Time Delay Compensation Schemes with Application to Networked Control System

Abstract

In the project an extensive study of network parameters like data packet drops, data packet delays are pursued by using a network simulator (NS-2). It simulates the transmission of sensor and control packets between plants and controllers. Some fundamental examples were done using this network simulator. Time delay occurs used for networked control system when the exchange of data among sensors, actuators and controllers connected through the shared medium. Such delays affect the system Performance degradation and the reduced stability or total instability of the closed-loop system. In order to compensate time-delay in the networked control system (NCS) there are different time delay compensation schemes are available, which is given by predictive controller, PID controller, LQR controller, fuzzy controller, etc. In this thesis the discrete-time PID controller is used for compensating the time delays in the networked control system. To study in reality an experimental work is done to transfer packet data between two computer systems through a Local area Network (LAN) using UDP protocol. Subsequently the transfer of signal between two computer systems through a LAN using UDP protocol has been also made. These experiments were carried out using SIMULINK Instrument Control Toolbox (ver7.6).
Networked predictive control is also designed for networked control of servo system. This control strategy is applied to a servo control system through the Local Area Network (LAN).SMITH-PREDICTOR proposed to compensate the communication delays in the networked control system.