nRTIS: Low-Cost Real-Time 3D Sonar Imaging Circular Array Supporting Beamforming for Industrial Applications

Abstract

Conventional ultrasonic inspection systems rely on phased arrays and high-performance computing hardware, making them costly, bulky, and unsuitable for portable or embedded use. In this work, we present nRTIS (nano Real-Time 3D Imaging Sonar), a compact ultrasonic sensing platform built around a circular array of MEMS microphones and a central ultrasonic transducer. The device achieves real-time acquisition through an RP2350 microcontroller and high-speed USB transfer. We validate the system using both simulations and controlled experiments: point spread function (PSF) simulations demonstrate beamforming resolution and sidelobe suppression, while reflector measurements confirm robust data acquisition. These results highlight the potential of nRTIS for scalable industrial applications such as weld inspection, pipe mapping, and robotic navigation.