MOVING AMOUNT ESTIMATING APPARATUS, AUTONOMOUS MOBILE BODY, AND MOVING AMOUNT ESTIMATING METHOD

• US 20160146591A1
• Filed: 09/08/2015
• Published: 05/26/2016
• Est. Priority Date: 11/12/2014
• Status: Active Grant

• Current Assignee: Murata Machinery Limited (Muratec)
• Original Assignee: Murata Machinery Limited (Muratec)
• Inventors: DENDA, Yuki
• Granted Patent: US 10,119,804 B2
• Time in Patent Office: Days
• CPC Class Codes: G01B 11/00 Measuring arrangements characterised by the use of optical techniques
• CPC Class Codes: G01C 22/00 Measuring distance traversed on the ground by vehicles, persons, animals or other moving solid bodies, e.g. using odometers, using pedometers
• CPC Class Codes: G01S 17/86 Combinations of lidar systems with systems other than lidar, radar or sonar, e.g. with direction finders
• CPC Class Codes: G01S 17/89 for mapping or imaging
• CPC Class Codes: G01S 7/4808 Evaluating distance, position or velocity data
• CPC Class Codes: G05D 1/0253 extracting relative motion information from a plurality of images taken successively, e.g. visual odometry, optical flow determining position or orientation from images G06T7/70
• 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

Abstract

A moving amount estimating apparatus includes a position data obtaining unit, an estimating unit, and an evaluating unit. The position data obtaining unit obtains a plurality of position data. The estimating unit estimates a moving amount of a parallel movement and/or a moving amount of a rotational movement of a plurality of moving position data calculated when a first projection object image matches with a moving projection object image, with respect to a plurality of second position data. The evaluating unit evaluates a data moving amount based on a maximum travelling amount, and adopts the data moving amount evaluated as being adequate as a moving amount of a mobile body.

Claims

1. A moving amount estimating apparatus that estimates a moving amount of a mobile body including a travelling unit, the apparatus comprising:

a position data obtaining unit that obtains a plurality of position data forming a projection object image obtained by projecting an object present around the mobile body onto a predetermined coordinate;

an estimating unit that estimates, when a plurality of moving position data are calculated such that a first projection object image data formed by a plurality of first position data obtained one of before and after the mobile body moves during a predetermined period matches with a moving projection object image formed by a plurality of moving position data obtained by a parallel movement and/or a rotational movement of a plurality of second position data obtained the other of before and after the movement on the predetermined coordinate, the moving amount of the parallel movement and/or the moving amount of the rotational movement from the plurality of second position data as an estimated moving amount in which the mobile body moves during the predetermined period; and

an evaluating unit that evaluates a data moving amount that is the moving amount of the parallel movement and/or the rotational movement on the predetermined coordinate when the plurality of moving position data are calculated from the plurality of second position data based on a maximum travelling amount in which the mobile body is enabled to travel by the travelling unit during the predetermined period, and adopts the data moving amount evaluated as being adequate as the moving amount of the mobile body.

2. The moving amount estimating apparatus according to claim 1, wherein when the data moving amount is larger than the maximum travelling amount, the evaluating unit evaluates the data moving amount as being inadequate.

3. The moving amount estimating apparatus according to claim 1, wherein when the estimated moving amount is evaluated as the data moving amount and the estimated moving amount is evaluated as being inadequate, the evaluating unit adopts the maximum travelling amount as the moving amount in which mobile body moves during the predetermined period.

4. The moving amount estimating apparatus according to claim 1, wherein

the mobile body includes a travelling controller that controls the travelling unit;

and

the moving amount estimating apparatus further comprises;

a control moving amount estimating unit that estimates a control moving amount to be calculated based on an acceleration command value and/or a speed command value output to the travelling unit by the travelling controller when the travelling unit is controlled during the predetermined period as the moving amount of the mobile body during the predetermined period;

the evaluating unit evaluates the data moving amount with the control moving amount being used as the maximum travelling amount.

5. The moving amount estimating apparatus according to claim 4, wherein the evaluating unit evaluates the estimated moving amount as the data moving amount, and when evaluating the estimated moving amount as being inadequate, the evaluating unit adopts the control moving amount as the moving amount in which the mobile body moves during the predetermined period.

6. The moving amount estimating apparatus according to claim 4, wherein

the travelling unit includes wheels, and travels via rotation of the wheels;

the control moving amount estimating unit calculates a wheel moving amount calculated based on a rotating amount of the wheels during the predetermined period as the control moving amount.

7. The moving amount estimating apparatus according to claim 6, wherein the evaluating unit evaluates the estimated moving amount as the data moving amount, and when evaluating the estimated moving amount as being inadequate, the evaluating unit adopts the wheel moving amount as the moving amount in which the mobile body moves during the predetermined period.

8. The moving amount estimating apparatus according to claim 1, wherein the evaluating unit evaluates a product of a maximum translation speed and/or a maximum rotation speed of the mobile body and the predetermined period as the maximum travelling amount.

9. The moving amount estimating apparatus according to claim 1, wherein the estimating unit includes:

a distance calculating unit that calculates a distance between the first projection object image and the moving projection object image; and

a first estimating unit that determines, based on a comparison of the distance between the first projection object image and the moving projection object image with a predetermined threshold, whether the first projection object image matches with the moving projection object image, and estimates the moving amount of the parallel movement and/or the moving amount of the rotational movement of the plurality of moving position data with respect to the plurality of second position data as the estimated moving amount when the moving projection object image matches with the first projection object image.

10. The moving amount estimating apparatus according to claim 9, wherein the evaluating unit evaluates the estimated moving amount estimated by the first estimating unit as the data moving amount, and when evaluating that the estimated moving amount estimated by the first estimating unit is inadequate, the evaluating unit discards the estimated moving amount estimated by the first estimating unit.

11. The moving amount estimating apparatus according to claim 1, wherein the estimating unit includes:

a histogram generator that generates a first histogram based on coordinate values of the plurality of first position data on a predetermined coordinate axis of the predetermined coordinate and a second histogram based on coordinate values of the plurality of second position data on the predetermined coordinate axis; and

a second estimating unit that determines that the first projection object image matches with the moving projection object image when a matching degree between the first histogram and the second histogram is maximum, and estimates a moving amount of the first histogram or the second histogram when the matching degree becomes maximum as the estimated moving amount.

12. The moving amount estimating apparatus according to claim 11, wherein the evaluating unit evaluates the moving amount in which the first histogram or the second histogram is moved in the calculation of the matching degree as the data moving amount.

13. The moving amount estimating apparatus according to claim 12, wherein the evaluating unit sets an absolute value of an upper limit value and/or a lower limit value of the moving amount in which the first histogram or the second histogram is moved as the maximum travelling amount.

14. An autonomous mobile body comprising:

the moving amount estimating apparatus according to claim 1;

a travelling unit;

a position estimating unit that estimates a current position based on a moving amount to be estimated in the moving amount estimating apparatus; and

a travelling controller that controls the travelling unit so that the travelling unit travels from the current position to a predetermined target position.

15. A moving amount estimating method to estimate a moving amount of a mobile body including a travelling unit, the method comprising:

obtaining a plurality of position data forming a projection object image obtained by projecting an object present around the mobile body onto a predetermined coordinate before and after the mobile body moves during a predetermined period;

estimating, when a plurality of moving position data are calculated such that a first projection object image data formed by a plurality of first position data obtained one of before and after a movement matches with a moving projection object image formed by a plurality of moving position data obtained by a parallel movement and/or a rotational movement of a plurality of second position data obtained the other of before and after the movement on the predetermined coordinate, the moving amount of the parallel movement and/or the moving amount of the rotational movement of the plurality of moving position data from the plurality of second position data as an estimated moving amount in which the mobile body moves during the predetermined period;

evaluating a data moving amount that is the moving amount of the parallel movement and/or the rotational movement on the predetermined coordinate when the plurality of moving position data are calculated from the plurality of second position data, based on a maximum travelling amount in which the mobile body is enabled to travel by the travelling unit during the predetermined period; and

adopting the data moving amount evaluated as being adequate as the moving amount of the mobile body.