Robust Coupling and Decoupling Control
In order to ensure the robustness of control systems with respect to parameter changes of the plant, robust control synthesis methods are needed. The focus in this research project is put on coupling and decoupling controllers which are, e.g., designed using pole region assignment.
To achieve this, geometric methods are used to determine requirements for the controller regarding controlled invariance. A controlled-invariant subspace is used in this context to describe the subspace of all allowed state trajectories (see picture). The obtained constraints can be transferred to matrix equality conditions that serve as side constraints in the synthesis process.
Using the developed method, arbitrary structures of the closed-loop transfer matrix can be obtained. Thus, partial coupling and decoupling controllers can be realized.
Control Design for Unmanned Tilt-Rotor Aircrafts
Tilt-rotor aircrafts combine the advantages of vertically landing helicopters and fixed-wing aircrafts. They have the ability to change the direction of their thrust vector due to their construction. Hence, they can take off and land without the need of a space consuming runway, but are able to transition into an energy efficient forward-flight.
Especially the automation of this transition phase between hovering and forward-flight poses a challenging control problem since the highly non-linear system structure changes. This research project aims at developing powerful control strategies to enable the safe transition between hovering and forward-flight and vice-versa.