Robust Control of Nonlinear Systems Subject to Unstructured Perturbations

9412340 Isidori，针对具有复杂非线性动态行为的系统的反馈律设计是一项具有挑战性的研究任务，近年来引起了越来越多的关注。非线性控制理论的发展将极大地改进轻量化机械臂、自动驾驶仪和高度机动飞行器的制导系统的设计，提高化工装置调节的灵活性和能效，有利于控制系统在发生故障后的实时重构。在必须面对的许多问题中，最重要的一个是设计反馈律以实现预定的性能目标，该目标通常表示为在存在大量模型不确定性的情况下对用于控制物理系统的一组预定命令输入的响应。对于线性系统，在存在非结构扰动的情况下，一种已被证明非常有效的设计鲁棒控制器的方法是基于最小化对外部干扰输入的频率响应的最大幅度。这项研究的目的是将这种设计方法扩展到非线性系统，并说明如何有效地利用这种方法来解决在非线性反馈律设计中出现的一些相关问题，以获得稳健的性能。***

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. ***