Optimal Control of Networked Control Systems with Uncertain Time-Varying Transmission Delay

This paper addresses optimal control of networked control systems (NCS) with uncertain but interval-bounded time-varying transmission delay. The NCS is described by a continuous-time plant model and cost function. Both the plant model and cost function are discretized, leading to a discrete-time plant model and cost function with nonlinear uncertainty. This nonlinear uncertainty is overapproximated by a polytopic uncertainty utilizing a Taylor series expansion. For the resulting discrete-time plant model and cost function with polytopic uncertainty, an optimal full state feedback control law is designed. The design is based on a parameter-depended Lyapunov function and formulated in terms of LMIs. The effectiveness of modeling and design is evaluated for networked control of an active suspension system.