Air-Coupled FMCW Ultrasonic Sensor for High Resolution 3D perception

As seamless object detection and localization are getting important in emerging systems, such as autonomous vehicles, robots, and extended reality devices, numerous 3D depth sensors have been developed. However, most of those sensors have focused more on far-distance applications, leaving near-field, including less than 50 cm, as a task for a conventional ultrasonic (US) sensor. Even though the conventional US sensor has many advantages including object detection in near field, it has limited capability on localizing objects and providing 3D point cloud preventing itself from further applications. In order to overcome these limitations, multi input multi output (MIMO) frequency modulated continuous wave (FMCW) method is adopted and demonstrated in this study. Presented computer simulation implies the US 3D object detection with 2.3 mm depth resolution and 0.6 o angular resolution preserving its minimum detection range lower than 5 cm and field-of-view (FoV) wider than 160 o . A novel MIMO US FMCW sensor system composed of commercially available components is implemented and evaluated. For 16 cm ∼ 2 m range, the proposed system shows fair depth and angular resolution (5.5 mm and 2.6 o ) at low sampling rate (overall 480 kHz). This study suggests that ultrasound can be a new modality capable of providing near field 3D point cloud at low system requirement.