ABSTRACT
This chapter introduces the Bode plot as a way of representing the performance of a dynamic system in the frequency domain. Patterns in the Bode space will allow inferences to be made about the order of control, the presence and magnitude of time delays, and the stability of a control system. The inverse relation between frequency and amplitude together with the one quarter cycle phase shift is the frequency signature for an integrator. The frequency of a sine wave determines how many cycles are completed in a fixed time. Bode analysis, however, can be used to discover the transfer function of a black box. The process of Bode analysis involves presenting sinusoidal inputs to the black box at different frequencies. The Bode plot is a useful convention for representing the change in amplitude and the phase shift that is produced by a particular linear system.
