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This paper provides a novel chain observer for a class of Lipschitz nonlinear systems where the nonlinear measured outputs are corrupted by multiple time‐varying long delays. The main contribution is to synthesize a chain observer for a wider class of Lipschitz nonlinear systems with multiple outputs (described by Lipschitz nonlinear functions) with long time‐varying delays. In the design of the proposed observation scheme, the provided observer is comprised of a chain of state observers, where each one has a similar structure. Each observer is tasked to estimate the state over a short time horizon, whereas the first item of the chain provides the actual state estimation. Moreover, each item of the chain observer furnishes a proportional‐integral dynamical term which allows to compensate for the time‐delay effect. The observer gains are obtained from the solution of a set of delay‐dependent Linear Matrix Inequalities (LMIs), which is based on less restrictive LMI synthesis conditions. The convergence analysis relies on a Lyapunov–Krasovskii functional, which demonstrates that the observation error decays to zero. Numerical examples are given, in order to highlight the effectiveness of the provided observer. [ABSTRACT FROM AUTHOR]

In this paper, the development of passivity‐based control (PBC) algorithms to stabilize an unmanned powered parachute aerial vehicle is presented. The equations of motion of the system are presented in both Lagrangian and Hamiltonian formalisms. The proposed controllers are based on the Hamiltonian function of the system and guarantee the parachute aircraft system stabilization. In the first control law a classic PBC strategy is proposed, and in the second, an interconnection and damping assignment‐passivity‐based control (IDA‐PBC) is chosen because of its inherent robustness against parametric uncertainty and unmodeled dynamics. The control objective is to reach a desired final position despite the initial launch conditions. Numerical simulations with variation in the parachute mass weight and in the presence of wind are carried out to validate our proposed schemes. [ABSTRACT FROM AUTHOR]

This paper presents a new approach of the continuous‐discrete observer design for a class of uncertain state‐affine non‐linear systems. A high‐gain observer redesign is developed and analysed under insightful conditions. The proposed observer estimates the state vector by using system output measurements with long sampling times. This result is achieved by considering a persistent excitation condition that can be validated online. The performance of the proposed algorithm is evaluated under time‐varying sampled measurements to estimate the friction factor of a pipeline where the case of noisy sampled output measurements is also considered. [ABSTRACT FROM AUTHOR]