SACCHELLI , Ludovic

Bounds on the logarithmic derivatives of the heat kernel on a compact Riemannian manifolds have been long known, and were recently extended, for the log-gradient and log-Hessian, to general complete Riemannian manifolds. Here, we further extend these bounds to incomplete Riemannan manifolds under the least restrictive condition on the distance...

In this paper, we are interested in the estimation of Particle Size Distributions (PSDs) during a batch crystallization process in which particles of two different shapes coexist and evolve simultaneously. The PSDs are estimated thanks to a measurement of an apparent Chord Length Distribution (CLD), a measure that we model for crystals of...

We consider the problem of dynamic output feedback stabilization at an unobservable target point. The challenge lies in according the antagonistic nature of the objective and the properties of the system: the system tends to be less observable as it approaches the target. In the literature, switching techniques rapidly appeared as a suitable...

Bounds on the logarithmic derivatives of the heat kernel on a compact Riemannian manifolds have been long known, and were recently extended, for the log-gradient and log-Hessian, to general complete Riemannian manifolds. Here, we further extend these bounds to incomplete Riemannan manifolds under the least restrictive condition on the distance...

We propose to explore switching methods in order to recover some properties of Kalmanlike observers for output feedback stabilization of state-affine systems that may present observability singularities. The self-tuning gain matrix in Kalman-like observers tend to be singular in the case of non-uniformly observable systems. We show in the case...

Stabilizing the state of a system relying only on the knowledge of a measured output is a classical control theory problem. Designing a stable closed-loop based on an observer design requires that some necessary information on the state can be accessed through the output trajectory. For non-linear systems, this may not be true for all controls....

We study the problem of online state estimation during wine fermentation. This problem becomes relevant when trying to control the alcoholic fermentation process with a control law relying on our capacity to estimate the full state, but with partial measurements of the system (which is the case in an industrial framework). We focus on studying...

We study the problem of online state estimation during wine fermentation. This problem becomes relevant when trying to control the alcoholic fermentation process with a control law relying on our capacity to estimate the full state, but with partial measurements of the system (which is the case in an industrial framework). We focus on studying...

This paper investigates the online estimation of neural activity within the primary visual cortex (V1) in the framework of observability theory. We focus on a low-dimensional neural fields modeling hypercolumnar activity to describe activity in V1. We utilize the average cortical activity over V1 as measurement. Our contributions include...

We propose an observer design for a 3-dimensional model of cortical activity dynamics in the visual cortex, under the measurement of the averaged activity. It is based on the construction of an embedding of the system into a triangular 4-dimensional system where the dynamics are not Lipschitzcontinuous but bear Hölder-continuity properties...

We study the minimum time problem for a simplified model of a ship towing a long spread of cables. Constraints are on the curvature of the trajectory as well as on the shape of what represent the spread of cables here. This model turns out to be the same as a cart towing two trailers and rolling without sleeping on a plane in uniform...

For nonlinear analytic control systems, we introduce a new paradigm for dynamic output feedback stabilization. We propose to periodically sample the usual observer based control law, and to reshape it so that it coincides with a "control template" on each time period. By choosing a control template making the system observable, we prove that...

We establish a separation principle for the output feedback stabilisation of state-affine systems that are observable at the stabilization target. Relying on control templates (recently introduced in [4]), that allow to approximate a feedback control while maintaining observability, we design a closed loop hybrid state-observer system that we...

For nonlinear analytic control systems, we introduce a new paradigm for dynamic output feedback stabilization. We propose to periodically sample the usual observer based control law, and to reshape it so that it coincides with a "control template" on each time period. By choosing a control template making the system observable, we prove that...

We establish a separation principle for the output feedback stabilisation of state-affine systems that are observable at the stabilization target. Relying on control templates (recently introduced in [4]), that allow to approximate a feedback control while maintaining observability, we design a closed loop hybrid state-observer system that we...

Motivated by problems in quantum control, we introduce a novel method for studying time optimal control problems of affine systems with unbounded controls. Several examples, including generation of noiseless and noisy qubit gates, as well as population transfer of open two-level systems, are discussed.

A longstanding open question in sub-Riemannian geometry is the following: are sub-Riemannian length minimizers smooth? We give a negative answer to this question, exhibiting an example of a C 2 but not C 3 length-minimizer of a real-analytic (even polynomial) sub-Riemannian structure.

A longstanding open question in sub-Riemannian geometry is the following: are sub-Riemannian length minimizers smooth? We give a negative answer to this question, exhibiting an example of a C 2 but not C 3 length-minimizer of a real-analytic (even polynomial) sub-Riemannian structure.