UMA Home page for Achille Sassi
Research activities
Ph.D. Thesis (2013-2016)
Numerical methods for hybrid control and chance-constrained optimization problems
This thesis is devoted to the analysis of numerical methods in the field of optimal control, and it is composed of two parts. The first part is dedicated to new results on the subject of numerical methods for the optimal control of hybrid systems, controlled by measurable functions and discontinuous jumps in the state variable simultaneously. The second part focuses on a particular application of trajectory optimization problems for space launchers. Here we use some nonlinear optimization methods combined with non-parametric statistics techniques. This kind of problems belongs to the family of stochastic optimization problems and it features the minimization of a cost function in the presence of a constraint which needs to be satisfied within a desired probability threshold.
This work is the result of the collaboration between ENSTA Paris and Airbus Safran Launchers. It is partially supported by the EU under the 7th Framework Programme Marie Curie Initial Training Network ``FP7-PEOPLE-2010-ITN'', SADCO project, GA number 264735-SADCO; and by iCODE Institute project funded by the IDEX Paris-Saclay, ANR-11-IDEX-0003-02.
Other activities
Stage (September-November 2014)
Three-month stage in Portugal for a collaboration with the Mathematics Department of the University of Porto.
Publications
Papers in peer-reviewed journals
2018
- Error estimates for numerical approximation of Hamilton-Jacobi equations related to hybrid control systems
, and
Applied Mathematics & Optimization, 2018 - Solving chance constrained optimal control problems in aerospace via Kernel Density Estimation
, , , and
Optimal Control, Applications and Methods, vol. 39(5), pp. 1818-1832, 2018
Paper in non peer-reviewed journals
2016
Conferences without proceedings
2016
- Chance constrained optimization of a three-stage launcher (work with J.B. Caillau, M. cerf, E. Trélat, and H. Zidani)
Journées SMAI-MODE 2016 (Toulouse), mar, 2016 - Kernel Density Estimation applied to the chance-constrained Goddard problem
, , , and
PGMO Days 2016 (Palaiseau), nov, 2016
2015
- Chance constrained optimization of a three-stage launcher
, , , and
Journées du GdR MOA 2015 (Dijon), dec, 2015 - Optimisation d’un lanceur
, , , and
SMAI 2015 (Les Karellis), jun, 2015
2014
- Recent Advances in the Numerical Analysis of Optimal Hybrid Control Problems
, and
MTNS 2014 (Groningen), jul, 2014
Doctoral these
2017
- Numerical methods for hybrid control and chance-constrained optimization problems
Université Paris-Saclay, jan, 2017