Random Vibration Control for Non-Gaussian Velocity and Displacement
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Solution Overview
Problem
Current vibration control systems for random vibration testing struggle to maintain non-Gaussian properties for kinematic quantities like velocity and displacement while adhering to prescribed acceleration PSD, often leading to test interruptions due to exceeding maximum specifications.
Innovation Solution
A vibration control system that uses acceleration sensors to control the vibration of test objects by calculating and modifying corresponding physical quantity PSDs and waveforms, ensuring non-Gaussian characteristics for velocity and displacement while maintaining the reference acceleration PSD, through techniques like clipping and phase manipulation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the acceleration signal follows Gaussian distribution to satisfy reference acceleration PSD, then the acceleration PSD requirement is met, but the velocity and displacement signals inevitably exceed maximum specifications causing test interruptions
Solution Approach 1:
The system performs preliminary waveform processing by clipping the velocity and displacement waveforms before generating the drive signal. This preliminary action prevents the kinematic quantities from exceeding maximum specifications during the actual test, thereby avoiding test interruptions while maintaining Gaussian acceleration PSD characteristics.
Solution Approach 2:
The system changes the statistical parameters of the velocity and displacement signals by applying clipping operations that limit their peak values. This parameter modification allows the signals to maintain controlled peak levels (within maximum specifications) while the acceleration signal preserves its Gaussian distribution properties, resolving the contradiction between test continuity and kinematic quantity control.
2Manufacturing precision
If the velocity and displacement signals are clipped to prevent exceeding maximum specifications, then test interruptions are avoided, but the Gaussian property of the acceleration signal is compromised
Solution Approach 1:
The system dynamically adjusts the drive waveform generation process by separating the clipping operation from the acceleration signal generation. The clipping is applied to the integrated velocity and displacement waveforms, while the acceleration waveform maintains its original Gaussian-random characteristics. This dynamic separation allows precise control of velocity and displacement peaks without compromising acceleration PSD accuracy.
Solution Approach 2:
The system segments the waveform processing into distinct stages: generating Gaussian-random acceleration waveform, integrating to obtain velocity waveform, integrating again to obtain displacement waveform, and then clipping the velocity and displacement waveforms separately. This segmentation allows independent optimization of acceleration PSD characteristics and velocity/displacement peak control, resolving the contradiction between maintaining Gaussian properties and preventing specification exceedance.
3Object-affected harmful factors
If the maximum peak values of velocity and displacement are strictly controlled, then safety limits are maintained, but the natural Gaussian distribution characteristics are lost
Solution Approach 1:
The system creates a copied version of the acceleration waveform for integration to generate velocity and displacement waveforms. This copied waveform is then clipped to enforce maximum peak value constraints. By operating on a copy rather than the original acceleration signal, the system maintains the stability and Gaussian characteristics of the acceleration distribution while imposing artificial peak limits on the derived kinematic quantities, thus preventing excessive vibration damage without compromising Gaussian stability.
Data Source
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AI summary
A vibration control system, while applying Gaussian vibration that matches a reference vibration physical quantity PSD to a test object, makes a corresponding vibration physical quantity non-Gaussian. Using a response vibration physical quantity PSD and a reference vibration physical quantity PSD, a vibration physical quantity PSD for control is generated by a vibration physical quantity PSD calculator for control. A PSD convertor converts the vibration physical quantity PSD for control into a corresponding vibration physical quantity PSD for control in another dimension. Using the corresponding vibration physical quantity PSD for control, a corresponding vibration physical quantity waveform that is non-Gaussian, is generated by a corresponding vibration physical quantity waveform calculator for control. At least based on the equalization characteristics and the corresponding vibration physical quantity waveform for control, a drive waveform calculator generates a next drive waveform such that vibration that matches the corresponding vibration physical quantity waveform for control is applied to a test object.