Granted Patent B2

US 9,041,592 · App. 13/650,893 · Granted May 26, 2015

Abstract

Claims (32)

1. A method of detecting an object using a radar sensor, the method comprising:

determining a minimum value and a maximum value of at least one feature vector for a target object or a minimum value and a maximum value of a combination of the at least one feature vector for the target object based on a displacement between each of at least one background feature vector of a radar signal reflected from a background when the target object does not exist in the back round and at least one feature vector of a radar signal reflected from the target object when the target object exists in the background, in different environment conditions;

storing in a database each of the at least one background feature vector and the minimum value and the maximum value of the at least one feature vector for the target object or the minimum value and the maximum value of the combination of the at least one feature vector for the target object, in the different environment conditions;

selecting the most similar environment condition by comparing at least one feature vector of a radar signal reflected from a background of a monitoring area with the stored at least one background feature vector when the radar sensor is installed; and

selecting a minimum value and a maximum value of at least one feature vector for the target object corresponding to the selected environment condition or a minimum value and a maximum value of a combination of the at least one feature vector for the target object corresponding to the selected environment condition as a reference minimum value and a reference maximum value;

receiving at least one radar signal reflected from the object in the monitoring area;

converting the received at least one radar signal to at least one signal in a frequency domain;

extracting at least one feature from the at least one signal in the frequency domain for a predetermined time; and

identifying the object by comparing the extracted at least one feature with the reference minimum value and the reference maximum value selected from the database.

2. The method of claim 1 , wherein the extracting the at least one feature comprises:

generating a frequency spectrogram based on the at least one signal; and

extracting the at least one feature vector from the frequency spectrogram.

3. The method of claim 2 , wherein the at least one feature vector comprises at least one of a signal periodicity, a frequency bandwidth, and an energy intensity.

4. The method of claim 1 , wherein the at least one feature vector comprises at least one of a signal periodicity, a frequency bandwidth, and an energy intensity.

5. The method of claim 1 , further comprising:

estimating a distance to the object based on the at least one radar signal; and

detecting a motion of the object from a distance change of the object over time.

6. The method of claim 1 , wherein the identifying the object comprises determining the object as the target object when the at least one extracted feature vector is included between the reference minimum value and the reference maximum value corresponding to the selected environment condition.

7. A radar sensor comprising:

a signal converter which converts at least one radar signal reflected from an object to at least one signal in a frequency domain;

a feature extractor which extracts at least one background feature vector of a radar signal reflected from a background when a target object does not exist in the background and at least one feature vector of a radar signal reflected from the target object when the target object exists in the background, in different environment conditions;

a database which stores each of the at least one background feature vector and a minimum value and a maximum value of the at least one feature vector the target object or a minimum value and a maximum value of a combination of the at least one feature vector for the target object which are determined based on a displacement between each of the at least one background feature vector of the radar signal reflected from the background when the target object does not exist in the background and the at least one feature vector of the radar sign reflected from the background when the target object exists in the background, in the different environment conditions; and

a determiner which selects the most similar environment condition by comparing at least one feature vector of a radar signal reflected from a background of a monitoring area with the stored at least one background feature vector when the radar sensor is installed, and selects a minimum value and a maximum value of at least one feature vector for the target object corresponding to the selected environment condition or a minimum value and a maximum value of a combination of the at least one feature vector for the target object corresponding to the selected environment condition as a reference minimum value and a reference maximum value,

wherein the signal converter converts at least one radar signal reflected from an object in the monitoring area to at least one signal in a frequency domain,

wherein the feature extractor extracts at least one feature of the object from the at least one signal in the frequency domain for a predetermined time,

wherein the database stores reference minimum values and reference maximum values corresponding to the different environment conditions, and

wherein the determiner identifies the object by comparing the extracted at least one feature with the reference minimum value and the reference maximum value.

8. The radar sensor of claim 7 , wherein the feature extractor generates a frequency spectrogram based on the at least one signal and extracts the at least one feature vector from the frequency spectrogram.

9. The radar sensor of claim 7 , wherein the at least one feature vector comprises at least one of a signal periodicity, a frequency bandwidth, and an energy intensity.

10. The radar sensor of claim 7 , further comprising:

a distance estimator which estimates a distance to the object based on the at least one radar signal; and

a motion detector which detects a motion of the object from a distance change of the object over time.

Assignments (7)