Disclosed sensors, sensor controllers, and sensor control methods enhance transducer performance using a model-based equalization method that can be performed in the field. One illustrative method for operating a piezoelectric-based sensor includes: sensing a response of a piezoelectric transducer as a function of frequency; deriving parameter values of an equivalent circuit for the piezoelectric transducer from the response; using a squared magnitude of the equivalent circuit's transfer function to determine a system level selectivity; and adapting at least one operating parameter of the sensor based on the system level selectivity. One illustrative controller for a piezoelectric transducer includes: a transmitter that drives the piezoelectric transducer; a receiver that senses a response of the piezoelectric transducer; and a processing circuit coupled to the transmitter and to the receiver to calibrate the transducer using the foregoing method.

Disclosed sensors, sensor controllers, and sensor control methods enhance transducer performance using a model-based equalization method that can be performed in the field. One illustrative method for operating a piezoelectric-based sensor includes: sensing a response of a piezoelectric transducer as a function of frequency; deriving parameter values of an equivalent circuit for the piezoelectric transducer from the response; using a squared magnitude of the equivalent circuit's transfer function to determine a system level selectivity; and adapting at least one operating parameter of the sensor based on the system level selectivity. One illustrative controller for a piezoelectric transducer includes: a transmitter that drives the piezoelectric transducer; a receiver that senses a response of the piezoelectric transducer; and a processing circuit coupled to the transmitter and to the receiver to calibrate the transducer using the foregoing method.

A self-testing measuring system includes at least three modes: an operating mode and at least two test modes. In a third test mode, a digital signal generating unit stimulates the digital input circuit directly by means of test signals. In a second test mode, the digital signal generating unit stimulates the analogue signal string and the digital input circuit by means of test signals. In a first test mode, the digital signal generating unit stimulates the analogue signal string, the measuring unit (typically an ultrasound transducer) and the digital input circuit by means of test signals, thereby allowing this signal string to be tested. In the operating mode, the digital signal generating unit stimulates the analogue signal string, the measuring unit (typically an ultrasound transducer) and the digital input circuit by means of output signals, thereby allowing the signal string to be monitored for parameter compliance.

A self-testing measuring system includes at least three modes: an operating mode and at least two test modes. In a third test mode, a digital signal generating unit stimulates the digital input circuit directly by means of test signals. In a second test mode, the digital signal generating unit stimulates the analogue signal string and the digital input circuit by means of test signals. In a first test mode, the digital signal generating unit stimulates the analogue signal string, the measuring unit (typically an ultrasound transducer) and the digital input circuit by means of test signals, thereby allowing this signal string to be tested. In the operating mode, the digital signal generating unit stimulates the analogue signal string, the measuring unit (typically an ultrasound transducer) and the digital input circuit by means of output signals, thereby allowing the signal string to be monitored for parameter compliance.

A method for providing an estimate of a time-of-flight between an ultrasonic signal emitted by a device and an ultrasonic echo signal returned by a target object hit by the ultrasonic signal and received at the device. The method includes acquiring the ultrasonic echo signal thereby obtaining an electric echo signal; determining a noise power of the electric echo signal; determining an envelope signal indicative of an envelope of the electric echo signal; determining a portion of the envelope signal based on at least one operative parameter, the at least one operative parameter being determined according to Particle Swarm Optimization; processing the portion of the envelope signal and the noise power of the echo ultrasonic signal according to an Unscented Kalman Filter to obtain an estimate of the envelope signal, wherein the estimate of the envelope signal is a regenerated version of the envelope signal being regenerated from the portion of the envelope signal, the processing being based on at least one Unscented Kalman Filter parameter determined according to the Particle Swarm Optimization, and providing the estimate of the time-of-flight according to the estimate of the envelope signal.

A system includes first, second, and third microphones configured to receive sound waves from a source of the sound waves. The system includes a memory configured to store first, second, and third phase difference maps for the first and second microphones, the second and third microphones, and the third and first microphones. The system includes a processor configured to measure first, second, and third phase differences between the sound waves received from the source by the first and second microphones, the second and third microphones, and the third and first microphones; receive the first, second, and third phase difference maps from the memory; and identify a location of the source of the sound waves based on the first, second, and third phase differences and the first, second, and third phase difference maps for the first and second microphones, the second and third microphones, and the third and first microphones.

An object detection device includes a transceiver that transmits ultrasonic waves encoded with frequency modulation and receives an ultrasonic wave and outputs a reception signal, a first quadrature detector that generates and outputs a complex reception signal based on quadrature detection of the reception signal, a second quadrature detector that generates and outputs a complex reference signal based on quadrature detection of the reference signal, a correlation filter that performs correlation detection between the complex reception signal and the complex reference signal and outputs a correlation signal, and a code determiner that determines a code included in the reception signal based on the correlation signal.

A ranging device includes transducers, a transmission circuit, a reception circuit, a transfer data generation circuit, and a transfer circuit. The transmission circuit causes the transducers to transmit transmission waves. The reception circuit outputs a received signal obtained by digitizing a reflected wave of the transmission wave with a sampling frequency equal to or more than a frequency of the transmission wave. The generation circuit separates, into a target period and a non-target period, time-series received signals. The target period is a period in which a wave height is equal to or more than a threshold. The non-target period is a period in which a wave height is less than the threshold. The generation circuit performs thinning-out processing on received signals in the non-target period and generates waveform information indicating a waveform received by the transducer. The transfer circuit outputs the waveform information.

A ranging device includes transducers, a transmission circuit, a reception circuit, a transfer data generation circuit, and a transfer circuit. The transmission circuit causes the transducers to transmit transmission waves. The reception circuit outputs a received signal obtained by digitizing a reflected wave of the transmission wave with a sampling frequency equal to or more than a frequency of the transmission wave. The generation circuit separates, into a target period and a non-target period, time-series received signals. The target period is a period in which a wave height is equal to or more than a threshold. The non-target period is a period in which a wave height is less than the threshold. The generation circuit performs thinning-out processing on received signals in the non-target period and generates waveform information indicating a waveform received by the transducer. The transfer circuit outputs the waveform information.

An example apparatus includes a transducer to receive a reference signal and a reflected signal, the reflected signal being the reference signal after being reflected of a target; a filter to generate a band-pass reference signal and a band-pass reflected signal by filtering (A) reference signal samples associated with the reference signal and (B) reflected signal samples associated with the reflected signal; a correlator to generate a first correlation by correlating the reference signal samples with the reflected signal samples and a second correlation by correlating the band-pass reference signal with the band-pass reflected signal; and a delay estimator to determine a distance to the target based on the first correlation (coarse delay) and the second correlation (fine delay) and output a signal including the distance to the target.