US 12,422,536 B2
Method of operating electro-acoustic transducers, corresponding circuit and device
Francesca Carminati, Agrate Brianza (IT); Marco Passoni, Cornate d'Adda (IT); Beatrice Rossi, Milan (IT); Diego Carrera, Lodi (IT); and Pasqualina Fragneto, Burago di Molgora (IT)
Assigned to STMICROELECTRONICS S.r.l., Agrate Brianza (IT)
Filed by STMICROELECTRONICS S.r.l., Agrate Brianza (IT)
Filed on Jan. 5, 2023, as Appl. No. 18/150,534.
Claims priority of application No. 102022000000464 (IT), filed on Jan. 13, 2022.
Prior Publication US 2023/0221422 A1, Jul. 13, 2023
Int. Cl. G01S 7/526 (2006.01); G01S 15/06 (2006.01); H04R 3/04 (2006.01); H04R 17/10 (2006.01); H04R 29/00 (2006.01)
CPC G01S 7/526 (2013.01) [G01S 15/06 (2013.01); H04R 3/04 (2013.01); H04R 17/10 (2013.01); H04R 29/001 (2013.01); H04R 2201/003 (2013.01)] 18 Claims
OG exemplary drawing
 
1. A method, comprising:
applying, over an excitation interval to a transmitter of an electro-acoustical transducer, an excitation signal that is configured to emit corresponding ultrasound pulses from the transmitter and towards a surrounding space;
acquiring, at a receiver of the electro-acoustical transducer, reflected ultrasound pulses that are reflected in the surrounding space;
generating a reference echo signal, the generating of the reference echo signal including:
determining an oscillation frequency of the transmitter based on a transmitter ringdown signal;
determining an oscillation frequency of the receiver based on a receiver ringdown signal;
performing frequency tuning on the transmitter and the receiver based on the oscillation frequency of the transmitter and the oscillation frequency of the receiver, respectively;
determining a frequency of a maximum displacement in the transmitter ringdown signal by sweeping an input frequency of the transmitter;
performing a frequency tuning of the receiver at the frequency of the maximum displacement in the transmitter ringdown signal;
exciting, with a high voltage corresponding to a non-linear operation zone, the transmitter at the oscillation frequency of the transmitter, and acquiring a corresponding ringdown;
determining a period from the corresponding ringdown;
feeding a trained neural network with a period curve, series parameters of a Butterworth-Van Dyke (BVD) model, and an initial value of the corresponding ringdown;
determining one or more non-linear parameters of the transmitter with the trained neural network; and
predicting the reference echo signal based on the one or more non-linear parameters;
performing a cross-correlation of the reflected ultrasound pulses with the reference echo signal; and
performing a measurement based on the cross-correlation, the measurement including a time of flight of the ultrasound pulses.