Discriminating Multiple Nearby Targets Using Single-Ping Ultrasonic Scene Mapping

We present a software simulation and a hardware proof of concept for a compact low-power lightweight ultrasonic echolocation design that is capable of imaging a 120 field of view with a single ping. The sensor uses a single transmitter and a linear array of ten microphones, followed by a bank of eight spatiotemporal filters to determine the bearing angle of returned echoes. The sensor is capable of detecting multiple objects with a single omnidirectional ping, even if their echoes interfere with each other at the microphone array. The hardware implementation detects the bearing of nearby objects with an rms accuracy of 1.6° and can reliably detect a 70-cm-long 5-cm-diameter metal table leg at a range of 3 m. Stronger reflectors, such as building corners, can be reliably detected at a range of 9 m.