Navigation of an Autonomous Vehicle is based on its interaction with the environment, through information acquired by sensors. The perception of the environment is a major issue in autonomous and (semi)-autonomous systems. This work presents the embedded real-time visual perception problem applied to experimental platform. In this way, a robust horizon finding algorithm that finds the horizon line was proposed and applied to generate the navigable area. It permits to investigate dynamically only a small portion of the image (road) ahead of the vehicle. From a dynamic threshold search method based on Otsu segmentation and Hough transform, this system was robust to illumination changes and does not need any contrast adjustments. It can also be used with infrared camera.