Motion tracking of a wind turbine blade during lifting using RTK-GPS/INS

This paper presents a case of object motion tracking where a real-time kinematic Global Positioning System (RTK-GPS) is used for correction of data obtained from an inertial navigation system (INS). The displacements obtained from the RTK-GPS and the accelerations obtained from the INS are combined using an unscented Kalman filter (UKF). The combined data are used to assess the motion of a 6 MW turbine blade during a hoisting operation and are compared to the blade motion obtained by use of three Leica total stations, that have been used for verification. Special focus in this paper goes to merging of heterogeneous data (displacements, rotations, and accelerations) obtained from different measurement systems. Analysis of the motion data shows that the RTK-GPS/INS measurement system allows for very accurate recording of displacement and rotation measurements.