IMU/LIDAR based positioning of a gangway for maintenance operations on wind farms

This article studies the feasibility of an exteroceptive system for the contactless control of a motion-compensated gangway which can be used for maintenance operations on offshore wind farms. Our study shows that current systems based only on inertial systems are not accurate enough to ensure the gangway is held in place without being secured mechanically. Using measurements from a 2D LIDAR system, we propose a method for the real-time monitoring of the position of the gangway in relation to the offshore wind turbine. Our algorithm involves detecting and estimating the position of the wind turbine pile in a 2D scatter diagram using robust approaches. To evaluate our method, we have installed a real-time 3D simulation chain fed with data from actual measurements. We obtain a measurement accuracy of the order of a centimeter, in real time, in representative sea state scenarios.