A first arithmetic circuit computes a propagation velocity of an ultrasonic wave based on a first time difference between an output timing, at which an ultrasonic element outputs an ultrasonic wave, and a reference timing, at which a comparator circuit outputs a detection signal on reflection off a distal end of a reference pipe, and a length of the reference pipe. A period circuit sets a propagation path detection period to detect a liquid level timing, at which the comparator circuit outputs the detection signal on reflection off the liquid level, based on a longest and shortest propagation path lengths and the propagation velocity. A second arithmetic circuit computes the length of the propagation path based on a second time difference, which is between the liquid level timing and the output timing during the propagation path detection period, and the propagation velocity.

A transmission/reception control device is configured to control transmission and reception in an ultrasonic sensor. The ultrasonic sensor includes an ultrasonic transducer. The ultrasonic transducer is configured to transmit a probe wave as an ultrasonic wave and receive a reception wave. The reception wave includes a reflected wave of the probe wave. The transmission/reception control device includes a transmission frequency setting unit, a reception signal processing unit, and an object detection unit. The transmission frequency setting unit sets a frequency of the probe wave to a transmission frequency different from a resonance frequency of the ultrasonic transducer. The reception signal processing unit processes a reception result of the reception wave based on the probe wave transmitted with the transmission frequency. The object detection unit detects the object based on a result of processing by the reception signal processing unit.

A shut-off device for a fluid includes a housing conducting the fluid, an inflow opening provided in the housing, an outflow opening provided in the housing, a flow channel formed in the housing between the inflow opening and the outflow opening, and a blocking device arranged in the flow channel. The blocking device has a blocking body receptacle and a blocking body movable in the blocking body receptacle. The flow cross-section for the fluid in the blocking device, and thus in the flow channel, can be changed by moving the blocking body in the blocking body receptacle. A reliable detection of the position of the blocking body is ensured in that an ultrasonic measuring device is arranged in or aligned on the housing such that the position of the blocking body can be determined by means of the ultrasonic measuring device.

A system for small space positioning comprises a transmitting element at a fixed and known location, which transmitting a modulated continuous wave, for example an ultrasonic wave, having a continuous carrier signal part and a base-band signal modulated thereon. The transmitting element transmits the modulated continuous wave over a range in which an object to be positioned may appear. A receiving element receives signals transmitted by the transmitting device and reflected by the object, and a position detection element determines a position of the object from analysis of both the carrier signal part and the base-band signal received from the reflected signal.

The invention relates to a temperature measuring device for measurement of the external temperature of the ambient air in a vehicle, wherein the temperature measuring device is disposed in a flow path of an air flow and the air flow can be generated from ambient air of the vehicle both through speed-dependent wind resistance of the vehicle and/or wind and also through a compressor unit disposed in the flow path.

A vehicle system includes a processor having a memory. The processor is programmed to receive a first distance signal output by a radar sensor and calibrate an ultrasound sensor in accordance with the first distance signal output by the radar sensor. A method includes receiving a first distance signal output by a radar sensor, receiving a second distance signal output by an ultrasound sensor, and calibrating the ultrasound sensor in accordance with the first distance signal output by the radar sensor.

An object detection apparatus includes a sensor module including a sensor, and a controller that controls the sensor and generates output information, based on a signal that the sensor outputs; and a detector that determines presence or absence of the object, based on the output information. The detector executes a reference object detection process of detecting a reference object existing at a predetermined position within the detection range, by comparing the output information and predetermined reference information, and, when the reference object is detected, executes a correction process of correcting at least one of the output information or a parameter for the sensor, based on the reference information and reference object information that is information indicative of the reference object in the output information.

The invention relates to a method for operating an ultrasonic sensor (4) of a vehicle (1), in which a sound transducer element (11) of the ultrasonic sensor (4) is excited with a predetermined excitation signal, wherein the excitation signal has a predetermined current amplitude, an electrical test voltage (U) at the sound transducer element (11) resulting from the excitation signal is measured, and a diagnosis of the ultrasonic sensor (4) is carried out on the basis of the test voltage (U), wherein the ultrasonic sensor (4) is excited with the excitation signal in a measuring mode for the transmission of an ultrasonic signal, the electrical test voltage (U) is measured during the transmission, on the basis of the electrical test voltage (U) a reduced diagnosis is carried out, wherein the ultrasonic sensor (4) either continues to be operated in the measuring mode or is operated in a diagnostic mode for a complete diagnosis, depending on a result of the reduced diagnosis.

In a drive device for driving an ultrasonic transmitter, a drive signal generating unit generates a drive signal for driving the ultrasonic transmitter, based on a base signal having a plurality of unit frequency signals arranged in a time series, corresponding to respective codes forming a code sequence. When a first unit frequency signal and a second unit frequency signal chronologically adjacent to it are switched in a discontinuously switching state that is different from a continuously switching state where the first and second unit frequency signals are switched such that a target frequency for a transmission frequency changes continuously at a substantially constant rate, the drive signal generating unit shifts the frequency in at least a switching portion immediately after start of the second unit frequency signal, in a same direction as a direction of frequency change from the first unit frequency signal to the second unit frequency signal.

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.