Calendar

Posted September 3, 2024

Control and Optimization Seminar Questions or comments?

Denis Efimov, University of Lille
Homogeneity with Respect to a Part of Variables and Accelerated Stabilization

The presentation addresses the problem of transforming a locally asymptotically stabilizing time-varying control law to a global one with accelerated finite/fixed-time convergence rates. The approach relies on an extension of the theory of homogeneous systems to homogeneity only with respect to a part of the state variables and on the associated partial stability properties. The proposed control design builds upon the kind of approaches first studied in [MCloskey and Murray,1997] and uses the implicit Lyapunov function framework. A sampled-time implementation scheme of the control law is also presented and its properties are characterized. The method is illustrated by finite-time and nearly fixed-time stabilization of a nonholonomic integrator.

Posted August 27, 2024

Control and Optimization Seminar Questions or comments?

Jean Auriol, CNRS Researcher, L2S, CentraleSupélec
Robust Stabilization of Networks of Hyperbolic Systems with Chain Structure

In this talk, we focus on recent developments for the stabilization of networks of elementary hyperbolic systems with a chain structure. Such a structure arises in multiple industrial processes such as electric power transmission systems, traffic networks, or torsional vibrations in drilling devices. The objective is to design feedback control laws that stabilize the chain using the available actuators and sensors. The different systems composing the network are called elementary in the sense that when taken alone, we know how to design stabilizing output-feedback control laws. We will first consider the case where the actuators and sensors are available at one end of the chain. Using appropriate state predictors, we will present a recursive approach to stabilize the whole chain. Then, we will focus on the case where the actuators and sensors are only available at the junction between two subsystems composing the chain. We will show that such a configuration does not always guarantee the controllability of the chain. Under appropriate controllability/observability conditions, we will design simple stabilizing control laws. Our approach will be based on rewriting the system as Integral Delay Equations (IDEs) with pointwise and distributed control terms. Finally, we will show how the proposed techniques can be used to develop output feedback control laws for traffic flow on two cascaded freeway segments connected by a junction.

Posted August 11, 2024

Control and Optimization Seminar Questions or comments?

Panagiotis Tsiotras, Georgia Institute of Technology AIAA and IEEE Fellow
TBA

Posted September 11, 2024
Last modified September 18, 2024

Control and Optimization Seminar Questions or comments?

Rushikesh Kamalapurkar, University of Florida
Operator Theoretic Methods for System Identification

Operator representations of dynamical systems on Banach spaces provide a wide array of modeling and analysis tools. In this talk, I will focus on dynamic mode decomposition (DMD). In particular, new results on provably convergent singular value decomposition (SVD) of total derivative operators corresponding to dynamic systems will be presented. In the SVD approach, dynamic systems are modeled as total derivative operators that operate on reproducing kernel Hilbert spaces (RKHSs). The resulting total derivative operators are shown to be compact provided the domain and the range RKHSs are selected carefully. Compactness is used to construct a novel sequence of finite rank operators that converges, in norm, to the total derivative operator. The finite rank operators are shown to admit SVDs that are easily computed given sample trajectories of the underlying dynamical system. Compactness is further exploited to show convergence of the singular values and the right and left singular functions of the finite rank operators to those of the total derivative operator. Finally, the convergent SVDs are utilized to construct estimates of the vector field that models the system. The estimated vector fields are shown to be provably convergent, uniformly on compact sets. Extensions to systems with control and to partially unknown systems are also discussed. This talk is based in part on joint works [RK23], [RK24], and [RRKJ24] with J.A. Rosenfeld.

Posted August 19, 2024
Last modified September 6, 2024

Control and Optimization Seminar Questions or comments?

Andrii Mironchenko, University of Klagenfurt IEEE CSS George S. Axelby Outstanding Paper Awardee
TBA

Posted August 26, 2024

Control and Optimization Seminar Questions or comments?

Angelia Nedich, Arizona State University
TBA

Posted September 6, 2024

Control and Optimization Seminar Questions or comments?

Laura Menini, Università degli Studi di Roma Tor Vergata
TBA

Posted August 29, 2024
Last modified September 12, 2024

Control and Optimization Seminar Questions or comments?

Piernicola Bettiol, Université de Bretagne Occidentale, France
TBA

Posted August 21, 2024
Last modified September 12, 2024

Control and Optimization Seminar Questions or comments?

Benedetto Piccoli, Rutgers University, Camden AMS Fellow, SIAM W. T. and Idalia Reid Prize Awardee
Control Theory in Traffic Applications: 100 Years of Traffic Models

In 1924, in The Quarterly Journal of Economics, Frank H. Knight debated on social costs using an example of two roads, which was the base of the Wardrop’s principle. The author suggested the use of road tolls and it was probably the first traffic model ever. A few other milestones of a long history include the traffic measurements by Greenshields in 1934, the Lighthill-Whitham-Richards model in late 1950s, and follow-the-leader microscopic models. After describing some of these milestones, we will turn to modern theory of conservation laws on topological graphs with application to traffic monitoring. The theory required advance mathematics such as BV spaces and Finsler-type metrics on L1. In the late 2000s, this theory was combined with Kalman filtering to deal with traffic monitoring using data from cell phones and other devices. Then we will turn to measure-theoretic approaches for multi-agent systems, which encompass follow-the-leader-type models. Tools from optimal transport allow us to deal with the mean-field limit of controlled equations, representing the action of autonomous vehicles. We will conclude by discussing how autonomy can dissipate traffic waves and reduce fuel consumption, then illustrating the results of a 2022 experiment with 100 autonomous vehicles on an open highway in Nashville.

Posted August 13, 2024

Control and Optimization Seminar Questions or comments?

Karl Johansson, KTH Royal Institute of Technology, Sweden Fellow of IEEE, IEEE CSS Hendrik W. Bode Lecture Prize Awardee
TBA

Posted September 4, 2024

Control and Optimization Seminar Questions or comments?

María Soledad Aronna, Escola de Matematica Aplicada, Brazil
TBA