Radar device and control method
The disclosure relates to a radar device and a control method. Specifically, according to the disclosure, a radar device comprises a transmitter controlling to transmit a frequency-modulated transmission signal, a receiver receiving a reception signal which is the transmitted transmission signal reflected by an object, an angle estimator estimating a first angle for a position of the object, with respect to a host vehicle, during one frame, based on a result obtained by performing fast Fourier transform (FFT) on the reception signal and estimating a second angle which is a virtual angle for the position of the object during a plurality of frames, and a controller calibrating the first angle by comparing the estimated first angle and the estimated second angle.
1. A radar device, comprising:
a transmitter controlling to transmit a frequency-modulated transmission signal;
a receiver receiving a reception signal which is the transmitted transmission signal reflected by an object;
an angle estimator estimating a first angle for a position of the object, with respect to a host vehicle, during one frame, based on a result obtained by performing fast Fourier transform (FFT) on the reception signal and estimating a second angle which is a virtual angle for the position of the object based on the results obtained by performing FFT on the reception signals during a plurality of frames; and
a controller calibrating the first angle by comparing the estimated first angle and the estimated second angle,
wherein the frame is defined as a time period from a transmission of the transmission signal to a retransmission of the transmission signal after analyzing the reception signal reflected by the object, and
wherein the number of the frames for estimating the second angle is differently set according to at least one of a driving velocity, a driving course and a driving place of the host vehicle.
2. The radar device of claim 1 , wherein the angle estimator calculates a range-velocity index for the reception signal and estimates the first angle and the second angle for the object based on the range-velocity index.
3. The radar device of claim 1 , wherein the angle estimator estimates an angle for the object based on a measurement included in a preset object candidate area among measurements included in the received reception signal.
4. The radar device of claim 1 , wherein the frame is a time from the transmission of the transmission signal to retransmission of the transmission signal after analyzing the reception signal reflected by the object and received, and receiving information for the reception signal.
5. The radar device of claim 1 , wherein the second angle is an average of angles for the object estimated in each of the plurality of frames.
6. The radar device of claim 5 , wherein the controller calibrates the first angle to the second angle.
7. The radar device of claim 5 , wherein the second angle is an average calculated by excluding a largest angle and a smallest angle among angles estimated in each of the plurality of frames.
8. The radar device of claim 1 , wherein the controller calibrates the first angle to the second angle if a difference between the first angle and the second angle is a threshold or more.
9. The radar device of claim 1 , wherein the controller calibrates the first angle to an intermediate value between the first angle and the second angle if a difference between the first angle and the second angle is less than a threshold.
10. The radar device of claim 1 , wherein if the plurality of frames include N frames, and an angle for the object estimated in each of an Nth frame, an N−1th frame, and an N−2th frame is increased or decreased while maintaining a predetermined value, the angle estimator estimates an angle for the object estimated in the Nth frame as the second angle.
11. A radar control method, comprising:
a transmission/reception step controlling to transmit a frequency-modulated transmission signal and receive a reception signal which is the transmitted transmission signal reflected by an object;
an angle estimation step estimating a first angle for a position of the object, with respect to a host vehicle, during one frame, based on a result obtained by performing fast Fourier transform (FFT) on the reception signal and estimating a second angle which is a virtual angle for the position of the object based on the results obtained by performing FFT on the reception signals during a plurality of frames; and
an angle calibration step calibrating the first angle by comparing the estimated first angle and the estimated second angle,
wherein the frame is defined as a time period from a transmission of the transmission signal to a retransmission of the transmission signal after analyzing the reception signal reflected by the object,
wherein the number of the frames for estimating the second angle is differently set according to at least one of a driving velocity, a driving course and a driving place of the host vehicle.
12. The radar control method of claim 11 , wherein the angle estimation step calculates a range-velocity index for the reception signal and estimates the first angle and the second angle for the object based on the range-velocity index.
13. The radar control method of claim 11 , wherein the angle estimation step estimates an angle for the object based on a measurement included in a preset object candidate area among measurements included in the received reception signal.
14. The radar control method of claim 11 , wherein the frame is a time from the transmission of the transmission signal to retransmission of the transmission signal after analyzing the reception signal reflected by the object and received, and receiving information for the reception signal.
15. The radar control method of claim 11 , wherein the second angle is an average of angles for the object estimated in each of the plurality of frames.
16. The radar control method of claim 15 , wherein the angle calibration step calibrates the first angle to the second angle.
17. The radar control method of claim 15 , wherein the second angle is an average calculated by excluding a largest angle and a smallest angle among angles estimated in each of the plurality of frames.
18. The radar control method of claim 11 , wherein the angle calibration step calibrates the first angle to the second angle if a difference between the first angle and the second angle is a threshold or more.
19. The radar control method of claim 11 , wherein the angle calibration step calibrates the first angle to an intermediate value between the first angle and the second angle if a difference between the first angle and the second angle is less than a threshold.
20. The radar control method of claim 11 , wherein if the plurality of frames include N frames, and an angle for the object estimated in each of an Nth frame, an N−1th frame, and an N−2th frame is increased or decreased while maintaining a predetermined value, the angle estimation step estimates an angle for the object estimated in the Nth frame as the second angle.