In recent years, short-range sensors like stereo cameras, radar and infrared cameras have become essential components of safety systems and user-friendly convenience systems, such as pre-crash safety or parking assist systems. However, they are generally too expensive to implement on lower-end vehicles. On the other hand, a conventional backup-assistance sonar has a very small coverage area, but it is more cost effective than the above-mentioned sensors.
This paper proposes an effective method to increase the range of detection of conventional sensor with the help of a pseudo-Wigner distribution-based likelihood function. The reflected wave detected by maximizing the p-WD-based likelihood function with respect to the parameter related to the time delay. This method is verified in actual experiment and the maximum detection range was found to be extended by about 2.5 times beyond that of the conventional approach.
