Blade Position and Motion Estimation on the Surface of a Rotating Wind Turbine Through a Single MEMS IMU

Abstract

Wind turbines have played a significant role in the transition toward renewable energy sources. Accurately determining the position and motion of the rotor blades has emerged as a crucial feature for advancing their adoption and widespread use. The problem addressed in this paper is the use of a single low-power and cost-effective Inertial Measurement Unit (IMU) mounted on a wind turbine blade for position and motion estimation. Standard attitude algorithms can be used to estimate the position of a sensor relative to the earth’s frame. However, they cannot extract information about additional blade features, such as the pitch angle or the occurrence of flap-wise deflections. This paper establishes a novel framework that facilitates the identification and estimation of dynamic wind turbine angles by defining appropriate reference frames. Experimentally acquired IMU data is used to extract rotation matrices that establish the relationship between reference frames. Experimental results show the possibility of estimating the blade orientation, deflection, and twist with a $\approx 1^{\circ}$ precision, in addition to the relative blade altitude with an error of 5 mm.