Autonomous mobile body

• US 8,924,068 B2
• Filed: 06/02/2011
• Issued: 12/30/2014
• Est. Priority Date: 07/13/2010
• Status: Active Grant

• Current Assignee: Murata Machinery Limited (Muratec)
• Original Assignee: Murata Machinery Limited (Muratec)
• Inventors: Shitamoto, Hideo, Nakano, Tsuyoshi, Tanaka, Shoji
• Primary Examiner(s): Cheung, Mary
• Assistant Examiner(s): BERNS, MICHAEL ANDREW
• Application Number:
  US13/809,719
• Publication Number:
  US 20130116880A1
• Time in Patent Office: 1,307 Days
• Field of Search: 701/25, 701/26
• US Class Current: 701/25
• CPC Class Codes: G05D 1/0223 involving speed control of the vehicle vehicle fittings for automatically controlling, i.e. preventing speed from exceeding an arbitrarily established velocity or maintaining speed at a particular velocity, as selected by the vehicle operator B60K31/00
• CPC Class Codes: G05D 1/0236 in combination with a laser lasers per se H01S
• CPC Class Codes: G05D 1/024 in combination with a laser lasers per se H01S
• CPC Class Codes: G05D 1/0274 using mapping information stored in a memory device navigation using map-matching G01C21/30

Abstract

An autonomous mobile body includes a storage unit arranged to store a size D2 of the autonomous mobile body, a laser range sensor arranged to acquire obstacle information, an obstacle identification unit arranged to identify, based on the acquired obstacle information, edge points indicating positions of both ends of a region in which an interfering obstacle exists, the both ends being both ends on a plane parallel or substantially parallel to a passage plane in a direction which is perpendicular or substantially perpendicular to a moving target direction of the autonomous mobile body, a direction setting unit arranged to set a pull-off direction based on the size D2 of the autonomous mobile body and the edge points, and a mobile controller arranged and programmed to control the autonomous mobile body to move toward the pull-off direction.

Claims

1. An autonomous mobile body which autonomously moves along a planned path, the autonomous mobile body comprising:

a storage unit arranged to store a size of the autonomous mobile body;

an obstacle information acquisition unit arranged to acquire obstacle information of obstacles around the autonomous mobile body;

an obstacle identification unit arranged to identify, based on the obstacle information acquired by the obstacle information acquisition unit, positions of both ends of a region in which an obstacle positioned in a moving target direction exists, the both ends being both ends on a plane parallel or substantially parallel to a passage plane in a direction which is perpendicular or substantially perpendicular to the moving target direction;

a direction setting unit arranged to set a pull-off direction based on the size of the autonomous mobile body stored in the storage unit and the positions of the both ends identified by the obstacle identification unit;

a mobile controller arranged and programmed to control the autonomous mobile body to move in the pull-off direction set by the direction setting unit; and

a stop position setting unit arranged to set a stop position in the pull-off direction based on a pull-off direction set by the direction setting unit, and an environmental map, wherein the mobile controller controls the autonomous mobile body to move to and stop at the stop position set by the stop position setting unit.

2. The autonomous mobile body according to claim 1, wherein the mobile controller controls the autonomous mobile body so that a speed of the autonomous mobile body becomes slower as a distance between the autonomous mobile body and the stop position becomes shorter.

3. The autonomous mobile body according to claim 2, further comprising:

an interference distance calculation unit arranged to calculate an interference distance between the obstacle positioned in the pull-off direction and the autonomous mobile body based on the obstacle information, while the autonomous mobile body is moving to the pull-off direction;

an estimation unit arranged to estimate a stopping distance required for the autonomous mobile body to stop; and

a determination unit arranged to determine whether the autonomous mobile body is to be stopped based on the interference distance calculated by the calculation unit and the stopping distance estimated by the estimation unit;

wherein

wherein the mobile controller stops the autonomous mobile body when the determination unit determines that the autonomous mobile body is to be stopped, and continues the control to move the autonomous mobile body to the pull-off direction when the determination unit determines that the autonomous mobile body is not to be stopped.

4. The autonomous mobile body according to claim 3, wherein the determination unit determines that the autonomous mobile body is to be stopped when the interference distance is less than a distance obtained by adding a clearance value to the stopping distance, and determines that the autonomous mobile body is not to be stopped when the interference distance is equal to or larger than the distance obtained by adding the clearance value to the stopping distance.

5. The autonomous mobile body according to claim 4, further comprising an avoidance determination unit arranged to determine whether an avoidance action of the autonomous mobile body moving forward while avoiding an obstacle positioned in the moving target direction based on the obstacle information, is possible on a passage which is a region where the planned path is set and the autonomous mobile body can move, wherein the mobile controller controls the autonomous mobile body to perform the avoidance action when the avoidance determination unit determines that the avoidance action is possible, and controls the autonomous mobile body to move in the pull-off direction when the avoidance determination unit determines that the avoidance action is not possible.

6. The autonomous mobile body according to claim 5, further comprising:

a pass point distance calculation unit arranged to calculate a distance between the planned path and a pass point within the passage that has been set to avoid interference with the obstacle existing in the moving target direction; and

a clearance identification unit arranged to identify a path clearance within the passage that is a distance that the autonomous mobile body can move from the planned path to a direction which is on the pass point side and which is perpendicular or substantially perpendicular to the path direction;

wherein

the avoidance determination unit determines that the avoidance action is possible when the distance calculated by the pass point distance calculation unit is larger than the path clearance identified by the clearance identification unit, and determines that the avoidance action is not possible when the distance calculated by the pass point distance calculation unit is equal to or less than the path clearance identified by the clearance identification unit.

7. The autonomous mobile body according to claim 6, wherein the mobile controller stops the movement of the autonomous mobile body to the pull-off direction and causes the autonomous mobile body to perform the avoidance action when the avoidance determination unit determines that the avoidance action is possible while the autonomous mobile body is moving to the pull-off direction.

8. The autonomous mobile body according to claim 2, wherein the mobile controller controls the autonomous mobile body to standby for a predetermined time after reaching the stop position, and thereafter to once again move along the planned path.

9. The autonomous mobile body according to claim 1, wherein the mobile controller controls the autonomous mobile body to standby for a predetermined time after reaching the stop position, and thereafter to once again move along the planned path.

10. The autonomous mobile body according to claim 1, further comprising:

an interference distance calculation unit arranged to calculate an interference distance between the obstacle positioned in the pull-off direction and the autonomous mobile body based on the obstacle information, while the autonomous mobile body is moving to the pull-off direction;

an estimation unit arranged to estimate a stopping distance required for the autonomous mobile body to stop; and

a determination unit arranged to determine whether the autonomous mobile body is to be stopped based on the interference distance calculated by the calculation unit and the stopping distance estimated by the estimation unit;

wherein

the mobile controller stops the autonomous mobile body when the determination unit determines that the autonomous mobile body is to be stopped, and continues the control to move the autonomous mobile body to the pull-off direction when the determination unit determines that the autonomous mobile body is not to be stopped.

11. The autonomous mobile body according to claim 10, wherein the determination unit determines that the autonomous mobile body is to be stopped when the interference distance is less than a distance obtained by adding a clearance value to the stopping distance, and determines that the autonomous mobile body is not to be stopped when the interference distance is equal to or larger than the distance obtained by adding the clearance value to the stopping distance.

12. The autonomous mobile body according to claim 11, further comprising an avoidance determination unit arranged to determine whether an avoidance action of the autonomous mobile body moving forward while avoiding an obstacle positioned in the moving target direction based on the obstacle information is possible, on a passage which is a region where the planned path is set and the autonomous mobile body can move, wherein the mobile controller controls the autonomous mobile body to perform the avoidance action when the avoidance determination unit determines that the avoidance action is possible, and controls the autonomous mobile body to move in the pull-off direction when the avoidance determination unit determines that the avoidance action is not possible.

13. The autonomous mobile body according to claim 12, further comprising:

a pass point distance calculation unit arranged to calculate a distance between the planned path and a pass point within the passage that has been set to avoid interference with the obstacle existing in the moving target direction; and

a clearance identification unit arranged to identify a path clearance within the passage that is a distance that the autonomous mobile body can move from the planned path to a direction which is on the pass point side and which is perpendicular or substantially perpendicular to the path direction;

wherein

the clearance determination unit determines that the clearance action is possible when the distance calculated by the pass point distance calculation unit is larger than the path clearance identified by the clearance identification unit, and determines that the clearance action is not possible when the distance calculated by the pass point distance calculation unit is equal to or less than the path clearance identified by the clearance identification unit.

14. The autonomous mobile body according to claim 13, wherein the mobile controller stops the movement of the autonomous mobile body to the pull-off direction and causes the autonomous mobile body to perform the avoidance action when the avoidance determination unit determines that the avoidance action is possible while the autonomous mobile body is moving to the pull-off direction.

15. An autonomous mobile body which autonomously moves along a planned path, the autonomous mobile body comprising:

a storage unit arranged to store a size of the autonomous mobile body;

an obstacle information acquisition unit arranged to acquire obstacle information of obstacles around the autonomous mobile body;

an obstacle identification unit arranged to identify, based on the obstacle information acquired by the obstacle information acquisition unit, positions of both ends of a region in which an obstacle positioned in a moving target direction exists, the both ends being both ends on a plane parallel or substantially parallel to a passage plane in a direction which is perpendicular or substantially perpendicular to the moving target direction;

a direction setting unit arranged to set a pull-off direction based on the size of the autonomous mobile body stored in the storage unit and the positions of the both ends identified by the obstacle identification unit;

a mobile controller arranged and programmed to control the autonomous mobile body to move in the pull-off direction set by the direction setting unit;

an interference distance calculation unit arranged to calculate an interference distance between the obstacle positioned in the pull-off direction and the autonomous mobile body based on the obstacle information, while the autonomous mobile body is moving to the pull-off direction;

an estimation unit arranged to estimate a stopping distance required for the autonomous mobile body to stop; and

a determination unit arranged to determine whether the autonomous mobile body is to be stopped based on the interference distance calculated by the calculation unit and the stopping distance estimated by the estimation unit;

wherein

the mobile controller stops the autonomous mobile body when the determination unit determines that the autonomous mobile body is to be stopped, and continues the control to move the autonomous mobile body to the pull-off direction when the determination unit determines that the autonomous mobile body is not to be stopped.

16. The autonomous mobile body according to claim 15, wherein the determination unit determines that the autonomous mobile body is to be stopped when the interference distance is less than a distance obtained by adding a clearance value to the stopping distance, and determines that the autonomous mobile body is not to be stopped when the interference distance is equal to or larger than the distance obtained by adding the clearance value to the stopping distance.

17. An autonomous mobile body which autonomously moves along a planned path, the autonomous mobile body comprising:

a storage unit arranged to store a size of the autonomous mobile body;

an obstacle information acquisition unit arranged to acquire obstacle information of obstacles around the autonomous mobile body;

an obstacle identification unit arranged to identify, based on the obstacle information acquired by the obstacle information acquisition unit, positions of both ends of a region in which an obstacle positioned in a moving target direction exists, the both ends being both ends on a plane parallel or substantially parallel to a passage plane in a direction which is perpendicular or substantially perpendicular to the moving target direction;

a direction setting unit arranged to set a pull-off direction based on the size of the autonomous mobile body stored in the storage unit and the positions of the both ends identified by the obstacle identification unit;

a mobile controller arranged and programmed to control the autonomous mobile body to move in the pull-off direction set by the direction setting unit; and

an avoidance determination unit arranged to determine whether an avoidance action of the autonomous mobile body moving forward while avoiding an obstacle positioned in the moving target direction, based on the obstacle information, is possible on a passage which is a region where the planned path is set and the autonomous mobile body can move, wherein the mobile controller controls the autonomous mobile body to perform the avoidance action when the avoidance determination unit determines that the avoidance action is possible, and controls the autonomous mobile body to move in the pull-off direction when the avoidance determination unit determines that the avoidance action is not possible.

18. The autonomous mobile body according to claim 17, further comprising:

a pass point distance calculation unit arranged to calculate a distance between the planned path and a pass point within the passage that has been set to avoid interference with the obstacle existing in the moving target direction; and

a clearance identification unit arranged to identify a path clearance within the passage that is a distance that the autonomous mobile body can move from the planned path to a direction which is on the pass point side and which is perpendicular or substantially perpendicular to the path direction;

wherein

the avoidance determination unit determines that the avoidance action is possible when the distance calculated by the pass point distance calculation unit is larger than the path clearance identified by the clearance identification unit, and determines that the avoidance action is not possible when the distance calculated by the pass point distance calculation unit is equal to or less than the path clearance identified by the clearance identification unit.

19. The autonomous mobile body according to claim 17, wherein the mobile controller stops the movement of the autonomous mobile body to the pull-off direction and causes the autonomous mobile body to perform the avoidance action when the avoidance determination unit determines that the avoidance action is possible while the autonomous mobile body is moving to the pull-off direction.