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On Robustness of Kernel-Based Regularized System Identification
(2021)IFAC-PapersOnLine ~ 19th IFAC Symposium on System Identification, SYSID 2021This paper presents a novel feature of the kernel-based system identification method. We prove that the regularized kernel-based approach for the estimation of a finite impulse response is equivalent to a robust least-squares problem with a particular uncertainty set defined in terms of the kernel matrix, and thus, it is called kernel-based uncertainty set. We provide a theoretical foundation for the robustness of the kernel-based approach ...Conference Paper -
Regularized classification and simulation of bifurcation regimes in nonlinear systems
(2021)IFAC-PapersOnLineThe paper proposes a multi-step identification approach to classify a nonlinear system into qualitatively different regimes and then estimate a low-dimensional subspace where predictions of the original state at future times can be obtained by simulation of low-order dynamics. Proper Orthogonal Decomposition is used to build a library of characteristic modes from training data and is combined with regularization techniques for both the ...Conference Paper -
A framework for distributed control based on overlapping estimation for cooperative tasks
(2017)IFAC-PapersOnLine ~ 20th IFAC World Congress. ProceedingsWe present a framework for distributed control where the subsystems estimate overlapping components of the state of the overall system. This enables the implementation of decentralized state feedback controllers, which depend on the overlapping state estimates. For a distributed framework, communication can be added. By choosing the amount of communication and the degree of overlap in the state estimates, a trade-off between increasing ...Conference Paper -
Modeling, Identification, Estimation and Adaptation for the Control of Power-Generating Kites
(2018)IFAC-PapersOnLine ~ 18th IFAC Symposium on System Identification, SYSID 2018. ProceedingsLarge-scale kites, flying high-force crosswind trajectories, have been proposed for wind power generation. A two phase operational cycle generates net positive power using a ground-based motor/generator. In the traction phase the kite flies a high-force trajectory while reeling out the generator-connected tethers. A low-force retraction phase reels in the tethers and returns the kite to the start of the cycle. Highly variable conditions ...Conference Paper -
Capturing nonlinearities with perturbation models
(1997)IFAC Proceedings Volumes ~ IFAC Symposium on System Identification (SYSID'97)This paper investigates the use of robust control perturbation models for describing nonlinear systems. We use model validation techniques to find the smallest linear dynamic perturbation required to describe a particular behaviour of a nonlinear system. The Moore-Greitzer model of rotating stall in jet engines is used as a detailed example.Conference Paper -
Emissions and performance tradeoffs for advanced marine diesel propulsion
(1998)IFAC Proceedings Volumes ~ Control applications in marine systems : a proceedings volume from the IFAC conferenceA multivariable control scheme is designed that reduces smoke generation on an experimental marine Diesel engine equipped with a variable geometry turbocharger (v). The variable geometry turbocharger allows the improvement of the steady-state ship hydrodynamic and propulsion characteristics and requires coordination with the injected mass fuel to achieve a good transient performance.Conference Paper -
Adaptive model predictive control for constrained MIMO systems
(2013)IFAC Proceedings Volumes ~ 11th IFAC International Workshop on Adaptation and Learning in Control and Signal Processing (ALCOSP 2013)An adaptive output feedback control algorithm for constrained multiple input multiple output linear systems is proposed, able to cope with input and output constraints, output disturbances and measurement noise. The approach relies on a real-time set membership identification algorithm to provide bounds on the predicted plant outputs. These bounds are exploited in a receding horizon control strategy that guarantees recursive satisfaction ...Conference Paper -
Frequency-domain identification of a ventilated room for model based control
(2014)IFAC Proceedings Volumes ~ 19th IFAC World Congress, IFAC 2014. ProceedingsEfficient and accurate modeling techniques have become increasingly important in the context of model predictive control (MPC) for building automation. For modeling single-input single-output systems such as a ventilated room (with either constant air flow or constant supply temperature), system identification methods are promising and provide insight into the physical nature of these systems. In collaboration with the company SAUTER an ...Conference Paper -
The stability analysis of sampled-data systems with averaging samplers and time delays
(1996)IFAC Proceedings Volumes ~ Proceedings of the 13th World CongressAn exact analysis of the stability of a sampled-data feedback loop, involving an averaging sampler and continuous-time delays, is presented. An equivalent discrete-time model is derived and it is shown that the continuous-time behaviour at frequencies greater than the sample frequency can significantly affect the system stability, leading to counterintuitive analysis results. An optical fiber link synchronization application is studied ...Conference Paper -
Parallel estimators and communication in spacecraft formations
(2005)IFAC Proceedings Volumes ~ Proceedings of the 16th IFAC World CongressThis paper investigates the closed-loop dynamics of systems controlled via parallel estimators. This structure arises in formation flying problems when each spacecraft bases its control action on an internal estimate of the complete formation state. For LTI systems a separation principle shows that the necessary and sufficient conditions for overall system stability are more stringent than the single controller case; the controllers’ ...Conference Paper