Pressure Output Feedback Control of Tollmien–Schlichting Waves in Falkner–Skan Boundary Layers

This paper investigates the use of point wall pressure measurements for output feedback control of Tollmien–Schlichtingwaves in Falkner–Skan boundary layers.Anewapproach is presented for input–outputmodeling of the linear dynamics of the fluid system and the integration withH2∕Linear Quadratic Gaussian reduced-order control design. The pressure...

Effectivity and efficiency of selective frequency damping for the computation of unstable steady-state solutions

Selective Frequency Damping (SFD) is a popular method for the computation of globally unstable steady-state solutions in fluid dynamics. The approach has two model parameters whose selection is generally unclear. In this article, a detailed analysis of the influence of these parameters is presented, answering several open questions with...

Finite-dimensional approximation and control of shear flows

Dynamical systems theory can significantly contribute to the understanding and control of fluid flows. Fluid dynamical systems are governed by the Navier-Stokes equations, which are continuous in both time and space, resulting in a state space of infinite dimension. To incorporate tools from systems theory it has become common practise to...

Localised estimation and control of linear instabilities in two-dimensional wall-bounded shear flows

A new framework is presented for estimation and control of instabilities in wall-bounded shear flows described by the linearised Navier-Stokes equations. The control design considers the use of localised actuators/sensors to account for convective instabilities in an optimal control framework. External sources of disturbances are assumed to...

Multivariate spline-based adaptive control of high-performance aircraft with aerodynamic uncertainties

In this paper, a new modular adaptive control system is presented to compensate for aerodynamic uncertainties in high-performance flight control systems. This approach combines nonlinear dynamic inversion with multivariate spline-based adaptive control allocation. A new real-time identification routine for multivariate splines is presented to...

Control of fluid flows using multivariate spline reduced order models

This paper presents a study on control of fluid flows using multivariate spline reduced order models. A new approach is presented for model reduction of the incompressible Navier-Stokes equations using multivariate splines defined on triangulations. State space descriptions are derived that can be used for control design. This paper considers...

Model Reduction of Parabolic PDEs using Multivariate Splines

A new methodology is presented for model reduction of linear parabolic partial differential equations (PDEs) on general geometries using multivariate splines on triangulations. State-space descriptions are derived that can be used for control design. This method uses Galerkin projection with B-splines to derive a finite set of ordinary...

Nonlinear and fault-tolerant flight control using multivariate splines

This paper presents a study on fault tolerant flight control of a high performance aircraft using multivariate splines. The controller is implemented by making use of spline model based adaptive nonlinear dynamic inversion (NDI). This method, indicated as SANDI, combines NDI control with nonlinear control allocation based on an onboard...

Nonlinear Multivariate Spline-Based Control Allocation for High-Performance Aircraft

High performance flight control systems based on the nonlinear dynamic inversion (NDI) principle require highly accurate models of aircraft aerodynamics. In general, the accuracy of the internal model determines to what degree the system nonlinearities can be canceled; the more accurate the model, the better the cancellation, and with that, the...