Autonomous movement system

Patent metadata

Field	Value
Publication number	US-9229450-B2
Application number	US-201114119312-A
Country	US
Kind code	B2
Filing date	May 31, 2011
Priority date	May 31, 2011
Publication date	Jan 5, 2016
Grant date	Jan 5, 2016

Abstract

A route decision system is provided to avoid an obstacle existing in a traceably moving direction for tracing a reference route from a current location of an autonomous movable body. The system computes traffic distance and a traffic width as a traffic region having a given traffic width and does not allow an obstacle to intrude in each of a plurality of moving The moving direction of the autonomous movable body is decided on the basis of the traceably moving direction and the traffic region. A speed decision device decides a moving speed allowing the autonomous movable body to stop before it collides with the obstacle in response to the braking condition of the autonomous movable body and the location and the speed of the obstacle.

First claim

The invention claimed is:

1. An autonomous movement system having an environmental information acquisition means to acquire environmental information around an autonomous movable body,
a memory information processing means to retain map information where a reference route is registered,
a self-location estimation means to estimate the self-location of the autonomous movable body on the basis of the environmental information and the map information,
an obstacle detection means to detect information on an obstacle on the basis of the environmental information,
a route decision means to decide a moving direction on the basis of the self-location, the information on the obstacle, and information on the reference route,
a speed decision means to decide a moving speed on the basis of the obstacle information,
and a vehicle control means to control the movement of the autonomous movable body on the basis of the moving direction and the moving speed, wherein:
the route decision means, in order to avoid the obstacle existing in a traceably moving direction for tracing the reference route from a current location of the autonomous movable body, computes a traffic region formed by a traffic distance and at least a given traffic width not allowing the obstacle to intrude in each of a plurality of moving directions and decides a moving direction of the autonomous movable body on the basis of the traceably moving direction, the traffic region, and an obstacle type, the obstacle type being detected by the obstacle detection means, and
the speed decision means decides a moving speed allowing the autonomous movable body to stop before it collides with the obstacle in response to a braking condition of the autonomous movable body and the location and the speed of the obstacle.

2. An autonomous movement system according to claim 1 , wherein the route decision means:
decides a route trace target point on the reference route on the basis of the location of the autonomous movable body;
computes a trafficable distance of the traffic region in each of a plurality of directions at a given traffic width allowing the autonomous movable body to move;
decides an obstacle avoidance target point on the basis of the length component of the trafficable distance in the route trace target point direction;
computes a traffic region having an expanded traffic width on the basis of the direction of the obstacle avoidance target point;
sets a traffic width expansion target point in the direction where the variation of the trafficable distance decreases and the traffic width having a given upper limit expands; and
decides a moving direction of the autonomous movable body.

3. An autonomous movement system according to claim 1 , wherein the memory information processing means records a value suitable for the traffic width of the autonomous movable body beforehand in accordance with a site and the route decision means adjusts narrow path running through performance by using the traffic width recorded by the memory information processing means as the traffic width when an obstacle avoidance target point is decided.

4. An autonomous movement system according to claim 1 , wherein the route decision means adjusts route traceability by deciding an obstacle avoidance target point by a value obtained by multiplying the length of the trafficable distance in the direction of the straight line connecting the autonomous movable body to a route trace target point by a given coefficient when the obstacle avoidance target point is decided.

5. An autonomous movement system according to claim 1 , wherein the route decision means adjusts route traceability and narrow path running through performance by, with regard to the length of a trafficable distance in the direction of the straight line connecting the autonomous movable body to the route trace target point and a trafficable width, deciding a traffic width expansion target point by a value obtained by adding the two values in the same direction or a value obtained by adding values each of which is obtained by multiplying it by a given coefficient when the traffic width expansion target point is decided.

6. An autonomous movement system according to claim 1 , wherein the obstacle detection means: converts the coordinate of a detected obstacle to a coordinate system not influenced by the movement of the autonomous movable body by the self-location information; computes a moving vector of the obstacle by obtaining locational difference from an obstacle obtained from past sensor information; and adjusts the moving vector of the obstacle to the moving speed of the obstacle envisioned in the safety speed calculation field of the speed decision means.

7. An autonomous movement system according to claim 6 , wherein the safety speed calculation field of the speed decision means adjusts the upper limit of the speed of the autonomous movable body or the envisioned moving speed of an obstacle in response to the angle of collision when the obstacle moves at an envisioned speed and approaches the autonomous movable body.

8. An autonomous movement system according to claim 1 , wherein the obstacle detection means:
has a function of identifying whether a detected obstacle is a human, a child, or an adult from the shape and picture information; and
adjusts the value of the moving speed of the obstacle envisioned in the safety speed calculation of the speed decision means.

9. An autonomous movement system according to claim 1 , wherein the speed decision means decides a speed of the autonomous movable body by computing point by point the speed of the autonomous movable body allowing to stop before collision occurs without using a safety speed calculation field when an obstacle approaches at an envisioned speed in consideration of the breaking condition of the autonomous movable body in response to the location of the obstacle.

10. An autonomous movement system according to claim 1 , wherein, in the autonomous movable body, the route decision means and the speed decision means are configured so as to be independent processes in a computer and the processing cycles are set individually.

Assignees

• Oshima Akira
• Yamamoto Kenjiro
• Ono Yukihiko
• Hara Yoshitaka
• Hitachi Ltd

Inventors

• Oshima Akira
• Yamamoto Kenjiro
• Ono Yukihiko
• Hara Yoshitaka

Classifications

• Y10S901/01

  Mobile robot · CPC title

• G05D2201/0206

  Physics · mapped topic

• G05D1/0238 Primary

  using obstacle or wall sensors (G05D1/0246 and G05D1/0289 take precedence; lidar systems designed for anti-collision purposes G01S17/93) · CPC title

• G05D1/0274

  using mapping information stored in a memory device (navigation using map-matching G01C21/30) · CPC title

• G05D1/021 Primary

  specially adapted to land vehicles · CPC title