Title
Structured Preconditioning of Conjugate Gradients for Path-Graph Network Optimal Control Problems
Abstract
A structured preconditioned conjugate gradient (PCG) based solver is developed for implementing the Newton updates in second-order methods for a class of constrained network optimal control problems. Of specific interest are problems with discrete-time dynamics arising from the path-graph interconnection of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$N$</tex-math></inline-formula> heterogeneous subsystems. The arithmetic complexity of each PCG step is <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$O(NT)$</tex-math></inline-formula> , where <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$T$</tex-math></inline-formula> is the length of the time horizon. The proposed preconditioning involves a fixed number of block Jacobi iterations per PCG step. A decreasing analytic bound on the effective conditioning is given in terms of this number. The associated computations are decomposable across the spatial and temporal dimensions of the optimal control problem, into subproblems of size independent of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$N$</tex-math></inline-formula> and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$T$</tex-math></inline-formula> . Numerical results are provided for two example systems.
Year
DOI
Venue
2022
10.1109/TAC.2021.3107246
IEEE Transactions on Automatic Control
Keywords
DocType
Volume
Optimal control of networks,structured second-order solver,system chains
Journal
67
Issue
ISSN
Citations 
8
0018-9286
0
PageRank 
References 
Authors
0.34
22
3
Name
Order
Citations
PageRank
Armaghan Zafar100.34
Michael Cantoni223938.80
Farhad Farokhi39522.77