A novel passivity-based design for Lipschitz nonlinear systems with application to hepatitis B disease.

In this paper, an innovative passive formulation has been developed for a wide range of nonlinear systems. During this formulation, a stable and passive state-observer is provided which leads to have a passive closed-loop system. Some remarkable definitions and charts are presented for time-invariant and time-varying Lipschitz systems in four different control scenarios. From a different perspective, a novel interconnection has been established which links the passivity of subsystems with passivity/stability of the closed-loop system. All definitions have been arranged according to the systematic approach named "virtually Euler-Lagrange" form of passivation. Since some design conditions will be released due to using the mentioned method and definitions, the process of analysis and design will be simplified. The proposed passivity-based controller has been applied to treat hepatitis B virus infection disease in several scenarios. All the proposed definitions have been validated by the simulation results.