Emerson’s Felipe Fakir shared a new book on these communication networks with me. He co-authored one of the chapter.
The book, Networked Control Systems: Research Challenges and Advances for Application, describes these network control systems (NCSs) as:
…distributed control systems in which the sensors, actuators, and controllers are physically separated and connected through an industrial network. NCSs represent the evolution of control architectures, providing greater modularity and control decentralization, maintenance ease and diagnosis, and lower cost of implementation. The R&D on NCSs has been overcoming the effects of the network delays, packet losses and message sampling intervals on NCS performance and stability. The advances in wireless networking technology and the proliferation of industrial wireless sensors have led to an increasing interest in using wireless networks for closed loop control. The main advantages of Wireless Networked Control Systems (WNCSs) are the reconfigurability, easy commissioning and the possibility of installation in places where cabling is impossible. Despite these advantages, a major problem must be considered for practical implementations of WNCSs. The technological concern in WNCSs is the energy efficiency of the devices. As the sensors are powered by batteries, the lowest possible consumption is required to extend battery lifetime without compromising the WNCS control performance. Recently, there has been great interest in the development of IoT-based NCSs. This new type of architecture in which control systems are integrated with IoT-based infrastructures represents the next evolution of networked control architectures. Even though this idea enables a whole range of novel functionalities, feedback control design and architectures for IoT imposes significant challenges that have not been addressed yet.
Felipe co-authored chapter 6, Multi-Rate Model Predictive Control for Energy Efficiency in Wireless Networked Control Systems. He shared a summary of this chapter:
The advances in wireless networking technology and the usage of industrial wireless sensors have led to an increasing interest in using wireless networks for closed loop control. The chapter details the several benefits that can be observed within the wireless technology when compared to traditional process control systems that uses wired instruments, despite these advantages, it also shows a major challenge that must be considered for practical implementations of WNCSs. The technological concern in WNCSs is the energy efficiency of the devices.
The chapter presents a process plant to be controlled as a case of study. It is proposed a multi-rate model predictive control (MPC) strategy over a WNCS to overcome the technological concern of the energy efficiency of the devices. Its presented the development of the mathematical model of the process plant using MATLAB/Simulink and in addition to this it shows the wireless multi-rate MPC that runs in a real-time simulator, TrueTime, a toolbox available in the MATLAB/Simulink environment.
Performance indexes were used to evaluate the control performance against the energy efficiency for the proposed wireless multi-rate MPC. The results were obtained in conditions of setpoint changes and the robustness of the controller were also verified with different types of disturbances applied to the system.
Through all results, it was confirmed that the multi-rate MPC applied to the WNCS presented the ability to maintain the system stable with adequate control performance with high energy efficiency using high sampling periods. It is pointed out that the technique of multi-rate MPC over WNCS is feasible and increases the energy efficiency of the system.