The Equivalence of Controlled Lagrangian
and Controlled Hamiltonian Systems
Chang, D., A. M. Bloch, N. Leonard, J. E. Marsden and C. Woolsey
Control and the Calculus of Variations (special issue
dedicated to J. L. Lions) 8, 393-422.
Abstract:
The purpose of this paper is to show that the method of controlled Lagrangians and
its Hamiltonian counterpart (based on the notion of passivity) are equivalent under rather general
hypotheses. We study the particular case of simple mechanical control systems (where the underlying
Lagrangian is kinetic minus potential energy) subject to controls and external forces in some detail.
The equivalence makes use of almost Poisson structures (Poisson brackets that may fail to satisfy the
Jacobi identity) on the Hamiltonian side, which is the Hamiltonian counterpart of a class of gyroscopic
forces on the Lagrangian side.