Wind Speed And Direction Measurement Based On Array Ultrasonic Sensor

Wind speed and direction measurement is always a hot research problem in meteorological survey,military industry,aviation and navigation.In recent years,ultrasonic wind measurement technology has been widely concerned and valued by people for its advantages of no mechanical rotation loss,wide measurement range,high measurement accuracy and low maintenance cost.In order to measure wind speed and direction by ultrasonic wave,many research methods have been put forward,such as time difference method,frequency difference method,cross-correlation method and adaptive time delay estimation method.Among them,the time difference method is the most widely used,which uses the difference of arrival time delay of ultrasonic wave under the influence of favorable and adverse wind fields to measure wind speed and direction.Therefore,the accurate measurement of time delay is the decisive factor of the measurement accuracy of time difference method.However,in harsh environment or strong noise background,the method of using threshold comparison method and hardware timing circuit for time delay measurement has a large error,which can not obtain accurate ultrasonic transmission time,thus affecting the measurement accuracy of wind speed and direction.In order to measure wind speed and direction more accurately,it is necessary to put forward a measurement method with strong noise suppression effect..There are many methods to suppress strong noise,among which the array signal processing technology adopts multi-sensor array to receive signals,which can effectively suppress the interference of noise in the space environment and has strong noise suppression ability.In this paper,the array signal processing technology is introduced into the field of ultrasonic wind measurement,and combined with ultrasonic sensor array,the noise suppression ability is improved,and the accurate measurement of wind speed and direction is realized.The main contents of this paper are as follows:1)A five-element arc ultrasonic sensor array is adopted,and the mathematical modeling of the received ultrasonic signal is carried out according to the array structure.Multiple Signal Classification(MUSIC)algorithm is used to process the received Signal,that is,wind speed and direction value is obtained.The feasibility,measurement range,noise,sampling point variation,array radius variation and measurement effect under different SNR are verified by simulation experiments.2)based on multiple signal classification(MUSIC)algorithm of the wind speed and direction measurement method to the problem of poor color noise suppression ability,puts forward the measuring method based on higher-order cumulant MUSIC algorithm,improve the ability of algorithm for noise suppression,derivation and analysis of the computational complexity of the proposed method,the estimation variance,measuring range and no fuzzy problems.The feasibility of the algorithm,measurement range,temperature effect and measurement effect under different SNR are verified by simulation experiments.Finally,an ultrasonic wind measurement system is designed and built,and the practicability of the proposed method is verified by off-line data measurement experiments.3)Aiming at the problem that the wind measurement method based on beamforming algorithm has poor noise suppression ability,this paper proposes the wind measurement method based on characteristic space(Eigenspace-based Beamformer,ESB)beamforming algorithm.This method of wind measurement was deduced under different criteria of beamforming weights,and to improve the beam weights under the minimum variance,introducing the signal feature space,improved the algorithm for noise suppression ability,and through the simulation experiments on the feasibility of this algorithm,direction finding,the success rate under different signal-to-noise ratio and the measurement results of the validation.