Research On Finite-time Control Of Two Types Of High-order Nonlinear Systems

This dissertation focuses on the problem of finite-time stabilization for two kinds of high-order nonlinear systems with output constraint and zero dynamics.I.Fast finite-time stabilization of high-order nonlinear systems with output constraint and zero dynamics.For a class of high-order nonlinear systems with output constraint and zero dynamics,this dissertation proposes a continuous controller by means of a new tangent function and a serial of nonnegative integral functions with sign functions.The controller proposed in this dissertation can achieve the state of closed-loop system converges to the origin in finite time and satisfies the preassigned constraint.In addition,under the action of the controller proposed in this paper,the convergence speed of the system state is faster than the traditional finite-time control.The novelty is attributed to a perspective to applying the fast finite-time stability in partial state feedback control design in the case when the output is restricted.II.Fast finite-time adaptive stabilization of high-order uncertain nonlinear systems with output constraint and zero dynamics.For a class of high-order uncertain nonlinear systems with an output constraint and zero dynamics.A continuous stabilizer with an adaptive mechanism is constructed by utilizing a tangent function and nonnegative integral functions equipped with sign functions,which guarantees the system output to be restricted in a pre-specified region and a faster convergence speed of system states compared to traditional finite-time stabilizers.The main novelty of this dissertation is the skillful selection of Lyapunov functions and the new perspective of constructing a fast finite-time adaptive stabilizer with the consideration of output constraints as well as dynamic and parameter uncertainties.