Improving iFEM-Based Wing Deformation Reconstruction Accuracy with IMU-Assisted Calibration

To address the degradation in reconstruction accuracy of inverse finite element methods (iFEM) for wing deformation—caused by discrepancies between the simulation model and the physical system, including model simplifications, mismatched loading conditions, and strain sensor installation errors—as well as the high cost and complexity associated with optical-based error identification and compensation systems, this study proposes an Inertial Measurement Unit (IMU) -assisted calibration approach. A deformation field function is first constructed from strain data using iFEM, establishing a mapping from the field to the angular deflection at each measurement point. The actual angles measured by IMUs are then compared to the theoretical predictions to define an error criterion. Based on this criterion, the degree-of-freedom (DOF) errors in the deformation field are identified through a least-squares-based inverse solution. Finally, by incorporating multi-condition training data, a nonlinear mapping is established between strain inputs and DOF errors. Importantly, once this calibration model is built, only strain measurements are required during service, enabling compensation of iFEM reconstruction errors without the need for IMUs. The proposed method is experimentally validated using a wing loading platform. Results demonstrate that even without relying on optical devices, the method significantly improves the accuracy of deformation reconstruction, while maintaining low cost and strong engineering applicability.