Anders Rantzer (Lund University)
Robust Control Revisited: A Quest for Scalability
The concept of Integral Quadratic Constraint (IQC) has long been known as a versatile tool for robustness analysis of dynamical systems. Numerous common model imperfections can be efficiently described this way, for example parametric uncertainty, disturbances with bounded frequency content and nonlinear effects such as friction and hysteresis. Based on this idea, rigorous bounds on performance deviations can be computed using semi-definite programming. Computer tools for robustness analysis using IQCs were developed already in the 1990s. However, computational complexity has remained an obstacle for more wide-spread use in applications.
In this presentation, we will discuss a method to improve the computational scalability of IQC analysis, using sparse decomposition of positive definite matrices. This makes it possible to verify stability and performance of large-scale systems with certificates that can be verified individually for each component. Applications in power systems will be discussed.