Range Finder and Method for Finding Range

• US 20100149407A1
• Filed: 05/14/2008
• Published: 06/17/2010
• Est. Priority Date: 05/16/2007
• Status: Active Grant

• Current Assignee: LG Innotek Company Limited (LG Corporation)
• Original Assignee: LG Innotek Company Limited (LG Corporation)
• Inventors: Lee, Ki Min, Lee, Jun Ki
• Granted Patent: US 8,310,585 B2
• Time in Patent Office: Days
• US Class Current: 348/348
• CPC Class Codes: G01S 17/42 Simultaneous measurement of distance and other co-ordinates indirect measurement G01S17/46
• CPC Class Codes: G01S 17/58 Velocity or trajectory determination systems; Sense-of-movement determination systems
• CPC Class Codes: G01S 17/89 for mapping or imaging
• CPC Class Codes: G01S 17/93 for anti-collision purposes
• CPC Class Codes: G01S 7/4802 using analysis of echo signal for target characterisation; Target signature; Target cross-section
• CPC Class Codes: G01S 7/4811 common to transmitter and receiver
• CPC Class Codes: G01S 7/4817 relating to scanning

Abstract

Provided is a range finder. The range finder comprises a light-emitting unit, a light-receiving unit, a reflection mirror, an actuator, and a controller. The light-emitting unit emits a light pulse, and a light-receiving unit detects reflected light incident thereto. The reflection minor reflects the light pulse emitted from the light-emitting unit to a measurement space, and reflecting the reflected light reflected by an object in the measurement space so that the reflected light is incident to the light-receiving unit. The actuator allows the reflection minor to move. The controller obtains distance information from a signal detected by the light-receiving unit, and obtains location information from the actuator.

Claims

1. A range finder comprising:

a light-emitting unit emitting a light pulse;

a light-receiving unit detecting reflected light incident thereto;

a reflection minor reflecting the light pulse emitted from the light-emitting unit to a measurement space, and reflecting the reflected light reflected by an object in the measurement space so that the reflected light is incident to the light-receiving unit;

an actuator allowing the reflection minor to move; and

a controller obtaining distance information from a signal detected by the light-receiving unit, and obtaining location information from the actuator.

2. The range finder according to claim 1, wherein the reflection mirror moves in a first direction and a second direction.

3. The range finder according to claim 1, wherein the controller stores the distance information and the location information by the frame or transmits the distance information and the location information to an external device by the frame.

4. The range finder according to claim 1, wherein the controller varies at least one of a frequency of the light pulse, a velocity at which the reflection mirror moves, and a range within which the reflection minor moves depending on an operating mode.

5. The range finder according to claim 2, wherein the light pulse is emitted to a location moved in a horizontal direction as the reflection mirror moves in the first direction, and the light pulse is emitted to a location moved in a vertical direction as the reflection mirror moves in the second direction.

6. The range finder according to claim 2, wherein the actuator comprises:

a rotating member moving to the first direction while supporting the reflection mirror such that the reflection minor is movable to the second direction;

a minor mount supporting the reflection mirror; and

a vertical moving body connected with the mirror mount and moving vertically to allow the reflection mirror to rotate in the second direction.

7. The range finder according to claim 6, wherein the mirror mount is coupled to the vertical moving body to be movable to the first direction, and allows the reflection mirror to move to the second direction by a hinge operation as the vertical moving body moves vertically.

8. The range finder according to claim 1, wherein a virtual rotational axis allowing the reflection mirror to move to a first direction and another virtual rotational axis allowing the reflection minor to move to a second direction are perpendicular to each other.

9. The range finder according to claim 3, wherein the controller combines location information and distance information of a plurality of frames to calculate new location information and distance information.

10. The range finder according to claim 3, wherein the controller compares location information and distance information of a plurality of frames to calculate movement or moving velocity of an object located in the measurement space.

11. The range finder according to claim 4, wherein the controller performs at least one of decreasing a moving velocity at which the reflection mirror moves around a vertical axis, decreasing a velocity or a range in which the reflection minor moves around a horizontal axis, and decreasing a pulse frequency of the light pulse when the operating mode is a long distance measurement mode, and performs at least one of increasing a moving velocity at which the reflection mirror moves around a vertical axis, increasing a velocity or a range in which the reflection mirror moves around a horizontal axis, and increasing a pulse frequency of the light pulse when the operating mode is a short distance measurement mode.

12. The range finder according to claim 1, wherein the controller replaces the location information by location information aligned in a horizontal direction and a vertical direction in the measurement space, and recognizes the object using the aligned location information and the distance information of the object.

13. The range finder according to claim 12, wherein the measurement space is divided into small regions each having a virtual reference point, and location information of an object located in each small region is replaced by location information of the reference point.

14. The range finder according to claim 1, wherein the controller maps the location information to new location information, and recognizes the object using the new location information and the distance information of the object.

15. A method for finding a range, the method comprising:

emitting a light pulse to a measurement space and detecting reflected incident light reflected by an object to obtain location information and distance information of the object; and

varying a direction in which the light pulse is emitted to obtain location information and distance information of the object.

16. The method according to claim 15, comprising emitting the light pulse to a direction moved to at least one of a first direction and a second direction perpendicular to the first direction to obtain the location information and the distance information of the object.

17. The method according to claim 16, wherein the light pulse moves to one of the first and second directions and then moves to the other direction.

18. The method according to claim 16, wherein the light pulse simultaneously moves to both the first direction and the second direction.

19. The method according to claim 15, wherein a direction in which the light pulse is emitted by a reflection mirror is varied.

20. The method according to claim 15, wherein the location information and the distance information are stored by the frame.

21. The method according to claim 20, comprising obtaining and storing the location information and the distance information for a plurality of frames, and combining the location information and the distance information of the plurality of frames to calculate new location information and new distance information.

22. The method according to claim 21, comprising comparing the location information and the distance information of the plurality of frames to calculate a movement or a moving velocity of an object located in the measurement space.

23. The method according to claim 15, comprising:

inputting an operating mode; and

varying at least one of a frequency of the light pulse, a displacement velocity in the direction in which the light pulse is emitted, and a displacement range in the direction in which the light pulse is emitted depending on the operating mode to obtain location information and distance information of the object.

24. The method according to claim 23, comprising:

performing at least one of decreasing a displacement velocity in a horizontal direction parallel to the direction in which the light pulse is emitted, decreasing a displacement velocity or a displacement range in a vertical direction perpendicular to the direction in which the light pulse is emitted, and decreasing a pulse frequency of the light pulse when the operating mode is a long distance measurement mode; and

performing at least one of increasing a displacement velocity in a horizontal direction parallel to the direction in which the light pulse is emitted, increasing a displacement velocity or a displacement range in a vertical direction perpendicular to the direction in which the light pulse is emitted, and increasing a pulse frequency of the light pulse when the operating mode is a short distance measurement mode.

25. The method according to claim 15, comprising:

inputting an operating mode; and

changing the direction in which the light pulse is emitted every frame when the operating mode is a precise measurement mode; and

maintaining the same direction in which the light pulse is emitted every frame when the operating mode is a movement measurement mode.

26. A method for finding a range, the method comprising:

emitting a light pulse to a measurement space and detecting reflected incident light reflected by an object to obtain location information and distance information of the object;

mapping the location information to new location information; and

measuring a distance of the object using the new location information and the distance information.

27. The method according to claim 26, wherein the mapping of the location information comprises mapping a location corresponding to the location information according to a distance from the new location information.

28. The method according to claim 26, wherein the new location information comprises location information aligned in at least one of a horizontal direction and a vertical direction.

29. The method according to claim 26, wherein the measurement space is divided into small regions each having a virtual reference point, and location information of an object located in each small region is replaced by location information of the reference point.