Control of Nonlinear Systems with Output Tracking Error Constraints

摘要

A constructive method is presented to design controllers that force the output of nonlinear systems in a strict feedback form to track a bounded and sufficient smooth reference trajectory asymptotically.Under suitable condition with the initial output tracking error,the proposed controllers guarantee the output tracking error within a symmetric or an asymmetric pre-specified limit range,and boundedness of all signals of the closed loop system.A transformation is introduced to take care of the output tracking error constraint.Smooth and/or p-times differentiable step functions are proposed and incorporated in the output tracking error transformation to overcome difficulties due to the asymmetric limit range on the output tracking error.As a result,there are no switchings in the proposed controllers despite of the asymmetric limit range.