confinement beam.

14. A method of confining a robot comprising:

detecting by a light beam receiver system when a robot encounters a confinement light beam directed along a substantially horizontal axis, the light beam receiver system oriented in a manner to have an omnidirectional field of view in a plane parallel to the plane of movement of the robot;

receiving confinement light beams substantially in a plane at the height of the field of view;

blocking or rejecting confinement light beams substantially above or substantially below the plane at the height of the field of view; and

controlling a drive motor of the robot based upon detection of the confinement light beam to move the robot until the confinement light beam is no longer detected.

15. The method of claim 14, wherein the drive motor is controlled to turn the robot after the confinement light beam is no longer detected, by an amount that generally prevents the robot from re-encountering the confinement light beam immediately after the confinement light beam is no longer detected.

16. The method of claim 14, further comprising following an obstacle defined by the confinement light beam by keeping the confinement light beam to one side of the robot.

17. The method of claim 14, wherein the drive motor is controlled to turn the robot in a randomly determined direction.

18. The method of claim 14, wherein the drive motor is controlled to turn the robot successively in a same direction, then in a randomly determined direction.

19. The robot of claim 14, wherein the drive motor is controlled to turn the robot in place until the confinement light beam is no longer detected.

20. The method of claim 14, wherein the drive motor is controlled to move the robot one of a predetermined distance and a predetermined time away from the confinement light beam.

21. The robot of claim 14, wherein the drive motor is controlled to reverse the direction of travel of the robot upon detection of the confinement light beam.