Method and radar apparatus for detecting target object

1. A radar apparatus mounted to a vehicle and detecting a target object around the vehicle, the radar apparatus comprising:

a signal transmitter/controller configured to variably control transmission start point intervals between transmission start points of transmission signals and transmit a transmission signal at every transmission start point determined by the controlled transmission start point intervals;

a signal receiver configured to receive a reflection signal generated by reflection of a transmitted signal by surroundings;

an interference signal remover configured to remove an interference signal from the received reflection signal by causing the reflection signal to pass through a filter; and

a target object detector configured to detect a target object through signal processing of the received reflection signal from which the interference signal has been removed,

wherein the signal transmitter/controller as configured to control the transmission start point intervals while making at least one of the transmission start point intervals become different from the other transmission start point intervals.

2. The radar apparatus as claimed in claim 1 , wherein the signal transmitter/controller is configured to transmit one transmission signal at every signal processing time set for the signal processing.

3. The radar apparatus as claimed in claim 1 , wherein the signal transmitter/controller as configured variably control the transmission start point intervals by controlling an interval from a start point of a signal processing time to a transmission start point of a corresponding transmission signal when the signal processing time is controlled to have a same fixed value for all transmission signals, and

the signal transmitter/controller as configured to variably control the transmission start point intervals by variably controlling the signal processing time of each transmission signal when the signal processing time is controlled to have a variable value according to each transmission signal.

4. The radar apparatus as claimed in claim 1 , wherein, in the signal processing, the target object detector is configured to perform a Fourier Transform so as to extract a frequency variance according to a distance and a Doppler frequency according to a speed, and calculates a speed and a distance of the target object based on the frequency variance according to the distance and the Doppler frequency according to the speed.

5. The radar apparatus as claimed in claim 1 , wherein the target object detector is configured to perform a tracking of the received signal, so as to count the number of times by which an estimation object estimated as a target object is detected, and determine the estimation object as the real target object when the counted number of times is larger than or equal to a predetermined threshold.

6. The radar apparatus as claimed in claim 1 , wherein the target object detector is configured to perform a tracking of the received signal so as to count the number of times by which an estimation object estimated as a target object is detected, and when the counted number of times is smaller than a predetermined threshold, the target object detector as configured determines the estimation object as a ghost object due to the interference signal and makes a control to prevent the ghost object from being detected as the target object.

7. The radar apparatus as claimed in claim 1 , wherein the signal transmitter/controller is configured to set a transmission frequency band of each transmission signal within an available frequency band while making at least one of all transmission frequency bands become different from the other transmission frequency bands.

8. The radar apparatus as claimed in claim 1 , wherein, after transmission of one transmission signal at a transmission start point, the signal receiver is configured to receive a corresponding reflection signal up to a time point at which a signal reflected by an object located at a predetermined maximum detection distance is received.

9. The radar apparatus as claimed in claim 1 , wherein the interference signal is a transmission signal transmitted from a radar apparatus mounted to another vehicle located around the vehicle.

10. A method for detecting a target object around a vehicle by a radar apparatus mounted to the vehicle, the method comprising:

variably controlling transmission start point intervals between transmission start points of transmission signals such that at least one of the transmission start point intervals becomes different from the other transmission start point intervals, and transmitting a transmission signal at every transmission start point determined according to the controlled transmission start point intervals;

receiving a reflection signal generated by reflection of a transmitted signal by surroundings;

removing an interference signal from the received reflection signal by causing the reflection signal to pass through a filter; and

detecting a target object through signal processing of the received reflection signal from which the interference signal has been removed.

11. The method as claimed in claim 10 , wherein, in transmitting of the transmission signal, the transmission is performed while variably setting a transmission frequency band of each transmission signal within an available frequency band.