NCS Basics

This page provides a collection of links and definitions for those relatively new to NCS and Internet Robotics.

What is a Networked Control System ?

Feedback control systems wherein the control loops are closed through a real-time network are called Networked Control Systems (NCSs). The defining feature of an NCS is that information (reference input, plant output, control input, etc.) is exchanged using a network among control system components (sensor, controller, actuator, etc.). The primary advantages of an NCS are reduced system wiring, ease of system diagnosis and maintenance, and increased system agility. The insertion of the communication network in the feedback control loop makes the analysis and design of an NCS complex. Conventional control theories with many ideal assumptions, such as equal-distance sensing, synchronized control, and non-delayed sensing and actuation, must be reevaluated before they can be applied to NCSs. (more...)

Another definition

When a traditional feedback control system is closed via a communication channel, which maybe shared with other nodes outside the control system, then the control system is called a Networked Control System (NCS). Many attractive advantages of introducing a communication network, like high system testability and resource utilization, as well as low weight, space, power and wiring requirements, motivate the research on the NCS. (more...)

What are the major issues and challenges in the field of Networked Control Systems ?

Networks can introduce unreliable and time-dependent levels of service in terms of, for example, delays, jitter, or losses. Quality-of-Service (QoS) can ameliorate the real-time network behavior, but the network behavior is still subject to interference (especially in wireless media), to routing transients, and to aggressive flows. In turn, network vagaries can jeopardize the stability, safety, and performance of the units in a physical environment. Active research aims at  devising integrated control and communication algorithms to compensate for the vagaries of network service. (more...)