From grid maps to Parametric Free Space maps — A highly compact, generic environment representation for ADAS

We propose a highly compact, generic representation of the driving environment, so-called Parametric Free Space (PFS) maps, specifically suitable for future Advanced Driver Assistance Systems (ADAS) and bring them into line with existing metric representations known from mobile robotics. PFS maps combine a closed contour description of arbitrarily shaped outer free space boundaries with a representation of inner free space boundaries, respectively objects, by geometric primitives. A real-time capable algorithm is presented that obtains the representation by building upon an intermediate occupancy grid map-based environment representation generated from an automotive radar and a stereo camera. The proposed representation preserves all relevant information contained in a grid map - thus remaining function-independent - in a much more compact way, which is considered particularly important for the transmission via low data-rate automotive communication interfaces. Examples are shown in real traffic scenarios.