Nonlinear Output Feedback Control: Performance and Robustness

提出对非线性系统的输出反馈控制设计进行研究。在过去的几年里，首席研究员的团队已经引入并开发了一种新的方法来解决这个问题，该方法将高增益观测器与饱和非线性相结合。该方法在实现半全局稳定、滑模控制、伺服机构和自适应控制方面取得了基本进展。早期的工作强调鲁棒性和渐近行为，这往往是以牺牲瞬态性能为代价的。本提案的目标是开发新的非线性设计工具，以确保可接受的瞬态性能，同时确保鲁棒性和期望的渐近行为。该提案有两个主要内容。第一个是开发条件积分器和自补偿器的工具，这是最近由首席研究员团队引入的，用于更广泛的非线性系统和设计方法。第二个是为一类非线性系统开发一种基于逻辑的切换控制策略，作为鲁棒和自适应控制的替代方案，以提高面对大模型不确定性时的性能。考虑的一类非线性系统出现在许多应用中，如机械系统，飞机控制和电动机驱动。早期的研究结果已经应用于感应电机的控制和一种被称为悬浮机器人的机械系统。计划继续使用这两个系统作为新技术的测试平台。

It is proposed to conduct research on the design of output feedback control of nonlinear systems.In the past several years, the principal investigator's team has introduced and developed a newapproach to this problem that combines high-gain observers with saturation nonlinearities. Theapproach proved useful in achieving fundamental progress in semiglobal stabilization, sliding-modecontrol, servomechanisms, and adaptive control. The earlier work has emphasized robustness andasymptotic behavior, which quite often come at the expense of the transient performance. Thegoal of this proposal is to develop new tools for nonlinear design that ensure acceptable transientperformance, while ensuring robustness and a desired asymptotic behavior. There are two mainthrusts in the proposal. The first one it to develop the tool of conditional integrators and ser-vocompensators, which was recently introduced by the principal investigator's team, to a muchwider class of nonlinear systems and design methods. The second one is to develop a logic-basedswitching control strategy for a class of nonlinear systems, as an alternative to robust and adaptivecontrol, in order to improve performance in the face of large model uncertainties.The class of nonlinear systems under consideration arises in many applications such as mechan-ical systems, aircraft control, and electric motor drives. Earlier results have been applied to thecontrol of induction motors and a mechanical system known as the pendubot. It is planned tocontinue using these two systems as testbeds for the new techniques.