QoS aware joint observer and networked PI/PID controller design using LMIs under specified rate of packet dropouts

Abstract

This paper develops a novel formulation for quality of service (QoS) aware networked observer and PI/PID controller design in the presence of specified rate of random packet dropouts. We here derive the stability conditions for the controller and observer gains using asynchronous dynamical system (ADS) formulation of the networked control system (NCS) in discrete time which yields a set of linear matrix inequalities (LMIs). The control design has been validated on two test-bench energy systems viz. battery with DC/DC converter and synchronous generator with power system stabilizer. Numerical simulations report the joint observer and controller’s performance in the presence of random packet drops within output feedback control scheme using PI/PID controllers and employing state estimation for the battery and synchronous generator systems. The major numerical challenge includes handling nonconvex constraints in LMIs and stabilizing the observer-based controller with specified rate of packet dropouts. Monte Carlo simulations are provided to compare the uncertain state trajectories, state estimation errors and control efforts under different probability of packet dropouts for the two test-bench energy systems.