|Optimal LQG Control for Networked Control Systems with Remote and Local Controllers
Xiao Liang, Juanjuan Xu, Xiao Lu*, Qingyuan Qi*, Haixia Wang, Rong Gao
International Journal of Control, Automation, and Systems, vol. 18, no. 1, pp.236-244, 2020
Abstract : We consider the finite horizon optimal LQG control problem for networked control systems with a remote controller, a local controller and communication channels with packet dropouts and transmission delays. The local controller can directly observe state signals and send them to the remote controller via a packet-dropout channel. Then the remote controller sends the received measurement signals to the local controller. Afterwards, the two controllers operate the plant through a delayed channel. The contributions of this paper are as follows: Firstly, at the side of the remote controller, we develop an optimal estimator to show that the separation principle holds. Secondly, we derive a non- homogeneous relationship between the state and the costate of systems in virtue of the maximum principle. Finally, a necessary and sufficient condition for the optimal control problem is derived in terms of the two coupled Riccati equations. Numerical examples are employed to illustrate the theoretical results.
Delay, maximum principle, optimal control, packet dropout, remote and local controllers