Apparatus and method for correcting location information of mobile body, and computer-readable media storing computer program for controlling the apparatus

• US 20060178815A1
• Filed: 07/11/2005
• Published: 08/10/2006
• Est. Priority Date: 02/04/2005
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Lee, Hyoungki, Choi, Kiwan
• Granted Patent: US 7,509,213 B2
• Time in Patent Office: Days
• US Class Current: 701/207
• CPC Class Codes: G05D 1/0225 involving docking at a fixed facility, e.g. base station or loading bay parking aids B62D15/027
• CPC Class Codes: G05D 1/0242 using non-visible light signals, e.g. IR or UV signals
• 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

There is provided an apparatus and method for correcting location information of a mobile body and a computer-readable recording medium storing at least a computer program for controlling the apparatus. The apparatus for correcting the location information of the mobile body, the location information regarding at least one of a location and an azimuth angle of the mobile body, includes a beam generator generating at least one beam; and a location information correcting unit receiving measured location information, sensing the generated beam, and correcting the received measured location information using the sensed beam, wherein the location information correcting unit is installed in the mobile body. Therefore, it is possible to easily correct location information of a mobile body using beams and more accurately correct the location information without accumulating errors, differently from a conventional dead reckoning system. Also, it is possible to correct the location information without an artificial landmark, even at night, or when no lighting exists, since the location information is corrected using an infrared ray, and to more accurately correct the location information of a mobile body by increasing the number of the beams. Further, it is possible to flexibly provide a trade-off between the number of the beams and accuracy in correcting of the location information, and to allow the mobile body to sense beams and accurately correct its location information, when the mobile body is picked up and moved to a different location. Therefore, it is possible to accurately correct at least one of a location and an azimuth angle measured by the dead reckoning system, for example, in a home robot having a home base.

Claims

1. An apparatus for correcting location information of a mobile body, the location information being at least one of a location and an azimuth angle of the mobile body, the apparatus comprising:

a beam generator generating at least one beam; and

a location information correcting unit receiving measured location information, sensing the generated beam, and correcting the received measured location information using the sensed beam,

wherein the location information correcting unit is installed in the mobile body.

2. The apparatus of claim 1, wherein the location information correcting unit comprises:

a beam sensor sensing the beam and outputting the sensed beam;

a beam information searching unit detecting a frequency of the sensed beam and searching for beam information corresponding to the detected frequency from pre-stored beam information; and

a location information updating unit updating at least one of the measured location and the measured azimuth angle to a corrected location and a corrected azimuth angle obtained using the searched beam information, respectively.

3. The apparatus of claim 2, wherein the location information updating unit comprises:

an azimuth angle calculating unit calculating the azimuth angle of the mobile body using an angle formed by the sensed beam and the mobile body and a slope of the sensed beam; and

an azimuth angle updating unit updating the measured azimuth angle of the mobile body to the calculated azimuth angle,

wherein the slope of the sensed beam is included in the searched beam information.

4. The apparatus of claim 3, wherein the azimuth angle calculating unit comprises:

an angle measuring unit measuring an angle formed by the sensed beam and the mobile body; and

an azimuth angle calculator calculating the azimuth angle using the slope of the sensed beam and the measured angle, according to the following equation;

θ

_r=(180°

−

θ

_m)+θ

_h,

where θ

_r represents the calculated azimuth angle, θ

_m represents an angle measured by the angle measuring unit, θ

_h represents arctan (a), and a is an angle corresponding to the slope of the sensed beam.

5. The apparatus of claim 4, wherein the angle measuring unit comprises:

an angle averaging unit calculating an average value of an angle formed by the beam sensed at an initial time and the mobile body and an angle formed by the beam sensed at a final time and the mobile body; and

a movement measuring unit determining whether the mobile body travels with uniform velocity and in a straight line and outputting the calculated average value as the measured angle to the azimuth angle calculator in response to the determined result,

wherein the angle measured by the angle measuring unit corresponds to an angle formed by a beam sensed at an intermediate time between the initial time and the final time and the mobile body.

6. The apparatus of claim 2, wherein the location information updating unit comprises a location updating unit updating the measured location of the mobile body to a corrected location calculated using the searched beam information.

7. The apparatus of claim 3, wherein the location information updating unit further comprises a location updating unit updating the measured location of the mobile body to a corrected location calculated using the searched beam information.

8. The apparatus of claim 6, wherein the location updating unit calculates the corrected location using the following equations:

y_tc=ax_tc+b, and
(x_tc−

x_p)²+(y_tc−

y_p)²=L²=(kR)²,

where t_c is a time at which the beam sensor senses the beam, x_tc represents an x-axis coordinate of the corrected location at the time t_c, y_tc represents a y-axis coordinate of the corrected location at the time t_c, a represents a slope of the beam, a and b are the beam information corresponding to the detected frequency, x_p and y_p represent x- and y-axis coordinates of the beam generator, respectively, k represents a scale factor, and R represents a distance from a center of the beam sensor to a location at which the beam is sensed.

9. The apparatus of claim 6, wherein the location updating unit calculates the corrected location using the following equations:

$\begin{array}{c}{y}_{\mathrm{tc}}^{\mathrm{\prime <br><br>}}=a^{\mathrm{\prime <br><br>}}<br><br>x_{\mathrm{tc}}^{\mathrm{\prime <br><br>}}+b^{\mathrm{\prime <br><br>}},\mathrm{and}\\ y_{\mathrm{tc}}^{\mathrm{\prime <br><br>}}=-\frac{1}{a^{\mathrm{\prime <br><br>}}}<br><br>\left(x_{\mathrm{tc}}^{\mathrm{\prime <br><br>}}-x_{\mathrm{tc}}^{\mathrm{\prime <br><br>\prime <br><br>}}\right)+y_{\mathrm{tc}}^{\mathrm{\prime <br><br>\prime <br><br>}},\end{array}$

where t_c is a time at which the beam sensor senses the beam, x′

_tc represents an x-axis coordinate of the corrected location at the time t_c, y′

_tc represents a y-axis coordinate of the corrected location at the time t_c, a′

represents a slope of the beam, a′ and

b′

are the beam information corresponding to the detected frequency, x′

_tc represents an x-axis coordinate of the measured location of the mobile body, and y″

_tc represents a y-axis coordinate of the measured location of the mobile body.

10. The apparatus of claim 1, wherein the location and the azimuth angle of the mobile body are measured by a dead reckoning system.

11. The apparatus of claim 1, wherein the beam generator generates the beam of infrared ray.

12. A method for correcting location information of a mobile body, the location information regarding at least one of a location and an azimuth angle of the mobile body, comprising:

generating at least one beam; and

sensing the generated beam and correcting measured given location information using the sensed beam,

wherein the sensing of the beam is performed by the mobile body.

13. The method of claim 12, wherein the correcting of the measured location information comprises:

sensing the beam;

detecting a frequency of the sensed beam and searching for beam information corresponding to the detected frequency from pre-stored beam information; and

updating at least one of the measured location and the measured azimuth angle to a corrected location and a corrected azimuth angle obtained using the searched beam information, respectively.

14. The method of claim 13, wherein the updating of the at least one of the measured location and the measure azimuth angle comprises:

calculating the azimuth angle of the mobile body using an angle formed by the sensed beam and the mobile body and a slope of the sensed beam; and

updating the measured azimuth angle of the mobile body to the calculated azimuth angle,

wherein the slope of the sensed beam is included in the searched beam information.

15. The method of claim 14, wherein the calculating of the azimuth angle comprises:

measuring an angle formed by the sensed beam and the mobile body; and

calculating the azimuth angle using a slope of the sensed beam and the measured angle according to the following Equation;

θ

_r=(180°

−

θ

_m)+θ

_h,

where θ

_r represents the calculated azimuth angle, θ

_m represents a measured angle θ

_h represents arctan (a), and a is an angle corresponding to the slope of the sensed beam.

16. The method of claim 15, wherein the measuring of the angle comprises:

calculating an average value of an angle formed by the beam sensed at an initial time and the mobile body and an angle formed by the beam sensed at a final time and the mobile body; and

determining whether the mobile body travels with uniform velocity and in a straight line,

wherein, if the mobile body travels with uniform velocity and in a straight line, the azimuth angle is calculated using the calculated average value as the measured angle and the measured angle corresponds to an angle formed by a beam sensed at an intermediate time of the initial time and the final time and the mobile body.

17. The method of claim 13, wherein the updating comprises:

updating the measured location of the mobile body to a corrected location calculated using the searched beam information.

18. The method of claim 14, wherein the updating of the at least one of the measured location and the measured azimuth angle further comprises:

updating the measured location of the mobile body to a corrected location calculated using the searched beam information.

19. A computer-readable recording medium storing at least a computer program for controlling an apparatus for correcting location information of a mobile body, the location information regarding at least one of a location and an azimuth angle of the mobile body, the computer program performing:

generating at least one beam; and

sensing the generated beam and correcting measured given location information using the sensed beam,

wherein the sensing of the beam is performed by the mobile body.

20. The computer-readable recording medium of claim 19, wherein the correcting of the location information comprises:

sensing the beam;

detecting a frequency of the sensed beam and searching for beam information corresponding to the detected frequency from pre-stored beam information; and

updating at least one of the measured location and the measured azimuth angle to a corrected location and a corrected azimuth angle calculated using the searched beam information, respectively.

21. The computer-readable recording medium of claim 20, wherein the updating of the at least one of the measured location and the measured azimuth angle comprises:

calculating the azimuth angle of the mobile body using an angle formed by the sensed beam and the mobile body and a slope of the sensed beam; and

updating the measured azimuth angle of the mobile body to the calculated azimuth angle,

wherein the slope of the sensed beam is included in the searched beam information.

22. The computer-readable recording medium of claim 21, wherein the calculating of the azimuth angle comprises:

measuring an angle formed by the sensed beam and the mobile body;

calculating the azimuth angle using the slope of the sensed beam and the measured angle, according to the following Equation;

θ

_r=(180°

−

θ

_m)+θ

_h,

where θ

_r represents the calculated azimuth angle, θ

_m represents the measured angle, θ

_h represents arctan (a), and a is an angle corresponding to the slope of the sensed beam.

23. The computer-readable recording medium of claim 22, wherein the calculating of the angle comprises:

calculating an average value of an angle formed by a beam sensed at an initial time and the mobile body and an angle formed by a beam sensed at a final time and the mobile body;

determining whether the mobile body travels with uniform velocity and in a straight line; and

if the mobile body travels with uniform velocity and in a straight line, calculating the azimuth angle using the calculated average value as the measured angle,

wherein the measured angle corresponds to an angle formed by a beam sensed at an intermediate time between the initial time and the final time and the mobile body.

24. The computer-readable recording medium of claim 20, wherein, in the updating, the measured location of the mobile body is updated to a corrected location calculated using the searched beam information.

25. The computer-readable recording medium of claim 21, wherein the updating of the at least one of the measured location and the measured azimuth angle further comprises:

updating the measured location of the mobile body to a corrected location calculated using the searched beam information.

26. The computer-readable recording medium of claim 21, wherein the beam is an infrared ray.