The subject matter of this specification can be embodied in, among other things, a position sensor system that includes a sensor housing defining a first cavity having a first face, a fluid effector including an actuator housing having an inner surface defining a second cavity, and a moveable body having a second face and configured for reciprocal movement within the second cavity, an acoustic transmitter system configured to emit a first emitted acoustic waveform toward the first face, and emit a second emitted acoustic waveform toward the second face, and an acoustic receiver system configured to detect a first reflected acoustic waveform based on a first reflection of the first emitted acoustic waveform based on the first face, and detect a second reflected acoustic waveform based on a second reflection of the second emitted acoustic waveform based on the second face.

An object detection device includes: a transmitter transmitting a transmission wave to an outside including a road surface; a receiver receiving a reflected wave of the transmission wave being reflected by an object as a reception wave; a CFAR processor acquiring a CFAR signal at a predetermined detection timing by CFAR processing based on a value of a first processing target signal based on a reception wave received at the detection timing and an average value of values of second processing target signals based on the reception waves received in predetermined sections before and after the detection timing; and an estimator estimating an absorption and attenuation value corresponding to the average value based on a road surface reflection estimation expression that defines a relation between the average value and the absorption and attenuation value in advance.

In an embodiment an ultrasonic transducer includes a container having an opening, a base and a wall, a piezoelectric disk arranged within the container on the base, a cover closing the container and an electronics system integrated in the cover, wherein the electronics system makes electrical contact with the piezoelectric disk and is configured to control and to read the piezoelectric disk.

An ultrasonic element generates an ultrasonic wave and converts an input ultrasonic wave into an electric signal. A transmission circuit outputs a drive signal to the ultrasonic element. A comparator circuit outputs a first detection signal when the electric signal becomes larger than a threshold value and outputs a second detection signal when the electric signal becomes smaller than the threshold value. An arithmetic circuit computes a distance of a propagation path of the ultrasonic wave based on a time difference between an output timing, at which the ultrasonic element outputs of the ultrasonic wave, and a liquid level timing, at which the comparator circuit outputs the first detection signal, and based on a propagation speed of the ultrasonic wave. A storage unit stores a time difference between the first detection signal and the second detection signal. The transmission circuit increases the drive signal, as the time difference decreases.

The present invention discloses a vehicle ultrasonic sensor control system including an ultrasonic sensor including an ultrasonic transducer generating ultrasonic waves and a control module controlling driving frequency of the ultrasonic waves emitted from the ultrasonic transducer, wherein a plurality of ultrasonic sensors are mounted on the outside of the vehicle; and a control unit setting a plurality of driving frequencies with a guard-band formed in between and controlling a control module so that the plurality of ultrasonic sensors emit and receive ultrasonic waves having driving frequencies different from each other.

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.

An object sensing apparatus includes an object sensing unit to sense an object using a direct wave, being a reflected wave received by a sensor having transmitted a probing wave among a plurality of ultrasonic sensors, and an indirect wave, being a reflected wave received by a sensor different from the sensor having transmitted the probing wave among the ultrasonic sensors, and a temperature change detection unit to detect a predetermined temperature change state where temperature change of a predetermined value or more has occurred or a possibility of the temperature change occurs in an ambient temperature of the moving object. When the predetermined temperature change state is detected by the temperature change detection unit, the object sensing unit performs sensing suppression control not to sense the object using the indirect wave or to make it difficult to sense the object using the indirect wave.