Patent ID: 7426426
Filing Date: 2008-09-16
Classification: G01M

Abstract:
1. A system for simultaneously controlling both frequency spectrum and kurtosis of a random vibration, comprising: at least one transducer for measuring motion of a test object, the transducer produces an output; an analog-to-digital (A/D) converter to convert the transducer output to a digital motion signal; a first converter to convert the digital motion signal to a power spectral density (PSD) representation; a first comparator for comparing the signal PSD to a reference PSD for compensating a desired drive PSD for error; a second converter to convert the digital motion signal to a kurtosis value; a second comparator for comparing the kurtosis to a reference value, the second comparator produces an output for compensating the kurtosis of a noise generator for error; a noise generator with kurtosis set by the output of the second comparator, the noise generator produces an output; a third converter to convert the desired drive PSD to a filter function; a filter to shape the frequency spectrum of the output from the noise generator to produce a digital drive signal; and a digital-to-analog (D/A) converter for converting the digital drive signal to an analog signal to drive a vibration generator.