Further results on nonlinear receding-horizon observers

In this paper, further results are proposed that concern the design and the convergence of receding horizon nonlinear observers. The key feature is the de nition of observability-radius in relation with a pre-speci ed compact set of initial con gurations. This enables a semi-global convergence result to be derived that turns to be a global convergence result when appropriate regularity assumptions are made. A simple example is proposed to illustrate the basic features of the paper.