Ertis: Real-Time 3D Acoustic Sonar Imaging Using Sparse Microphone Arrays

In recent years, our research group has developed state of the art 3D sonar sensors which use a low-cost MEMS microphone array for real-time acoustic imaging in air. Using this sensor, various robotic applications have been developed, including obstacle avoidance, corridor following and SLAM. The developed sensor is capable of localizing an arbitrary number of reflectors, and generates 2D (range versus azimuth) or 3D (range versus azimuth and elevation) acoustic images of the environment by emitting a broadband, spatially omnidirectional acoustic emission. This emission is reflected back by the environment to the microphone array. Using array beamforming algorithms an acoustic image of the environment is created, which subsequently can be either visualized or used in various control algorithms. In this show-and-tell demonstration we will demonstrate the real-time imaging capabilities of our eRTIS 3D Sonar sensor. Using a ground-truth sensing mechanism using LIDAR, we show the 3D point-clouds generated obtained by analyzing acoustic reflections obtained from our sonar sensor. The overlay of the 3D LIDAR and Sonar point-clouds allows the visitor of the show-and-tell session to experience 3D perception of the world through acoustic imaging. A previous version of this demonstration has been shown on the IEEE Sensors Conference 2019, where we won best demonstration award for our setup. A movie can be found here: https://www.youtube.com/watch?v=NV9Wkc2j6CY