Equivalence of control systems with linear systems on Lie groups and homogeneous spaces

LMRS, CNRS UMR 6085, Université de Rouen, avenue de l'Université, BP 12, 76801 Saint-Étienne-du-Rouvray, France. Philippe.Jouan@univ-rouen.fr

Received: 5 December 2008

Abstract

The aim of this paper is to prove that a control affine system on a manifold is equivalent by diffeomorphism to a linear system on a Lie group or a homogeneous space if and only if the vector fields of the system are complete and generate a finite dimensional Lie algebra.

A vector field on a connected Lie group is linear if its flow is a one parameter group of automorphisms. An affine vector field is obtained by adding a left invariant one. Its projection on a homogeneous space, whenever it exists, is still called affine.

Affine vector fields on homogeneous spaces can be characterized by their Lie brackets with the projections of right invariant vector fields.

A linear system on a homogeneous space is a system whose drift part is affine and whose controlled part is invariant.

The main result is based on a general theorem on finite dimensional algebras generated by complete vector fields, closely related to a theorem of Palais, and which has its own interest. The present proof makes use of geometric control theory arguments.