Tracking objects with multiple reflections based on ultrasonic transducer raw data using a PDAF

摘要

When mounted on a vehicle bumper, ultrasonic transducer signal contains information from valid objects as well as ground reflections. In order to remove ground echoes, the classic approach is to use thresholds to filter reflections of small amplitude. However, valid object reflections can frequently occur beneath the ground thresholds, reducing the detection rate of the sensor. We present an approach where tracks are initialized only with echoes above the ground thresholds, but updated with all echoes using a PDAF. As objects can often reflect a second echo, we propose a modification of the PDAF to avoid interference between the first echo real object position and the second echo. Simulation and real measurements both show the advantage of our method which improves tremendously the detection rate.