Maximum Allowable Delay Bound Estimation in Networked Control of Bounded Nonlinear Systems

Networked Control Systems (NCSs) has been recognized as an area where theory is behind the development of technology. The defining feature of NCSs can be considered as the information is exchanged through a network among control system components. So the network induced time delay is inevitable in NCSs. The time delay may degrade the performance of control systems and even destabilize the systems if they are designed without considering the effects of the time delays properly. Once the structure of a NCS is confirmed, it is essential to identify what the maximum t ime delay is allowed for maintaining the system stability which, in turn, is also associated with the process of controller design. Th is paper proposes a new method for estimating the maximum allowable time delay in networked control systems with norm bounded nonlinearity. The relation between the maximum nonlinearity and the maximum allowable delay is studied using the proposed method, and it is found that increasing the maximum nonlinearity bound reduces the maximum allowable delay. Furthermore, increasing the time delay leads to shrink the domain of attraction. The results of the maximum allowable delay bound and the maximum nonlinearity are compared with some of the published results.