Trailer estimation improvement

1. A trailer-detection system configured to detect a trailer towed by a host-vehicle, said system comprising:

a radar-sensor used to detect a radar-signal indicative of an object proximate to the host-vehicle;

an angle-detector used to determine a trailer-angle relative to the host-vehicle of a trailer towed by the host-vehicle; and

a controller in communication with the angle-detector and the radar-sensor, said controller configured to determine a trailer-presence of the trailer based on the radar-signal and the trailer-angle;

determine a sensing-boundary that defines a blind-zone of an operator of the host-vehicle;

determine a trailer-boundary within the sensing-boundary based on the radar-signal;

adjust the sensing-boundary based on the trailer-angle when the host-vehicle is turning;

adjust the trailer-boundary based on the adjusted sensing-boundary; and

adjust the blind-zone based on the adjusted trailer-boundary to maintain the blind-zone proximate to the trailer-boundary.

2. The system in accordance with claim 1 , wherein where the controller is further configured to determine a trailer-presence when the trailer is not directly behind the host-vehicle.

3. The system in accordance with claim 2 , wherein the trailer-angle of zero degrees is defined as a trailer-longitudinal-axis being parallel to a host-vehicle-longitudinal-axis, and the trailer-presence is determined when the trailer-angle is greater than five degrees.

4. The system in accordance with claim 1 , wherein the system includes an alert-device detectable by an operator of the host-vehicle, and the controller is further configured to activate the alert-device when the object detected is not the trailer.

5. The system in accordance with claim 1 , wherein the angle-detector includes a yaw-sensor used to determine a yaw-rate of the host-vehicle, and the trailer-angle is determined based on the yaw-rate.

6. The system in accordance with claim 1 , wherein the controller is further configured to use the radar-sensor to determine a relative-velocity of a tracked-target associated with the trailer, wherein an expected-location of the tracked-target is determined based on the trailer-angle.

7. The system in accordance with claim 1 , wherein the controller determines a length of the trailer based on the radar-signal.

8. The system in accordance with claim 1 , wherein the controller determines a width of the trailer based on the radar-signal.

9. The system in accordance with claim 6 , wherein the controller determines a distance from a trailer-hitch to a trailer-axle based on the radar-signal.

10. A method to detect a trailer towed by a host-vehicle, said method comprising:

receiving a radar-signal from a radar-sensor, said radar-signal indicative of an object proximate to the host-vehicle;

receiving an indication of a trailer-angle of a trailer towed by the host-vehicle from an angle-detector;

determining, with a controller in communication with the radar-sensor and the angle-detector, a trailer-presence of the trailer based on the radar-signal and the trailer-angle;

determining, with the controller, a sensing-boundary that defines a blind-zone of an operator of the host-vehicle;

determining, with the controller, a trailer-boundary within the sensing-boundary based on the radar-signal;

adjusting, with the controller, the sensing-boundary based on the trailer-angle when the host-vehicle is turning;

adjusting, with the controller, the trailer-boundary based on the adjusted sensing-boundary; and

adjusting, with the controller, the blind-zone based on the adjusted trailer-boundary to maintain the blind-zone proximate to the trailer-boundary.

11. The method in accordance with claim 10 , wherein the step of determining the trailer-presence is performed when the trailer is not directly behind the host-vehicle.

12. The method in accordance with claim 11 , wherein the trailer-angle of zero degrees is defined as a trailer-longitudinal-axis being parallel to a host-vehicle-longitudinal-axis, and the trailer-presence is determined when the trailer-angle is greater than five degrees.

13. The method in accordance with claim 10 , wherein the system further includes an alert-device in communication with the controller, wherein the method further includes the step of activating the alert-device detectable by an operator of the host-vehicle when the object detected is not the trailer.

14. The method in accordance with claim 10 , wherein the system further includes a yaw-sensor in communication with the controller, wherein the method further includes the step of determining a yaw-rate of the host-vehicle using the yaw-sensor, and the trailer-angle is determined based on the yaw-rate.

15. The method in accordance with claim 10 , wherein the method includes determining a relative-velocity of a tracked-target associated with the trailer using the radar-sensor, and the trailer-angle based on the relative-velocity.

16. The method in accordance with claim 10 , wherein determining the trailer-boundary includes determining a length of the trailer based on the radar-signal.

17. The method in accordance with claim 10 , wherein determining the trailer-boundary includes determining a width of the trailer based on the radar-signal.

18. The method in accordance with claim 10 , wherein the method includes determining a distance from a trailer-hitch to a trailer-axle based on the radar-signal.