Mobile Robot and Method of Operating Thereof

• US 20120185091A1
• Filed: 09/23/2011
• Published: 07/19/2012
• Est. Priority Date: 11/30/2010
• Status: Active Grant

• Current Assignee: Flir Detection, Inc. (Teledyne Technologies Incorporated)
• Original Assignee: iRobot Corporation
• Inventors: Field, Timothy G., Weatherwax, David F., Hoffman, Orin P.F., Lenser, Scott R.
• Granted Patent: US 9,146,558 B2
• Time in Patent Office: Days
• US Class Current: 700/254
• CPC Class Codes: G05D 1/0044 by providing the operator with a computer generated representation of the environment of the vehicle, e.g. virtual reality, maps maps used for automatic navigation G05D1/0274; flight directors G01C23/005
• CPC Class Codes: G05D 1/0088 characterized by the autonomous decision making process, e.g. artificial intelligence, predefined behaviours using knowledge based models G06N5/00
• CPC Class Codes: G05D 1/027 comprising intertial navigation means, e.g. azimuth detector inertial navigation G01C21/16; inertial navigation combined with non-inertial navigation instruments G01C21/165
• CPC Class Codes: G05D 1/0274 using mapping information stored in a memory device navigation using map-matching G01C21/30
• CPC Class Codes: G05D 1/0278 using satellite positioning signals, e.g. GPS

Abstract

A method of operating a mobile robot that includes driving the robot according to a drive direction, determining a driven path of the robot from an origin, and displaying a drive view on a remote operator control unit in communication with the robot. The drive view shows a driven path of the robot from the origin. The method further includes obtaining global positioning coordinates of a current location of the robot and displaying a map in the drive view using the global positioning coordinates. The driven path of the robot is displayed on the map.

Claims

1. A method of operating a mobile robot, the method comprising:

driving the robot according to a drive direction;

determining a driven path of the robot from an origin;

displaying a drive view on a remote operator control unit in communication with the robot, the drive view having a driven path of the robot from the origin;

obtaining global positioning coordinates of a current location of the robot; and

displaying a map in the drive view using the global positioning coordinates, the driven path of the robot displayed on the map.

2. The method of claim 1, further comprising at least periodically obtaining the global positioning coordinates of the current location of the robot to determine the driven path.

3. The method of claim 1, further comprising:

receiving robot position and movement data including gyro data;

determining if the robot is at rest, and if at rest, determining a gyro bias;

determining a three-dimensional gravity vector of the robot;

determining an ego-motion estimate of the robot based at least in part on the three-dimensional gravity vector, gyro bias, and gyro data; and

determining a robot global position by combining the ego-motion estimate and the global positioning coordinates of the robot.

4. The method of claim 3, wherein the robot position and movement data comprises:

gyro data including a robot angular rate and a robot acceleration;

robot odometry; and

global positioning coordinates of the robot.

5. The method of claim 4, further comprising determining the ego-motion estimate of the robot based at least in part on odometry.

6. The method of claim 3, further comprising using a Kalman filter to determine the three-dimensional gravity vector of the robot.

7. The method of claim 3, further comprising using a particle filter to determine the robot global position.

8. The method of claim 3, further comprising at least periodically receiving the robot global position in the remote operator control unit and connecting the sequentially received robot global positions with a displayed line.

9. The method of claim 1, further comprising determining the driven path of the robot before obtaining the global positioning coordinates and displaying the driven path in the drive view.

10. The method of claim 9, further comprising determining the driven path of the robot during a loss of communication with a satellite for obtaining the global positioning coordinates and displaying the driven path in the drive view.

11. The method of claim 10, further comprising determining the driven path of the robot using at least one of an inertial measurement unit, odometry, and dead reckoning.

12. The method of claim 1, further comprising determining a retro-traverse drive command after experiencing a loss of communications with the operator control unit to maneuver the robot along a path back to a communication location where the robot had established communications with the operator control unit and driving the robot according to the determined retro-traverse drive command.

13. The method of claim 1, wherein the path back to the communication location coincides at least in part with a portion of the driven path.

14. The method of claim 1, further comprising displaying a heading of the robot in the drive view.

15. A method of operating a mobile robot, the method comprising:

driving the robot according to a drive command issued by a remote operator control unit in communication with the robot;

determining a driven path of the robot from an origin;

after experiencing a loss of communications with the operator control unit, determining a retro-traverse drive command to maneuver the robot along a return path back to a communication location where the robot had established communications with the operator control unit; and

driving the robot according to the determined retro-traverse drive command.

16. The method of claim 15, further comprising at least periodically obtaining global positioning coordinates of a current location of the robot to determine the driven path.

17. The method of claim 15, wherein the return path back to the communication location coincides at least in part with a portion of the driven path.

18. The method of claim 15, further comprising storing the determined driven path in memory and continuously removing a portion of the determined driven path from the memory corresponding to the return path back to the communication location.

19. The method of claim 15, further comprising ceasing driving the robot according to the determined retro-traverse drive command when the robot is within a threshold distance of the operator control unit.

20. The method of claim 15, further comprising displaying a drive view on the remote operator control unit in communication with the robot, the drive view having the driven path of the robot from the origin.

21. The method of claim 20, further comprising obtaining global positioning coordinates of a current location of the robot and displaying a map in the drive view using the global positioning coordinates, the driven path of the robot displayed on the map.

22. The method of claim 21, further comprising:

receiving robot position and movement data including gyro data;

determining if the robot is at rest, and if at rest, determining a gyro bias;

determining a three-dimensional gravity vector of the robot;

determining an ego-motion estimate of the robot based at least in part on the three-dimensional gravity vector, gyro bias, and gyro data; and

determining a robot global position by combining the ego-motion estimate and the global positioning coordinates of the robot.

23. The method of claim 22, wherein the robot position and movement data comprises:

gyro data including a robot angular rate and a robot acceleration;

robot odometry; and

global positioning coordinates of the robot.

24. The method of claim 23, further comprising determining the ego-motion estimate of the robot based at least in part on odometry.

25. The method of claim 22, further comprising using a Kalman filter to determine the three-dimensional gravity vector of the robot.

26. The method of claim 22, further comprising using a particle filter to determine the robot global position.

27. The method of claim 22, further comprising at least periodically receiving the robot global position in the remote operator control unit and connecting the sequentially received robot global positions with a displayed line.

28. A method of operating a mobile robot, the method comprising:

driving the robot according to a drive command issued by a remote operator control unit in communication with the robot;

determining a driven path from an origin;

after experiencing a loss of communications with the operator control unit, determining an orientation of the robot; and

executing a self-righting maneuver when the robot is oriented upside down, the self-righting maneuver comprising;

rotating an appendage of the robot from a stowed position along side a main body of the robot downward and away from the main body, raising and supporting the main body on the appendage, and then

further rotating the appendage to drive the upright main body past a vertical position, causing the robot to fall over and thereby invert the main body.

29. The method of claim 28, wherein the appendage comprises at least one flipper rotatably mounted near one end of the main body of the robot, the flipper rotatable in a continuous 360 degrees with respect to the main body.

30. The method of claim 28, further comprising moving each arm attached to the main body to place its respective center gravity in a position that maintain an overall center of gravity of the robot within the envelope of the 360 degree rotation of the at least one flipper.

31. A method of operating a mobile robot, the method comprising:

driving the robot according to a heading issued by a remote operator control unit in communication with the robot;

upon detecting a deviation between a drive heading of the robot and the issued heading, determining a heading correction; and

driving the robot according to the determined heading correction until the drive heading matches the issued heading.

32. The method of claim 31, further comprising displaying a drive view on the remote operator control unit, the drive view showing a driven path of the robot from an origin and the heading of the robot.

33. The method of claim 31, further comprising obtaining global positioning coordinates of a current location of the robot and displaying a map in the drive view using the global positioning coordinates, the driven path of the robot displayed on the map.

34. The method of claim 33, further comprising:

receiving robot position and movement data including gyro data;

determining if the robot is at rest, and if at rest, determining a gyro bias;

determining a three-dimensional gravity vector of the robot;

determining an ego-motion estimate of the robot based at least in part on the three-dimensional gravity vector, gyro bias, and gyro data; and

determining a robot global position by combining the ego-motion estimate and the global positioning coordinates of the robot.

35. The method of claim 34, wherein the robot position and movement data comprises:

gyro data including a robot angular rate and a robot acceleration;

robot odometry; and

global positioning coordinates of the robot.

36. The method of claim 35, further comprising determining the ego-motion estimate of the robot based at least in part on odometry.

37. The method of claim 34, further comprising using a Kalman filter to determine the three-dimensional gravity vector of the robot.

38. The method of claim 34, further comprising using a particle filter to determine the robot global position.

39. The method of claim 34, further comprising at least periodically receiving the robot global position in the remote operator control unit and connecting the sequentially received robot global positions with a displayed line.