Method, and apparatus for measuring distance using radio frequency signal

• US 7,649,490 B2
• Filed: 10/18/2007
• Issued: 01/19/2010
• Est. Priority Date: 12/19/2006
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Park, Jun-ho, Bang, Seok-won, Park, Ji-young
• Primary Examiner(s): Tarcza; Thomas H
• Assistant Examiner(s): Bythrow; Peter M
• Application Number:
  US11/907,947
• Publication Number:
  US 20080143582A1
• Time in Patent Office: 824 Days
• Field of Search: 342 70- 72, 342/118, 342123-125, 342/165, 342/173, 342/174, 340/854.1, 340/854.2, 340/854.6, 701/26, 701/117, 701/223, 701/301, 318/568.12, 901/1, 901/46
• US Class Current: 342/118
• CPC Class Codes: G01S 13/74 Systems using reradiation of radio waves, e.g. secondary radar systems; Analogous systems
• CPC Class Codes: G01S 7/40 Means for monitoring or calibrating

Abstract

Provided are a method, apparatus, and medium for measuring a distance using a radio frequency (RF) signal. The method of measuring a distance includes setting the transmitter power of an RF signal of a signal generating module to a minimum so as to measure the longest distance when no obstacle exists, measuring a distance between the signal generating module and a fixed module using the RF signal whose transmitter power is set to the minimum, if the measured distance between the signal generating module and the fixed module is available, determining that no obstacle exists therebetween, and if the measured distance is not available, determining that an obstacle exists therebetween, and determining the distance according to the result of the determination of existence of an obstacle.

Claims

1. A method for measuring a distance using a radio frequency (RF) signal, the method comprising:

setting a transmitter power of an RF signal of a signal generating module to a minimum so as to measure the longest distance within a region when no obstacle exists between the signal generating module and a fixed module;

measuring a distance between the signal generating module and the fixed module using the RF signal whose transmitter power is set to the minimum;

if the measured distance between the signal generating module and the fixed module is available, determining that no obstacle exists therebetween, and if the measured distance is not available, determining that an obstacle exists therebetween; and

determining the distance according to the result of the determination of existence of an obstacle.

2. The method of claim 1, wherein if it is determined that no obstacle exists, a value of the measured distance is determined as the distance.

3. The method of claim 2, further comprising correcting the value of the measured distance by comparing the value of the measured distance with distance data that is pre-measured with respect to the transmitter power and the distance when the obstacle does not exist.

4. The method of claim 2, further comprising correcting the measured distance by comparing a value of the distance measured when the transmitter power is set to a maximum with distance data that is pre-measured with respect to the distance at a maximum transmitter power when the obstacle does not exist.

5. The method of claim 1, further comprising, if it is determined that the obstacle exists, determining the distance by comparing the distance value measured by increasing the transmitter power so that the measured distance is available, with distance data that is pre-measured with respect to the transmitter power and the distance when the obstacle exists.

6. The method of claim 1, further comprising, if it is determined that the obstacle exists, determining the distance by comparing a value of the distance measured when the transmitter power is set to a maximum with distance data that is pre-measured at a maximum transmitter power when the obstacle does not exist.

7. The method of claim 1, wherein the signal generating module moves with being mounted on a mobile robot.

8. A method of measuring a distance using an RF signal, the method comprising:

setting the transmitter power of an RF signal of a signal generating module to a minimum so that when no obstacle exists in a region between the signal generating module and a fixed module, a longest distance within the region can be measured;

generating the signal by increasing the transmitter power set to the minimum, of the signal, by a preset interval until the transmitter becomes a maximum, and storing the distance values measured between the signal generating module and the fixed module, and the transmitter powers;

using the stored distance values with respect to transmitter powers, if the measured distance is available using the signal at the transmitter power set to the minimum, determining that no obstacle exists between the signal generating module and the fixed module, and if the distance cannot be measured, determining that an obstacle exists; and

determining the distance according to whether or not an obstacle exists.

9. The method of claim 8, wherein if it is determined that no obstacle exists, the mean of the values of the measured distance with respect to the transmitter powers is determined as the distance.

10. The method of claim 9, further comprising correcting the distance, by comparing the mean of the measured distance values with the mean of distance data that is pre-measured with respect to the transmitter power and the distance when the obstacle does not exist.

11. The method of claim 8, wherein if it is determined that the obstacle exists, the distance is determined by comparing the minimum transmitter power at which the measured distance is available, and the mean of the measured distance values, with distance data that is pre-measured with respect to the transmitter power and the distance when the obstacle exists.

12. The method of claim 8, wherein the signal generating module moves with being mounted on a mobile robot.

13. An apparatus for measuring a distance using an RF signal, the apparatus comprising:

a signal generating module to generate an RF signal and to receive back the transmitted signal;

a fixed module at a fixed position to receive the transmitted signal and then, to transmit the received signal;

a distance measuring module to measure the distance between the signal generating module and the fixed module, using the generated signal;

an obstacle determining module to determine whether or not an obstacle exists between the signal generating module and the fixed module; and

a distance determining module to determine the distance using the measured distance value and distance data that is pre-measured with respect to the transmitter power and the distance,

wherein the signal generating module generates an RF signal, by setting the transmitter power of the RF signal to a minimum so that when no obstacle exists between the signal generating module and the fixed module in the region, a longest distance within the region can be measured, and the distance measuring module measures the distance using the generated signal, and if the measured distance is available, the obstacle determining module determines that no obstacle exists between the signal generating module and the fixed module, and if the distance cannot be measured, the obstacle determining module determines that the obstacle exists.

14. The apparatus of claim 13, wherein if the obstacle determining module determines that no obstacle exists, the distance determining module determines the measured distance value as the distance.

15. The apparatus of claim 14, wherein the distance determining module corrects the measured distance value, by comparing the measured distance value with distance data that is pre-measured with respect to the transmitter power and the distance when the obstacle does not exist.

16. The apparatus of claim 14 wherein the distance determining module corrects the measured distance value, by comparing the distance value measured by increasing the transmitter power to a maximum, with distance data that is pre-measured with respect to the distance at the transmitter power set to a maximum when the obstacle does not exist.

17. The apparatus of claim 13, wherein if the obstacle determining module determines that the obstacle does not exist, the distance determining module determines the distance, by comparing the distance value measured by increasing the transmitter power so that the measured distance is available, with distance data that is pre-measured with respect to the transmitter power and the distance.

18. The apparatus of claim 13, wherein the signal generating module moves with being mounted on a mobile robot.

19. The apparatus of claim 13, wherein the distance data that is pre-measured is measured with respect to thickness and type of the obstacle.

20. The apparatus of claim 13, wherein if the obstacle determining module determines that the obstacle exists, the distance determining module determines the distance, by comparing the distance value measured by increasing the transmitter power to a maximum, with distance data that is pre-measured with respect to the distance at the transmitter power set to a maximum when the obstacle exists.

21. An apparatus for measuring a distance using an RF signal, the apparatus comprising:

a signal generating module to generate an RF signal and receiving back the transmitted signal;

a fixed module at a fixed position to receive the transmitted signal and then, to transmit the received signal;

a distance measuring module to measure the distance between the signal generating module and the fixed module, using the generated signal;

a storage module to store the measured distance and the transmitter power;

an obstacle determining module to determine whether or not an obstacle exists between the signal generating module and the fixed module; and

a distance determining module to determine the distance using the measured distance value and distance data that is pre-measured with respect to the transmitter power and the distance,

wherein the signal generating module sets the transmitter power of an RF signal to a minimum so that when no obstacle exists between the signal generating module and a fixed module in a region, a longest distance within the region measured can be measured, and the distance measuring module measures the distance by increasing the transmitter power of the signal by a preset interval until the transmitter power becomes a maximum, and the storage module stores the measured distance values and the corresponding transmitter powers, and if the measured distance is available using the signal generated at the transmitter power set to the minimum, the obstacle determining module determines that no obstacle exists between the signal generating module and the fixed module, and if the distance cannot be measured, the obstacle determining module determines that the obstacle exists.

22. The apparatus of claim 21, wherein if the obstacle determining module determines that the obstacle does not exist, the distance determining module determines the mean of the distance values measured with respect to the transmitter powers.

23. The apparatus of claim 22, wherein the distance determining module corrects the distance, by comparing the mean of the measured distance values with the mean of distance data that is pre-measured with respect to the transmitter power and the distance when the obstacle does not exist.

24. The apparatus of claim 21, wherein if the obstacle determining module determines that the obstacle exists, the distance determining module determines the distance, by comparing the minimum transmitter power at which the measured distance is available and the mean of the measured distance values, with distance data that is pre-measured with respect to the distance at the transmitter power when the obstacle exists.

25. The apparatus of claim 21, wherein the distance data that is pre-measured is measured with respect to thickness and type of the obstacle.