Mechanical vibration system and control method with limited displacement

摘要

A control method for a mechanical vibration system independently modifies the higher and lower frequency components of the drive signal satisfying a target profile in a manner that limits displacement in the driven vibration. In particular, phases of the lower frequency components in a preliminary drive spectrum are independently adjusted so that peaks of the respective components are non-simultaneous and distributed in time to avoid contributing constructively. For example, the lower frequency components may be applied as a filter to a narrow-band time waveform, such as one with a swept frequency, to obtain the lower-frequency time waveform. The higher frequency components are randomized in their phase, transformed into the time domain, and recombined with the lower frequency part to obtain the drive signal.

主权项

1. A method for controlling a vibration-producing device for limited displacement, comprising:
continuously sensing vibration from the device to obtain a vibration signal in time domain; transforming both the vibration signal and a drive signal into frequency domain to obtain frequency spectra of the respective vibration and drive signals; calculating an inverse frequency response function from the frequency spectra of both the vibration and drive signals; adjusting the inverse frequency response function with a target profile that represents a desired spectral content of the vibration from the device so as to obtain a preliminary drive spectrum; independently modifying higher frequency and lower frequency components of the preliminary drive spectrum, including combining the higher frequency components with components of a randomized phase and converting the randomized signal back into time domain to obtain a higher-frequency time waveform, and modifying the lower frequency components by applying the lower frequency components to a narrowband time waveform having a low frequency range that is swept in time over the lower frequency components then converting the modified lower frequency components into time domain to obtain a lower frequency time waveform; combining both the higher-frequency and lower-frequency time waveforms together to obtain the drive signal; and applying the drive signal to the vibration-producing device.