A sensor and a method for detecting a position of the sensor relative to a guide surface, comprising a housing and an electronic analysis device which outputs measurement values for the position of the guide surface on the basis of the measurement signals. The sensor contains an ultrasonic transducer array, each of the two outer ends of which is additionally equipped with a respective reference ultrasonic transducer and a respective reflector surface flush with the reference piezo disc at a distance from the base side, said ultrasonic transducers and reflector surfaces being inclined by 45° relative to the base side and pointing towards one another, thus forming a reference measurement path with a known length between the two reference ultrasonic transducers. In the method for detecting the relative position, the measurement values are corrected with respect to environmental influences by measurements in a reference path.

An object detection device includes a transceiver configured to transmit/receive an ultrasonic wave; a drive signal generation unit configured to generate a drive signal for driving the transceiver; a transmitter circuit configured to cause the transceiver to transmit a probe wave, which is an ultrasonic wave, by driving the transceiver based on the drive signal; and a receiver circuit configured to generate a reception signal corresponding to a reception result of the ultrasonic wave of the transceiver, wherein the drive signal generation unit is configured to generate the drive signal so that frequency of the probe wave changes over time. The device further includes: a voltage measurement unit configured to measure a voltage signal generated in the transceiver while the transceiver transmits the probe wave with frequency changing over time; and a state determination unit configured to make a state determination regarding the transceiver based on the voltage signal.

In general, the subject matter described in this disclosure can be embodied in methods, systems, and computer-readable devices. An audio processing device plays a source audio signal, including causing the source audio signal to be audibly output by an electroacoustic transducer of a user earpiece. The audio processing device records, while playing the source audio signal, a recorded audio signal using the electroacoustic transducer. The audio processing device identifies one or more parameters that indicate how properties of the user earpiece affect playing of the source audio signal, at least one of the parameters being temperature dependent. The audio processing device determines a temperature value estimated to cause the source audio signal that was played by the audio processing device to result in the recorded audio signal, accounting for changes to the source audio signal that occur due to the one or more parameters.

An ultrasonic transducer having a piezoelectric element for use on a vehicle is disclosed. The transducer has a control and evaluation circuit for generating a control voltage for the piezoelectric element, which generates and emits an ultrasonic signal based on the control voltage, and for outputting an output signal on the basis of an echo signal received at the piezoelectric element. A gyrator circuit is included for providing a compensation inductance for adapting the control and evaluation circuit, for compensating for a parasitic connection capacitance of the piezoelectric element. The gyrator circuit has a variable compensation inductance. A method for compensating for an ultrasonic transducer having a piezoelectric element for adapting a reception sensitivity is also disclosed. The method involves recording a measurement variable for adapting the reception sensitivity, and compensating for the ultrasonic transducer by changing the compensation inductance of the gyrator circuit based on the recorded measurement variable.

A measuring device is provided, having a housing having a circuit board and processor; a first transducer arranged on a surface of the housing and configured to transmit an ultrasonic pulse towards a target surface; a second transducer adjacent to the first transducer configured to receive a reflection of the ultrasonic pulse off of the target surface; and a thermistor on the surface of the housing adjacent to the first and second transducers and configured to measure air temperature surrounding the device. The processor of the device is configured to measure a time duration between transmitting the ultrasonic pulse by the first transducer and receiving the reflection of the ultrasonic pulse by the second transducer, and to determine a distance between a ground surface upon which the device is resting and the target surface based at least upon the measured time duration and the measured air temperature.

Techniques are disclosed for systems and methods to provide accurate and reliable compact sonar systems for mobile structures. A sonar system includes multiple sensor channels, each comprising a sonar transmitter and a sonar receiver, and a logic device configured to provide control signals and receive sensor signals from the sensor channels. The logic device is configured to provide transmission signals to sonar transducer assemblies, where signal patterns of the transmission signals are differentiated based at least in part on frequency content. Acoustic returns are processed using the signal patterns to reduce inter-channel pickup between the sensor channels. Resulting sonar data and/or imagery may be displayed to a user and/or used to adjust a steering actuator, a propulsion system thrust, and/or other operational systems of the mobile structure.

Disclosed are a displacement sensor-combined electrostatic measurement potential sensor, and an operation method therefor, wherein a displacement sensor and an electrostatic measurement potential sensor are provided in one device, and operations thereof are linked; a distance to an electrified body measured by the displacement sensor is stored in a main controller to automatically correct a measurement value of the amount of static electricity obtained by the potential sensor; a change in capacitance that the displacement sensor affects with respect to the potential sensor is applied to correction of an error in a result value measured by the potential sensor, so that it is possible to solve the problem of malfunction according to detection of the electrified body, wherein the distance thereto is changed, and accurately measure the potential; and by manufacturing the device in a small size, easy use is achieved and manufacturing and installation costs are reduced.

An ultrasonic distance measuring device retrieves an ultrasonic wave propagation speed from a correlation between an output of a medium sensor and a corresponding ultrasonic wave propagation speed. The ultrasonic distance measuring device sets a propagation path detection period for detecting a detection signal, which corresponds to the ultrasonic wave reflected by a liquid surface, based on a longest propagation path length and a shortest propagation path length between the liquid surface and the retrieved propagation speed of the ultrasonic wave. The ultrasonic distance measuring device calculates a distance of the propagation path based on a time difference between a detection timing of the detection signal and an output timing of the ultrasonic wave in a propagation path detection period, and the propagation speed of the ultrasonic wave.