Observer analysis and synthesis for perturbed Lipschitz systems under noisy time-varying measurements

Etienne, Lucien; Hetel, Laurentiu; Efimov, Denis

doi:10.1016/j.automatica.2019.04.003

Cited by 11 publications

(4 citation statements)

References 18 publications

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“…Researchers in various applications have considered Lipschitz systems with uncertain input [24,25]. They also applied methods of adaptive control and integrator backstepping using barrier functions [26][27][28] by which they could inhibit external disturbances knowing only their maximum modulo values.…”

Section: Introductionmentioning

confidence: 99%

Dynamic Models with Sigmoid Corrections to Generation of an Achievable 4D-Trajectory for a UAV and Estimating Wind Disturbances

2023

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For an unmanned aerial vehicle (UAV) of an aircraft type, the problems of planning achievable trajectories as well as robust control under wind disturbances are considered. A computationally simple method for compiling a primary non-smooth 4D trajectory is proposed. Its segments connect the given waypoints and determine the desired average velocity in various sections. Instead of time-consuming methods of analytical smoothing of broken path joints using polynomials, a tracking differentiator with S-shaped smooth and limited sigmoid corrective actions is developed. This virtual dynamic model provides natural smoothing of the primary trajectory considering the design constraints on the velocity, acceleration, and thrust of the UAV. The tracking differentiator variables create an achievable trajectory and are used to synthesize the UAV tracking system. To compensate for the action of wind disturbances on the UAV, a disturbance observer is developed. It is a replica of the equations of the control plant model, which are directly affected by external uncontrolled disturbances. These algorithms also use sigmoid corrections. Unlike standard disturbances observers, this approach does not require the development of a dynamic model of external disturbances and does not assume their smoothness. The effectiveness of the developed algorithms was confirmed by numerical simulation.

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Section: Introductionmentioning

confidence: 99%

Dynamic Models with Sigmoid Corrections to Generation of an Achievable 4D-Trajectory for a UAV and Estimating Wind Disturbances

2023

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“…However, we should point out that the methods mentioned above are only suitable for linear systems [18], or require some prior knowledge of nonlinear dynamics. For instance, the nonlinear part is completely known [19]- [21], [24], [26], [27], the nonlinear function is Lipschitz [20], [23], [25], [28]. More importantly, no attempt is made in the overall estimation of nonlinear uncertainty, which is sometimes demanded in control devices such as the feedback linearization technique.…”

Section: Introductionmentioning

confidence: 99%

Active Disturbance Rejection Control for Uncertain Nonlinear Systems With Sporadic Measurements

Dong

Wang

2022

IEEE/CAA J. Autom. Sinica

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This paper deals with the problem of active disturbance rejection control (ADRC) design for a class of uncertain nonlinear systems with sporadic measurements. A novel extended state observer (ESO) is designed in a cascade form consisting of a continuous time estimator, a continuous observation error predictor, and a reset compensator. The proposed ESO estimates not only the system state but also the total uncertainty, which may include the effects of the external perturbation, the parametric uncertainty, and the unknown nonlinear dynamics. Such a reset compensator, whose state is reset to zero whenever a new measurement arrives, is used to calibrate the predictor. Due to the cascade structure, the resulting error dynamics system is presented in a non-hybrid form, and accordingly, analyzed in a general sampled-data system framework. Based on the output of the ESO, a continuous ADRC law is then developed. The convergence of the resulting closedloop system is proved under given conditions. Two numerical simulations demonstrate the effectiveness of the proposed control method.

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“…Globally Lipschitz nonlinear systems have often been considered in sampled-value control [5][6][7][8]. The assumption of global Lipschitz continuity restricts their applications compared with local Lipschitz continuity.…”

Section: Introductionmentioning

confidence: 99%

Local robust stability on compact set for nonlinear systems with continuous time controller against to aperiodic sampling and disturbance

Umemoto

Endo

Matsuno

2022

IET Control Theory & Appl

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In this study, the stability of a sampled-value control system with time-and state-dependent disturbance and aperiodic sampling is investigated. To expand the application class of the sampled-value controller, the local stability on a compact set is considered under the assumption of local Lipschitz continuity on the compact set. Because the assumption is weaker than the global Lipschitz continuity, the proposed stability analysis is applicable to a wider class of controlled systems. Global stability under the assumption of global Lipschitz continuity is also considered. The effectiveness of the derived stability condition is verified by conducting numerical simulations with some control parameters variations such as the disturbance magnitude and sample interval.

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Observer analysis and synthesis for perturbed Lipschitz systems under noisy time-varying measurements

Cited by 11 publications

References 18 publications

Dynamic Models with Sigmoid Corrections to Generation of an Achievable 4D-Trajectory for a UAV and Estimating Wind Disturbances

Dynamic Models with Sigmoid Corrections to Generation of an Achievable 4D-Trajectory for a UAV and Estimating Wind Disturbances

Active Disturbance Rejection Control for Uncertain Nonlinear Systems With Sporadic Measurements

Local robust stability on compact set for nonlinear systems with continuous time controller against to aperiodic sampling and disturbance

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