Method and system for tracking position of vehicle using ultrasonic sensor in rear-cross blind spot

1. A system for tracking a tracking-target vehicle, comprising:

a rear-cross sensor disposed on a rear portion of a subject vehicle and composed of at least one of a radar, a lidar, or a camera;

a front ultrasonic sensor disposed on a front portion of the subject vehicle;

a rear ultrasonic sensor disposed on the rear portion of the subject vehicle; and

a controller comprising at least one processor,

wherein

the controller is configured to set a range of a dangerous area of a rear-cross blind spot of the subject vehicle differently for (i) passive passing in which the tracking-target vehicle passes the subject vehicle and (ii) active passing in which the subject vehicle passes the tracking-target vehicle, and

the controller is configured to

compare a measured distance to the tracking-target vehicle by the front ultrasonic sensor and a measured distance to the tracking-target vehicle by the rear ultrasonic sensor, and

determine whether the tracking-target device enters or exits the dangerous area for each of the passive passing and active passing, using a result of the comparing.

2. The system of claim 1 , further comprising:

a display configured to display information about entry or exit to a driver when the tracking-target vehicle enters or exits the dangerous area as the result of determining by the controller.

3. The system of claim 2 , wherein the dangerous area is set further forward in the passive passing than in the active passing.

4. The system of claim 1 , wherein the controller configured to

track the tracking-target vehicle in a rear-cross sensor area using the rear-cross sensor; and

calculate a position of a specific portion of the tracking-target vehicle while the measured distance to the tracking-target vehicle by the rear ultrasonic sensor increases with the measured distance to the tracking-target vehicle by the front ultrasonic sensor maintained at a constant level, and

wherein whether the tracking-target vehicle exits the dangerous area is determined on the basis of whether the position of the specific portion of the tracking-target vehicle exits a reference position.

5. A method of tracking a position of a tracking-target vehicle from a subject vehicle comprising a rear-cross radar sensor, which is composed of at least one of a radar, a lidar, or a camera, a front ultrasonic sensor, and a rear ultrasonic sensor, the method comprising:

comparing a measured distance to the tracking-target vehicle by the front ultrasonic sensor and a measured distance to the tracking-target vehicle by the rear ultrasonic sensor; and

determining whether the tracking-target vehicle enters or exits a dangerous area in a rear-cross blind spot of the subject vehicle using a result of the comparing,

wherein

a range of the dangerous area is set differently for (i) passive passing in which the tracking-target vehicle passes the subject vehicle and (ii) active passing in which the subject vehicle passes the tracking-target vehicle, and

whether the tracking-target vehicle enters or exits the range of the dangerous area is determined for each of the passive passing and the active passing.

6. The method of claim 5 , wherein the dangerous area is set further forward in the passive passing than in the active passing.

7. The method of claim 5 , wherein further comprising, in the passive passing:

tracking the tracking-target vehicle in a rear-cross sensor area using the rear-cross sensor; and

calculating a position of a specific portion of the tracking-target vehicle while the measured distance to the tracking-target vehicle by the rear ultrasonic sensor increases with the measured distance to the tracking-target vehicle by the front ultrasonic sensor maintained at a constant level,

wherein whether the tracking-target vehicle exits the dangerous area is determined on the basis of whether the position of the specific portion of the tracking-target vehicle exits a reference position.

8. The method of claim 7 , wherein the specific portion of the tracking-target vehicle is a rear bumper.

9. The method of claim 7 , wherein the reference position is a frontmost horizontal line of the dangerous area.

10. The method of claim 5 , further comprising, in the active passing:

calculating a position of a specific portion of the tracking-target vehicle while the measured distance to the tracking-target vehicle by the front ultrasonic sensor increases with the measured distance to the tracking-target vehicle by the rear ultrasonic sensor maintained at a constant level as a result of comparing the measured distance to the tracking-target vehicle by the front ultrasonic sensor and the measured distance to the tracking-target vehicle by the rear ultrasonic sensor;

determining that the tracking-target vehicle has entered the dangerous area when the specific portion of the tracking-target vehicle enters a reference position; and

tracking the tracking-target vehicle in a rear-cross sensor area using the rear-cross sensor.

11. The method of claim 10 , wherein the specific portion of the tracking-target vehicle is a front bumper.

12. The method of claim 10 , wherein the reference position is a frontmost horizontal line of the dangerous area.

13. The method of claim 5 , further comprising, displaying information about entry or exit to a driver when the tracking-target vehicle enters or exits the dangerous area.

14. A method of tracking a position of a tracking-target vehicle from a subject vehicle comprising a rear-cross radar sensor, which is composed of at least one of a radar, a lidar, or a camera, a front ultrasonic sensor, and a rear ultrasonic sensor in passive passing in which the tracking-target vehicle passes the subject vehicle, the method comprising:

tracking the tracking-target vehicle in a rear-cross sensor area using the rear-cross sensor;

comparing a measured distance to the tracking-target vehicle by the front ultrasonic sensor and a measured distance to the tracking-target vehicle by the rear ultrasonic sensor;

calculating a position of a specific portion of the tracking-target vehicle while the measured distance to the tracking-target vehicle by the rear ultrasonic sensor increases with the measured distance to the tracking-target vehicle by the front ultrasonic sensor maintained at a constant level; and

determining whether the tracking-target vehicle exits a dangerous area in a rear-cross blind spot of the subject vehicle,

wherein whether the tracking-target vehicle exits the dangerous area is determined on the basis of whether the position of the specific portion of the tracking-target vehicle exits a reference position.

15. The method of claim 14 , wherein the specific portion of the tracking-target vehicle is a rear bumper.

16. The method of claim 14 , wherein the reference position is a frontmost horizontal line of the dangerous area.

17. A method of tracking a position of a tracking-target vehicle from a subject vehicle comprising a rear-cross radar sensor, which is composed of at least one of a radar, a lidar, or a camera, a front ultrasonic sensor, and a rear ultrasonic sensor in active passing in which the subject vehicle passes the tracking-target vehicle, the method comprising:

comparing a measured distance to the tracking-target vehicle by the front ultrasonic sensor and a measured distance to the tracking-target vehicle by the rear ultrasonic sensor;

calculating the position of a specific portion of the tracking-target vehicle while the measured distance to the tracking-target vehicle by the front ultrasonic sensor increases with the measured distance to the tracking-target vehicle by the rear ultrasonic sensor maintained at a constant level as a result of comparing the measured distance to the tracking-target vehicle by the front ultrasonic sensor and the measured distance to the tracking-target vehicle by the rear ultrasonic sensor;

determining that the tracking-target vehicle enters the dangerous area when the position of the specific portion of the tracking-target vehicle enters a reference position; and

tracking the tracking-target vehicle in a rear-cross sensor area using the rear-cross sensor.

18. The method of claim 17 , wherein the specific portion of the tracking-target vehicle is a front bumper, and

wherein the reference position is a frontmost horizontal line of the dangerous area.