Response of a particular nonlinear control system to random signals

The response of an electromechanical control system, which incorporates by design a hard-spring amplitude characteristic, is evaluated for inputs having a Gaussian amplitude-probability distribution and no constant components. These inputs are considered not as noise, but as true signals. The analysis is limited to a system with a second-order characteristic equation and is based on a general extension of the describing function technique. The control system considered is simulated on an analogue computer and experimental verification of the analysis is obtained.