Advantages of Bilinear Koopman Realizations for the Modeling and Control of Systems With Unknown Dynamics

@article{Bruder2020AdvantagesOB,
  title={Advantages of Bilinear Koopman Realizations for the Modeling and Control of Systems With Unknown Dynamics},
  author={Daniel Bruder and Xun Fu and Ram Vasudevan},
  journal={IEEE Robotics and Automation Letters},
  year={2020},
  volume={6},
  pages={4369-4376}
}
Nonlinear dynamical systems can be made easier to control by lifting them into the space of observable functions, where their evolution is described by the linear Koopman operator. This letter describes how the Koopman operator can be used to generate approximate linear, bilinear, and nonlinear model realizations from data, and argues in favor of bilinear realizations for characterizing systems with unknown dynamics. Necessary and sufficient conditions for a dynamical system to have a valid… 

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