机器人机械系统综述外文翻译资料

英文原文

译文

Chapter 1 An Overview of Robotic Mechanical Systems

第一章 机器人机械系统综述

1.1 Introduction

1.1介绍

In defining the scope of our subject, we have to establish the genealogy of robotic mechanical systems. These are, obviously, a subclass of the much broader class of mechanical systems. Mechanical systems, in turn, constitute a subset of the more general concept of dynamic systems. In the end, we must have an idea of what, in general, a system is.

在定义我们的主题的范围时，我们必须要建立机器人机械系统的谱系。显然，这是更广泛的机械系统的一个子学科。反过来说，机械系统组成了动力系统更普遍概念上的子集。最后，我们一定要有大致上“系统是什么“的概念

The Concise Oxford Dictionary defines system as a “complex whole, set of connected things or parts, organized body of material or immaterial things,” whereas the Random House College Dictionary defines the same as “an assemblage or combination of things or parts forming a complex or unitary whole.” Le Petit Robert, in turn, defines system as “Ensemble posseacute;dant une structure, constituant un tout organique,” which can be loosely translated as “A structured assemblage constituting an organic whole.” In the foregoing definitions, we note that the underlying idea is that of a set of elements interacting as a whole.

简明牛津字典把系统定义为一个“复杂的整体，一系列相互连接的事物或部分，有组织的物质或非物质的东西”，然而兰登书屋大学词典把系统定义为“ 一个可组装/结合的事物的组成或形成复杂/单一整体的部分。然而，小罗伯特把系统定义为“Ensemble posseacute;dant une structure, constituant un tout organique,”把这粗略的翻译过来就是：“一个组合成有机整体的结构。“ 在之前的定义中，我们注意到”一组相互作用的元素作为整体“是基本观点

On the other hand, a dynamic system is a subset of the set of systems. For our purposes, we can dispense with a rigorous definition of this concept. Suffice it to say that, to qualify as dynamic, a system should be endowed with three elements, namely, a state, an input, and an output, in addition to a rule of transition from one current state to a future one. Moreover, the state is a functional of the input and a function of a previous state. In this concept, then, the idea of order is important, and can be taken into account by properly associating each state value with time. The state at every instant is a functional, as opposed to a function, of the input, which is characteristic of dynamic systems. This means that the state of a dynamic system at a certain instant is determined not only by the value of the input at that instant, but also by the past history of the input—besides, of course, its initial state. By virtue of this property, dynamic systems are said to have memory.

另一方面，动态系统是系统集的子集。为了达到我们的目的，我们可以免除对这个概念的严格的定义。可以说，一个作为动态的系统，除了有从一种当前的状态转为未来状态的规则，还应该具有三个要素：状态、输入、输出。 以外，状态是输入的泛函数，也是前一个状态的函数。在这种概念下，顺序的观点是重要的，并且可以适当的将状态值和时间关联起来考虑。状态在每一瞬间都是输入的泛函数而不是函数，这是动态系统的特征。这意味着动态系统的状态在特定的瞬间不但被那一瞬间的输入值所决定，还被过去的输入决定，当然华友它的初始状态。由于这个特性，动态系统被认为有记忆。

On the contrary, systems whose state at a given instant is only a function of the input at the current time are static, and said to have no memory. Additionally, since the state of a dynamic system is a result of all the past history of the input, the future values of this having no influence on the state, dynamic systems are said to be nonanticipative or causal. By the same token, systems whose state is the result of future values of the input are said to be anticipative or noncausal. In fact, we need not worry about the latter, and hence, all systems we will study will be assumed to be causal.

正相反，如果系统的状态在给定的瞬间只是当前时间的输入函数那么它就是静态的，并且被认为没有记忆功能。此外，由于动态系统的状态是所有过去的输入的结果，因此输入的未来值对状态没有影响，动态系统被称为非预期的或者是因果的。同样的，如果系统的状态是输入的未来值的结果，则这个系统被称为可预测的或非因果的。事实上，我们不需要担心后者，因此所有我们学的系统将被假设为因果的。

Obviously, a mechanical system is a system composed of mechanical elements. If this system complies with the definition of dynamic system, then we end up with a dynamic mechanical system. For brevity, we will refer to such systems as mechanical systems, the dynamic property being implicit throughout the book. Mechanical systems of this type are those that occur whenever the inertia of their elements is accounted for. Static mechanical systems are those in which inertia is neglected. Moreover, the elements constituting a mechanical system are rigid and deformable solids, compressible and incompressible fluids, and inviscid and viscous fluids.

显然，机械系统是由机械元素组成的。如果这个系统遵从动态系统的定义，那我们就得到了动态机械系统。未来简便，我们把这种系统称为机械系统，它的动态特性在整本书中都蕴含。这种机械系统是只要考虑到它的原件的惯性就会发生的系统。静态机械系统是那些惯性被忽略的系统。此外，组成一个机械系统的元素是刚性的和可变性的固体，可压缩和不可压缩的流体，粘性和非粘性的流体。

From the foregoing discussion, then, it is apparent that mechanical systems can be constituted either by lumped-parameter or by distributed-parameter elements. The former reduce to particles; rigid bodies; massless, conservative springs; and massless, nonconservative dashpots. The latter appear whenever bodies are modeled as continuous media. In this book, we will focus on lumped-parameter mechanical systems. In mechanical systems, the driving forces and moments exerted by the actuators and the environment play the role of the input, the set of signals picked up by the sensors that of the output. Finally, the rules of transition are dictated by the laws of nature, especially from mechanics, electromagnetics and biology.

从前面的讨论可知，显然机械系统可以由集中参数或者分布参数元素组成。前者归纳为粒子，刚体，无质量的保守弹簧，无质量非保守阻尼器。当物体被建模为连续介质时后者将会出现。在这本书里，我们将专注于集中参数机械系统。在机械系统中，驱动器和环境施加的驱动力起着输入的作用，传感器接收信号集，起着输出的作用。最后，转换的规则是由自然法则决定的，尤其从机械，电磁学，生物学之中。

Furthermore, a mechanical system can be either natural or engineered, the latter being the subject of our study. Engineered mechanical systems can be either controlled or uncontrolled. Most engineering systems are controlled mechanical systems, and hence, we will focus on these. Moreover, a controlled mechanical system may be robotic or nonrobotic. The latter are systems supplied with primitive controller

剩余内容已隐藏，支付完成后下载完整资料

资料编号：[238296]，资料为PDF文档或Word文档，PDF文档可免费转换为Word