Force Identification Based on Subspace Identification Algorithms and Homotopy Method

This paper addresses an inverse problem to determine dynamic forces acting on a structure from response data. Data-driven subspace algorithms and the linear regression are used to facilitate the estimation of the state sequences and system parameters. The force identification model is then reasonably established on the basis of the estimated system model. A weighted algorithm based on the homotopy analysis method is employed to discretize the well-known ill-posed problems. Moreover, a criterion based on L-curves is adopted for choosing the level of regularization. Finally, laboratory experiments are presented to demonstrate robustness and effectiveness of the proposed solution technique.