Optimal Synchronization Control of Heterogeneous Asymmetric Input-Constrained Unknown Nonlinear MASs via Reinforcement Learning

• Published in: IEEE/CAA journal of automatica sinica 2022-03, Vol.9 (3), p.520-532
• Main Authors: Xia, Lina, Li, Qing, Song, Ruizhuo, Modares, Hamidreza
• Format: Article
• Language: English
• Subjects: Algorithms; Approximation algorithms; Artificial neural networks; Asymmetric input-constrained; Asymmetry; Constraints; Cost function; Hamilton-Jacobi-Bellman (HJB) equation; heterogeneous nonlinear multiagent systems (MASs); Heuristic algorithms; Machine learning; Multiagent systems; Nonlinear systems; novel observer; Observers; Optimization; Prediction algorithms; Reinforcement learning; reinforcement learning (RL); Synchronism
• ISSN: 2329-9266; 2329-9274
• DOI: 10.1109/JAS.2021.1004359

The asymmetric input-constrained optimal synchronization problem of heterogeneous unknown nonlinear multiagent systems (MASs) is considered in the paper. Intuitively, a state-space transformation is performed such that satisfaction of symmetric input constraints for the transformed system guarantees satisfaction of asymmetric input constraints for the original system. Then, considering that the leader's information is not available to every follower, a novel distributed observer is designed to estimate the leader's state using only exchange of information among neighboring followers. After that, a network of augmented systems is constructed by combining observers and followers dynamics. A nonquadratic cost function is then leveraged for each augmented system (agent) for which its optimization satisfies input constraints and its corresponding constrained Hamilton-Jacobi-Bellman (HJB) equation is solved in a data-based fashion. More specifically, a data-based off-policy reinforcement learning (RL) algorithm is presented to learn the solution to the constrained HJB equation without requiring the complete knowledge of the agents' dynamics. Convergence of the improved RL algorithm to the solution to the constrained HJB equation is also demonstrated. Finally, the correctness and validity of the theoretical results are demonstrated by a simulation example.