TOA-based lateral distance measurement system using UWB impulse radio

Lateral distance between two traffic participants is an important context for intelligent transportation systems for realizing a collision prediction system. Obtaining lateral distance requires costly hardware, prohibiting traffic participants such as pedestrians and/or bicyclists to receive benefits of lateral distance information for securing their safety. In this paper, a time-of-arrival (TOA) based bilateration is proposed for estimating relative lateral distance using ultra-wideband impulse radio (UWB-IR). Ranging error of UWB-IR systems affecting the estimation accuracy of lateral distance is coped with applying a low pass filter to angular data. Experimental results show that the estimation error is reduced from 8 m to 3 m when the relative distance between a target vehicle and a pedestrian is less than 15 m, using a portable UWB-IR system with 30 cm ranging accuracy.