Autonomous mobile body and control method of same

• US 8,886,385 B2
• Filed: 11/10/2010
• Issued: 11/11/2014
• Est. Priority Date: 11/20/2009
• Status: Active Grant

• Current Assignee: Murata Machinery Limited (Muratec)
• Original Assignee: Murata Machinery Limited (Muratec)
• Inventors: Takahashi, Masaki, Moriguchi, Toshiki, Suzuki, Takafumi
• Primary Examiner(s): Cheung, Mary
• Assistant Examiner(s): BRUSHABER, FREDERICK M
• Application Number:
  US13/510,549
• Publication Number:
  US 20120232739A1
• Time in Patent Office: 1,462 Days
• Field of Search: 701/26, 701/25
• US Class Current: 701/25
• CPC Class Codes: B25J 5/007 mounted on wheels
• CPC Class Codes: G05D 1/0217 in accordance with energy consumption, time reduction or distance reduction criteria
• 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 1/0274 using mapping information stored in a memory device navigation using map-matching G01C21/30

Abstract

An autonomous mobile body is configured to smoothly avoid obstacles. The mobile body has a movement mechanism configured to translate in a horizontal plane and rotate around a vertical axis, and the distance to an obstacle is derived for each directional angle using an obstacle sensor. Using a model having two arcs, one at each end in a major axis direction, connected by line segments that lie in the major axis direction and containing the autonomous mobile body, the movement mechanism is driven with a combination of translation and rotation, without interference between the obstacle and the model.

Claims

1. An autonomous mobile body having a major axis and a minor axis in plan view, and configured to avoid an obstacle and move autonomously to a goal, comprising:

a platform vehicle having a movement mechanism configured to translate in a horizontal plane and rotate around a vertical axis;

an obstacle sensor for outputting distance information indicating a distance from the autonomous mobile body to an obstacle for each of predetermined directional angles,

a data processor further comprising a model storage unit for storing an anisotropic model having two arcs, one at each end in the major axis direction, connected by line segments that lie in the major axis direction, and containing the autonomous mobile body; and

a motion controller further comprising a drive unit for driving the movement mechanism with a combination of translation and rotation, without interference between the obstacle and the model, based on the distance information output from the obstacle sensor and the anisotropic model stored in the model storage unit.

2. The autonomous mobile body according to claim 1, comprising a potential generator for generating a translational potential and a rotational potential of the autonomous mobile body for avoiding interference with the obstacle, based on the distance information output from the obstacle sensor and the model stored in the model storage unit.

3. The autonomous mobile body according to claim 2,

the obstacle sensor outputting the distance information indicating the distance from the autonomous mobile body to the obstacle for each directional angle at a plurality of heights, and

the model storage unit storing a plurality of the models according to height.

4. The autonomous mobile body according to claim 3, the movement mechanism having three or more drive wheels each provided, on a perimeter thereof, with a roller configured to rotate in a direction parallel to a wheel axis, and the three or more drive wheels including a drive wheel having a different wheel axis direction.

5. The autonomous mobile body according to claim 2, the movement mechanism having three or more drive wheels each provided, on a perimeter thereof, with a roller configured to rotate in a direction parallel to a wheel axis, and the three or more drive wheels including a drive wheel having a different wheel axis direction.

6. The autonomous mobile body according to claim 1,

the obstacle sensor outputting the distance information indicating the distance from the autonomous mobile body to the obstacle for each directional angle at a plurality of heights, and

the model storage unit storing a plurality of the models according to height.

7. The autonomous mobile body according to claim 6, comprising the platform vehicle and an upper part supported by the platform vehicle and having a movable part, and

the model storage unit changing the anisotropic model at the height corresponding to the upper part, according to deformation of the upper part.

8. The autonomous mobile body according to claim 7, the movement mechanism having three or more drive wheels each provided, on a perimeter thereof, with a roller configured to rotate in a direction parallel to a wheel axis, and the three or more drive wheels including a drive wheel having a different wheel axis direction.

9. The autonomous mobile body according to claim 6, the movement mechanism having three or more drive wheels each provided, on a perimeter thereof, with a roller configured to rotate in a direction parallel to a wheel axis, and the three or more drive wheels including a drive wheel having a different wheel axis direction.

10. The autonomous mobile body according to claim 1, the movement mechanism having three or more drive wheels each provided, on a perimeter thereof, with a roller configured to rotate in a direction parallel to a wheel axis, and the three or more drive wheels including a drive wheel having a different wheel axis direction.

11. A method of controlling an autonomous mobile body having a major axis and a minor axis in plan view to avoid an obstacle and move autonomously to a goal, the mobile body having a movement mechanism configured to translate in a horizontal plane and rotate around a vertical axis, the method causing the mobile body to perform the steps of

deriving a distance to an obstacle for each of predetermined directional angles using an obstacle sensor;

reading out an anisotropic model, stored in a model storage unit, having two arcs, one at each end in the major axis direction, connected by line segments that lie in the major axis direction, and containing the autonomous mobile body; and

driving the movement mechanism with a combination of translation and rotation using a drive unit, without interference between the obstacle and the model, based on distance information output from the obstacle sensor and the anisotropic model stored in the model storage unit.