On the Structure of Robust Controllers and Weight Selection in the Mixed Sensitivity Minimization
Year: 2025
Type: conference-paper
Abstract: In this paper we examine the structure of robust controllers obtained from the mixed sensitivity minimization for a class of mechanical systems consisting of rigid body dynamics, weak flexible modes, and small time delays (or non-minimum phase effects due to non-collocated actuator and sensor). In particular, we study the weight selection in the mixed sensitivity design and illustrate that for certain performance and robustness objectives, the resulting H-infinity optimal controller is in the form of a classical PID controller cascaded by a filter suppressing the uncertain flexible modes. Furthermore, we provide a link between this H-infinity optimal controller and the conventional three-loop controller/autopilot (3LC) scheme frequently used in aerospace applications. More precisely, the 3LC scheme is shown to be equivalent to a two-degree-of-freedom (2DoF) control structure where the H-infinity controller is used in the feedback loop and the reference signal is filtered outside the loop.
Source: AIAA SciTech Forum
DOI: 10.2514/6.2025-2462
Institutions: Bilkent University, Roketsan
Language: English
Subfield: Control and Systems Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W4407412511