Integrated Synthesis of Control and Bandwidth Scheduling on Networked Control Systems

Many Networked Control Systems (NCS) comprise several control loops that are closed over a network of computation nodes. In those systems, periodic, sporadic and non-periodic packets share the network bandwidth, complex timing behavior and communication lead to delay and jitter, which both degrade the control performance. That is to say the performance of NCS is determined not only by control algorithms, but also by the quality of serves (QoS) of network. Therefore, the network QoS must be considered during the controller synthesis. Also, the control performance should be taken into account during system scheduling. In this paper, a control–scheduling co-design method that integrates controller and scheduler design is proposed. The transmission periods of control packets are calculated to optimize the overall performance of control loops. The transmission phases and resource utilization of sporadic and non-periodic packets are controlled by the resource reservation server running on each node to guarantee the temporal requirements of those data and also to limit the effect on the transmission of control packets. Further more, a harmonization algorithm of transmission periods of packets is also presented to improve the bandwidth utilization. An integrated simulation platform based on Truetime is present, and the experimental results show that the scheme is more effective than the former ones.