Networked Control Systems

Using the various communication technologies, it has become much easier to interconnect several distributed subsystems to form a networked system. The different types of monitoring and automation systems, internets of things (IoT) used in the wide range of existing applications including the industrial internet o things (IIoT) are some examples. One of the current challenges in the field of automatic control is to deal with networked control systems (NCSs) as a special form of networked system that are used for real-time control. In NCSs, communication networks are used for transferring information between distributed controllers, sensors, and actuators. In general, the control performance in an NCS is affected by the networking constraints which must be taken into account. Considerable research has been devoted to various networked control problems. Now, NCSs appear in a wide spectrum of applications ranging from simple industrial control loops to complex cyber-physical systems like multi-robot systems and different types of transport systems.
The networking constraints in NCSs can be categorized into the constraints on interconnection graph of the NCS subsystems, and communication constraints in each of the network links. There are various forms of communication constraints including network-induced delays, packet losses, limited bitrate, and limited channel access. Sometimes the controller uses additional mechanisms such as event-triggering in order to actively manage the communication through networks, and improve the joint control-communication performance. A considerable research effort has been devoted to solve the problems arising in the different NCS applications. Two main obstacles of applying these existing works to practical NCS problems are: (1) conservativeness of the results and (2) usage of control structures that are different from the commonly used control algorithms such as PID (proportional integral derivative). Our research in the field of NCS is mainly devoted to investigation of these two issues.