Position detection device for mobile robot and robot cleaner including the same

• US 8,306,662 B2
• Filed: 01/07/2009
• Issued: 11/06/2012
• Est. Priority Date: 04/23/2005
• Status: Active Grant

• Current Assignee: LG Electronics, Inc. (LG Corporation)
• Original Assignee: LG Electronics, Inc. (LG Corporation)
• Inventors: Kim, Sang Yun
• Primary Examiner(s): Tran, Dalena
• Application Number:
  US12/349,873
• Publication Number:
  US 20090218478A1
• Time in Patent Office: 1,399 Days
• Field of Search: 700/245, 700/250, 700/255, 700/258, 700/259, 356/28, 318/567, 318/568.12, 318/568.16, 318/577
• US Class Current: 700/259
• CPC Class Codes: G01S 17/48 Active triangulation systems, i.e. using the transmission and reflection of electromagnetic waves other than radio waves
• CPC Class Codes: G01S 7/495 Counter-measures or counter-counter-measures using electronic or electro-optical means
• CPC Class Codes: G05D 1/0242 using non-visible light signals, e.g. IR or UV signals

Abstract

The present invention relates to a position detection device for a mobile robot, including a light-emitting element for emitting light, a light reception element on which light transferred from a bottom, of the light emitted from the light-emitting element and then reflected from an obstacle, is focused, and a signal processing unit for calculating a distance between a position where the light incident on the light reception element is focused and the obstacle. A position detection method using a mobile robot may include operating a robot cleaner, receiving light transferred from a bottom, of light emitted from the robot cleaner and then reflected from an obstacle, and detecting a distance between the robot cleaner and the obstacle from which the light is reflected, determining whether the distance between the robot cleaner and the obstacle increases, and determining whether the robot cleaner has approached the obstacle.

Claims

1. A position detection device for a mobile robot, comprising:

a light-emitting element for emitting light toward a bottom;

a light reception element on which light transferred from the bottom, of the light emitted from the light-emitting element and then reflected from an obstacle, is focused; and

a signal processing unit for calculating a distance between the light-emitting element and the obstacle.

2. The position detection device of claim 1, further comprising an incorrect signal processing unit for determining the light reflected from the bottom by considering a change occurring while the mobile robot moves within the calculated distance.

3. The position detection device of claim 1, wherein the light-emitting element comprises:

an infrared light-emitting diode for emitting infrared light; and

a light transmission lens for condensing the infrared light emitted from the infrared light-emitting diode so that the infrared light goes straight ahead.

4. The position detection device of claim 1, wherein the light reception element comprises:

a light reception lens for condensing the light reflected from the obstacle; and

a position-sensitive detector on which the light condensed by the light reception lens is focused.

5. The position detection device of claim 4, wherein the light reception lens is oriented toward the bottom.

6. A robot cleaner, comprising:

position detection devices for emitting light toward a bottom and detecting distances between the position detection devices and an obstacle from which the light is reflected, and

an information processing unit for transmitting or receiving signals to or from the position detection devices and controlling a traveling unit so that the robot cleaner cleans a cleaning space of itself while the robot cleaner moves within the cleaning space.

7. The robot cleaner of claim 6, further comprising:

a casing forming an external portion of a main body;

a cleaning unit placed in the main body and configured to clean the cleaning space; and

a traveling unit for supporting the main body against a bottom of the cleaning space and move the main body.

8. The robot cleaner of claim 7, wherein each of the position detection devices further comprises an incorrect signal processing unit for determining the light reflected from the bottom by considering a change occurring while the robot cleaner moves within the detected distance.

9. The robot cleaner of claim 6, wherein each of the position detection devices comprises:

a light-emitting element for emitting light toward a bottom;

a light reception element on which light transferred from the bottom, of the light emitted from the light-emitting element and then reflected from an obstacle, is focused; and

a signal processing unit for calculating a distance between the light-emitting element and the obstacle.

10. The robot cleaner of claim 9, wherein the light-emitting element comprises:

an infrared light-emitting diode for emitting infrared light; and

a light transmission lens for condensing the infrared light emitted from the infrared light-emitting diode so that the infrared light goes straight ahead.

11. The robot cleaner of claim 9, wherein the light reception element comprises:

a light reception lens for condensing the light reflected from the obstacle; and

a position-sensitive detector on which the light condensed by the light reception lens is focused.

12. The robot cleaner of claim 11, wherein the light reception lens is oriented toward the bottom.

13. A position detection method using a mobile robot, comprising:

a light-emitting element emitting light toward a bottom;

a light reception element receiving light transferred from the bottom, of the light emitted from the light-emitting element and then reflected from an obstacle;

a signal processing unit calculating a distance between the light-emitting element and the obstacle;

an incorrect signal processing unit determining whether the distance between the robot cleaner and the obstacle increases; and

an incorrect signal processing unit determining whether the robot cleaner has approached the obstacle.

14. A position detection method using a mobile robot which comprises:

emitting light from a light-emitting element toward a bottom location;

receiving light by a light-receiving element from the bottom location and reflected from an obstacle;

calculating a distance between the light-emitting element and the obstacle by a signal processing unit;

determining whether or not the distance between a robot cleaner and the obstacle changes; and

determining whether or not the robot cleaner has approached the obstacle.

15. The method of claim 14, wherein as a result of determining whether or not the distance between the robot cleaner and the obstacle changes, the method returns to and repeats the light-emitting and light-receiving detection method.