Persons

A variant of the microprocessor complex construction for speed and airflow direction determining has been suggested. The structure of the sensor element based on the hot cylinder has been presented. The temperature distribution over the heated surface of the sensor element with cross airflow has been considered. The results of the studies on the accuracy and speed of the microprocessor complex have been presented. Further ways to improve the basic characteristics of the device have been indicated.

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For operation of the control systems for mobile objects there is a need to consider the longitudinal and transverse component of the air velocity. In present work it has been proposed to use a measuring device of the airflow velocity on the basis of the acoustic method, which is characterized by low inertia and the lack of moving parts. However, big size and the existence of the construction elements, subjected to considerable distortion under mechanical impact, complicate their implementation as the parts of mobile objects. The operation of the algorithm for the device measuring the airflow velocity using the ultrasonic transducers has been analyzed. It has been shown that reducing the dimensions of devices leads to a decrease in the accuracy of measurement without improving the methods for determining the time of passage of the ultrasonic pulse between the transducers and periodic calibration of the device. The block diagram of the computing device of determining 2 components of the airflow velocity with using 4 ultrasonic transducers has been developed and the main elements of the computing device have been considered. The laboratory tests have shown that the device allows determining the velocity of the airflow with a maximum absolute measurement error of 2.5 m/s. The structural elements of the device that obscure the measurement area have a significant effect upon this error formation, but provide the required strength characteristics. The proposed error compensation algorithm based on the method of approximation by trigonometric functions has permitted to reduce the measurement error to 1.2 m/s. Further improvement of the characteristics of the device requires an additional work to find the shape of the block of the sensing elements and an improvement of the error compensation algorithms.

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