Output-Dependent Constraints Control for MIMO Nonlinear Systems With Boundary Modification Capability

This paper addresses the output and state constrained control problem for a class of multi-input multi-output (MIMO) nonlinear systems, in which the constraints on system output are functions of the output variables. Unlike existing works on static and time-dependent output constraint control, we consider more general irregularly constrained regions by introducing output-dependent constrained functions. Moreover, existing works on full-state constraints assume that all constraints on system states are compatible and that feasible control strategies exist to enforce such constraints. In this paper, we propose a boundary modification approach utilizing designed switching signals and dynamic adjustment variables, which can automatically correct incompatible boundaries, thereby avoiding the controller singularity problem caused by the constrained variables approaching the constraint boundaries. Our proposed control strategy ensures that all signals remain bounded and the system output is constrained within the output-dependent region, while the system states evolve within the constraint region with boundary modification capability. Finally, simulation is provided to showcase the effectiveness of the approach.