四川大学自动化专业英语Chapter two.pptVIP

Chapter two Transfer Function Models of physical Systems Introduction In this chapter differential equation are derived to describe the dynamic behavior of mechanical, electrical, thermal(热力的), and fluid（流体） systems. These are used to obtain transfer functions between selected variables. The same differential equations can also be formulated into state-space models. This alternative, mentioned in Section 1.5, is discussed in Chapter 12. Assignment (1)Reading the remainder of this chapter, and write English equivalent of the following key words: 弹簧，阻尼器，质量，惯性，杠杆，（外、内）力，阻力，齿轮，摩擦力，重力，转矩，分压器，阻抗，电动机，发电机，T-桥网络，电路，扭转，角度，旋转运动，励磁，电枢 (2)Reading example 2.8.1 (p59~60) How does the value of gain K impact on the behavior of transient and steady-state responses of the DC-motor position Servo system (using your words in English.) * The chapter will concentrate on(把…集中在…上；全神贯注于 ) subsystem blocks, with attention to the restrictions that must be observed when separating a system into blocks. Block diagram reduction can then provide overall system transfer functions. For many system that include feedback control, the division into blocks is far from(完全不) obvious. Such system, in which all system equations and the block diagram are derived directly, are discussed in Chapter 4. Frequently, the precise nature of the feedback may be evident only from this block diagram. Introduction It is useful to note that a model should not be expected to be evident “by inspection“. Rather（更确切地说） , it usually will emerge gradually from equations written for parts of the system(过去分词短语做定语). Introduction 应该注意到，不应期望一个模型仅通过观测（就能得到）那么明显，它通常是从对系统各部分所写的方程中逐渐得出的 Mechanical System Fig.2.1 shows common elements of mechanical system with linear and rotational（a.旋转的） motion（介词短语做定语）, together with equations used to describe them. It is noted that in Fig.2.1 and diagrams to follow（状语从句）, the arrows identify the positive directions of the associated variables（It所代表的主语在此）. (1) Spring（弹簧）: These occ