Robust IDA-PBC for non-separable PCH systems under time-varying external disturbances

This work tackles the time-varying matched external disturbances rejection problem of robust Interconnection and Damping Assignment-Passivity Based Control methodology. The main objective of this paper is the stabilization of under-actuated non-separable Port-controlled Hamiltonian (PCH) systems with an inertia matrix dependent of the unactuated coordinates, where the control input is affected by time-varying matched external disturbances. The proposed methodology adds an extension in the system coordinates, such that the system’s closed-loop stability and its PCH structure are preserved despite the presence of time-varying disturbances. The theoretical results are applied to an overhead crane and illustrated through numerical simulations.