Distributed Joint Optimal Network Scheduling and Controller Design for Wireless Networked Control Systems
Wireless network is now being utilized in control systems, making the systems distributed in contrast to traditional dedicated control systems. These novel distributed systems are known as wireless networked control systems (WNCS) (Nilsson et al. 1998; Branicky et al. 2000; Baillieul and Antsaklis 2007; Schenato et al. 2007). Practical examples of such systems include smart power grid, network-enabled manufacturing, water distribution, traffic, and so on. In WNCS, wireless communication packets carry sensed data and control commands from different physical systems (or plants) and remote controllers. Although WNCS can reduce system wiring, ease of system diagnosis and maintenance, and increase agility, the uncertainty caused by shared wireless network and its protocols bring many challenging issues for both wireless network protocol and controller designs. As observed in the previous chapters network imperfections can transform a linear time-invariant system to an uncertain and stochastic system, which can become unstable unless a proper controller is designed. The wireless network is more unreliable due to channel issues such as path losses and fading when compared to a wired network as in controller area network (CAN) in automotive applications.