Dense Stereo-Based Robust Vertical Road Profile Estimation Using Hough Transform and Dynamic Programming

This paper proposes a dense stereo-based robust vertical road profile estimation method. The vertical road profile is modeled by a cubic B-spline curve, which is known to be accurate and flexible but difficult to estimate under a large proportion of outliers. To robustly estimate a cubic B-spline curve, the proposed method utilizes a two-step strategy that initially estimates a piecewise linear function and then obtains a cubic B-spline curve based on the initial estimation result. A Hough transform and dynamic programming are utilized for estimating a piecewise linear function to achieve robustness against outliers and guarantee optimal parameters. In the experiment, a performance evaluation and comparison were conducted using three publicly available databases. The result shows that the proposed method outperforms three previous methods in all databases. In particular, its performance is superior to the others in the cases of a large proportion of outliers and road surfaces distant from the ego-vehicle.