Frequency response analysis methods for open-loop servo drives and control systems

The paper presents results of development of frequency response analysis methods for open-loop servo drives and control systems, which use frequency response data of closed-loop servo drives and control systems obtained using Fourier and Laplace transforms of transient response calculated using their linear or linearized math models. The methods that have been developed can be used for approximate calculation of frequency response of servo drives and control systems based on their math models with slight non-linearities. Equations are derived for calculating frequency response of open-loop servo drives and control systems for several particular cases of feedback loop transfer function. The paper studies the efficiency of the developed frequency response analysis methods for open-loop servo drives and control systems. The obtained frequency response data for open-loop servo drives and control systems can be used for evaluating the amplitude and phase stability margins for these entities.