๐ค AI Summary
This paper addresses uncertain nonlinear systems subject to bounded disturbances and unmodeled nonlinear dynamics, proposing a robust adaptive model predictive control (MPC) framework. Methodologically, it pioneers the integration of contraction metrics into robust prediction using Gaussian process (GP) models, coupled with online GP learning for real-time model adaptation; probabilistic contraction constraints are formulated to rigorously ensure recursive feasibility, state convergence, and high-probability constraint satisfaction. Key contributions are: (1) the first application of contraction metrics in GP-based MPC for robust prediction under uncertainty; and (2) a unified analytical framework jointly characterizing uncertainty propagation and contraction-based control synthesis. Experimental validation on a quadrotor platform severely affected by ground effect disturbances demonstrates significant improvements in trajectory tracking accuracy and robustness against disturbances.
๐ Abstract
In this paper, we present a robust and adaptive model predictive control (MPC) framework for uncertain nonlinear systems affected by bounded disturbances and unmodeled nonlinearities. We use Gaussian Processes (GPs) to learn the uncertain dynamics based on noisy measurements, including those collected during system operation. As a key contribution, we derive robust predictions for GP models using contraction metrics, which are incorporated in the MPC formulation. The proposed design guarantees recursive feasibility, robust constraint satisfaction and convergence to a reference state, with high probability. We provide a numerical example of a planar quadrotor subject to difficult-to-model ground effects, which highlights significant improvements achieved through the proposed robust prediction method and through online learning.