Robust Nonlinear Control: Feedback Passivation and Input Saturation Techniques

鲁棒非线性控制：反馈钝化和输入饱和技术

• 批准号: 9972045
• 负责人: Wei Lin
• 金额: $ 11.7万
• 依托单位: Case Western Reserve University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-07-01 至 2002-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9972045&HistoricalAwards=false
• 关键词: Robust; Nonlinear; Control; Feedback; Passivation

9972045LinNonlinear feedback designs offer the potential to take advantage of genuinely nonlinear effects, for instance, to induce large effects using small controls. The objective of this proposal is to develop theoretically-sound, practically-useful passivity-based low-gain and low-and-high gain control methods for designing feedback controllers that achieve global asymptotic stability, performance robustness against modeling uncertainty, and disturbance attenuation, for a large class of nonlinear systems which cannot be adequately controlled by existing methods. A unique thread in our theoretical development would be the systematic use of small controls and feedback passivation, which focus on ways to exploit the inherently dominant nonlinearities of the dynamic system in the feedback design, rather than to design controllers by canceling the nonlinearities via feedback linearization. The purpose of a feedback control is to stabilize or regulate the system globally and do so in a robust fashion, that is, in a manner that is not sensitive to various perturbations and structural uncertainties in the system. A unified, passivity-based theory of robust nonlinear control would contribute to our ability to design high performance nonlinear controllers capable of attenuating disturbances and tracking desired trajectories, without relying as much on an accurate description of the system model or model parameters and on explicit descriptions of the disturbance signals as does conventional modern control theory.Many dynamic systems of practical importance (e.g. robotics, electrically stimulated muscles, rotating machines, induction motors, power systems, aerospace vehicles, aircraft, missiles and so on) have essentially inherent nonlinear characteristics that cannot be ignored in feedback design. More importantly, control systems that exploit their genuine nonlinearities are likely to achieve better performance than those that do not. Because most engineering systems involve highly nonlinear actuators, sensors and process elements, a goal of active research is to transform a nonlinear system into a linear system for which well-defined linear control techniques are readily applicable. This approach has serious limitations, e.g. the requirement of high energy actuators and the lack of robustness of such schemes to parameter variations and disturbances. Consequently, these techniques have had relatively little successful in solving real-world problems. The research plan in this proposal addresses the needs called for in feedback design, and it proposes approaches to tackle some of the most important issues that we believe are critical to the advancement and application of nonlinear control theory. The main outcome of the proposed research will be new, systematic design methodologies for the control of nonlinear dynamic systems, which are not available in the existing literature. The significance of this proposal is that it identifies the main barriers that hamper the advance and application of nonlinear control theory, but also delineates concrete problems for the control of inherently nonlinear systems, and suggests theoretically innovative and practically feasible methods to resolve them. A number of important and challenging open problems will be solved. In the long term, it will provide insight and thrust for future investigations into several theoretical and practical issues. It is believed that the benefits to a systematic approach towards using low energy control will be becoming more widely appreciated, particularly in industries (e.g. manufacturing, aerospace, power and biomedical engineering) where many applications of nonlinear control with actuator saturation can be found. It is also expected that the nonlinear control schemes to be developed in this program will find much broader applications in other branches of engineering than traditional control theory, due to their significant features and the inclusion of realistic assumptions.

9972045linnonlineareare反馈设计提供了利用真正非线性效应的可能性，例如，使用小型控件诱导大型效果。该提案的目的是开发理论上的，实际上可以使用的基于被动性的低增益和低和高增益控制方法，用于设计反馈控制器，以实现全球渐近稳定性，抗建模不确定性和干扰衰减的性能鲁棒性，对于无法通过现有方法充分控制的大型非线性系统，这些方法是不平等的。我们的理论发展中的一个独特线程将是对小型控件和反馈钝化的系统使用，该线程的重点是在反馈设计中利用动态系统固有的主要非线性，而不是通过反馈线性化来取消非线性来设计控制器。反馈控制的目的是在全球范围内稳定或调节系统，并以强大的方式进行系统，即以对系统中各种扰动和结构不确定性不敏感的方式。一种基于统一的，基于消极的稳健非线性控制的理论将有助于我们设计高性能非线性控制器，能够衰减干扰和跟踪所需的轨迹，而无需太多依赖对系统模型或模型参数的准确描述以及对骚动的显式描述的准确描述，就像传统的现代启发性启发性动力学效果。机器，感应电动机，电源系统，航空航天车，飞机，导弹等基本上具有固有的非线性特性，在反馈设计中不能忽略。更重要的是，利用其真正的非线性的控制系统可能比没有实现的控制系统更好。 由于大多数工程系统都涉及高度非线性的执行器，传感器和过程元素，因此主动研究的目标是将非线性系统转换为线性系统，适用于定义明确的线性控制技术。这种方法有严重的局限性，例如高能量执行器的要求以及此类方案缺乏对参数变化和干扰的鲁棒性。因此，这些技术在解决现实世界中的问题方面几乎没有成功。 该提案中的研究计划解决了反馈设计中要求的需求，并提出了解决一些我们认为对非线性控制理论的进步和应用至关重要的最重要问题的方法。拟议研究的主要结果将是用于控制非线性动态系统的新型系统设计方法，这些方法在现有文献中不可用。该提案的意义在于，它确定了妨碍非线性控制理论的进步和应用的主要障碍，但也描述了对固有非线性系统控制的具体问题，并建议理论上创新且实际上可行的方法来解决它们。将解决许多重要且具有挑战性的开放问题。从长远来看，它将为未来对几个理论和实际问题进行调查提供洞察力和推动力。人们认为，使用低能控制的系统方法将受到广泛的认识，尤其是在工业（例如制造，航空航天，电力和生物医学工程）中，可以找到许多具有执行器饱和的非线性控制的应用。还可以预期，由于其重要特征和包括现实的假设，因此在该计划中开发的非线性控制方案将在其他工程分支中找到比传统控制理论更广泛的应用。