Autonomous mobile body

• US 9,020,682 B2
• Filed: 06/02/2011
• Issued: 04/28/2015
• 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, Moriguchi, Toshiki
• Primary Examiner(s): Olszewski, John R
• Assistant Examiner(s): Do, Truc M
• Application Number:
  US13/809,699
• Publication Number:
  US 20130166134A1
• Time in Patent Office: 1,426 Days
• Field of Search: 700/245, 700/253, 700/258, 700/255, 700/250, 700/259, 700/90, 701/23, 701/3, 701/28, 701/400, 701/414, 701/464, 701/469
• US Class Current: 701/26
• CPC Class Codes: B60W 60/0011 involving control alternatives for a single driving scenario, e.g. planning several paths to avoid obstacles
• 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 1/0223 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 1/024 in combination with a laser lasers per se H01S
• 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 1/0255 using acoustic signals, e.g. ultra-sonic singals sonar systems designed for anti-collision purposes G01S15/93
• 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 1/0274 using mapping information stored in a memory device navigation using map-matching G01C21/30

Abstract

An autonomous mobile body includes a laser range sensor and an electronic control device. The electronic control device includes a storage unit that stores a size D2 of the autonomous mobile body, a width identification unit that identifies a spatial size D1 in a width direction of a passage which is a region where the autonomous mobile body can move, a calculation unit that calculates a size D8 of an interfering obstacle in a direction which is substantially perpendicular to a moving target direction on a road surface based on obstacle information, an action selection unit that selects a stopping action or a retreat action based on the spatial size D1, the size D2 of the autonomous mobile body, and the size D8 of the interfering obstacle, and a mobile control unit that controls the autonomous mobile body to stop when the stopping action is selected and control the autonomous mobile body to retreat when the retreat action is selected.

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 in a horizontal direction;

a width identification unit arranged to identify a passage width of a passage which is a region where the planned path is set and the autonomous mobile body can move;

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

a calculation unit arranged to calculate, based on the obstacle information acquired by the obstacle information acquisition unit, a size of an obstacle existing in a moving target direction with respect to a direction which is perpendicular to the moving target direction of the autonomous mobile body on a plane which is parallel to a passage plane;

a selection unit arranged to select a stopping action or a retreat action based on the size of the autonomous mobile body stored in the storage unit, the passage width identified by the width identification unit, and the obstacle size calculated by the calculation unit; and

a mobile controller that is arranged and programmed to control the autonomous mobile body to stop when the selection unit selects the stopping action, and to control the autonomous mobile body to retreat when the selection unit selects the retreat action.

2. The autonomous mobile body according to claim 1, wherein the selection unit selects the stopping action when a total value of the size of the autonomous mobile body and the obstacle size is smaller than the passage width, and selects the retreat action when the total value is equal to or larger than the passage width.

3. The autonomous mobile body according to claim 1, wherein the calculation unit includes:

a nearest neighbor identification unit arranged to identify, among points which are located on an environmental map identified based on the obstacle information and which show existence of obstacles around the autonomous mobile body, a point which exists in the moving target direction and is closest to the autonomous mobile body; and

an obstacle identification unit arranged to identify, among the points on the map, points included in a strip-shaped region which contains the point identified by the nearest neighbor identification unit and extends in a direction which is perpendicular to the moving target direction;

wherein

the obstacle size is calculated by using the points identified by the obstacle identification unit.

4. The autonomous mobile body according to claim 3, wherein the calculation unit calculates, as the obstacle size, a distance between two points that are most distant from each other in the direction which is perpendicular to the moving target direction, among a plurality of points identified by the obstacle identification unit.

5. The autonomous mobile body according to claim 1, wherein

the storage unit stores a diameter of a circle which encompasses the autonomous mobile body on a horizontal plane, as the size of the autonomous mobile body;

and

the width identification unit identifies a movement clearance that is a distance that the autonomous mobile body can move in a width direction within the passage, and identifies a total value of the movement clearance and the size of the autonomous mobile body as the passage width.

6. The autonomous mobile body according to claim 5, wherein the movement clearance is represented using a parameter in which a value can be arbitrarily changed.

7. The autonomous mobile body according to claim 1, further comprising a stop position setting unit arranged to set a stop position at an edge of the passage based on the obstacle information, 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 when the selection unit selects the stopping action.

8. The autonomous mobile body according to claim 1, further comprising a standby position setting unit arranged to set a standby position on a retreat path which intersects with the passage, wherein the mobile controller controls the autonomous mobile body to retreat toward the standby position when the selection unit selects the retreat action.

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

10. The autonomous mobile body according to claim 1, further comprising a search unit arranged to search for a detour route from a passage where an obstacle exists in the moving target direction, wherein the mobile controller controls the autonomous mobile body to retreat to the detour route searched by the search unit when the selection unit selects the retreat action.

11. The autonomous mobile body according to claim 7, wherein, when the selection unit selects the retreat action, the mobile controller controls the autonomous mobile body to move to and stop at the stop position set by the stop position setting unit, and thereafter retreat.

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

a width identification unit arranged to identify a movement clearance that is a distance that the autonomous mobile body can move in a width direction within a passage on which the planned path is set;

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

a calculation unit arranged to calculate, based on the obstacle information acquired by the obstacle information acquisition unit, a size of an obstacle existing in a moving target direction with respect to a direction which is perpendicular to the moving target direction of the autonomous mobile body on a plane which is parallel to a passage plane;

a selection unit arranged to select a stopping action or a retreat action based on the movement clearance identified by the width identification unit and the obstacle size calculated by the calculation unit; and

a mobile controller arranged and programmed to control the autonomous mobile body to stop when the selection unit selects the stopping action, and to control the autonomous mobile body to retreat when the selection unit selects the retreat action.

13. The autonomous mobile body according to claim 12, wherein the calculation unit includes:

a nearest neighbor identification unit arranged to identify, among points which are located on an environmental map identified based on the obstacle information and which show existence of obstacles around the autonomous mobile body, a point which exists in the moving target direction and is closest to the autonomous mobile body; and

an obstacle identification unit arranged to identify, among the points on the map, points included in a strip-shaped region which contains the point identified by the nearest neighbor identification unit and extends in the direction which is perpendicular to the moving target direction;

wherein

the obstacle size is calculated by using the points identified by the obstacle identification unit.

14. The autonomous mobile body according to claim 13, wherein the calculation unit calculates, as the obstacle size, a distance between two points that are most distant from each other in the direction which is perpendicular to the moving target direction, among a plurality of points identified by the obstacle identification unit.

15. The autonomous mobile body according to claim 12, further comprising a storage unit that stores a diameter of a circle which encompasses the autonomous mobile body on a horizontal plane, as the size of the autonomous mobile body, wherein the width identification unit identifies a movement clearance showing a distance that the autonomous mobile body can move in a width direction within the passage, and identifies a total value of the movement clearance and the size of the autonomous mobile body as the passage width.

16. The autonomous mobile body according to claim 15, wherein the movement clearance is represented using a parameter in which a value can be arbitrarily changed.

17. The autonomous mobile body according to claim 12, further comprising a stop position setting unit arranged to set a stop position at an edge of the passage based on the obstacle information, 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 when the selection unit selects the stopping action.

18. The autonomous mobile body according to claim 12, further comprising a standby position setting unit arranged to set a standby position on a retreat path which intersects with the passage, wherein the mobile controller controls the autonomous mobile body to retreat toward the standby position when the selection unit selects the retreat action.

19. The autonomous mobile body according to claim 18, wherein the mobile controller controls the autonomous mobile body to standby for a predetermined time after retreating to the standby position, and thereafter to once again move along the planned path.

20. The autonomous mobile body according to claim 17, further comprising a search unit arranged to search for a detour route from a passage where an obstacle exists in the moving target direction, wherein the mobile controller controls the autonomous mobile body to retreat to the detour route searched by the search unit when the selection unit selects the retreat action.