Removing the Feasibility Conditions Imposed on Full-State Constraint Control Design for Discrete-Time Nonlinear Systems

In this brief, a novel full state constraint scheme for a class of high-order discrete-time nonlinear systems subjected to unknown parameters is investigated. The new prescribed performance functions are used to ensure that all states of systems can be constrained in a predefined region. Compared with the existing state constraint control and prescribed performance function schemes, the new prescribed performance functions have the advantage of not requiring the feasibility conditions that the virtual controllers are assumed to be bounded. Unlike the conventional switch multiple model set, the proposed multiple model method not only does not rely on a large number of identification models, but also it avoids the potential chattering problem from the switch multiple model method. It is demonstrated that the presented control method can ensure the global boundedness of all the closed-loop signals and that all states converge to the predefined regions. The demonstrated control scheme is implemented on one simulation example for illustrating the effectiveness of the reported scheme.