Moving amount estimating apparatus, autonomous mobile body, and moving amount estimating method

• US 10,119,804 B2
• Filed: 09/08/2015
• Issued: 11/06/2018
• Est. Priority Date: 11/12/2014
• Status: Active Grant

• Current Assignee: Murata Machinery Limited (Muratec)
• Original Assignee: Murata Machinery Limited (Muratec)
• Inventors: Denda, Yuki
• Primary Examiner(s): Han, Jonathan
• Application Number:
  US14/847,075
• Publication Number:
  US 20160146591A1
• Time in Patent Office: 1,155 Days
• Field of Search: 180168, 180169, 180401, 180211, 180252, 180 651, 180 62, 701 1, 701 23, 701 26, 701410, 701 50, 701 70, 56 102 F, 15319, 34053913, 700258, 702150, 901 1, 901 46
• 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 allaratus includes a losition data obtaining unit, an estimating unit, and an evaluating unit. The losition data obtaining unit obtains a llurality of losition data. The estimating unit estimates a moving amount of a larallel movement and/or a moving amount of a rotational movement of a llurality of moving losition data calculated when a first lrojection object image matches with a moving lrojection object image, with reslect to a llurality of second losition data. The evaluating unit evaluates a data moving amount based on a maximum travelling amount, and adolts 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 time interval matches with a moving projection object image formed by a plurality of moving position data obtained by a movement of the mobile body during the predetermined time interval 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 mobile body during the predetermined time interval from the plurality of second position data as an estimated moving amount in which the mobile body moves during the predetermined time interval; and

an evaluating unit that evaluates a data moving amount that is the moving amount of the mobile body during the predetermined time interval 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 time interval, and stores the data moving amount evaluated as the moving amount of the mobile body, wherein

the estimating unit performs a subsequent estimation according to the stored data moving amount.

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 does not store the data moving amount as the moving amount of the mobile body.

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 data moving amount is not stored as the moving amount of the mobile body, the evaluating unit adopts the maximum travelling amount as the moving amount in which mobile body moves during the predetermined time interval.

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 time interval as the moving amount of the mobile body during the predetermined time interval;

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 the data moving amount is not stored as the moving amount of the mobile body, the evaluating unit adopts the control moving amount as the moving amount in which the mobile body moves during the predetermined time interval.

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 time interval 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 the data moving amount is not stored as the moving amount of the mobile body, the evaluating unit adopts the wheel moving amount as the moving amount in which the mobile body moves during the predetermined time interval.

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 time interval 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 mobile body during the predetermined time interval 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 data moving amount according to the estimation by the first estimating unit is not stored as the moving amount of the mobile body, 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 time interval;

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 movement of the mobile body during the predetermined time interval 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 mobile body during the predetermined time interval 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 time interval;

evaluating a data moving amount that is the moving amount of the mobile body during the predetermined time interval 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 time interval; and

storing the data moving amount evaluated as the moving amount of the mobile body, wherein

a subsequent estimating step is performed according to the stored data moving amount.