An Online Event-Triggered Near-Optimal Controller for Nash Solution in Interconnected System

This article proposes a real-time event-triggered near-optimal controller for the nonlinear discrete-time interconnected system. The interconnected system has a number of subsystems/agents, which pose a nonzero-sum game scenario. The control inputs/policies based on proposed event-based controller methodology attain a Nash equilibrium fulfilling the desired goal of the system. The near-optimal control policies are generated online only at events using actor-critic neural network architecture whose weights are updated too at the same instants. The approach ensures stability as the event-triggering condition for agents is derived using Lyapunov stability analysis. The lower bound on interevent time, boundedness of closed-loop parameters, and optimality of the proposed controller are also guaranteed. The efficacy of the proposed approach has been validated on a practical heating, ventilation, and air-conditioning system for achieving the desired temperature set in four zones of a building. The control update instants are minimized to as low as 27% for the desired temperature set.