This paper proposes a solution for utilizing multi-body models in nonlinear state observers, to directly estimate the loads acting on the aircraft structure from measurement data of sensors that are commonly available on modern aircraft, such as accelerometers on the wing, rate gyros and strain gages.
A high-fidelity aeroelastic multi-body model of a fixed-wing large passenger aircraft is presented, suitable for the monitoring of landing maneuvers. The model contains a modally reduced flexible airframe and aerodynamic forces modeled with a doublet-lattice method. In addition, detailed multi-body models of the nose and main landing gear are attached to the flexible structure, allowing to accurately capture the loads during a hard landing event.
It is expected that this approach will make way for embedding non-linear multi-body models, with a high number of degrees of freedom, in state estimation algorithms, and hence improve health monitoring applications.