**6. References**

	- [11] C. Nataraj and R. Thimmaraya, "Tracking Control of Unmanned Surface Vehicles with Abkowitz Steering Model," *Proc of the* ASME *Dynamic Systems and Control Conference(DSCC)*, Cambridge, MA, Sept, 2010.

**Chapter 0**

**Chapter 3**

**Issues on Communication Network Control**

**System Based Upon Scheduling Strategy**

Oscar Esquivel-Flores, Héctor Benítez-Pérez and Jorge Ortega-Arjona

Nowadays, industry has successfully used Network Control Systems (NCS) therefore several lines of research have arisen. A NCS is a current application of a Real-Time Distributed Systems (RTDS), composed of a number of nodes capable of developing a complete control process. In these systems several nodes exchange information through a communication network to achieve specific control goals, nevertheless network traffic increases. This affects the overall system performance. Several approaches have been developed to satisfy requirements of both control and communication performance. Particularly, some methodologies focus on saving bandwidth, one of such methodologies is network scheduling. The objective of this methodology is the accurately use of the computing resources. NCS

1. *Control of network:* Study and research on communications and networks to make them suitable for real-time NCS, e.g. routing control, congestion reduction, efficient data

2. *Control over network:* This area deals with control strategies and control systems design over the network trying to minimize the effect of adverse network parameters on NCS

These systems have many challenges to maintain the the Quality of Service (QoS) and Quality of Control (QoC). In the networks, QoS is the idea that transmission rates, error rates, and other characteristics can be measured and improved. The QoS can be degraded due to

There are two general NCS configurations, *Direct structure* and *Hierarchical structure* [14]. Direct structure consists of a controller and a remote system containing a physical plant, sensors and actuators. The controller and the plant are physically located at different points and are directly linked by a data network in order to perform remote closed-loop control. Fig.

and reproduction in any medium, provided the original work is properly cited.

©2012 Esquivel-Flores et al., licensee InTech. This is an open access chapter distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is

© 2012 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons Attribution License http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution,

**Using Numerical Simulations**

Additional information is available at the end of the chapter

research is categorized into two main parts [5]:

communication, networking protocol.

performance such as network delay.

**1.1. Architecture and overview of a NCS**

1 presents a schematic diagram of a direct structure of a NCS [15].

properly cited.

congestion and interference.

http://dx.doi.org/10.5772/48578

**1. Introduction**

[12] D. Lee and C. Nataraj, "Adaptive Tracking Control of Linear Time-varying Unmanned Surface Vehicles with Disturbances", Intelligent Ships Symposium IX (ISSIX) 2011, Intelligent Control, May 25-26, Philadelphia, PA
