The Research Of Measurement Of Wind Speed And Wind Direction For Sail-assisted Ship

Sail-assisted ships require precise values of wind conditions during voyage, which sets a high demand for measurements of wind direction and speed. In practice, sail-assisted ships must find out the correct angle relative to the wind direction in order to maximize the use of wind energy. Anemometers currently available on the market are designed for static circumstances and do not involve movements of sensors, thus producing some errors on board of ships.In this paper, the main factors which affect measurement accuracy of wind speed and direction are analyzed through simulating the movements of the ship by using a cradle head in the wind tunnel. With the interference of angular speed and the rotation angle, the error between the measured value and the true value is obtained by analyzing a large number of experimental data. An error compensation algorithm is established, which accurately measures wind speed and direction.This paper analyzes the wind speed and direction measurement principle and method, discusses advantages and disadvantages of various measuring devices, and builds an experimental platform with wind tunnel simulating natural wind, cradle head simulating ship motion. By analyzing experimental data from sensors placed on the cradle head at different speeds and tilt angles, wind speed and direction measurement errors are acquired. The curves between the speed, tilt angle and the error are derived by multivariable fitting. The paper also analyzes effects on wind speed and direction outcomes when sensor at an arbitrary point in the space changes angle and speed. A model for velocity and angle measurement error compensation is built by processing experimental data. Finally, a number of experimental results demonstrate the effectiveness and accuracy of the compensation model.In this paper, data acquisition interface is coded in VB, and the hardware system consisting of attitude angle measurement, cradle head control, error correction is based on msp430controller. Error compensation is realized by communications program of the upper computer and wind speed and direction gathering and processing program, thus obtaining more accurate values of wind speed and direction. The calibrated value after error compensation meets the application requirements on the wind speed and direction of sail-assisted ships.