Hough transform based ego‐velocity estimation in automotive radar system

Abstract In general, the velocity estimated through the automotive radar is the relative velocity between the ego‐vehicle and the target. To estimate the absolute velocity of the ego‐vehicle (i.e. ego‐velocity), it is necessary to get help from other automotive sensors, such as cameras and lidars. In this letter, therefore, a method for estimating the ego‐velocity is proposed using only radar sensor data. To estimate the ego‐velocity, stationary targets in the detection result have to be identified because the velocity relative to the stationary target can be directly converted to the ego‐velocity. In the proposed method, the radar data is first processed to extract the relative distance from the ego‐vehicle to the target, relative velocity between the ego‐vehicle and the target, and angle between the ego‐vehicle and the target. Then, the detected targets are represented in the angle‐velocity domain because moving and stationary targets in this domain exhibit different characteristics. In other words, the moving targets are randomly placed, but the stationary targets exist around a specific line. Finally, the Hough transformation is applied to automatically determine the line, and the ego‐velocity is calculated from the transform result. The proposed method shows a maximum error of 2.4% in the velocity range of 30–90 km/h