Marouane Alma

Adaptive observers design for a class of linear descriptor systems

In this paper, we propose a new approach to an adaptive observer design for a class of multi-input-multi-output linear descriptor systems. Global exponential convergence for joint state-parameter estimation is established for noise-free systems. For noise corrupted descriptor systems, it is proved that the state and parameter estimation errors are bounded and converge in the mean to zero, when the noises are bounded and have zero means. Potential applications of the presented adaptive observer are online system identification, fault detection and adaptive control of descriptor systems. Numerical example is presented to illustrate the performance of the proposed adaptive observer.

Adaptive control of Aerial Manipulation Vehicle

Adaptive Control of an Aerial Manipulation Vehicle is discussed here. The aerial manipulation vehicle consisting of a quadrotor and a robotic arm has a highly coupled dynamics. The nonlinear coupling introduces additional forces and moments on the quadrotor which prevents it from precisely hovering at a position and tracking of reference trajectory. A decentralized control of robotic arm and quadrotor is considered. The robotic arm is controlled by a PID approach with acceleration feedback, and the quadrotor is controlled by PD method in the inner loop and adaptive position control in the outer loop. The proposed method successfully handles the problem of hover stabilization and trajectory tracking.

On observer-based estimation enhancement by parametric amplification in a weak force measurement device

This paper focuses on the problem of force estimation performances in some EFM-like device (Electric Force Microscope). In this context it is shown how those performances can be significantly improved w.r.t. noise measurement by combining techniques in the spirit of the so-called ¿parametric amplification¿ in particular investigated in physics, with observer techniques as they are developed in the control community. The minimal force which can be estimated in this way is expressed in terms of estimation rate and measurement noise variance.

New unified H ∞ dynamic observer design for linear systems with unknown inputs

In this paper, a unified H ∞ dynamic observer (UO) is proposed for a class of linear systems in the presence of unknown inputs and disturbances. It generalizes the existing results on the proportional observer (PO), the proportional integral observer (PIO) and the dynamic observer (DO). The design approach of the UO is derived from the solution of the linear matrix inequality (LMI), based on the new dynamic observer formulation and the solution of the algebraic constraints obtained from the unbiased estimation error. A numerical example is provided to show the applicability and the performance of our results.

A Formal Modeling Framework for Anaerobic Digestion Systems

The complexity of modeling the anaerobic digestion process meets the difficulty to describe and analyze them mathematically. This paper sets the fundamentals for further fully automatic modelling and analysis of biogas systems. Hence, a simplified mathematical model for the anaerobic digestion process of organic matter, in a continuous stirred tank reactor is proposed. With the aim of upgrading the produced biogas and integrate biogas plants in a virtual power plant, new control inputs reflecting addition of stimulating substrates (acetate and bicarbonate) are added. Based on two step (acidogenesis-methanogenesis) mass balance non linear model, a step-by-step model parameters identification procedure is presented.

Invariant observer applied to anaerobic digestion model

In this note, we design an invariant observer for a two step (acidogenesis-methanogenesis) mass balance non linear model, in order to estimate simultaneously all bacteria and substrate concentrations found in the anaerobic digestion process. The particularity of the designed observer is the use of only the methane flow rate which is cheap to measure and commonly measured online even at industrial scale.

An H ∞ adaptive observer design for linear descriptor systems

This paper is devoted to the design of an H∞ adaptive observer for a class of linear descriptor systems in order to estimate simultaneously the system states and its parameters. Based on a mathematical transformation on the system, a new method is presented in order to get an augmented measure matrix from which the observer is built. The existence conditions of the observer are given through matrices equations and are so easily verified via rank conditions. The H∞ observer is then designed using a mathematical parameterization via LMI, in order to ensure the minimization of the disturbances effects on the observation errors. A numerical example is then given to illustrate the design procedure.

H∞ decentralized dynamic-observer-based control for large-scale uncertain nonlinear systems

In this paper an H∞ decentralized observer-based control is proposed for large-scale uncertain nonlinear systems. These systems are coupled by N interconnected subsystems where the interconnections satisfy the quadratic constraints. The proposed control is based on a new form of dynamic observer (DO) which generalizes the existing results on the proportional observer (PO) and the proportional integral observer (PIO). The design approach is derived from the solution of matrix inequality and based on the algebraic constraints obtained from the analysis of the estimation error. A numerical example is provided to show the effectiveness of the proposed control.

H ∞ dynamic observer design for linear time invariant systems

This paper proposes an H∞ dynamic observer (DO) for a class of linear time invariant (LTI) systems in the presence of disturbances. It generalizes the existing results on the proportional observer (PO), the proportional integral observer (PIO) and the DO. The design method is derived from a new formulation of linear matrix inequality (LMI), based on the solutions of the algebraic constraints obtained from the unbiasedness conditions of the estimation error. A numerical example is provided to show the applicability and performances of our observer.

Functional observers design for descriptor systems via LMI: Continuous and discrete-time cases

This paper investigates the design of functional observers for linear time-invariant descriptor systems. A new method for designing these observers is given by using an LMI (Linear matrix inequality) formulation. The obtained result unifies the design, it considers the continuous-time and discrete-time cases and concerns the observers of various orders.