Infinite-Horizon Sequence-based Networked Control without Acknowledgments

In this paper, we consider infinite-horizon networked LQG control over multipurpose networks that do not provide acknowledgments (UDP-like networks). The information communicated over the network experiences transmission delays and losses that are modeled as stochastic processes. In oder to mitigate the delays and losses in the controller-actuator channel, the controller transmits sequences of predicted control inputs in addition to the current control input. To be able to reduce the impact of delays and losses in the feedback channel, the estimator computes the estimate using the M last measurements. In this scenario, the separation principle does not hold and the optimal control law is in general nonlinear. However, we show that by restricting the controller and the estimator to linear systems with constant gains, we can find the optimal solution. The presented control law is demonstrated in a numerical example.