From what I’ve seen a relatively simple radar is what many automakers are using as the main sensor for AEB. You can see them on the front grille, usually a smal

From what I’ve seen a relatively simple radar is what many automakers are using as the main sensor for AEB. You can see them on the front grille, usually a small rectangular patch in the plastic about the size of paperback book. Though those have had their problems too. Obviously easier for them to detect other vehicles but harder for pedestrians.