Provided are a three-dimensional (3D) ultrasonic anemometer, a 3D wind velocity measuring method, and a wind turbine. The 3D ultrasonic anemometer includes: an ultrasonic sensor including three pairs of ultrasonic transceivers arranged in different directions, wherein the ultrasonic sensor is installed at a rotation body rotating around a rotation axis and rotates around the rotation axis together with the rotation body; a signal processor outputting a 3D sensed wind velocity sensed by the ultrasonic sensor; and a coordinate converter converting the 3D sensed wind velocity into a 3D fixed wind velocity on a fixed coordinate system by using a rotation angle of the rotation body.

Method and apparatus relating to ultrasound flow probes Measurement of time of flight of ultrasound pulses comprises: transmitting the pulses across a fluid flow; detecting a waveform (200) of the pulses, generating a cross-correlation between the waveform (200) and a tone (210) and identifying a plurality of peaks (220) in the cross-correlation; fitting a curve template (310) to the waveform at locations (300) corresponding to the peaks (220) and identifying the location (330) of the minimum error; performing a further cross-correlation (420) between the waveform (200) and the tone (210) over only a portion of the waveform (200) containing the minimum error location (330); and determining the temporal location corresponding to the maximum (430) of the further cross-correlation (430).

In one embodiment, a system includes a vehicle, one or more probes coupled to the vehicle, and a controller. The vehicle is operable to traverse a distance. The one or more probes are operable to measure wind pressure and generate one or more wind pressure measurements. The controller is operable to receive the one or more wind pressure measurements from the one or more probes, determine a wind angle relative to the vehicle using the one or more wind pressure measurements, and determine a wind speed relative to the vehicle using the one or more wind pressure measurements and the wind angle.

An electronic device may include a housing and a display in the housing. The display may be used as an anemometer to measure the speed of ambient air in the device's environment. In particular, the display may be monitored by a temperature sensor until it reaches an equilibrium temperature, at which point it may be heated by increasing the brightness of the display or using a separate heater. After heating, a cooling response of the display may be measured, and the ambient air speed may be calculated based on the cooling response of the display. Instead of measuring the air speed using the display, other components, such as a pressure sensor, may be used to measure the air speed by heating the components and measuring a cooling response of the components. Multiple temperature sensors may be incorporated into the device to determine a wind direction in addition to air speed.

An apparatus and method for measuring air flow in a duct, e.g. in a ventilation duct, includes a sensor fittable into connection with the duct, the sensor including an ultrasound transmitter and at least two ultrasound receivers, and a control unit to which the ultrasound transmitter and ultrasound receivers are connectable. The control unit is adapted to measure, during the measuring of air flow, the phase difference of an ultrasound signal received at the same moment in time by at least two ultrasound receivers fitted into connection with the duct and, based on the measured phase difference, to determine the flow velocity and/or flow direction of the air. The apparatus is adapted to perform a calibration of the apparatus by transmitting with an ultrasound transmitter at least one calibration signal and by receiving the calibration signal with at least two ultrasound receivers. The apparatus is further adapted to analyze the received calibration signal and based on the analysis to select the parameters to be used in measuring to be such that at least one analysis result of the calibration signal meets predetermined criteria with the parameters.

Provided are a three-dimensional (3D) ultrasonic anemometer, a 3D wind velocity measuring method, and a wind turbine. The 3D ultrasonic anemometer includes: an ultrasonic sensor including three pairs of ultrasonic transceivers arranged in different directions, wherein the ultrasonic sensor is installed at a rotation body rotating around a rotation axis and rotates around the rotation axis together with the rotation body; a signal processor outputting a 3D sensed wind velocity sensed by the ultrasonic sensor; and a coordinate converter converting the 3D sensed wind velocity into a 3D fixed wind velocity on a fixed coordinate system by using a rotation angle of the rotation body.

A method of determining flow speed in a low pressure environment. The method includes obtaining bi-directional acoustic data from a plurality of transducer pairs as a fluid moves relative to the plurality of transducer pairs. The method further includes measuring phase lags corresponding to the bi-directional acoustic data, and determining bi-directional flight times using the phase lags. Additionally, the method includes calculating a flow speed of the fluid corresponding to each transducer pair from the bi-directional flight times. The method includes correcting for at least one of temperature effects, pressure effects, and wake effects, using a system model. The method further includes generating a report including the flow speed of the fluid.

A grain cleaning system for a combine harvester having a transmitter adapted to transmit a base signal at a known frequency and one or more spaced receivers for detecting signals of a different frequency as reflected from airborne grain and other materials within the duct of the grain cleaning system. An Electronic Control Unit modulates the base signal and the reflected signals to obtain Doppler signals or frequencies from which an average particle velocity is determined. The particle velocity is used as an input parameter for the generation of control signals for the adjustment of various working units of the combine harvester including, by way of example, the fan and sieves.

Method and apparatus relating to ultrasound flow probes Measurement of time of flight of ultrasound pulses comprises: transmitting the pulses across a fluid flow; detecting a waveform (200) of the pulses, generating a cross-correlation between the waveform (200) and a tone (210) and identifying a plurality of peaks (220) in the cross-correlation; fitting a curve template (310) to the waveform at locations (300) corresponding to the peaks (220) and identifying the location (330) of the minimum error; performing a further cross-correlation (420) between the waveform (200) and the tone (210) over only a portion of the waveform (200) containing the minimum error location (330); and determining the temporal location corresponding to the maximum (430) of the further cross-correlation (430).

According the present invention, air velocity and speed of sound which can be used to estimate air temperature can be measured from a sonic anemometer system attached to an airborne platform. Using multiple sonic emitters and receivers coupled to an assembly attached to an airborne platform where the atmosphere is free to pass through the volume between the acoustic elements, air data products can be estimated from the acoustic transit time between acoustic emitters and receivers for use in an airborne data system. The measurement method has high update rates and is resilient against acoustic noise and icing conditions making it a robust sensing platform for use on aircraft.