Expertise in modeling and control of space systems
The founders of DYCSYT are recognized by the international GNC community for their expertise in the modeling and control of space systems. In particular, they have a long experience in collaborating with ESA through calls for tender, collaborative projects, or research activities (PhDs, postdocs).
DYCSYT offers consulting services, such as technical support or customized R&D studies. We can also be involved in collaborations in calls for tenders: ESA ITTs, GSTPs, CNES R&T proposals…
Modeling
The development of the SDTlib has been driven by our research on the modeling of multi-body flexible structures. Based on the TITOP (Two-Input Two-Output Port) formalism, the SDTlib produces a high-fidelity model of system dynamics. Our methods are also able to model complex mechanisms and their coupling with flexible dynamics. Our activity particularly focused on taking into account parametric uncertainties, in order to enable robust control tools and facilitate the verification and validation (V&V).
Robust control
Modern robust control tools make it possible to evaluate performance right from the start of a project. They take advantage of the high-fidelity modelling of the system to automatically optimize the controller and push the design to the limits of the achievable performance. They are also able handle model uncertainties directly in the controller synthesis. This speeds up the design and validation of the GNC/AOCS system, and even unlocks technical locks where traditional methods fail.
Service in orbit
Our modeling and robust control methods are particularly useful for in-orbit service missions: modeling docking mechanisms, taking into account translation/rotation couplings, inertia variations during robotic handling of a target satellite, in-orbit assembly….
Precision pointing
Our work has been largely motivated by the development of high-precision pointing missions: modeling and active control of microvibrations, disturbance rejection, flexible dynamics, pointing performance assessment, controller optimization, comparison of control architectures…
Verification and Validation (V&V) of space systems
According to NASA, in a typical satellite project, 80% of GNC time is dedicated to V&V (as opposed to design itself), due to the increasing complexity of space systems.
As a result, NASA and ESA have set up numerous initiatives within the international GNC community – R&D project funding, GNC V&V seminars, education and training, creation and dissemination of benchmark problems – to improve the autonomy of guidance, navigation and control systems, while limiting the complexity of the system and the various phases of the life cycle.
Our research activities, and in particular SDTlib, are a response to this need. Once these tools were sufficiently mature, DYCSYT was created with the aim of contributing to their transfer to the industrial world.
For more information:
The TITOP approach to multi-body modeling of flexible structures
The TITOP (Two-Input Two-Output Port) formalism enables flexible structures to be modeled within a multi-body formalism, in order to build models of complex structures. It is compatible with the representation of parametric uncertainties.
Precision pointing for an observation mission
This R&D study, under ESA contract in collaboration with Thalès Alenia Space, focused on optimizing the pointing performance of an observation mission. The system was modeled using SDTlib to perform a frequency analysis of the system and optimize the controllers.
Robust control (H infinity and H2)
In modern theory control, the performances of a system can be measured with the $\mathcal H_\infty$ (H infini) et $\mathcal H_2$ (H2) norms. A multi-objectives optimization problem is then formulated to tune the controller while ensuring robustness to uncertainties.
Robotic arm manipulation for on-orbit servicing
This R&D study, carried out in collaboration with ESA, focused on the high-fidelity modeling of a robotic arm manipulation scenario, as part of an in-orbit servicing mission. The system was modeled and analyzed using SDTlib.
LFT modeling of uncertain systems
This article presents how the LFT (Linear Fractional Transformation) representation can be used to represent uncertainties on system parameters in a continuous way (without sampling the parametric space).
R&D study, consortium collaboration, technical support, customized training, SDTlib license: contact us to discuss your project, and together we’ll choose the solution best suited to your needs.
