Autonomous moving body and control method thereof

• US 9,164,512 B2
• Filed: 11/27/2009
• Issued: 10/20/2015
• Est. Priority Date: 11/27/2009
• Status: Active Grant

• Current Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Yabushita, Hidenori, Oobayashi, Souichi, Ogura, Takashi
• Primary Examiner(s): Olszewski, John R
• Assistant Examiner(s): CASS, JEAN PAUL
• Application Number:
  US13/126,860
• Publication Number:
  US 20120035797A1
• Time in Patent Office: 2,153 Days
• Field of Search: 701/23, 700/258
• US Class Current: 1/1
• CPC Class Codes: G05D 1/0214 in accordance with safety or protection criteria, e.g. avoiding hazardous areas monitoring the location of vehicles within a certain area, e.g. forbidden or allowed areas, in traffic control systems for road vehicles G08G1/13
• CPC Class Codes: G05D 1/024 in combination with a laser lasers per se H01S
• CPC Class Codes: G05D 1/0242 using non-visible light signals, e.g. IR or UV signals
• 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

To enable stable collision avoidance operation without the need to install an infrastructure or the like even in a dangerous area where running out is likely to occur. An autonomous moving body according to the present invention includes: a distance measuring sensor that measures a distance to an object existing in an environment; a distance information acquisition unit that acquires a distance measurement value of the distance measuring sensor as distance information on a measurement point; and a dangerous area extraction unit that categorizes adjacent measurement points as an identical object according to a distance difference between the measurement points, and extracts an endpoint of the object as a dangerous area when the categorized object itself has a size equal to or larger than a predetermined threshold and when an opening formed between endpoints of the objects has a width equal to or larger than a predetermined threshold, in which the autonomous moving body travels so as to avoid a collision in the extracted dangerous area.

Claims

1. An autonomous moving body that autonomously travels from a travel start point to a travel end point in an environment, comprising:

a distance measuring sensor that measures distances to a plurality of objects existing in the environment;

a control unit, the control unit further comprising an acquisition unit and an extraction unit that extracts an endpoint of the object as a collision point with the moving body, the control unit programmed to;

acquire distance measurement values as distance information on a plurality of measurement points measured by the distance measuring sensor, wherein if distances between measurement points of the plurality of measurement points are equal to or smaller than a predetermined threshold, the measurement points are categorized as being one object;

extract a candidate point as the collision point from an end point and a start point of each of the plurality objects that satisfies all of the following conditions (1) to (3);

(1) as for an object (n) with an object number n, the length of the object (n) is equal to or larger than a fixed preprogrammed threshold length, wherein the length of the object (n) is calculated from a distance between the start point and the end point of the object (n);

(2) a distance difference between the end point of the object (n) and a start point of another object (n+1) of the plurality of objects is equal to or larger than a second fixed preprogrammed threshold length, which indicates a potentially dangerous area; and

(3) a distance difference between the end point of the object (n) and a start point of an object (n+2) is equal to or larger than a third fixed preprogrammed threshold length, which further indicates the potentially dangerous area, and

designate the candidate point as the endpoint of the object as the collision point if the following condition (4) is satisfied;

(4) providing an imaginary straight line connecting the candidate point as a base point and an endpoint of the object, and determining whether an angle between the straight line and the traveling direction of the vehicle, in a plane defined by the imaginary straight line and the traveling direction of the vehicle, is equal to or larger than a fixed preprogrammed threshold angle,

wherein the autonomous moving body travels so as to avoid a collision in the one or more designated endpoints of the objects.

2. The autonomous moving body according to claim 1, wherein the control unit further comprises a safe speed selection unit which selects a traveling speed to decelerate according to a relative distance between the one or more designated endpoints of the objects and a position of the autonomous moving body when the autonomous moving body enters the one or more endpoints of the objects extracted by the extraction unit,

wherein the autonomous moving body enters the endpoints of the objects according to the traveling speed selected by the safe speed selection unit.

3. The autonomous moving body according to claim 1, wherein the control unit further comprises a path planning unit that creates a path from the travel start point to the travel end point,

wherein when the autonomous moving body travels to avoid the one or more endpoints of the objects extracted by the extraction unit, the path planning unit creates a path for avoiding the endpoints of the objects using map information reflecting the endpoints of the objects, and the autonomous moving body travels along the created path.

4. The autonomous moving body according to claim 1, wherein the control unit is programmed to extract and designate the candidate point free of any pre-installed infrastructure.

5. A control method for an autonomous moving body including a distance measuring sensor that measures a distance to an object existing in an environment and a control unit including a distance acquisition unit and a unit that extracts an endpoint of the object as a collision point with a moving body, the control method comprising:

measuring distances to a plurality of objects existing in the environment with the distance measuring sensor;

acquiring distance measurement values as distance information on a plurality of measurement points measured by the distance measuring sensor with the control unit,

categorizing, with the control unit, the measuring points as being one object if distances between measurement points of the plurality of measurement points are equal to or smaller than a predetermined threshold;

extracting, with the control unit, a candidate point as the collision point from an end point and a start point of each of the plurality objects that satisfy all of the following conditions (1) to (3);

(1) as for an object (n) with an object number n, the length of the object (n) is equal to or larger than a fixed preprogrammed threshold length, wherein the length of the object (n) is calculated from a distance between the start point and the end point of the object (n);

(2) a distance difference between the end point of the object (n) and a start point of another object (n+1) of the plurality of objects is equal to or larger than a second fixed preprogrammed threshold length, which indicates a potentially dangerous area; and

(3) a distance difference between the end point of the object (n) and a start point of an object (n+2) is equal to or larger than a third fixed preprogrammed threshold length, which further indicates the potentially dangerous area, and

designating, with the control unit, the candidate point the endpoint of the object as the collision point if the following condition (4) is satisfied;

(4) providing an imaginary straight line connecting the candidate point as a base point and an end point of the object, and determining whether an angle between the straight line and the traveling direction of the vehicle, in a plane defined by the imaginary straight line and the traveling direction of the vehicle, is equal to or larger than a fixed preprogrammed threshold angle,

wherein the autonomous moving body travels so as to avoid a collision in the one or more designated endpoints of the objects.

6. The control method for an autonomous moving body according to claim 5, wherein in the extraction of the endpoints of the objects, assuming that the endpoint of the object extracted as the collision point is a candidate point, it is determined whether an angle formed between a straight line connecting the candidate point as a base point and another endpoint of the identical object and a traveling direction of the autonomous moving body is equal to or larger than a predetermined threshold;

and when the angle is equal to or larger than the predetermined threshold, the candidate point is extracted as a collision point.

7. The control method for an autonomous moving body according to claim 5, wherein when the autonomous moving body enters the endpoints of the objects, a traveling speed to decelerate according to a relative distance between the endpoints of the objects and a position of the autonomous moving body is selected, and the autonomous moving body travels according to the selected traveling speed.

8. The control method for an autonomous moving body according to claim 5, wherein when the autonomous moving body travels to avoid the endpoints of the objects, a path for avoiding the endpoints of the objects is created using map information reflecting the endpoints of the objects, and the autonomous moving body travels along the created path.

9. The control method for an autonomous moving body according to claim 5, wherein when the autonomous moving body approaches the endpoints of the objects, the autonomous moving body decelerates according to a relative distance between the endpoints of the objects and a position of the autonomous moving body, or travels along a path for avoiding the endpoints of the objects.

10. The control method for an autonomous moving body according to claim 5, wherein the control unit is programmed to extract and designate the candidate point free of any pre-installed infrastructure.