Model-Free Reinforcement Learning for Fully Cooperative Consensus Problem of Nonlinear Multiagent Systems.

This article presents an off-policy model-free algorithm based on reinforcement learning (RL) to optimize the fully cooperative (FC) consensus problem of nonlinear continuous-time multiagent systems (MASs). First, the optimal FC consensus problem is transformed into solving the coupled Hamilton-Jacobian-Bellman (HJB) equation. Then, we propose a policy iteration (PI)-based algorithm, which is further proved to be effective to solve the coupled HJB equation. To implement this scheme in a model-free way, a model-free Bellman equation is derived to find the optimal value function and the optimal control policy for each agent. Then, based on the least-squares approach, the tuning law for actor and critic weights is derived by employing actor and critic neural networks into the model-free Bellman equation to approximate the target policies and the value function. Finally, we propose an off-policy model-free integral RL (IRL) algorithm, which can be used to optimize the FC consensus problem of the whole system in real time by using measured data. The effectiveness of this proposed algorithm is verified by the simulation results.