Method for detecting position of mobile body

Patent metadata

Field	Value
Publication number	US-10539653-B2
Application number	US-201715713788-A
Country	US
Kind code	B2
Filing date	Sep 25, 2017
Priority date	Mar 26, 2015
Publication date	Jan 21, 2020
Grant date	Jan 21, 2020

Abstract

A method for detecting a position of a mobile body moving on a plane includes setting X-axis and Y-axis direction reference lines on the plane, disposing a dummy mobile body on intersection points of the reference lines, detecting a position of the dummy mobile body, determining position variation amounts at the intersection points as an X-axis direction error and a Y-axis direction error based on a difference from true position data, determining X-axis and Y-axis direction error approximate formulas based on the errors to calculate errors at each position on the reference lines, detecting the position of the mobile body, correcting acquired detected X-Y coordinate data by a linear interpolation method using the X-axis and Y-axis direction error approximate formulas, and obtaining position data close to the true position of the mobile body.

First claim

What is claimed is:

1. A method for detecting a position of a mobile body on a plane with a position detecting sensor to detect the position of the mobile body in cooperation with a sensor in or on the mobile body moving on the plane, the method comprising the steps of:
assuming X-Y coordinates on the plane;
disposing one of the mobile body including the sensor at a predetermined position and a dummy mobile body including a sensor at a same position as the mobile body, at a plurality of positions specified by the X-Y coordinates on the plane, which are different positions in an X direction and a Y direction;
acquiring calibration X-Y coordinate data by detecting the position of one of the mobile body and the dummy mobile body at each of the plurality of positions, with the position detecting sensor;
determining correction data for the plurality of positions, based on a difference between the acquired calibration X-Y coordinate data, and true position data regarding the plurality of positions where one of the mobile body and the dummy mobile body is disposed; and
in a stage to actually detect the position of the mobile body moving on the plane, detecting a position of the mobile body moving on the plane with the position detecting sensor to acquire a detected X-Y coordinate data, and obtaining a position data close to a true position of the mobile body by correcting the detected X-Y coordinate data by an interpolation method using the correction data.

2. The method according to claim 1 , wherein the mobile body is a robot or a sphere-ride robot.

3. The method according to claim 1 , wherein the mobile body is capable of moving on the plane or rotating on a sphere.

4. The method according to claim 1 , wherein the position detecting sensor includes an ultrasonic transmitter.

5. The method according to claim 1 , wherein the position detecting sensor to detect the position of the mobile body includes two ultrasonic transmitters held by sensor holders.

6. The method according to claim 1 , wherein the plane is a surface of a table.

7. The method according to claim 1 , wherein the sensor of the mobile body and the sensor of the dummy mobile body have same characteristics.

8. The method according to claim 1 , wherein the plurality of X-axis direction reference lines and the plurality of Y-axis direction reference lines are arranged on the plane at equal intervals or substantially equal intervals.

9. The method according to claim 1 , wherein the sensor of the dummy mobile body includes two sensors, and a center axis of the dummy mobile body does not coincide with positions of the two sensors.

10. The method according to claim 1 , wherein the sensor of the dummy mobile body includes two sensors, and the calibration X-Y coordinate data of the dummy mobile body at each of the plurality of positions is determined based on a transmission time of ultrasonic signals transmitted from the two sensors.

11. A method for detecting a position of a mobile body on a plane with a position detecting sensor to detect the position of the mobile body in cooperation with a sensor in or on the mobile body moving on the plane, the method comprising the steps of:
assuming X-Y coordinates, a plurality of X-axis direction reference lines parallel to an X-axis direction, and a plurality of Y-axis direction reference lines parallel to a Y-axis direction, on the plane;
disposing one of the mobile body including the sensor at a predetermined position and a dummy mobile body including a sensor at a same position as the mobile body, on a plurality of intersection points of the X-axis direction reference lines and the Y-axis direction reference lines;
acquiring calibration X-Y coordinate data by detecting the position of one of the mobile body and the dummy mobile body at each of the plurality of intersection points, with the position detecting sensor;
determining position variation amounts in the X-axis direction and the Y-axis direction at the plurality of intersection points, as an X-axis direction error and a Y-axis direction error, based on a difference between the acquired calibration X-Y coordinate data, and true position data regarding the plurality of intersection points where one of the mobile body and the dummy mobile body is disposed;
determining an X-axis direction error approximate formula and a Y-axis direction error approximate formula based on the X-axis direction error and the Y-axis direction error, the X-axis direction error approximate formula and the Y-axis direction error approximate formula each being a formula to calculate an error at each position on the plurality of X-axis direction reference lines and the plurality of Y-axis direction reference lines; and
in a stage to actually detect the position of the mobile body moving on the plane, detecting a position of the mobile body moving on the plane with the position detecting sensor to acquire a detected X-Y coordinate data, and obtaining a position data close to a true position of the mobile body by correcting the detected X-Y coordinate data by a linear interpolation method using the X-axis direction error approximate formula and the Y-axis direction error approximate formula.

12. The method according to claim 11 , wherein
in a case where the mobile body includes a plurality of sensors at predetermined positions, a rotation direction position of the mobile body rotated around a rotation axis which is an axis perpendicular to the plane is capable of being detected based on a positional relationship of the plurality of sensors detected with the position detecting sensor; and
the method further comprises the steps of:
acquiring calibration rotation direction position data by detecting a rotation direction position of one of the mobile body and the dummy mobile body with the position detecting sensor at each of the plurality of intersection points after one of the mobile body including the plurality of sensors at the predetermined positions and the dummy mobile body including the plurality of sensors at the same positions as the mobile body is disposed on the plurality of intersection points so that the rotation direction position of one of the mobile body and the dummy mobile body faces a predetermined direction;
determining a rotation direction position error at the plurality of intersection points, based on a difference between the acquired calibration rotation direction position data, and true rotation direction position data regarding the plurality of intersection points;
determining a rotation direction error approximate formula based on the rotation direction position error used to calculate an error at each position; and
in a stage to actually detect the rotation direction position of the mobile body moving on the plane, detecting a rotation direction position of the mobile body moving on the plane with the position detecting sensor to acquire a detected rotation direction position data, and obtaining a rotation direction position data close to a true rotation direction position of the mobile body by correcting the detected rotation direction position data by a linear interpolation method using the rotation direction error approximate formula.

13. The method according to claim 11 , wherein the mobile body is a robot or a sphere-ride robot.

14. The method according to claim 11 , wherein the mobile body is capable of moving on the plane or rotating on a sphere.

15. The method according to claim 11 , wherein the position detecting sensor includes an ultrasonic transmitter.

16. The method according to claim 11 , wherein the position detecting sensor to dete

Assignees

• Murata Manufacturing Co

Inventors

• Tanaka Yuta
• Nishimura Michio

Classifications

• G01S5/30 Primary

  Determining absolute distances from a plurality of spaced points of known location · CPC title

• G01S1/80

  using a comparison of transit time of synchronised signals transmitted from non-directional transducers or transducer systems spaced apart, i.e. path-difference systems · CPC title

• G01S1/72

  using ultrasonic, sonic or infrasonic waves · CPC title

• G01S5/18

  using ultrasonic, sonic or infrasonic waves · CPC title