Non-fragile Controller Design And Simulation For Networked Control Systems

With the rapid development of information technology, in modern industry, a control system which has realized signals tansmission between controlled device, sensors and actuators via network, is called a Networked Control System(NCS). Compared with traditional control systems, networked control systems have many advantages, such as lower cost, handy installation and maintenance, more reliability, etc, which make NCS a hotspot of research in recent decades.In fact, in networked control systems, limited band width has brought up some challenges like Quantization and Time-delays, both of which has a negative impact in the system performance. Besides, controllers themselves have some undetermined factors, for instance,FWL effect,analogue-digital conversion, roundoff, etc.Motivated by the problems mentioned above, based on the networked control systems with quantization and time-delays, this paper aims to design a non-fragile H∞controller that ensures the system to be asymptotically stable and has a certain perturbation attentuation levelγ.In this paper, networked control system is a linear time invariant system, By adopting the combination of Lyapunov functional and logarithmic quantizers, H∞condition for stability in a set of LMIs as well as H∞controller design is achieved, based on which by applying gain variation of interval type and relative lemmas, a.non-fragile H∞controller is finally obtained.Simulation has been carried out by MATLAB. A comparison about system H∞attentuation level and output response curve has been made in the condition of applying H∞controller and non-fragile H∞controller respectively, which confirms the validity and superiority of the proposed non-fragile H∞controller.