Daniel Ossmann

Active control concepts for helicopter rotors, such as trailing edge morphing structures, offer significant potential for vibration reduction, noise mitigation, and performance improvement. An effective usage of these additional control inputs requires linear, control-oriented models that accurately capture the relevant rotor dynamics while remaining suitable for advanced model-based control design methods. This article presents a data-driven methodology to derive linear state-space representations from high-fidelity nonlinear rotor simulations, providing a systematic transition from detailed geometrical and aerodynamic modeling to control-oriented models. The proposed approach is based on subspace system identification and explicitly exploits the degrees of freedom provided by the algorithm to ensure both model fidelity and suitability for advanced control designs. The proposed methods are easily adaptable to real test data if flight measurements are available. The methodology is successfully demonstrated on a Bo 105 rotor blade simulator equipped with a trailing edge morphing structure.

By Hao Deng, Cristina Stoica, Daniel Ossmann, et al., Published on 06/03/26

This paper proposes a novel sufficient condition for the leaky-integrator echo state network controller design based on Incremental Input-to-State Stability criteria for discrete-time systems. The controller design conditions are derived via Linear Matrix Inequalities. A novel leaky-integrator echo state network-based controller structure is presented, demonstrating enhanced system performance. The simulation results highlight the performance improvements achieved by adopting the proposed controller structure.

This paper introduces a novel methodology for designing linear time-varying (LTV) fault detection filters and solve the LTV fault detection problem for LTV systems. The proposed approach builds upon the nullspace-based design technique formulated for linear time-invariant (LTI) systems. The general definition of the LTV fault detection problem sets the basis for the extension of the nullspace-based method to LTV systems. In contrast to the numeric solutions for LTI fault detention problems, symbolic nullspace computations are proposed herein in order to explicitly take the time-dependent nature of the design problem into account. The proposed methodology is demonstrated using the launch trajectory of a space rocket with its time-varying dynamics. The fault detection performance and robustness against false alarms of the proposed LTV detection filter are verified through nonlinear simulations of the rocket along the launch trajectory.