什么是伺服系统？该系统的主要组成部件有哪些？

维基百科有相关的介绍，

The Meaning of Servo System

Servo is the abbreviation of ServoMechanism, which comes from Greece, and its meaning is slave. As the name suggests, it means that the system follows external instructions to perform the desired movement, and the movement elements include position, speed, torque and other quantities.

Servo是ServoMechanism的缩写，来源于希腊语，意思是奴隶。顾名思义，是指系统按照外界指令进行所需的运动，运动指令包括位置、速度、扭矩或其他的控制量。

一个伺服系统的构成通常包含受控体（plant）、致动器（actuator）、传感器（sensor）、控制器（controller）等几个部分。

伺服控制系统的基本组成，

参考链接：

https://medium.com/@m.stepperonline/what-is-a-servo-system-brief-introduction-19c055b68709

科尔摩根在自己网站的一篇博客中提到了伺服系统，

In its basic form, a servo system consists of an actuator (the muscle), a control device (the brain), and a feedback element (the senses). In the automation world, while the muscle can be a variety of mechanisms, it is most likely represented by a servo motor. The brain can also be represented by a variety of elements but is typically a motion controller or servo drive. The sense provides feedback information to the brain through a current sensor and/or an encoder, resolver, or even a vision system.

参考链接

https://www.kollmorgen.com/en-us/blogs/what-are-basic-elements-servo-system

因此伺服系统，基本组成包括驱动器、伺服电机、控制器、反馈装置（传感器）以及被控负载。

参考链接：

http://www.wiki-kollmorgen.eu/wiki/DanMoBilder/file/s300s700help/reference/overview_servo_drives.htm