Method and apparatus for measuring distance
A distance measuring method and apparatus are provided. The distance measuring apparatus emits a transmission signal while changing a frequency over time, receives a reception signal from an object in response to the transmission signal being reflected from the object, samples a beat frequency indicating a difference between a frequency of the transmission signal and a frequency of the reception signal in a sampling range that changes based on the beat frequency, and determines a distance to the object based on the sampling.
1. A distance measuring method comprising:
emitting a transmission signal while changing a frequency over time;
receiving a reception signal from an object, in response to the transmission signal being reflected from the object;
adjusting a sampling frequency range to be a first sampling frequency range and sampling a beat frequency in the first sampling frequency range in response to the beat frequency being a first beat frequency;
adjusting the sampling frequency range to be a second sampling frequency range and sampling the beat frequency in the second sampling frequency range in response to the beat frequency being a second beat frequency; and
determining a distance to the object based on the sampling,
wherein the beat frequency indicates a difference between the frequency of the transmission signal and a frequency of the reception signal,
wherein the first sampling frequency range is less than the second sampling frequency range, and
wherein the first beat frequency is less than the second beat frequency.
2. The distance measuring method of claim 1 , wherein the frequency of the transmission signal changes with time.
3. The distance measuring method of claim 1 , wherein the frequency of the transmission signal linearly changes with time for a single period.
4. The distance measuring method of claim 1 , wherein the determining of the distance comprises calculating the distance to the object based on the difference between the frequency of the transmission signal and the frequency of the reception signal.
5. The distance measuring method of claim 1 , further comprising
converting an original signal having a low frequency to the transmission signal having a high frequency, based on a carrier frequency, and
converting the reception signal to the original signal based on the carrier frequency.
6. The distance measuring method of claim 1 , wherein
the transmission signal is transmitted by a radio detection and ranging (RADAR) antenna, and
the reception signal is received by the RADAR antenna.
7. The distance measuring method of claim 1 , wherein the sampling frequency range varies based on the distance of the object from the vehicle.
8. The distance measuring method of claim 1 , further comprising:
narrowing the sampling frequency range, in response to the beat frequency being equal to a threshold value.
9. The distance measuring method of claim 1 , further comprising:
narrowing the sampling frequency range, in response to a decrease in the beat frequency.
10. A non-transitory computer-readable storage medium storing instructions that, when executed by a processor, cause the processor to perform the method of claim 1 .
11. A distance measuring apparatus comprising:
an antenna,
a processor configured to:
emit a transmission signal using the antenna while changing a frequency over time;
receive a reception signal from an object using the antenna in response to the transmission signal being reflected from the object;
adjust a sampling frequency range to be a first sampling frequency range and sample a beat frequency the first sampling frequency range in response to the beat frequency being a first beat frequency, and
adjust the sampling frequency range to be a second sampling frequency range and sample the beat frequency in the second sampling frequency range in response to the beat frequency being a second beat frequency; and
determine a distance to the object based on the sampling,
wherein the beat frequency indicates a difference between a frequency of the transmission signal and a frequency of the reception signal,
wherein the first sampling frequency range is less than the second sampling frequency range and the first beat frequency is less than the second beat frequency.
12. The distance measuring apparatus of claim 11 , wherein the frequency of the transmission signal linearly changes with time for a single period.
13. The distance measuring apparatus of claim 11 , wherein the processor is further configured to determine the distance to the object based on the difference between the frequency of the transmission signal and the frequency of the reception signal.
14. The distance measuring apparatus of claim 11 , further comprising:
an oscillator configured to generate a carrier frequency;
an upconverter configured to convert an original signal having a low frequency to the transmission signal having a high frequency based on the carrier frequency; and
a downconverter configured to convert the reception signal to the original signal based on the carrier frequency.