Shape monitoring of morphing wing structures using the inverse Finite Element Method

Abstract

This work presents a closed-loop control strategy for morphing wing structures where the feedback originates from monitoring the actual deformed shape of the morphed skin. The approach is based on the inverse Finite Element Method (iFEM), able to reconstruct the displacement field of a structure by minimizing, in a least squares sense, the error between the analytical strains and those experimentally measured in some discrete locations. Once the actual shape has been reconstructed, the actuation loads required to achieve the target shape are computed. The iFEM-based control strategy is assessed numerically on the example problem of a wing segment whose trailing-edge camber is modified via the morphing strategy. Actuation loads are represented by concentrated forces or by a distributed pressure, the effect of aerodynamic loads is taken into account, and strain data are measured on the top and bottom morphing skin. The results show accurate convergence to the target shape, thus demonstrating the potential of the proposed control-loop strategy.