Immersion and invariance stabilization of nonlinear systems via virtual and horizontal contraction

Lei Wang (1) , Fulvio Forni (2) , R. Ortega (3) , Zhitao Liu (1) , Hongye Su (1)

1 Zhejiang University
2 CAM - University of Cambridge [UK]
3 L2S - Laboratoire des signaux et systèmes

The main objective of this paper is to revisit one of the key steps of immersion and invariance stabilizing controller design. Namely, the one that ensures attractivity of the manifold whose internal dynamics contains a copy of the desired system behavior. Towards this end we invoke contraction theory principles and propose two alternative procedures to carry out this step: (i) to replace attractivity of the manifold by virtual contraction of the off-the-manifold coordinate and (ii) to ensure the attractivity of the manifold rendering it horizontally contractive. This makes more systematic the design with more explicit degrees of freedom to accomplish the task. Several examples, including the classical case of systems in feedback form, are used to illustrate the proposed design.

Domains: Automatic Control Engineering; Automatic

Lei Wang, Fulvio Forni, R. Ortega, Zhitao Liu, Hongye Su. Immersion and invariance stabilization of nonlinear systems via virtual and horizontal contraction. IEEE Transactions on Automatic Control, 2017, 62 (8), pp.4017-4022. ⟨10.1109/tac.2016.2614888⟩. ⟨hal-01815976⟩