Robust Control of Nonlinear Systems Subject to Unstructured Perturbations

小行星9412340 具有复杂非线性动力学行为的系统的反馈控制律设计是一个具有挑战性的研究课题，近年来引起了人们越来越多的兴趣。 非线性控制理论的发展将大大改善轻型机器人手臂的控制系统设计，用于高度可折叠的飞机的自动驾驶仪和制导系统，增加化工厂调节的灵活性和能量效率，便于发生故障后控制系统的实时重构。 在必须面对的许多问题中，最重要的一个是设计反馈律，以达到规定的性能目标，通常表示为在存在大量模型不确定性的情况下对物理系统控制的一组规定的命令输入的响应。 在线性系统的情况下，在存在非结构化扰动的情况下，已经证明在鲁棒控制器的设计中非常有效的一种方法是基于对外部扰动输入的频率响应的最大幅度的最小化。 本研究的目的是有助于这种设计方法的扩展到非线性系统，并显示如何可以有效地用于解决一些相关的问题，出现在非线性反馈律的设计实现鲁棒性能。 ***

9412340 Isidori The design of feedback laws for systems characterized by complicated nonlinear dynamical behavior is challenging research task which has attracted an increasing interest in recent years. Advances in nonlinear control theory will substantially improve the design of control systems for light-weighted robot arms, for autopilots and guidance systems of highly maneuverable aircrafts, increase the flexibility and energy efficiency in the regulation of chemical plants, facilitate the real-time reconfiguration of a control system after the occurrence of a failure. Among the many problems which must be confronted, a most important one is the design of feedback laws achieving a prescribed performance objective, usually expressed in terms of the response to a prescribed set of command inputs for the control of a physical system in the presence of substantial model uncertainties. A methodology which, in the case of linear systems, has proven very effective in the design of robust controllers in the presence of unstructured perturbations, is that based on the minimization of the maximal amplitude of the frequency response to exogenous disturbance inputs. The purpose of this research is to contribute to the extension of this design methodology to nonlinear systems and to show how this can be effectively used to address a number of relevant problems which arise in the design of nonlinear feedback laws achieving robust performance. ***