Steering assist apparatus in response to lane departure direction and vehicle in neighboring lane

1. A steering assist apparatus of a vehicle, for applying steering force to a steering mechanism of the vehicle so that the vehicle travels on a target traveling position in a traveling lane; comprising:

a lane set unit configured to recognize an environment ahead the vehicle and set the traveling lane;

a deviation determination unit configured to determine whether the vehicle has a deviation tendency from the traveling lane;

a steering control unit configured to apply steering force in a deviation avoiding direction to the steering mechanism when it is determined that the vehicle has a deviation tendency;

a neighboring vehicle detection unit configured to detect a neighboring vehicle, which travels ahead of the vehicle and in a lane next to the traveling lane of the vehicle, based on the recognized environment; and

an approach degree calculation unit configured to calculate an approach degree of the neighboring vehicle toward the vehicle based on the neighboring vehicle detection,

wherein the steering control unit performs a steering force reduction control for reducing the steering force in the deviation avoiding direction according to an increase of the approach degree when the deviation determination unit determines that the vehicle has a deviation tendency in a direction away from the traveling lane of the neighboring vehicle.

2. The steering assist apparatus according to claim 1 , further comprising:

a distance detection unit configured to detect a distance between the vehicle and the neighboring vehicle in a traffic direction of the vehicle;

a relative velocity detection unit configured to detect a relative velocity of the neighboring vehicle with respect to the vehicle; and

an end time estimation unit configured to estimate an end time of a parallel travel of the vehicle and the neighboring vehicle based on the distance and the relative velocity,

wherein the steering control unit ends the steering force reduction control based on the end time estimated by the end time estimation unit.

3. The steering assist apparatus according to claim 2 , further comprising:

a side surface recognition unit configured to recognize a front end of a side surface in the neighboring vehicle based on a group of images of the neighboring vehicle captured by a plurality of imaging units,

wherein the distance detection unit and the relative velocity detection unit detect the distance and the relative velocity respectively by referring to the recognized front end.

4. The steering assist apparatus according to claim 1 , further comprising:

a decelerating operation detection unit configured to detect a decelerating operation by a driver,

wherein the steering control unit reduces the steering force at a greater degree when the decelerating operation is detected than the case where the decelerating operation is not detected.

5. The steering assist apparatus according to claim 1 , wherein

the steering control unit performs a steering force increase control for increasing the steering force in the deviation avoiding direction according to an increase of the approach degree when the deviation determination unit determines that the vehicle has a deviation tendency toward the traveling lane of the neighboring vehicle.

6. The steering assist apparatus according to claim 1 , wherein

the steering control unit applies steering force, in which a predetermined gain is multiplied to a lateral displacement of the vehicle from the traveling lane, to the steering mechanism, and switches the gain to a predetermined value smaller than the normal gain when the approach degree of the neighboring vehicle is kept greater than a predetermined threshold value for longer than a predetermined period of time.