Ultrasound is sound at frequencies that are inaudible to human ears. Well-known applications are underwater (SONAR) and non-invasive medical imaging. Ultrasound is also in use today for reliable 1D distance measurement when we park our cars.

Sonair is developing a 3D distance sensor which provides autonomous robots with omnidirectional depth sensing. We call this new technology ADAR (acoustic detection and ranging)

It operates by emitting a burst of ultrasound and then analyzing the signals received by an array of receivers. This gives a 3D view of the area in front of the robot, up to a range of 5 meters.

The innovation is made possible by the integration of piezoelectric actuation in MEMS (micro electro mechanical system). The MEMS transducers are a proprietary Sonair design and manufactured by the SINTEF MiNaLab.

The transducers, made of silicon, are ready for mass production. They have an acoustic impedance which is well matched to air, and above all, they are of millimeter size. As opposed to commercially available transducers, they can be placed in an array with a separation corresponding to half an ultrasonic pulse wavelength. This opens for image reconstruction of the full volume in front of the array by methods known from medical ultrasound.

The imaging method is called beamforming. It's the backbone of processing for SONAR and RADAR, as well as in medical ultrasound imaging.

Sonair’s innovation lies in combining wavelength-matched transducers with cutting-edge software for beamforming and object recognition algorithms. This innovation makes 3D spatial information available simply by transmitting sound and listening.

By using 3D ultrasonic imaging in robotics applications, Sonair delivers safe navigation, miniaturization, cost efficiency, and low power consumption compared to other methods for creating 3D images.