Putting energy back in control
Putting energy back in control
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DOI：
10.1109/37.915398
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发表时间：
2001-04
影响因子：
5.7
通讯作者：
R. Ortega;A. Schaft;I. Mareels;B. Maschke
中科院分区：
文献类型：
--
作者：
R. Ortega;A. Schaft;I. Mareels;B. Maschke
能量是科学和工程实践中的基本概念之一，通常将动力系统视为能量转换装置。这种观点在研究复杂的非线性系统时特别有用，它将它们分解成更简单的子系统，在相互连接的基础上，将它们的能量相加以确定整个系统的行为。控制器的动作也可以用能量术语理解为另一个动力系统。然后，控制问题可以被重新定义为寻找一个动力系统和一个相互连接的模式，使整体能量函数采取所需的形式。这种能量整形方法是基于被动控制（PBC）的本质，这是一种在机械系统中非常著名的控制器设计技术。我们在这篇文章中的目标有三个。首先，请注意PBC并不依赖于机械系统的某些特定结构特性，而是依赖于更基本（和普遍）的能量平衡特性。其次，确定阻碍在机械系统以外的应用中使用标准PBC的物理障碍。特别是，我们证明了标准PBC受到无界能量耗散的存在的阻碍，因此它仅适用于具有无源控制器的可稳定系统。第三，重新审视为克服耗散障碍以及使过程先验知识的纳入更加系统化而发展起来的PBC理论。这两个重要特性使我们能够为各种物理系统设计基于能量的控制器。
Energy is one of the fundamental concepts in science and engineering practice, where it is common to view dynamical systems as energy-transformation devices. This perspective is particularly useful in studying complex nonlinear systems by decomposing them into simpler subsystems that, upon interconnection, add up their energies to determine the full system's behavior. The action of a controller may also be understood in energy terms as another dynamical system. The control problem can then be recast as finding a dynamical system and an interconnection pattern such that the overall energy function takes the desired form. This energy-shaping approach is the essence of passivity-based control (PBC), a controller design technique that is very well known in mechanical systems. Our objectives in the article are threefold. First, to call attention to the fact that PBC does not rely on some particular structural properties of mechanical systems, but hinges on the more fundamental (and universal) property of energy balancing. Second, to identify the physical obstacles that hamper the use of standard PBC in applications other than mechanical systems. In particular, we show that standard PBC is stymied by the presence of unbounded energy dissipation, hence it is applicable only to systems that are stabilizable with passive controllers. Third, to revisit a PBC theory that has been developed to overcome the dissipation obstacle as well as to make the incorporation of process prior knowledge more systematic. These two important features allow us to design energy-based controllers for a wide range of physical systems.