Method to Account for Estimator-Induced Previewed Information Losses - Application to Synthesis of Lidar-Based Gust Load Alleviation Functions

Abstract

Preview control using wind estimates derived from Doppler wind lidar measurements is a promising technique for designing active gust load alleviation functions. Due to high noise levels in the lidar measurements, the associated estimator must use some type of smoothing to obtain a reasonable estimate, which entails a loss of some information. Taking this loss into account during control synthesis should help ease the tuning procedure and improve the performance and robustness of the resulting controller. This paper proposes a method to consistently design a linear filter which closely approximates the behavior of the wind estimator and which can be integrated into a linear robust control framework. Its characteristics are shown to closely match the real estimator over a range of types of turbulence using a standard set of system parameters, and in a control synthesis example, it demonstrates a significant improvement in load alleviation performance.