Balancing Act: Trading Off Doppler Odometry and Map Registration for Efficient Lidar Localization

Most autonomous vehicles rely on accurate and efficient localization, which is achieved by comparing live sensor data to a preexisting map, to navigate their environment. Balancing the accuracy of localization with computational efficiency remains a significant challenge, as high-accuracy methods often come with higher computational costs. In this paper, we present two ways of improving lidar localization efficiency and study their impact on performance. First, we integrate a lightweight Doppler-based odometry method into a topometric localization pipeline and compare its performance against an iterative closest point (ICP)-based method. We highlight the trade-offs between these approaches: the Doppler estimator offers faster, lightweight updates, while ICP provides higher accuracy at the cost of increased computational load. Second, by controlling the frequency of localization updates and leveraging odometry estimates between them, we demonstrate that accurate localization can be maintained while optimizing for computational efficiency using either odometry method. Our experimental results show that localizing every 10 lidar frames strikes a favourable balance, achieving a localization accuracy below 0.05 meters in translation and below 0.1 degrees in orientation while reducing computational effort by over 30% in an ICP-based pipeline. We quantify the trade-off of accuracy to computational effort using over 100 kilometers of real-world driving data in different on-road environments.