Signal synthesis and analysis for swept-sine vibration control

The objective of a swept-sine test is to subject the device under test (DUT) to a low-distortion sinusoidal vibration environment of smoothly changing frequency and amplitude. The testing also requires that the controller be able to measure the response of this type of excitation. The output swept-sine wave generation has been accomplished using the governing differential equation for the phase function associated with the linear sweep and the logarithmic sweep mode. This method has increased the accuracy of the output signal and has the suitability of heterodyne generation. The purpose of the heterodyne is to translate the response signal spectrum about 0-Hz. The term at DC either represents the root mean square (RMS) or the real and imaginary components of its AC amplitude. The 0-Hz intermediate frequency detector implements tracking filter and root mean square processing by a low-pass filter that extracts the DC component. The engineering practice proves that the technique of digital signal processing can be applied to time-variable spectral analysis of the swept-sine wave.