Linear-quadratic optimization in discrete-time control of dynamic plants operated with delay over communication network

The paper addresses the problem of remote plant control in networked environment with the use of linear-quadratic (LQ) optimal controller. Since information exchange in networked control systems is essentially a discrete-time process, the controller design is conducted directly in discrete time domain. It is formally shown that the optimization problem for systems involving delay may be reduced to an equivalent delay-free problem with variables expressed in delay compensator dynamics. As a result, the computational complexity to solve the matrix design equations is reduced. The robustness of optimal control system is evaluated analytically and its properties illustrated experimentally.