Distance measuring device and method thereof

Patent metadata

Field	Value
Publication number	US-9995576-B2
Application number	US-201414572488-A
Country	US
Kind code	B2
Filing date	Dec 16, 2014
Priority date	Dec 18, 2013
Publication date	Jun 12, 2018
Grant date	Jun 12, 2018

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.

First claim

What is claimed is:

1. A distance measuring device comprising:
a light transmitter configured to emit one of a first distance measuring beam and a second distance measuring beam selectively onto an object;
a light receiver configured to sense light reflected by the object and collected by the distance measuring device;
a rotating substrate configured to rotate about a vertical line, wherein the light transmitter and the light receiver are fixed to the rotating substrate such that the light transmitter and the light receiver rotate together when the rotating substrate rotates about the vertical line;
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 when the first distance measuring beam is emitted from the light transmitter;
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 when the second distance measuring beam is emitted from the light transmitter;
a controller configured to:
cause the light transmitter to emit the first distance measuring beam by transmitting a first control signal to the light transmitter;
cause the light transmitter to emit the second distance measuring beam by transmitting a second control signal to the light transmitter, the first control signal and the second control signal having different frequencies;
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; and

a main substrate on which the controller, the first distance calculator, and the second distance calculator are disposed.

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 greater than the reference distance, the controller determines the final distance by assigning the weight to the value of the second distance.

3. 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.

4. 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).

5. The distance measuring device according to claim 1 , wherein the main substrate and the rotating substrate are connected by a power and communication connector.

6. The distance measuring device according to claim 5 , wherein power is supplied to the rotating substrate via the power and communication connector.

7. 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.

8. The distance measuring device according to claim 7 , wherein the weight is differently set according to a difference between the reference distance and the value of the first distance.

9. The distance measuring device according to claim 8 , 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.

10. A distance measurement method for a distance measuring device, comprising:
emitting, by a light transmitter, one of a first distance measuring beam and a second distance measuring beam selectively onto an object;
sensing, by a light receiver, light reflected by the object and collected by the distance measuring device, wherein the light transmitter and the light receiver are fixed to a rotating substrate configured to rotate about a vertical line such that the light transmitter and the light receiver rotate together when the rotating substrate rotates about the vertical line;
calculating, by a first distance calculator, a value of a first distance between the distance measuring device and the object through the sensed light using a first measurement scheme when the first distance measuring beam is emitted from the light transmitter;
calculating, by a second distance calculator, a value of a second distance between the distance measuring device and the object through the sensed light using a second measurement scheme when the second distance measuring beam is emitted from the light transmitter;
comparing, by a controller, 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,
wherein the first distance measuring beam is emitted by the light transmitter when a first control signal is received by the light transmitter from the controller,
wherein the second distance measuring beam is emitted by the light transmitter when a second control signal is received by the light transmitter from the controller,
wherein the first control signal and the second control signal have different frequencies, and
wherein the controller, the first distance calculator, and the second distance calculator are disposed on a main substrate.

11. The distance measurement method according to claim 10 , 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.

12. The distance measurement method according to claim 10 , 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.

13. The distance measurement method according to claim 10 , 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. The distance measurement method according to claim 10 , wherein the weight is differently set according to a difference between the reference distance and the value of the first distance.

15. The distance measurement method according to claim 14 , 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 lager value as the difference between the reference distance and the value of the first distance becomes large.

Assignees

• Lg Electronics Inc

Inventors

• Lee Jejong
• Cho Sungjin
• Lee Gyeongeon
• Cha Sunghoon

Classifications

• G01S7/497

  Means for monitoring or calibrating · CPC title

• G01S17/42

  Simultaneous measurement of distance and other co-ordinates (indirect measurement G01S17/46) · CPC title

• G01S7/4808

  Evaluating distance, position or velocity data · CPC title

• G01S17/87

  Combinations of systems using electromagnetic waves other than radio waves · CPC title

• G01S17/48

  Active triangulation systems, i.e. using the transmission and reflection of electromagnetic waves other than radio waves · CPC title