US 7,426,426 B2 · System and method for simultaneously controlling spectrum and kurtosis of a random vibration

Abstract

A system and method for producing and controlling a random signal with simultaneous control of both the power spectral density (PSD) and kurtosis (100) where a controlled signal is measured from a transducer, and converted to a PSD (111) using a Fast Fourier Transform (FFT). The measured PSD is compared (117) with a reference PSD (121) where an adaptive filter (119) is updated to compensate for the error. Simultaneously the kurtosis of the measured data is computed (125) and compared to a reference kurtosis (123). A feedback control loop (127) is employed to adjust the kurtosis of a white noise random generator with variable kurtosis (101). This white noise is then filtered by the adaptive filter (119) to provide the output signal used to drive the control process.

Claims12

Dependent claims

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.

8 more elements

Dependencies are inferred from the claim text.

System and method for simultaneously controlling spectrum and kurtosis of a random vibration

Life of this patent

System and method for simultaneously controlling spectrum and kurtosis of a random vibration

Life of this patent

Abstract

Claims12