Approximating the Solution to LQR Problems with Bounded Controls

New equations involving the unknown final states and initial costates corresponding to families of LQR problems are shown to be useful in calculating optimal strategies when bounded control restrictions are present, and in approximating the solution to fixed-end problems. The missing boundary values...

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Bibliographic Details
Authors: Costanza, Vicente, Rivadeneira Paz, Pablo Santiago
Format: article
Status:Published version
Publication Date:2011
Country:Argentina
Institution:Consejo Nacional de Investigaciones Científicas y Técnicas
Repository:CONICET Digital (CONICET)
Language:English
OAI Identifier:oai:ri.conicet.gov.ar:11336/13105
Online Access:http://hdl.handle.net/11336/13105
Access Level:Open access
Keyword:Optimal Control
Constrained Control
Lqr
First Order Pdes
https://purl.org/becyt/ford/2.11
https://purl.org/becyt/ford/2
Description
Summary:New equations involving the unknown final states and initial costates corresponding to families of LQR problems are shown to be useful in calculating optimal strategies when bounded control restrictions are present, and in approximating the solution to fixed-end problems. The missing boundary values of the Hamiltonian equations are obtained by (off-line) solving two uncoupled, first-order, linear partial differential equations for two auxiliary n×n matrices, whose independent variables are the time-horizon duration T and the eigenvalues of the final-penalty matrix S. The solutions to these PDEs give information on the behavior of the whole (T,S)-family of control problems.  Illustrations of numerical results are provided and checked against analytical solutions of  ´the cheapest stop of a train´ problem.