Comparison of frequency response analysis technique and transient response analysis technique in control systems

The transient response analysis of a control system analyzes the control system response to a sudden input such as the initial deflection of a structure due to an impact load and the subsequent vibration of the structure due to the initial impact load. The frequency response of a system is defined as the steady-state response of a system to a sinusoidal input. The response characteristics of the system resulting from different frequencies are a necessary design component for loading conditions that are cyclic in nature. An example of a sinusoidal input is the influence of a jet engine which is a rotating equipment rotating at a certain frequency during its steady state operation on the aircraft wing. This steady state frequency cannot be close to the lower natural frequencies of the wing due to the resonance effect. Another example is analyzing a structure for its earthquake response in place of a single or a series of impact loads. This article presents both transient analysis and frequency response analysis examples. The examples were used as lab assignments in a computer lab portion of a controls course.