不确定非线性系统的鲁棒适应H_∞几乎干扰解耦问题

本文研究了带有不确定参数的非线性系统的鲁棒适应 H∞ 控制的几乎干扰解耦问题 .运用改进的加幂积分器技巧与递归设计方法 ,构造性地设计了一种光滑鲁棒动态反馈控制律 ,在保证闭环系统内稳定的基础上 ,使系统达到干扰衰减 .     

关于高阶不确定非线性系统的鲁棒适应干扰衰减问题

研究一类高阶不确定非线性系统的鲁棒适应H∞干扰衰减问题。本质改进了加幂积分器技巧及backstepping算法,并设计出一个光滑鲁棒适应动态反馈控制律,使得闭环系统既具有内稳定性,又使系统达到干扰衰减．所得结果改进了相关文献中的结论．     

一类高阶非线性系统的几乎干扰解耦问题

对于一类高阶下三角形结构的非线性系统内稳几乎干扰解耦问题 ( ADD)的可解性 ,本文按 L2 —L2 p增益 ,使用“加幂积分器”方法 ,没有对系统中的函数作任何增长性条件限制 ,证明了文中非线性系统的ADD问题有一个连续状态反馈解 .并且可以显式解出此连续状态反馈控制器使得干扰对输出的影响可限制到任一精度且保持系统内稳 .     

一类最小相高阶串联系统的几乎干扰解耦问题

讨论了一类最小相高阶串联系统的几乎干扰解耦问题的反馈设计,对一般的由L_2m-L_2mp所定义的非线性增益指标,利用加幂积分器和Back-stepping方法,我们构造性的给出了一种光滑控制律的设计方法,保证闭环系统在内稳定的基础上,使系统达到干扰衰减。     

高阶非完整系统的适应调节

通过综合利用“加幂积分器”的方法、“不连续投影”技巧和state scaling技巧构造出了一个不连续的动态适应控制律,解决了一类高阶参数非完整系统的适应调节问题．且所求控制律能确保未知参数的估值在一个预先给定范围内．     

一类随机非线性系统的全局有限时间状态反馈镇定

研究一类连续但非光滑的随机非线性系统的全局有限时间状态反馈镇定控制问题.通过增加幂次积分器技术和四次Lyapunov函数的构造,系统地给出了系统状态反馈有限时间镇定控制器的设计方法.基于引入的随机非线性系统有限时间稳定的判定准则,可以证明闭环系统的有限时间稳定性.仿真结果进一步验证了所设计控制器的有效性.     

带调和势的非线性Schrdinger方程爆破解的L~2集中率

本文讨论了带调和势的具有临界幂的非线性Schrodinger方程,得到其爆破解在t→T(爆破时间)的L2集中率．     

带调和势的非线性Schrdinger方程爆破解的L~2集中率

本文讨论了带调和势的具有临界幂的非线性Schrodinger方程,得到其爆破解在t→T(爆破时间)的L2集中率．     

带双势的非线性Schr dinger方程爆破解的L^2集中性质和L^2集中率

本文研究一类带双势的具有临界幂的非线性Schrodinger方程的初值问题.得到该方程爆破解的L2集中性质并在此基础上得到其爆破解为径向对称情形的L2集中速率.     

带双势的非线性Schr(o)dinger方程爆破解的L2集中性质和L2集中率

本文研究一类带双势的具有临界幂的非线性Schr(o)dinger方程的初值问题.得到该方程爆破解的L2集中性质并在此基础上得到其爆破解为径向对称情形的L2集中速率.     

Adaptive stabilization of high order nonholonomic systems with strong nonlinear drifts

This paper investigates the problem of adaptive stabilization control design for a class of high order nonholonomic systems in power chained form with strong nonlinear drifts, including unmodeled dynamics, and dynamics modeled with unknown nonlinear parameters. A parameter separation technique is introduced to transform the nonlinear parameterized system into a linear-like parameterized system. Then, by the use of input-state scaling technique and adding a power integrator backstepping approach, an adaptive state feedback controller is obtained. The adaptive control based switching strategy is proposed to eliminate the phenomenon of uncontrollability. Global asymptotic regulation of the closed-loop system states and the boundedness of other signals are guaranteed. Simulation examples demonstrate the effectiveness of the proposed scheme.     

Global fixed-time stabilization for a class of switched nonlinear systems with general powers and its application

This paper investigates the problem of global fixed-time stabilization for a class of uncertain switched nonlinear systems with the general powers, namely, the powers of the considered systems can be different odd rational numbers, even rational numbers or both odd and even rational numbers. By skillfully using the common Lyapunov function method and the adding a power integrator technique, a common state feedback control strategy is developed. It is proved that the proposed controller can guarantee that the state of the resulting closed-loop system converges to zero for any given fixed time under arbitrary switchings. Simulation results of the liquid-level system are provided to show the effectiveness of the proposed method.     

Output feedback stabilization for planar switched nonlinear systems with asymmetric output constraints

In this paper, smooth output feedback controllers are presented to stabilize a class of planar switched nonlinear systems with asymmetric output constraints (AOCs). A new common barrier Lyapunov function (CBLF) is developed to prevent the switched system from violating AOCs. Combining the adding a power integrator technique (APIT) and the CBLF, state feedback controllers are designed. Then, reduced-order nonlinear observers are constructed and smooth output feedback controllers are proposed to globally stabilize planar switched nonlinear systems under arbitrary switchings. Meanwhile, the system output meets the prescribed AOCs during operation. The method proposed in this paper is a unified tool because it works not only for switched nonlinear systems with asymmetric or symmetric output constrains but also for those without output constraints. Simulations are presented to verify the proposed method.     

Robust Adaptive Finite-Time Stabilization of Nonlinearly Parameterized Nonholonomic Systems

This paper investigates the problem of adaptive finite-time stabilization of nonlinearly parameterized nonholonomic systems. By skilly using the parameter separation, input-state-scaling, and adding a power integrator techniques, an adaptive state feedback controller is obtained. Based on switching strategy to eliminate the phenomenon of uncontrollability, the proposed controller can guarantee that the system states globally finite-time converge to the origin, while other signals remain bounded. Simulation examples demonstrate the effectiveness and the robust features of the proposed approach.     

Robust adaptive synchronization of different uncertain chaotic systems subject to input nonlinearity

In this paper, an adaptive controller is designed to ensure robust synchronization of two different chaotic systems with input nonlinearities. For this purpose, a stable sliding surface is defined and an adaptive sliding mode controller is designed to achieve robust synchronization of the systems when the control input is influenced through nonlinearities produced by actuator or external uncertainty recourses. The adaptation law guarantees the synchronization assuming of unknown model uncertainty. Furthermore by adding an integrator and incorporating a saturation function in the control law, the chattering phenomenon caused by the sign function is avoided. The simulation results for synchronization of Chua’s circuit and Genesio systems show the efficiency of the proposed technique.