DISTANCE MEASURING DEVICE AND METHOD THEREOF

• US 20150168541A1
• Filed: 12/16/2014
• Published: 06/18/2015
• Est. Priority Date: 12/18/2013
• Status: Active Grant

• Current Assignee: LG Electronics, Inc. (LG Corporation)
• Original Assignee: LG Electronics, Inc. (LG Corporation)
• Inventors: CHO, Sungjin, LEE, Jejong, LEE, Gyeongeon, CHA, Sunghoon
• Granted Patent: US 9,995,576 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G01C 3/06 Use of electric means to obtain final indication
• CPC Class Codes: G01S 17/08 for measuring distance only indirect measurement G01S17/46; active triangulation systems G01S17/48
• CPC Class Codes: G01S 17/42 Simultaneous measurement of distance and other co-ordinates indirect measurement G01S17/46
• 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 17/87 Combinations of systems using electromagnetic waves other than radio waves
• CPC Class Codes: G01S 7/4808 Evaluating distance, position or velocity data
• CPC Class Codes: G01S 7/497 Means for monitoring or calibrating

Abstract

A laser distance measuring device and a control method for the same are disclosed. More specifically, disclosed herein are a laser distance measuring device capable of quickly measuring horizontal and vertical distances using laser and a control method for the same. The laser distance measuring device may include a light transmitter, a light receiver, a sensing unit, and a controller configured to perform an control operation to emit split laser through the light transmitter, acquire time difference information indicating a difference between a time to emit the split laser and a time to sense, through the sensing unit, the split laser reflected from a target position, and calculate a distance to the target position using the time difference information.

Claims

1. A distance measuring device comprising:

a light transmitter configured to emit a distance measuring beam onto an object;

a light receiver configured to sense light reflected by the object and collected by the distance measuring device;

a first distance calculator configured to calculate a value of a first distance between the distance measuring device and the object through the sensed light using a first measurement scheme;

a second distance calculator configured to calculate a value of a second distance between the distance measuring device and the object through the sensed light using a second measurement scheme; and

a controller configured to compare the value of the first distance and the value of the second distance with a reference distance, assign a weight according to a result of the comparison, and determine a final distance between the distance measuring device and the object.

2. The distance measuring device according to claim 1, wherein, when both the value of the first distance and the value of the second distance are less than the reference distance, the controller determines the final distance by assigning the weight to the value of the first distance.

3. The distance measuring device according to claim 1, wherein, when both the value of the first distance and the value of the second distance are greater than the reference distance, the controller determines the final distance by assigning the weight to the value of the second distance.

4. The distance measuring device according to claim 2, wherein the weight is differently set according to a difference between the reference distance and the value of the first distance.

5. The distance measuring device according to claim 4, wherein the controller assigns the weight set to a smaller value as the difference between the reference distance and the value of the first distance becomes small, and

assigns the weight set to a larger value as the difference between the reference distance and the value of the first distance becomes large.

6. The distance measuring device according to claim 1, wherein the controller determines the final distance by assigning weights to both the value of the first distance and the value of the second distance.

7. The distance measuring device according to claim 1, wherein the first measurement scheme is triangulation, and the second measurement scheme is Time of Flight (TOF).

8. A distance measurement method for a distance measuring device, comprising:

emitting a distance measuring beam onto an object;

sensing light reflected by the object and collected by the distance measuring device;

calculating a value of a first distance between the distance measuring device and the object through the sensed light using a first measurement scheme;

calculating a value of a second distance between the distance measuring device and the object through the sensed light using a second measurement scheme;

comparing the value of the first distance and the value of the second distance with a reference distance, assigning a weight according to a result of the comparison, and determining a final distance between the distance measuring device and the object.

9. The distance measurement method according to claim 8, wherein the determining of the final distance comprises:

determining the final distance by assigning the weight to the value of the first distance when both the value of the first distance and the value of the second distance are less than the reference distance.

10. The distance measurement method according to claim 8, wherein the determining of the final distance comprises:

determining the final distance by assigning the weight to the value of the second distance when both the value of the first distance and the value of the second distance are greater than the reference distance.

11. The distance measurement method according to claim 8, wherein the weight is differently set according to a difference between the reference distance and the value of the first distance.

12. The distance measurement method according to claim 11, wherein the assigning and determining comprises:

assigning the weight set to a smaller value as the difference between the reference distance and the value of the first distance becomes small; and

assigning the weight set to a larger value as the difference between the reference distance and the value of the first distance becomes large.

13. The distance measurement method according to claim 8, wherein the assigning and determining comprises:

assigning weights to both the value of the first distance and the value of the second distance and determining the final distance.

14. A laser distance measuring device comprising:

a light transmitter;

a light receiver;

a sensing unit; and

a controller configured to perform an control operation to emit split laser through the light transmitter, acquire time difference information indicating a difference between a time to emit the split laser and a time to sense, through the sensing unit, the split laser reflected from a target position, and calculate a distance to the target position using the time difference information.

15. The laser distance measuring device according to claim 14, further comprising a rotation drive unit configured to rotate the light transmitter, the light receiver, the sensing unit, and the controller.

16. The laser distance measuring device according to claim 15, wherein the split laser comprises at least two laser beams emitted along a vertical line, the laser beams being spaced a predetermined distance from each other.

17. The laser distance measuring device according to claim 16, wherein the controller controls the time to emit the split laser.

18. A laser distance measurement method comprising:

emitting line laser through a light transmitter;

acquiring time difference information indicating a difference between a time to emit the line laser and a time to sense, through a sensing unit, the line laser reflected from a target position; and

calculating a distance to the target position using the time difference information.

19. The laser distance measurement method according to claim 18, wherein the line laser is laser having a form of a vertical line with a certain length.

20. The laser distance measurement method according to claim 19, further comprising:

controlling the time to emit the line laser such that the time corresponds to a desired accuracy.