Autonomous Robot Localization

• US 20160100521A1
• Filed: 10/10/2014
• Published: 04/14/2016
• Est. Priority Date: 10/10/2014
• Status: Active Grant

• Current Assignee: iRobot Corporation
• Original Assignee: iRobot Corporation
• Inventors: Pierce, Travis, Halloran, Mike, Miliken, Jamie, Peters, Eric Charles
• Granted Patent: US 9,510,505 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: A01D 2101/00 Lawn-mowers
• CPC Class Codes: A01D 34/008 for automated or remotely controlled operation
• CPC Class Codes: G01S 13/46 Indirect determination of position data
• CPC Class Codes: G01S 17/06 Systems determining position data of a target
• CPC Class Codes: G01S 17/42 Simultaneous measurement of distance and other co-ordinates indirect measurement G01S17/46
• CPC Class Codes: G01S 17/48 Active triangulation systems, i.e. using the transmission and reflection of electromagnetic waves other than radio waves
• CPC Class Codes: G01S 17/931 of land vehicles
• CPC Class Codes: G01S 7/4813 Housing arrangements
• CPC Class Codes: G01S 7/4817 relating to scanning
• CPC Class Codes: G01S 7/4868 Controlling received signal intensity or exposure of sensor
• CPC Class Codes: G05D 1/0236 in combination with a laser lasers per se H01S
• CPC Class Codes: G05D 1/0259 using magnetic or electromagnetic means

Abstract

A location estimation system for use with an autonomous lawn mowing robot, comprises a plurality of synthetic surfaces positioned with respect to a mowable space in an environment, a radiation source coupled to the lawn mowing robot, a detector coupled to the lawn mowing robot and configured to detect radiation reflected by objects in the environment, and a controller configured to controllably direct radiation from the radiation source to scan the environment, and to vary at least one of an output power of the directed radiation and a scan rate of the directed radiation, as a function of detected radiation reflected from one or more of the synthetic surfaces.

Claims

1. A location estimation system for use with an autonomous lawn mowing robot, the system comprising:

a plurality of synthetic surfaces positioned with respect to a mowable space in an environment;

a radiation source coupled to the lawn mowing robot;

a detector coupled to the lawn mowing robot and configured to detect radiation reflected by objects in the environment; and

a controller configured to controllably direct radiation from the radiation source to scan the environment, and to vary at least one of an output power of the directed radiation and a scan rate of the directed radiation, as a function of detected radiation reflected from one or more of the synthetic surfaces.

2. The location estimation system of claim 1, wherein the controller is configured to vary a spin rate of the radiation source.

3. The location estimation system of claim 1, further comprising a modulator coupled to the radiation source and configured to modulate radiation emitted from the radiation source.

4. The location estimation system of claim 3, wherein the controller is configured to direct the modulator to vary the output power of the radiation source in response to detection of reflected radiation.

5. The location estimation system of claim 3, wherein the controller is configured to direct the modulator to vary a beam focus of the radiation source in response to detection of reflected radiation.

6. The location estimation system of claim 1, comprising a rotational scanner that directs radiation from the radiation source to scan the environment.

7. The location estimation system of claim 1, wherein the controller is further configured to compare data indicative of detected reflected radiation to stored data, and to identify the detected radiation as radiation reflected from a particular object associated with the stored data.

8. The location estimation system of claim 7, wherein the particular object is one of the synthetic surfaces.

9. The location estimation system of claim 1, wherein the controller is further configured to direct the radiation source to make a first scan of the environment at a first scan rate.

10. The location estimation system of claim 9, wherein the controller is configured to direct the radiation source to make a second scan of the environment at a second scan rate different from the first scan rate.

11. The location estimation system of claim 9, wherein the modulator is configured to direct the radiation source to make a second scan of the environment, a limited portion of the second scan performed at a second scan rate different from the first scan rate.

12. The location estimation system of claim 1, further comprising a second detector of a different wavelength responsiveness than a first detector.

13. The location estimation system of claim 1, wherein the radiation source is a laser.

14. The location estimation system of claim 13, wherein the radiation is emitted across a distributed plane.

15. The location estimation system of claim 14, wherein the plane extends at 45 degrees to a surface supporting the autonomous lawn mowing robot.

16. The location estimation system of claim 1, wherein the controller is configured to modulate the output power of the radiation source.

17. A method of estimating a location of a self-propelled lawn mowing robot in an environment, the method comprising:

positioning a plurality of synthetic surfaces at locations with respect to a mowable space in an environment; and

placing a lawn mowing robot in the environment, the robot comprising;

a radiation source coupled to the lawn mowing robot;

a detector coupled to the lawn mowing robot and configured to detect radiation reflected by objects in the environment; and

a controller configured to controllably direct radiation from the radiation source to scan the environment, and to vary at least one of an output power of the directed radiation and a scan rate of the directed radiation, as a function of detected radiation reflected from one or more of the synthetic surfaces.

18. The method of claim 17, wherein the controller is configured to vary the scan rate of the radiation source.

19. The method of claim 17, further comprising a modulator coupled to the radiation source and configured to modulate radiation emitted from the radiation source.

20. The method of claim 19, wherein the controller is configured to direct the modulator to vary the output power of the radiation source in response to detection of reflected radiation.

21. The method of claim 20, wherein the modulator scans a portion of a second scan at a scan speed different from at least a portion of the scan speed of a first scan.

22. The method of claim 19, wherein the controller scans the environment during a motion of the robot.

23. An autonomous robot comprising:

a body configured to move over a surface;

two driven wheels carried by the body and defining a transverse axis, with each wheel carried on a respective side of the body;

a radiation source coupled to the autonomous robot;

a detector coupled to the autonomous mowing robot and configured to detect radiation reflected by objects in the environment; and

a controller configured to controllably direct radiation from the radiation source to scan the environment, and to vary at least one of an output power of the directed radiation and a scan rate of the directed radiation, as a function of detected radiation reflected from one or more of synthetic surfaces placed in the environment.

24. The autonomous robot of claim 23, wherein the controller is configured vary the scan rate of the radiation source.

25. The autonomous robot of claim 23, further comprising a modulator coupled to the radiation source and configured to modulate radiation emitted from the radiation source.

26. The autonomous robot of claim 25, wherein the controller is configured to direct the modulator to vary the output power of the radiation source in response to detection of reflected radiation.

27. The autonomous robot of claim 23, further comprising an odometer in communication with the wheels, wherein the controller is further configured to compare the position of the robot resulting from the identified radiation to a position of the robot indicated by the odometer.

28. The autonomous robot of claim 27, wherein the controller is further configured to drive the wheels so as to change a trajectory of the robot in response to determining the robot position.

29. The autonomous robot of claim 23, wherein the radiation source scans during a motion of the robot.