Strain-Based Deformation Shape-Estimation Algorithm for Control and Monitoring Applications

A new deformation shape-sensing methodology is investigated for the purposes of real-time condition assessment, control, and health monitoring of flexible lightweight aerospace structures. The fiber optic strain sensing technology was recently proposed by the NASA Dryden Flight Research Center. The methodology implements the use of fiber optic sensors to obtain strain measurements from the target structure and to estimate the corresponding displacement field. In this paper, the methodology is investigated through an experimental aluminum winglike swept-plate model. The proposed algorithm is implemented for three distinct loading cases and compared to a well-established modal-based shape-estimation algorithm. The estimation results from both methods are also compared to reference displacements from photogrammetry and computational analyses. The estimation error for each method is quantified using the root-mean-square measure, and the range of validity of the approach for damage detection is established. Furthermore, the disadvantages and the advantages of each method are discussed, demonstrating the additional benefits of using the proposed fiber optic strain sensing methodology to achieve a robust method for monitoring ultra-lightweight flying wings or next-generation commercial airplanes.