ABSTRACT
Chapter 1 introduces the basics of feedback control. The purpose of feedback is to make the output insensitive to plant parameter variations and disturbances. Negative, positive, and large feedback are de‘ned and discussed along with sensitivity and disturbance rejection. The notions of frequency response, the Nyquist diagram, and the Nichols chart are introduced. (The Nyquist stability criterion is presented in Chapter 3.)
Feedback control and block diagram algebra are explained at an elementary level in Appendix 1, which can be used as an introduction to this chapter. Laplace transfer functions are described in Appendix 2.
