Autonomous traveling vehicle and reproduction travel method

• US 9,846,433 B2
• Filed: 10/16/2014
• Issued: 12/19/2017
• Est. Priority Date: 11/11/2013
• Status: Active Grant

• Current Assignee: Murata Machinery Limited (Muratec)
• Original Assignee: Murata Machinery Limited (Muratec)
• Inventors: Tanaka, Shoji
• Primary Examiner(s): Khatib, Rami
• Assistant Examiner(s): Boomer, Jeffrey C
• Application Number:
  US15/033,934
• Publication Number:
  US 20160274588A1
• Time in Patent Office: 1,160 Days
• 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 1/0221 involving a learning process

Abstract

An autonomous traveling vehicle is controlled to faithfully reproduce a planned traveling route and to autonomously travel. The autonomous traveling vehicle includes a platform, a traveling unit, a teaching unit, a curvature calculation unit, and a control parameter adjustment unit. The traveling unit is mounted on the platform and controls the platform to travel. In a teaching travel mode, the teaching unit acquires subgoal points. The teaching unit stores planned traveling route data as an aggregate of the subgoal points. The curvature calculation unit calculates and stores a key curvature radius. In a reproduction travel mode, the control parameter adjustment unit adjusts a control parameter to determine an direction angle feedback control amount of the traveling unit based on the key curvature radius calculated by the curvature calculation unit.

Claims

1. An autonomous traveling vehicle that executes a teaching travel mode in which a planned traveling route is taught, and a reproduction travel mode in which the autonomous travelling vehicle travels autonomously while reproducing the planned traveling route, the planned traveling route being a traveling route taught by a user when traveling from a travel start position to a travel end position, the autonomous traveling vehicle comprising:

a platform;

a traveling unit mounted on the platform to control the platform to travel; and

a controller including a processor that is configured or programmed to include;

a teaching unit that acquires subgoal points when the teaching travel mode is executed and stores planned traveling route data expressing the planned traveling route as an aggregate of subgoal points, the subgoal points being information of positions through which the platform passes from the travel start position to the travel end position in a travel environment;

a curvature calculation unit that calculates and stores a key curvature radius of a partial planned traveling route at a key subgoal point, the key subgoal point being one of the subgoal points included in the planned traveling route data, the partial planned traveling route including the key subgoal point and a predetermined number of subgoal points before and after the key subgoal point in the planned traveling route data; and

a control parameter adjustment unit that adjusts a control parameter to determine a control amount of the traveling unit based on the key curvature radius calculated by the curvature calculation unit, when the reproduction travel mode is executed;

wherein

the control amount is calculated based on a product of the control parameter and a direction angle difference between a direction angle indicating a current direction of the platform and a direction angle indicating a direction of the platform at a next target travel point.

2. The autonomous traveling vehicle according to claim 1, wherein

the traveling unit includes a first main wheel and a second main wheel disposed to face the first main wheel;

a first main wheel rotation speed of the first main wheel includes a first rotation speed and a second rotation speed, and a second main wheel rotation speed of the second main wheel includes a first rotation speed and a second rotation speed; and

the second rotation speed is controlled based on the control amount.

3. The autonomous traveling vehicle according to claim 1, wherein the planned traveling route data contains the key curvature radius in association with the subgoal point.

4. The autonomous traveling vehicle according to claim 1, wherein the planned traveling route data contains a direction angle at the subgoal point in association with the subgoal point.

5. The autonomous traveling vehicle according to claim 1, wherein

the partial planned traveling route is a traveling route including the key subgoal point, a first subgoal point before the key subgoal point in a traveling direction, and a second subgoal point after the key subgoal point in the traveling direction;

and

the first subgoal point and the second subgoal point are subgoal points closest to the key subgoal point among the subgoal points separated from the key subgoal point by a predetermined distance or more.

6. The autonomous traveling vehicle according to claim 1, wherein the curvature calculation unit calculates, as the key curvature radius, a radius of a key circle that passes a predetermined number of subgoal points included in the partial planned traveling route.

7. The autonomous traveling vehicle according to claim 1, wherein a predetermined control period is selected and the control amount is calculated every predetermined control period.

8. The autonomous traveling vehicle according to claim 1, wherein the processor is configured or programmed to further include a position estimating unit that estimates the position and/or the direction of the platform.

9. A method of a reproduction travel in which an autonomous traveling vehicle, which includes a platform, a traveling unit, and a controller including a processor, autonomously travels while reproducing a planned traveling route, the processor being configured or programmed to perform the method comprising:

calculating a key curvature radius of a partial planned traveling route at a key subgoal point, the key subgoal point being one of subgoal points included in planned traveling route data expressing the planned traveling route, the partial planned traveling route including the key subgoal point and a predetermined number of subgoal points before and after the key subgoal point in the planned traveling route data;

adjusting a control parameter based on the key curvature radius; and

determining a control amount to control the autonomous traveling vehicle to perform the reproduction travel based on the control parameter;

wherein

the control amount is calculated based on a product of the control parameter and a direction angle difference between a direction angle indicating a current direction of a platform and a direction angle indicating a direction of the platform at a next target travel point.