Autonomous moving body, its control method, and control system

• US 9,182,762 B2
• Filed: 01/19/2009
• Issued: 11/10/2015
• Est. Priority Date: 02/07/2008
• Status: Active Grant

• Current Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Yabushita, Hidenori, Mima, Kazuhiro, Asahara, Yoshiaki
• Primary Examiner(s): Zeender, Ryan
• Assistant Examiner(s): ORTIZ ROMAN, DENISSE Y
• Application Number:
  US12/866,555
• Publication Number:
  US 20100324771A1
• Time in Patent Office: 2,486 Days
• Field of Search: None
• US Class Current: 1/1
• CPC Class Codes: G01C 21/26 specially adapted for navigation in a road network
• CPC Class Codes: G05D 1/00 Control of position, course, altitude or attitude of land, water, air or space vehicles, e.g. using automatic pilots drive control systems specially adapted for autonomous road vehicles B60W60/00
• CPC Class Codes: G05D 1/024 in combination with a laser lasers per se H01S
• CPC Class Codes: G05D 1/0246 using a video camera in combination with image processing means
• CPC Class Codes: G05D 1/0261 using magnetic plots
• 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

To provide an autonomous moving body capable of moving with efficiency along a path toward a travel end point while avoiding a collision with a moving obstacle, its control method, and its control system. An autonomous moving body in accordance with the present invention includes means to create a traveling path of the autonomous moving body that extends from a travel start point to a travel end point, means to calculate a point at which a moving obstacle located within the moving area crosses the created traveling path of the autonomous moving body as a collision prediction point, means to calculate a first passage time period during which the moving obstacle passes through the collision prediction point, and means to calculate a second passage time period during which the autonomous moving body passes through the collision prediction point. Further, if at least a part of the second passage time period overlaps the first passage time period, the traveling speed of the autonomous moving body is adjusted so that the second passage time period does not overlap the first passage time period.

Claims

1. An autonomous moving body that starts traveling from a travel start point located within a moving area and arrives at a travel end point located within the moving area, comprising a control unit programmed to:

define a traveling path of the autonomous moving body, the traveling path extending from the travel start point to the travel end point;

calculate a collision prediction point, the collision point being a point at which a moving obstacle located within the moving area crosses the traveling path of the autonomous moving body;

define a time-space coordinate system in which an elapsed time from a current time is indicated on a horizontal axis and a distance from a current position of the autonomous moving body along the traveling path is indicated on a vertical axis;

draw a movement track of the autonomous moving body on the time-space coordinate system;

determine, when the moving obstacle passes through the collision prediction point, four time-space coordinates on the time-space coordinate system, the four time-space coordinates defining a square-shaped temporal-spatial area containing the moving obstacle;

determine if the movement track overlaps the square-shaped temporal-spatial area; and

adjust, if the movement track overlaps the square-shaped temporal-spatial area, a traveling speed of the autonomous moving body by either decreasing the traveling speed so that the movement track passes through time-space coordinate at which the square-shaped temporal-spatial area has completely passed the traveling path and whose value on the vertical axis is smaller than that of the four time-space coordinates, or increasing the traveling speed so that the movement track passes through another time-space coordinate at which the square-shaped temporal-spatial area starts to pass the traveling path and whose value on the vertical axis is larger than that of the four time-space coordinates.

2. The autonomous moving body according to claim 1, wherein, after the square-shaped temporal-spatial area has completely passed through the traveling path, the control unit is programmed to change the traveling speed from the adjusted traveling speed to a predetermined traveling speed.

3. The autonomous moving body according to claim 1, wherein the control unit is further programmed to:

calculate a movement prediction path of the moving obstacle based on a current position information and a movement direction information of the moving obstacle; and

calculate an intersection point of the traveling path of the autonomous moving body and the calculated movement prediction path of the moving obstacle as the collision prediction point.

4. A control method of an autonomous moving body that starts traveling from a travel start point located within a moving area and arrives at a travel end point located within the moving area, the control method comprising:

defining a traveling path of the autonomous moving body, the traveling path extending from the travel start point to the travel end point;

calculating a collision prediction point, the collision point being a point at which a moving obstacle located within the moving area crosses the traveling path of the autonomous moving body;

defining a time-space coordinate system in which an elapsed time from a current time is indicated on a horizontal axis and a distance from a current position of the autonomous moving body along the traveling path is indicated on a vertical axis;

drawing a movement track of the autonomous moving body on the time-space coordinate system;

determining, when the moving obstacle passes through the collision prediction point, four time-space coordinates on the time-space coordinate system, the four time-space coordinates defining a square-shaped temporal-spatial area containing the moving obstacle;

determining if the movement track overlaps the square-shaped temporal-spatial area;

adjusting, if the movement track overlaps the square-shaped temporal-spatial area, a traveling speed of the autonomous moving body by either decreasing the traveling speed so that the movement track passes through a time-space coordinate at which the square-shaped temporal-spatial area has completely passed the traveling path and whose value on the vertical axis is smaller than that of the four time-space coordinates, or increasing the traveling speed so that the movement track passes through another time-space coordinate at which the square-shaped temporal-spatial area starts to pass the traveling path and whose value on the vertical axis is larger than that of the four time-space coordinates.

5. The control method of an autonomous moving body according to claim 4, wherein, after the square-shaped temporal-spatial area has completely passed through the traveling path, the adjusted traveling speed is changed to a predetermined traveling speed.

6. An autonomous moving body that starts traveling from a travel start point located within a moving area and arrives at a travel end point located within the moving area, comprising:

a control unit that

defines a traveling path of the autonomous moving body, the traveling path extending from the travel start point to the travel end point,

calculates a collision prediction point, the collision point being a point at which a moving obstacle located within the moving area crosses the traveling path of the autonomous moving body,

defines a time-space coordinate system in which an elapsed time from a current time is indicated on a horizontal axis and a distance from a current position of the autonomous moving body along the traveling path is indicated on a vertical axis,

draws a movement track of the autonomous moving body on the time-space coordinate system,

determines, when the moving obstacle passes through the collision prediction point, four time-space coordinates on the time-space coordinate system, the four time-space coordinates defining a square-shaped temporal-spatial area containing the moving obstacle;

determines if the movement track overlaps the square-shaped temporal-spatial area, and

adjusts, if the movement track overlaps the square-shaped temporal-spatial area, a traveling speed of the autonomous moving body by either decreasing the traveling speed so that the movement track passes through a time-space coordinate at which the square-shaped temporal-spatial area has completely passed the traveling path and whose value on the vertical axis is smaller than that of the four time-space coordinates, or increasing the traveling speed so that the movement track passes through another time-space coordinate at which the square-shaped temporal-spatial area starts to pass the traveling path and whose value on the vertical axis is larger than that of the four time-space coordinates.