Stability analysis for wireless networked control system in unslotted IEEE 802.15.4 protocol

Wireless networked control systems (WNCS) with the control loops closed over a wireless network are prevailing these days. But it also produces new challenges for stability analysis when considering the nuance of the practical communication protocols. The IEEE 802.15.4 protocol has been very popular among communication protocols utilized in WNCS. However, usually its medium access control (MAC) is not tailored towards WNCS which may be greatly affected by the choice of MAC parameters. Most previous research either focuses on WNCS or the communication protocol but few of them considered the modelling and analysis on both. To this end, this paper serves to bridge these two interactive parts. We first propose a Markov chain model to analyze the communication network´s impact on the delay from sensor to controller and apply an extended Bernoulli jump linear system framework to study how MAC parameters affect control system stability. It has been revealed that there are certain MAC parameters greatly affect system stability and they have to be carefully designed and tuned systematically.