English

Wasserstein Tube MPC with Exact Uncertainty Propagation

Optimization and Control 2023-04-25 v1

Abstract

We study model predictive control (MPC) problems for stochastic LTI systems, where the noise distribution is unknown, compactly supported, and only observable through a limited number of i.i.d. noise samples. Building upon recent results in the literature, which show that distributional uncertainty can be efficiently captured within a Wasserstein ambiguity set, and that such ambiguity sets propagate exactly through the system dynamics, we start by formulating a novel Wasserstein Tube MPC (WT-MPC) problem, with distributionally robust CVaR constraints. We then show that the WT-MPC problem: (1) is a direct generalization of the (deterministic) Robust Tube MPC (RT-MPC) to the stochastic setting; (2) through a scalar parameter, it interpolates between the data-driven formulation based on sample average approximation and the RT-MPC formulation, allowing us to optimally trade between safety and performance; (3) admits a tractable convex reformulation; and (4) is recursively feasible. We conclude the paper with a numerical comparison of WT-MPC and RT-MPC.

Keywords

Cite

@article{arxiv.2304.12093,
  title  = {Wasserstein Tube MPC with Exact Uncertainty Propagation},
  author = {Liviu Aolaritei and Marta Fochesato and John Lygeros and Florian Dörfler},
  journal= {arXiv preprint arXiv:2304.12093},
  year   = {2023}
}