Abstract: At present, most civil UAVs do not accurately measure wind speed, wind direction and early warning wind field. However, forest fire fighting and other scenarios require them to provide accurate wind speed. In this paper, a wind speed and wind direction measuring technology based on the coordinate data of the rotor UAV is proposed. The relative coordinate information of the propeller point is accurately obtained by the RTK (real time kinematic) coordinate information and the azimuth and inclination data. The rotor UAV with different carriers is flying at different speeds of 1 m/s to 16 m/s for more than 30 seconds. According to the change value of the propeller coordinate information, combined with the wind tunnel test data and the wind field dynamics principle, the relationship between the wind speed and the azimuth is studied. The accuracy of the method is tested by wind tunnel experiments. The wind direction can be judged based on the propeller coordinate change information calculated by the RTK. The results show that the wind speed is positively correlated with the azimuth. When the carriers is increased, the azimuth corresponding to the wind speed disturbance would be relatively reduced. The probability of the UAV flight being affected by the gust disturbance, the high altitude area is larger than the low altitude area, and the wind speed estimation model of the flying angle of the six-rotor UAV is established, y=-1.043 5+1.150 1x, the median error value of wind speed measured by this model is 0.966, and the absolute value is less than 1, which meets the requirement of wind speed measurement accuracy of UAV on the scene of emergency command. The method had high accuracy of wind speed measurement, and could provide a feasible method for real-time wind speed and direction measurement of the rotor UAV which had certain practical value.

Key words: rotor drone, azimuth, wind speed, measurement