13,526 research outputs found
Hybrid Control of a Bioreactor with Quantized Measurements: Extended Version
We consider the problem of global stabilization of an unstable bioreactor
model (e.g. for anaerobic digestion), when the measurements are discrete and in
finite number ("quantized"), with control of the dilution rate. The model is a
differential system with two variables, and the output is the biomass growth.
The measurements define regions in the state space, and they can be perfect or
uncertain (i.e. without or with overlaps). We show that, under appropriate
assumptions, a quantized control may lead to global stabilization: trajectories
have to follow some transitions between the regions, until the final region
where they converge toward the reference equilibrium. On the boundary between
regions, the solutions are defined as a Filippov differential inclusion. If the
assumptions are not fulfilled, sliding modes may appear, and the transition
graphs are not deterministic
Contracting Nonlinear Observers: Convex Optimization and Learning from Data
A new approach to design of nonlinear observers (state estimators) is
proposed. The main idea is to (i) construct a convex set of dynamical systems
which are contracting observers for a particular system, and (ii) optimize over
this set for one which minimizes a bound on state-estimation error on a
simulated noisy data set. We construct convex sets of continuous-time and
discrete-time observers, as well as contracting sampled-data observers for
continuous-time systems. Convex bounds for learning are constructed using
Lagrangian relaxation. The utility of the proposed methods are verified using
numerical simulation.Comment: conference submissio
LMI-Based Reset Unknown Input Observer for State Estimation of Linear Uncertain Systems
This paper proposes a novel kind of Unknown Input Observer (UIO) called Reset
Unknown Input Observer (R-UIO) for state estimation of linear systems in the
presence of disturbance using Linear Matrix Inequality (LMI) techniques. In
R-UIO, the states of the observer are reset to the after-reset value based on
an appropriate reset law in order to decrease the norm and settling time
of estimation error. It is shown that the application of the reset theory to
the UIOs in the LTI framework can significantly improve the transient response
of the observer. Moreover, the devised approach can be applied to both SISO and
MIMO systems. Furthermore, the stability and convergence analysis of the
devised R-UIO is addressed. Finally, the efficiency of the proposed method is
demonstrated by simulation results
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