Anticipating the Loss of Unknown Input Observability for Sampled LPV Systems

Nonlinear Unknown Input Observability: Extension of the Observability Rank Condition and the Case of a Single Unknown Input

This paper investigates the unknown input observability problem in the nonlinear case under the assumption that the unknown inputs are differentiable functions of time (up to a given order). The goal is not to design new observers but to provide simple analytic conditions in order to check the weak local observability of the state. The analysis starts by extending the observability rank conditi...

Unknown input observer for LPV systems with parameter varying output equation

This paper addresses a discussion about Unknown Input Observers (UIO) for Linear Parameter Varying (LPV) systems designed classically by using the polytopic representation. It is shown that even if the rank conditions ensuring the existence of an UIO are satisfied, the design may fail, due to the polytopic representation of the LPV system. In this paper a new design approach is proposed via a m...

Nonlinear Unknown Input Observability: Analytical expression of the observable codistribution in the case of a single unknown input

Characterisation of observability and controllability for nonuniformly sampled discrete systems

A joint characterisation of the observability and controllability of a particular kind of discrete system has been developed. The key idea of the procedure can be reduced to a correct choice of the sampling sequence. This freedom, owing to the arbitrary choice of the sampling instants, is used to improve the sensitivity of system observability and controllability, by exploiting an adequate geom...

Interpolated Modeling of LPV Systems Based on Observability and Controllability

This paper presents a State-space Model Interpolation of Local Estimates (SMILE) technique to compute linear parameter-varying (LPV) models for parameter-dependent systems through the interpolation of a set of linear time-invariant (LTI) state-space models obtained for fixed operating conditions. Since the state-space representation of LTI models is not unique, a suitable coherent representatio...