Nonlinear Unknown Input Observability and Unknown Input Reconstruction: The General Analytical Solution. (arXiv:2201.07610v1 [math.OC])

Observability is a fundamental structural property of any dynamic system and
describes the possibility of reconstructing the state that characterizes the
system from observing its inputs and outputs. Despite the huge effort made to
study this property and to introduce analytical criteria able to check whether
a dynamic system satisfies this property or not, there is no general analytical
criterion to automatically check the state observability when the dynamics are
also driven by unknown inputs. Here, we introduce the general …

arxiv math observability