US Patent 11189140 Calibration and detection techniques in haptic systems

Described is a system for producing an acoustic field from a plurality of ultrasonic transducer arrays, each of which has known relative positions and orientations. The acoustic field comprises a carrier wave and a modulated wave. The carrier wave has a plurality of modulated focal areas. A plurality of control points having a known spatial relationship relative to at least one of the plurality of ultrasonic transducer arrays is used. The plurality of ultrasonic transducer arrays are calibrated by using the relative position of each of the plurality of ultrasonic transducer arrays.