Spacecraft attitude control is a widely studied problem that presents several challenges (actuator saturation, parametric uncertainties, external disturbances, and system non-linearity). Due to these challenges, attitude control systems require a particularly careful design to ensure the stability of the closed-loop system. Against this background, the aim of this course is to introduce the students to a practical approach to the design of control systems for handling the attitude dynamics of spacecraft. Furthermore, as spacecraft swarm is a hot topic in the space community and a source of continuous research, the course also delves into multi-spacecraft attitude coordination problems.

A basic knowledge of theory of dynamical systems and of Matlab-Simulink can facilitate the comprehension of the proposed topics.

The very first part of the course will introduce the concepts and elements underlying control systems and will give some theoretical remarks on the stability of dynamic systems. The lectures will also explore the distributed coordination of autonomous systems, with a specific focus on consensus control. Through concepts borrowed from graph theory, it will be explained how to perform distributed tasks in first-, second-, and higher-order linear systems, as well as in continuous and discrete time. Then, the mathematical models describing spacecraft attitude dynamics and kinematics will be studied, including practical aspects such as actuator saturation, parametric uncertainties, and external disturbances. The lectures will then focus on the sliding mode control theory, delving into the elements and special features of this algorithm. By exploiting Lyapunov stability theory, it will be shown how to design different types of sliding mode algorithms to stabilize the uncertain and constrained spacecraft attitude dynamics. A multi-spacecraft attitude coordination problem will be investigated, featuring several practical issues such as communication delay, flexible appendages, and heterogeneous mass distribution.

In presenza

Presentazione orale

P.D.2-2 - Marzo