Networked Control System Simulation Methods:A Comparative Study

In this paper, we examine several frameworks for NCS simulation: a MATLAB-based package called True Time, the Agent/Plant addition to the ns-2 network simulator, and other MATLAB -based frameworks. We analyze the accuracy, speed, and ease of use of two different methods of simulating system dynamics using the Agent/Plant extension to ns-2. We also introduce a hybrid system model, which we simulate in MATLAB, to verify the simulation of system dynamics in ns-2. We then proceed to use the ns-2 framework and Agent/Plant, using an Euler approximation for the continuous system dynamics, to simulate both the inverted pendulum and pitch control systems on the network topology described in Chapter 2. We examine the performance of these systems as the traffic on the network increases, due to both additional NCSs and non-NCS cross-traffic. We also examine the effects of non-random vs. random sample scheduling, and observe the periodicity of packet loss under both scheduling policies.