Mesh Network Scheduling Based on Cyber-Physical Sensitivity for Wireless Control Systems

Wireless control systems (WCSs) are gaining rapid development in industrial automation. Compared to the star topology, mesh networks offer greater compatibility for large-scale applications that require high reliability, scalability, and extended coverage. In WCSs, multiple control loops share the multi-hop mesh network, leading to non-negligible and long- span communication latency in critical flows, which can severely degrade the overall control performance. Additionally, the criticality of each control flow largely depends on the features of the physical plant dynamics and the mesh network configuration, which is essential to properly and exactly represent. Moreover, the online scheduling and reconfiguration for large-scale mesh network for WCSs also pose unique challenges. In this paper, we propose a mesh network scheduling mechanism based on cyber-physical sensitivity. Firstly, we model each control loop as a switched system to represent the impact of arbitrary and fluctuating communication latency. Second, we propose a novel online criticality indicator, cyber-physical sensitivity (CP-Sensi), which accurately reflects the criticality of each control flow by synthesizing the switched model, runtime physical states, and network conditions. Finally, we design a CP-Sensi-based scheduling mechanism and an efficient piggyback-based network reconfiguration protocol tailored for mesh networks. Extensive studies with 12 control loops demonstrate that the proposed CP-Sensi and online mesh network scheduling achieve superior control performance compared to state-of-the-art approaches.