US Patent 9340227 Vehicle lane keep assist system

A lane keep assist system for a vehicle includes a forward facing camera and an image processor. The forward facing camera is disposed at a vehicle and has a forward field of view exterior of the vehicle. The image processor is operable to process image data captured by the forward facing camera. The lane keep assist system is operable to process image data to determine lane markers in the field of view and to determine a time to lane crossing value. The lane keep assist system determines a first time to lane crossing value via a first algorithm and a second time to lane crossing value via a second algorithm. The lane keep assist system is operable to apply a steering signal to adjust the steering of the vehicle at least in part responsive to the determined first and second time to lane crossing values.