Application of Wavelet Transform for Ultrasonic Time of Flight Estimation

Abstract

The measurement of wind speed is a key issue for the optimization of energy generation in wind farms. Currently, there are numerous ways to perform its estimation, however, the usual mechanical anemometers are rudimentary and have a considerable margin of error due to friction between parts and the inertia of the system. In this way, it is observed in the current scenario a greater trend towards the use of ultrasonic anemometers, which are based on the calculation of the time of flight of the ultrasonic wave, a variable that consists of the time interval required for a wave emitted from a ultrasonic transducer to reach a receiving transducer. Thus, one of the techniques to estimate the time of flight of the ultrasonic wave is Threshold Detection, however, this method is profoundly affected by noisy signals. In this paper, in order to make this method more robust, an application of the Wavelet Transform integrated to the Threshold Detection method is presented, its construction commented as well as its results.