自动化专业英语二.doc

一. Control systems are designed so that certain designated signals, such as tracking errors and actuator inputs, do not exceed pre-specified levels. Hindering the achievement of this goal are uncertainty about the plant to be controlled (the mathematical models that we use in representing real physical systems are idealizations) and errors in measuring signals (sensors can measure signals only toa certain accuracy). Despite the seemingly obvious requirement of bringing plant uncertainty explicitly into control problems, it was only in the early 1980s that control researchers re-established the link to the classical work of Bode and others by formulating a tractable mathematical notion of uncertainty in an input-output framework and developing rigorous mathematical techniques to cope with it. This book formulates a precise problem, called the robust performance problem, with the goal of achieving specified signal levels in the face of plant uncertainty. 控制系统的设计, 某些指定的标志, 如跟踪误差及致动器的输入, 不超过预先规定的水平。阻碍这一目标的实现是不确定性的植物需要控制( 数学模型, 我们用来代表真正的物理系统都理想化) 和测量误差信号( 传感器可以测量信号只在一定精度)。尽管看似明显的需求将控制不确定性明确用控制问题, 它只是在20世纪80 年代早期, 研究人员重新控制链接的经典之作, 另一些则是通过制定一个容易处理的数学概念的不确定性在输入输出框架和开发严谨的数学技巧来应对它。这本书制定一个精确的问题, 叫做鲁棒性能问题, 其目标是实现信号电平指定在面对不确定性的控制。二. The process of designing a control system generally involves many steps. A typical scenario is as follows: 1. Study the system to be controlled and decide what