System for recognizing trailer of vehicle and method thereof

1. A trailer recognizing device of a vehicle, the device comprising:

a sensor configured to sense a distance value between the vehicle and a rear object;

a controller configured to:

receive the distance value from the sensor in a go-straight state of the vehicle to determine whether the rear object is detected,

predict a first hitch angle based on a vehicle model and a second hitch angle based on the distance value, and

match the first hitch angle with the second hitch angle to determine whether the trailer is connected; and

a trailer mode controller configured to control a trailer mode of the vehicle, when it is determined that the trailer is connected.

2. The trailer recognizing device of claim 1 , wherein the controller includes:

an offset correction device configured to receive an internal signal to correct a yaw rate offset;

a rear object detection device configured to detect the rear object;

a vehicle model hitch angle prediction device configured to predict the first hitch angle based on the vehicle model;

a sensor hitch angle prediction device configured to predict the second hitch angle based on the sensor;

a hitch angle matching device configured to match the first hitch angle with the second hitch angle; and

a trailer determination device configured to:

determine whether the trailer is connected in response to an output of the hitch angle matching device, and

generate the control signal.

3. The trailer recognizing device of claim 2 , wherein the offset correction device includes:

a stop state determination device configured to determine whether the vehicle is a stop state, in response to the internal signal;

a yaw rate correction device configured to apply a first yaw rate value at a point in time when the vehicle is in the stop state to correct the yaw rate offset;

a yaw rate calculation device configured to calculate a second yaw rate value based on the vehicle model; and

a go-straight determination device configured to determine whether the vehicle moves straight.

4. The trailer recognizing device of claim 3 , wherein the yaw rate calculation device is configured to calculate the second yaw rate value based on a two-degree-of-freedom vehicle model.

5. The trailer recognizing device of claim 3 , wherein the go-straight determination device is configured to:

compare the first yaw rate value corrected by the yaw rate correction device with the second yaw rate value calculated by the yaw rate calculation device, and

determine that the vehicle moves straight when each of the first and second yaw rate values is within a specific value.

6. The trailer recognizing device of claim 3 , wherein the rear object detection device is configured to receive the distance value from the sensor when a determination result of the go-straight determination device indicates that the vehicle moves straight.

7. The trailer recognizing device of claim 2 , wherein the rear object detection device is configured to average distance values to set a distance of a trailer layout, when a difference between a previously measured distance value and the distance value is maintained less than or equal to a specific value.

8. The trailer recognizing device of claim 2 , wherein the vehicle model hitch angle prediction device is configured to:

predict a radius of turn, using a kinematic vehicle model, and

calculate the first hitch angle by reflecting a wheelbase value of the trailer.

9. The trailer recognizing device of claim 2 , wherein the vehicle model hitch angle prediction device is configured to calculate a hitch angle again by reflecting an updated wheelbase value of a trailer, when an update signal is received from the trailer determination device.

10. The trailer recognizing device of claim 2 , wherein the trailer determination device is configured to output an update signal for updating a wheelbase value of the trailer, to the vehicle model hitch angle prediction device, when a difference value between the first hitch angle and the second hitch angle is not less than a specific value.

11. The trailer recognizing device of claim 2 , wherein the sensor hitch angle prediction device is configured to:

define a change value as a difference of a distance of a trailer layout set by the rear object detection device, and

calculate a hitch angle changed using the distance value.

12. The trailer recognizing device of claim 11 , wherein the sensor hitch angle prediction device is configured to:

calculate a distance value between fixed points of the sensor and the calculated change value, and

average hitch angles, which are changed, to calculate the second hitch angle.

13. The trailer recognizing device of claim 12 , wherein the sensor hitch angle prediction device is configured to:

average remaining hitch angles other than an unmeasured distance value of the distance value to calculate the second hitch angle.

14. The trailer recognizing device of claim 2 , wherein the hitch angle matching device includes:

a vehicle speed determination device configured to determine whether a vehicle speed of the vehicle is not greater than a specific speed;

a hitch angle determination device configured to determine whether the first hitch angle and the second hitch angle are within a specific range, to apply a dead zone in a go-straight state of the vehicle;

a hitch angle sign determination device configured to determine whether signs of the first hitch angle and the second hitch angle are the same; and

a hitch angle comparator configured to compare a difference value between the first hitch angle and the second hitch angle.

15. The trailer recognizing device of claim 14 , wherein the hitch angle comparator is configured to determine that the trailer is connected to activate a connection signal, when the difference value between the first hitch angle and the second hitch angle is not greater than a specific value.

16. The trailer recognizing device of claim 2 , wherein the controller further includes a reset device configured to control whether to reset the sensor and the controller in response to an output of the trailer determination device and the rear object detection device.

17. A trailer recognizing method of a vehicle, the method comprising:

receiving a distance value from a sensor in a go-straight state of the vehicle to determine whether an object is detected at a rear side of the vehicle;

predicting a first hitch angle based on a vehicle model and predicting a second hitch angle based on the distance value;

matching the first hitch angle with the second hitch angle to determine whether the trailer is connected; and

controlling a trailer mode of the vehicle, when it is determined that the trailer is connected.

18. The method of claim 17 , wherein the receiving a distance value includes:

receiving an internal signal of the vehicle to correct a yaw rate offset when the vehicle is in a stop state; and

averaging distance values to set the averaged distance value to a distance of a trailer layout, when a difference between a previously measured distance value and the distance value sensed by the sensor is maintained less than or equal to a specific value.

19. The method of claim 17 , wherein the matching the first hitch angle includes:

determining whether signs of the first hitch angle and the second hitch angle are the same when a vehicle speed of the vehicle is not greater than a specific speed; and

determining that the trailer is connected, when a difference of the two hitch angle values is maintained for a specific period of time to be less than or equal to a specific value when the difference of the two hitch angle values is not greater than the specific value.