  Wireless networked control systems (WNCS) are composed of spatially
distributed sensors, actuators, and con- trollers communicating through
wireless networks instead of conventional point-to-point wired connections. Due
to their main benefits in the reduction of deployment and maintenance costs,
large flexibility and possible enhancement of safety, WNCS are becoming a
fundamental infrastructure technology for critical control systems in
automotive electrical systems, avionics control systems, building management
systems, and industrial automation systems. The main challenge in WNCS is to
jointly design the communication and control systems considering their tight
interaction to improve the control performance and the network lifetime. In
this survey, we make an exhaustive review of the literature on wireless network
design and optimization for WNCS. First, we discuss what we call the critical
interactive variables including sampling period, message delay, message
dropout, and network energy consumption. The mutual effects of these
communication and control variables motivate their joint tuning. We discuss the
effect of controllable wireless network parameters at all layers of the
communication protocols on the probability distribution of these interactive
variables. We also review the current wireless network standardization for WNCS
and their corresponding methodology for adapting the network parameters.
Moreover, we discuss the analysis and design of control systems taking into
account the effect of the interactive variables on the control system
performance. Finally, we present the state-of-the-art wireless network design
and optimization for WNCS, while highlighting the tradeoff between the
achievable performance and complexity of various approaches. We conclude the
survey by highlighting major research issues and identifying future research
directions.
