Learning Data-Driven Stable Koopman Operators
@article{Mamakoukas2020LearningDS, title={Learning Data-Driven Stable Koopman Operators}, author={Giorgos Mamakoukas and Ian Abraham and Todd D. Murphey}, journal={ArXiv}, year={2020}, volume={abs/2005.04291} }
In this paper, we consider the problem of improving the long-term accuracy of data-driven approximations of Koopman operators, which are infinite-dimensional linear representations of general nonlinear systems, by bounding the eigenvalues of the linear operator. We derive a formula for the global error of general Koopman representations and motivate imposing stability constraints on the data-driven model to improve the approximation of nonlinear systems over a longer horizon. In addition…
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References
SHOWING 1-10 OF 61 REFERENCES
Linear predictors for nonlinear dynamical systems: Koopman operator meets model predictive control
- MathematicsAutom.
- 2018
Local Koopman Operators for Data-Driven Control of Robotic Systems
- EngineeringRobotics: Science and Systems
- 2019
The authors exploit the Koopman operator to develop a systematic, data-driven approach for constructing a linear representation in terms of higher order derivatives of the underlying nonlinear dynamics, which enables fast control synthesis of nonlinear systems.
On Robust Computation of Koopman Operator and Prediction in Random Dynamical Systems
- Computer ScienceJ. Nonlinear Sci.
- 2020
This paper proposes a robust optimization-based framework for the robust approximation of the transfer operators, where the uncertainty in data set is treated as deterministic norm bounded uncertainty and the robust optimization leads to a min–max type optimization problem for the approximation of transfer operators.
Robust Approximation of Koopman Operator and Prediction in Random Dynamical Systems
- Computer Science2018 Annual American Control Conference (ACC)
- 2018
This paper proposes a robust optimization-based framework for the robust approximation of the transfer operators, where the uncertainty in data-set is treated as deterministic norm bounded uncertainty and leads to a min-max type optimization problem for the approximation of transfer operators.
Koopman Invariant Subspaces and Finite Linear Representations of Nonlinear Dynamical Systems for Control
- MathematicsPloS one
- 2016
This work presents a data-driven strategy to identify relevant observable functions for Koopman analysis by leveraging a new algorithm to determine relevant terms in a dynamical system by ℓ1-regularized regression of the data in a nonlinear function space and demonstrates the usefulness of nonlinear observable subspaces in the design of Koop man operator optimal control laws for fully nonlinear systems using techniques from linear optimal control.
Data-driven discovery of Koopman eigenfunctions for control
- Mathematics
- 2017
This work illustrates a fundamental closure issue of this approach and argues that it is beneficial to first validate eigenfunctions and then construct reduced-order models in these validated eigen Functions, termed Koopman Reduced Order Nonlinear Identification and Control (KRONIC).
On Computation of Koopman Operator from Sparse Data
- Computer Science2019 American Control Conference (ACC)
- 2019
This paper enrichs the sparse data set with artificial data points, generated by adding bounded artificial noise and formulate the noisy robust learning problem as a robust optimization problem and shows that the optimal solution is the Koopman operator with the smallest error.
Linear identification of nonlinear systems: A lifting technique based on the Koopman operator
- Mathematics2016 IEEE 55th Conference on Decision and Control (CDC)
- 2016
The proposed linear identification technique is efficient to recover (polynomial) vector fields of different classes of systems, including unstable, chaotic, and open systems, and robust to noise, well-suited to model low sampling rate datasets, and able to infer network topology and dynamics.
A Data–Driven Approximation of the Koopman Operator: Extending Dynamic Mode Decomposition
- MathematicsJ. Nonlinear Sci.
- 2015
This approach is an extension of dynamic mode decomposition (DMD), which has been used to approximate the Koopman eigenvalues and modes, and if the data provided to the method are generated by a Markov process instead of a deterministic dynamical system, the algorithm approximates the eigenfunctions of the Kolmogorov backward equation.