ABSTRACT

This chapter discusses the steady state response of a system to a sinusoidal input signal sinusoid. It observes that the response of a linear time-invariant system to a sinusoidal input signal is an output sinusoidal signal at the same frequency as the input. The chapter investigates the steady state response of the system to sinusoidal inputs as the frequency varies. Hence, the frequency-response design method offers a practical and important alternative approach to the analysis and design of control systems. A Bode plot gives the magnitude and phase of a system in response to a sinusoidal input for a range of frequencies. Each point on the Bode plot represents the system response for a given frequency input. Bode plots can be used to derive system models or verify models by using information from experimental frequency data. Nyquist analysis is a graphical procedure carried out in the frequency domain in order to determine absolute and relative stability of closed-loop control systems.