Pascal Grieder

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This paper presents an efficient algorithin for coiiiputing the solution to the constrained infinite time linear quadratic regulator (CLQR) problem for discrete time systems. The algorithm coinbiiies multi-parametric quadratic programming with reachability analysis to obtain the optiinal piecewise affine (PWA) feedback law. The algorithm reduces the time(More)
Piecewise affine (PWA) systems are useful models for describing nonlinear and hybrid systems. They also result from LTI systems subject to constrained optimal control. Recently, stability analysis of PWA systems has received increased interest since it can help to obtain explicit feedback control laws of low complexity (Grieder et al., 2003b; Grieder and(More)
We derive a control theoretic model of sector-based air traffic flow using hybrid automata theory. This model is Lagrangian, meaning that it models the properties of the system along its trajectories. A subset of this model is used to generate analytic predictions of air traffic congestion: we define and derive a dynamic sector capacity which we use to(More)
In this paper we present an approach to test stability and feasibility of discrete-time LTI systems subject to constrained optimal control. The analysis is based on the feedback solution of the constrained optimal control problem formulated in a Receding Horizon fashion. The validation procedure consists of two independent parts. For stability, a piecewise(More)
We present an algorithm for the computation of explicit optimal control laws for piecewise affine (PWA) systems with polyhedral performance indices. The algorithm is based on dynamic programming (DP) and represents an extension of ideas initially proposed in Kerrigan and Mayne [(2003). Optimal control of constrained, piecewise affine systems with bounded(More)
A closed-loop controller for hypnosis was designed and validated on humans at our laboratory. The controller aims at regulating the Bispectral Index (BIS) a surrogate measure of hypnosis derived from the electroencephalogram of the patient with the volatile anesthetic isoflurane administered with a closed-circuit breathing system. The control algorithm(More)
We report the results of a search for neutrino-induced particle cascades using a deep ocean water Čerenkov detector. The effective mass of the detector, a string of seven 40 cm diameter photomultipliers (PMT) at 5.2 m spacing, is found through simulation analysis to be surprisingly large: greater than 10 tons of water at incident neutrino energies of 10 GeV(More)