A new "model-free" control methodology is applied for the first time to power converters, and in particular a buck converter, Ćuk converter. We evaluate its performances regarding load supply variations. Our approach, which utilizes "intelligent" PI controllers, does not require any converter identification while ensuring stability robustness of synthesis. Simulation experimental results show that, with simple structure, insensitivity fluctuations large variations ensured.

In this article, a recently developed adaptive version of super-twisting is applied to the control aerodynamic lift on wind turbine blade section, while considering local disturbances in airflow. The proposed law serves as model-free strategy, relying only two parameters. This strategy reduces need for tuning and modeling efforts: first parameter governs speed gain variation, second associated with desired accuracy, enabling unknown dynamics. We discuss capability model track reference...

Abstract. The present paper proposes a comparison of three well-established controllers: robust proportional–integral–derivative (PID) controller (Conord and Peaucelle, 2021), model-free control (Fliess Join, 2013, 2022) an adaptive sliding-mode based on the super-twisting algorithm (Shtessel et al., 2023). benchmark considered is airfoil section equipped with trailing edge jets, load sensors perturbation system. objective to track lift command under external wind perturbations. outcome this...

In this paper, we propose an insulated gate bipolar transistor (IGBT) driver that provides optimal signal to manage the IGBT switching mechanism, without need of a feedback current measurement across parasitic inductance circuit. Our approach is based on Posicast method, which allows determining shape from pulses whose characteristics are determined model. Experimental results demonstrate effectiveness proposed method minimize electrical constraints.

Abstract This work addresses the problem of developing control algorithms for aerodynamic lift wind turbine blades using air injection, taking into account disturbances caused by turbulent perturbations. For this, a test bench is used where 2D blade section in tunnel can be controlled set micro-jets close to trailing edge. Through continuous, local identification variations model-free that does not need any prior knowledge system proposed. It allows flow and stabilizes around tracking...

It is well known that the homogeneous differentiator strategies reduce chattering in implementation of sliding-mode algorithms and recent implicit framework based projector provides very interesting properties when associated with design. In this article, it proposed to evaluate different differentiators on Euler explicit promising semi-implicit strategies, for which discrete implementations have been realized a pneumatic actuator. Experimental results highlight benefit semi-implicit-based...

This work is dedicated to the application of a semi-implicit homogeneous differentiator estimate angular velocity and acceleration each eight electric motors CRAFT cable-driven parallel robot from recording position their respective output shaft. These drive winding or unwinding cables move moving-platform. The results show that this differentiator, whose definition respectively based on two projectors, an extremely efficient tool for estimating velocities accelerations motors. estimated are...

In this paper, a semi-implicit Euler approximation scheme is proposed for second-order homogeneous differ-entiator. Compared to an explicit approximation, it well-known that implicit offers better performances like reducing high frequency oscillations. However, the works well only when dealing with classical sliding mode differentiator. order keep advantages of applied in case differentiators, system. Validation on real data conducted highlight well-founded differentiation strategy.

We propose, in this paper, the development of an efficient IGBT model especially designed for simulation and associated free wheeling diode that can describe recovery current. Although, switching mechanism with a good precision, procedure is presented order to make able reproduce better losses. Both models have advantage be configured exclusively from datasheets are built as electrical circuits, which realized easily classical simulators.

Consider a dynamical system $u \mapsto x, \dot{x} = f_{nl}(x,u)$ where $f_{nl}$ is nonlinear (convex or nonconvex) function, combination of functions that can eventually switch. We present, in this preliminary work, generalization the standard model-free control, either control system, given an output reference trajectory, optimize as derivative-free optimization based "extremum-seeking" procedure. Multiple applications are presented and robustness proposed method studied simulation.

Graphene-supported, highly reduced, high surface area CoO thin films, produced by straight-forward NaBH₄ reduction of cobalt nitrate in a sonicated DMF suspension bulk graphite, are active for low temperature CO oxidation.

It is well known that the implicit Euler strategy a chattering-free implementation of sliding mode algorithms. In this paper, we propose to mix explicit and discretizations in order deal with homogeneous control. More precisely, semi-implicit discretization for observer-based control proposed one dimensional case theoretical stability proof. The effectiveness solution illustrated simulation by comparison discretization.

We present experimental and theoretical results concerning the forced filling spontaneous drying of hydrophobic cylindrical mesopores in dynamical regime. Pores are structured with organic/inorganic moieties responsible for a periodicity surface energy along their axis. find that intrusion water these pores presents slow dynamics: pressure decreases as logarithm time. this dynamics is well described quantitatively by classical model activated wetting at nanoscale, giving access to structural...

Based on the projector introduced in recent Euler semi-implicit methods, main contribution of this paper is reduction effect noise sliding surface discretized homogeneous differentiator. For that, an adaptation law according to magnitude high frequency proposed modify behavior when differentiator remains surface. Experimental results are shown order highlight well founded contribution.

We propose a theoretical development of the model-free control in order to extend its robustness capabilities. The proposed method is based on auto-tuning controller parameter using an optimal approach. Some examples are discussed illustrate our

Graphite is a widely available natural form of carbon with peculiar chemical and surface properties. It essentially hydrophobic consists in very stable stacks graphene layers held together by highly delocalized pi-pi interactions. Its use chemistry particular for catalytic applications requires modification its structure to increase area. This commonly achieved harsh oxidation methods which also modifies the composition graphite enables subsequent deposition phases via common impregnation /...

Gold-catalyzed CO oxidation is a reaction of both practical and fundamental interest. In particular, rate-determining oxygen activation pathways have attracted lot attention. They been found to depend on the surface chemistry catalyst support, titania providing most active catalysts carbon nitride leading inactive catalysts. Here, we show that C3N4-TiO2 composites with rather similar chemistries can be engineered by using nanotubes as hard templates performing polycondensation melamine...

With their strong confining porosity and versatile surface chemistry, zeolitic imidazolate frameworks—including the prototypical ZIF-8—display exceptional properties for various applications. In particular, forced intrusion of water at high pressure (∼25 MPa) into ZIF-8 nanopores is interest energy storage. Such a system reveals also ideal to study experimentally dynamics thermodynamics in an ultrahydrophobic confinement. Here, we report on neutron scattering experiments probe molecular...

A new "model-free" control methodology is applied to a boost power converter. The properties of the converter allow evaluate performances model-free strategy in case switching nonlinear transfer functions, regarding load variations. Our approach, which utilizes "intelligent" PI controllers, does not require any model identification while ensuring stability and robustness controlled system. Simulation results show that, with simple structure, proposed method almost insensitive fluctuations large

It is well-known that implicit-based and projector-based differentiator schemes offer better performances, like reducing high frequency oscillations, compared to the corresponding explicit schemes. To keep advantages of such implicit Euler approximations, when this approximation applied in case homogeneous differentiators, a semi-implicit has been recently proposed for second-order systems. In paper, generalization third order differentiation taking into account attenuation noise considering...