The Research Of Priority Scheduling Of Network Control System Based On NS2

The rapid development of network communication technology has changed the traditional way of information interaction of people. In the production life, the relationship between human and internet is becoming more and more closely. Therefore, it is inevitably developed that a new type system combing network technology and control theory. The kind of control system has many advantages. Utilizing network channel, the information resources can be shared with each other, at the same time, this technology reduces the difficulty of the system construction, expansion, maintenance and it also improves the overall performance of the system. Applying the technoligy in large industrial control system can show its obvious advantage. So it is widely used in various fields such as medical, military and environmental monitoring. While the system performance,except its control strategy, are also decided by uncertain network factors. It is particularly important to further study of network control system.In this paper, the priority queue algorithm which has priority scheduling policy and two kinds of node which have control signal processing ability are designed by using the network simulation software NS2. This research focuses on the modeling method of network control system based on NS2 and the performance of the priority algorithm. By analyzing the simulation data of the delay, the packet loss, the throughput and the system response curves, the superior effort of priority queue algorithm called in network control system is verified. This main work of this paper as follows:(1)First of all, the research significance of network control system is discussed deeply. The composition of network control system and the simulation principle are also introduced in detail.(2)Build the mathematical model of network control system, calculate the mathematical model of controller node and plant node with the signal processing method and PID control strategy.(3)Design the plant node and controller node utilizing the NS2 according to the mathematical. The plant node contains the function of the sensor, actuation and the plant object. The controller node include PID control strategy. As the system runs, two types of nodes can establish basic communication links and can also deal with the control signal. A simple experiment should be done in order to verify the feasibility of the algorithm.(4)Analyzing and comparing the performance of different algorithm based on the network controller system model, it is developed that a new priority queue method which can scheduling bandwidth resources. The algorithm inherits from the Queue Class and includes the mechanism of FIFO, priority identifying and packet choosing. A test should be done for verifying the feasibility of the algorithm.(5)The network competition model should be built on controller node and plant node and the performance of the priority algorithm should be tested.By analyzing and comparing the information including control performance,delay,packet loss,throughput and response curve,the validity of priority algorithm should be confirmed.