We have implemented the linear quadratic Gaussian (LQG) controller in our physical optics sky coverage simulator (MAOS) for the Thirty Meter Telescope (TMT) Narrow Field InFrared Adaptive Optics System (NFIRAOS) aimed for improved correction of tip/tilt and plate scale modes. The LQG controller has a built-in capability to correct narrow frequency vibrations that are above the closed loop bandw...

We propose a new framework to design controllers for high-dimensional nonlinear systems. The control is designed through the iterative linear quadratic regulator (ILQR), an algorithm that computes by iteratively applying on local linearization of system at each time step. Since ILQR computationally expensive, we first construct reduced-order models (ROMs) system. derive ROMs via projection, whe...

In this paper we summarize loop quantum gravity (LQG) and we show how ideas developed in LQG can solve the black hole singularity problem when applied to a minisuperspace model.

The strengthened discrete-time optimal projection equations (SDOPE) are presented in a form based on the delta operator. This form unifies discrete-time and continuous-time results. Based on this unification, recently established results and algorithms for finite and infinite-horizon fixed-order LQG compensation of discrete-time systems are carried over to the continuous-time case. The results ...

This paper addresses the problem of congestion control for transmission control protocol (TCP) traffic in the Internet. The method proposed builds on the ideas of TCP Vegas, a true feedback control approach to congestion management of TCP traffic. The new method is based on an adaptive linear quadratic Gaussian (LQG) formulation which uses an extended least squares system identification algorit...

In this paper, we study the existence of linear quadratic Gaussian (LQG)–balanced realizations for discrete-time infinite-dimensional systems. LQG-balanced realizations are those for which the smallest nonnegative self-adjoint solutions of the control and filter Riccati equations are equal. We show that the control (filter) Riccati equation has a nonnegative self-adjoint solution if and only if...

This paper presents an overview of some recent results concerning the emerging theory of minimax LQG control for uncertain systems with a relative entropy constraint uncertainty description. This is an important new robust control system design methodology providing minimax optimal performance in terms of a quadratic cost functional. The paper first considers some standard uncertainty descripti...

Using the dual Youla parametrizations of controller based coprime factor plant perturbations and plant based co-prime factor controller perturbations, we provide a computational procedure for computing an optimal innnite horizon Linear Quadratic Gaussian (LQG) controller from any stabilizing controller. The method allows us to calculate a new optimal LQG controller from a previous one when the ...