Obstacle sensor and robot cleaner having the same

• US 9,239,389 B2
• Filed: 09/14/2012
• Issued: 01/19/2016
• Est. Priority Date: 09/28/2011
• Status: Expired due to Fees

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Jeong, Yeon Kyu, Kim, Shin, Kim, Jeong Hun, Kim, Jong Owan, Yoon, Sang Sik, Lee, Dong Hun, So, Jea Yun
• Primary Examiner(s): Perungavoor, Sath V
• Assistant Examiner(s): Hilaire, Clifford
• Application Number:
  US13/616,137
• Publication Number:
  US 20130076893A1
• Time in Patent Office: 1,222 Days
• Field of Search: 348/36, 348/37, 348/38, 348/39
• US Class Current: 1/1
• CPC Class Codes: G01S 17/00 Systems using the reflection or reradiation of electromagnetic waves other than radio waves, e.g. lidar systems
• CPC Class Codes: G01S 17/88 Lidar systems specially adapted for specific applications
• CPC Class Codes: G01S 17/931 of land vehicles
• CPC Class Codes: G01S 7/4813 Housing arrangements
• CPC Class Codes: G01S 7/4814 of transmitters alone
• CPC Class Codes: G01S 7/4816 of receivers alone
• CPC Class Codes: G02B 17/0808 on-axis systems with at least one of the mirrors having a central aperture
• CPC Class Codes: G05D 1/0238 using obstacle or wall sensors G05D1/0246 and G05D1/0289 take precedence; lidar systems designed for anti-collision purposes G01S17/93
• CPC Class Codes: G05D 1/0248 in combination with a laser lasers per se H01S

Abstract

An obstacle sensor includes a line light irradiating unit including a light-emitting unit, a light-emitting driving unit to drive the light-emitting unit, and a first conical mirror, an apex of which is disposed towards the light-emitting unit in a light irradiation direction of the light-emitting unit and which converts light emitted from the light-emitting unit into line light irradiated in all directions, and a reflected light receiving unit including a second conical mirror to condense light, that is irradiated from the first conical mirror and is then reflected from an obstacle, a lens, that is spaced from the apex of the second conical mirror by a predetermined distance and transmits the reflected light, an imaging unit to image the reflected light that passes through the lens, an image processing unit, and an obstacle sensing control unit.

Claims

1. An obstacle sensor comprising:

a line light irradiating unit comprising a light-emitting unit, and a first conical mirror, an apex of which is disposed towards the light-emitting unit in a light irradiation direction of the light-emitting unit and which converts light emitted from the light-emitting unit into line light irradiated in all directions; and

a reflected light receiving unit comprising a second conical mirror to condense light, that is irradiated from the first conical mirror and is then reflected from an obstacle, a lens, that is spaced from the apex of the second conical mirror by a predetermined distance and transmits the reflected light, and an imaging unit to image the reflected light that passes through the lens, wherein the line light irradiating unit and the reflected light receiving unit are arranged in a row in a vertical line or are arranged at different positions in a vertical line or horizontal line, and wherein the first conical mirror is formed by joining two or more conical fragments having different bottom diameters.

2. The obstacle sensor according to claim 1, wherein the line light irradiating unit further comprises:

a slit or an axicon lens disposed between the light-emitting unit and the first conical mirror to form light irradiated from the light-emitting unit in the form of a ring.

3. The obstacle sensor according to claim 1, wherein the line light irradiating unit further comprises:

a slit having at least one groove disposed between the light-emitting unit and the first conical mirror.

4. The obstacle sensor according to claim 3, wherein the slit has a groove having a ring, cross (+), circular or linear (−

) shape.

5. The obstacle sensor according to claim 1, further comprising:

a rotator to rotate the first conical mirror.

6. The obstacle sensor according to claim 1, wherein an angle of two sides formed on the apex on the vertical cross-section of the first conical mirror is about 88 to about 90 degrees.

7. The obstacle sensor according to claim 1, wherein the lens of the reflected light receiving unit is spaced from the apex of the second conical mirror by a focal distance of the lens.

8. The obstacle sensor according to claim 1, wherein the surface of lens or the second conical mirror of the reflected light receiving unit is coated with a band pass filter to transmit only wavelength of the reflected light.

9. The obstacle sensor according to claim 1, wherein the apex of the first conical mirror of the line light irradiating unit and the apex of the second conical mirror of the reflected light receiving unit are disposed in opposite directions.

10. The obstacle sensor according to claim 1, wherein the apex of the first conical mirror of the line light irradiating unit and the apex of the second conical mirror of the reflected light receiving unit are disposed in one direction.

11. The obstacle sensor according to claim 9, wherein the apex of the first conical mirror of the line light irradiating unit and the apex of the second conical mirror of the reflected light receiving unit face each other.

12. The obstacle sensor according to claim 1, wherein the lens of the reflected light receiving unit is a wide-angle lens.

13. The obstacle sensor according to claim 1, further comprising:

a structure having a hole smaller than an irradiation cross-section area of light irradiated from the light-emitting unit,

wherein the hole is disposed between the light-emitting unit and the first conical mirror in a light irradiation path of the light-emitting unit.

14. The obstacle sensor according to claim 1, wherein the line light irradiating unit or the light-emitting unit is inclined at a predetermined angle from a perpendicular line that is vertical to the ground.

15. The obstacle sensor according to claim 1, further comprising:

an obstacle sensing control unit to analyze an image recorded on the imaging unit and thereby extract the distance or shape of the obstacle.

16. The obstacle sensor according to claim 15, wherein the line light irradiating unit is provided in plural at different heights from the ground and the obstacle sensing control unit analyzes an image recorded on the imaging unit and determines a height of the obstacle.

17. A robot cleaner comprising an obstacle sensor to sense obstacles and a driving control unit to control driving based on the sensing results of the obstacle sensor,

wherein the obstacle sensor comprises:

a line light irradiating unit comprising a light-emitting unit, a light-emitting driving unit to drive the light-emitting unit, and a first conical mirror, an apex of which is disposed towards the light-emitting unit in a light irradiation direction of the light-emitting unit and which converts light emitted from the light-emitting unit into line light irradiated in all directions; and

a reflected light receiving unit comprising a second conical mirror to condense light, that is irradiated from the first conical mirror and is then reflected from an obstacle, a lens, that is spaced from the apex of the second conical mirror by a predetermined distance and transmits the reflected light, an imaging unit to image the reflected light that passes through the lens, and an image processing unit to process the image obtained in the imaging unit; and

an obstacle sensing control unit to analyze the image recorded in the imaging unit and thereby extract the distance or shape of the obstacle,

wherein the line light irradiating unit and the reflected light receiving unit are arranged in a row in a vertical line or are arranged at different positions in a vertical line or horizontal line, and

wherein the first conical mirror is formed by joining two or more conical fragments having different bottom diameters.

18. The robot cleaner according to claim 17, wherein the apex of the first conical mirror of the line light irradiating unit and the apex of the second conical mirror of the reflected light receiving unit are disposed in the opposite directions.

19. The robot cleaner according to claim 17, wherein the line light irradiating unit is mounted on the bottom of the front surface of the robot cleaner and the reflected light receiving unit is mounted on the top of the front surface of the robot cleaner.

20. The robot cleaner according to claim 17, wherein the driving control unit receives a shape or distance of the obstacle from the obstacle sensor and determines a travel path based on the shape or distance of the obstacle.

21. The robot cleaner according to claim 17, wherein the line light irradiating unit is provided in plural at different heights from the ground and the obstacle sensing control unit analyzes an image recorded on the imaging unit and thereby determines a height of the obstacle.

22. The robot cleaner according to claim 17, wherein the obstacle sensing control unit transmits a control signal to the light-emitting driving unit to turn the light-emitting unit off, when the obstacle sensing control unit determines that the robot cleaner is lift from the ground.

23. The robot cleaner according to claim 17, wherein the obstacle sensing control unit transmits a control signal to the light-emitting driving unit to turn the light-emitting unit off, when the obstacle sensing control unit determines that a sensor window of the robot cleaner is detached.

24. The robot cleaner according to claim 17, further comprising:

a switch or a photo-interrupter adjacent to the sensor window,

wherein the obstacle sensing control unit analyzes a signal output from the switch or the photo interrupter and thereby determines detachment of the sensor window.

25. The robot cleaner according to claim 17, wherein the obstacle sensing control unit turns the light-emitting unit on, when the robot cleaner begins to travel, and turns the light-emitting unit off, when the robot cleaner finishes travel.