AUTONOMOUS BEHAVIORS FOR A REMOTE VEHICLE

• US 20120166024A1
• Filed: 03/05/2012
• Published: 06/28/2012
• Est. Priority Date: 05/14/2007
• Status: Active Grant

• Current Assignee: Flir Detection, Inc. (Teledyne Technologies Incorporated)
• Original Assignee: iRobot Corporation
• Inventors: PHILLIPS, Emilie, RUDAKEVYCH, Pavlo E., TAKA, Orjeta, WOLFE, James Gordon Jr., FROST, Tom
• Granted Patent: US 8,447,440 B2
• Time in Patent Office: Days
• US Class Current: 701/2
• 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 1/0251 extracting 3D information from a plurality of images taken from different locations, e.g. stereo vision stereoscopic image analysis H04N13/00; depth recovery from images G06T7/593
• 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 1/0278 using satellite positioning signals, e.g. GPS
• CPC Class Codes: G06F 9/451 Execution arrangements for user interfaces
• CPC Class Codes: G07C 5/008 communicating information to a remotely located station transmission systems for measured values G08C

Abstract

A method comprising running a persistent self-righting behavior comprising sensing an orientation of the remote vehicle and performing a progression of flipper movements until the remote vehicle is righted, and performing a retrotraverse behavior comprising: generating a list of time stamped waypoints separated by at least a minimum difference in time and distance; storing the list of time stamped waypoints in the memory; and generating, using a control system, a current return path interconnecting previously-traversed waypoints in reverse order of timestamps upon losing communication with the operator control unit or upon receiving a command from the operator control unit.

Claims

1. A method for performing retrotraverse and self-righting behaviors for a remote vehicle having a control system comprising a memory and being configured to communicate with an operator control unit, the method comprising:

running a persistent self-righting behavior comprising sensing an orientation of the remote vehicle and performing a progression of flipper movements until the remote vehicle is righted; and

performing a retrotraverse behavior comprising;

generating a list of time stamped waypoints separated by at least a minimum difference in time and distance;

storing the list of time stamped waypoints in the memory; and

generating, using a control system, a current return path interconnecting previously-traversed waypoints in reverse order of timestamps upon losing communication with the operator control unit or upon receiving a command from the operator control unit.

2. The method of claim 1, further comprising causing the remote vehicle to traverse the current return path.

3. The method of claim 1, further comprising maintaining a list of previously-performed retrotraverses by recording a list of start time and end time pairs for each retrotraverse period of time.

4. The method of claim 3, further comprising excluding waypoints recorded during previously-performed retrotraverses from the current return path.

5. The method of claim 4, further comprising excluding waypoints recorded during previously-performed retrotraverses by excluding waypoints recorded between the start time and end time pairs for each previously-performed retrotraverse.

6. The method of claim 3, further comprising excluding waypoints from the current return path that were traversed during previously-performed retrotraverses along previous return paths included in the previously-traversed waypoints.

7. The method of claim 1, further comprising utilizing a lookahead vector to allow smooth navigation along the path interconnecting previously-traversed waypoints.

8. The method of claim 2, further comprising selecting a forward or backward direction for remote vehicle traversal along the current return path based on a determination of which direction requires the least rotation.

9. The method of claim 1, further comprising determining a strategy for righting the remote vehicle prior to performing the progression of flipper movements.

10. The method of claim 1, further comprising determining the remote vehicle'"'"'s position by maintaining a global map and placing the remote vehicle'"'"'s coordinates within the global map.

11. The method of claim 10, further comprising maintaining a destination point within the global map and adjusting the remote vehicle'"'"'s heading to move toward the destination point.

12. The method of claim 1, further comprising using one or more of a global positioning system or navigation beacon points to determine the remote vehicle'"'"'s position.

13. A method for controlling a remote vehicle with persistent autonomous behaviors including a retrotraverse behavior and a self-righting behavior, the method comprising:

sensing an orientation of the remote vehicle and, if the orientation indicates a non-righted remote vehicle, performing a progression of flipper motions until the remote vehicle is righted; and

determining whether the retrotraverse behavior is active;

if the retrotraverse behavior is active;

erasing previously-used waypoints;

determining a current position of the remote vehicle and a current time,

and pre-pending the current position and the current time to a list of time stamped waypoints;

generating additional waypoints and adding them to the list of time stamped waypoints;

storing the list of time stamped waypoints;

determining whether a control signal has been received from an operator control unit;

if a control signal has not been received from the operator control unit;

setting a retrotraverse start time to the current time;

generating a return path interconnecting previously-traversed waypoints in reverse order of timestamps;

navigating the remote vehicle along the return path until a control signal is received from the operator control unit; and

setting a retrotraverse end time to the current time.

14. The method of claim 13, wherein the time stamped waypoints are separated by at least a minimum difference in time and distance.

15. The method of claim 13, further comprising maintaining a list of previously-performed retrotraverses by recording a list of start time and end time pairs for each retrotraverse period of time.

16. The method of claim 15, wherein excluding waypoints comprises excluding waypoints recorded during previously-performed retrotraverses from the return path.

17. The method of claim 15, further comprising excluding waypoints recorded during previously-performed retrotraverses by excluding waypoints recorded between the start time and end time pairs for each previously-performed retrotraverse.

18. The method of claim 15, further comprising excluding waypoints traversed during previously-performed retrotraverses from the return path.

19. The method of claim 13, further comprising determining a strategy for righting the remote vehicle prior to performing the progression of flipper movements.

20. The method of claim 13, further comprising determining the remote vehicle'"'"'s position using one or more of a global positioning system or navigation beacon points.