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Case History Periodic Impulse Detection Vertical stripes indicate - - PowerPoint PPT Presentation
Case History Periodic Impulse Detection Vertical stripes indicate - - PowerPoint PPT Presentation
Production NVH Test Tools and Methods Case History Periodic Impulse Detection Vertical stripes indicate periodic impulse events Production NVH Test Tools and Methods Case History Periodic Impulse Detection Re-sample the file relative
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Production NVH Test Tools and Methods
Case History – Periodic Impulse Detection
4 Rev Frames stacked into a frame ensemble and viewed top-down form a matrix A column-wise variance statistic indicates periodic impulse
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Production NVH Test Tools and Methods
Case History – Periodic Impulse Detection
The impulse indicator shows angular position of recurring impulse events that are periodic A metric representing the maximum will define the severity of the impulsive event
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Production NVH Test Tools and Methods
Case History – Periodic Impulse Detection
The metric is added to the overall Decision matrix All metrics in the table are computed and tested simultaneously
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Production NVH Test Tools and Methods
Case History – Periodic Impulse Detection
Classification of the periodic impulse is a requirement
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Production NVH Test Tools and Methods
Case History – Periodic Impulse Detection
4Revs will show a repeating impulse pattern that can be quantified by the relative distance in revs of each impulse event
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Production NVH Test Tools and Methods
Case History – Periodic Impulse Detection
Qualifying peaks above a threshold produce a metric that returns the position
- f the peak in revs
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Production NVH Test Tools and Methods
Case History – Periodic Impulse Detection
A Formula metric is defined that will report the distance between peaks Rev 3 position – Rev 1 position will equal 2 if this a 1/cycle impulse in the first rotation of the shaft Rev 4 position – Rev 2 position will equal 2 if this a 1/cycle impulse in the second rotation of the shaft Subtract 2 to make the metric = 0 if a periodic impulse in the correct rotation is detected
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Production NVH Test Tools and Methods
Case History – Periodic Impulse Detection
If a formula metric is = 0, then a periodic impulse is found at the correct interval and position and the Boolean is TRUE A Boolean metric is created by testing the numeric formula result
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Production NVH Test Tools and Methods
Case History – Periodic Impulse Detection
On the Decision table, classification is simple and intuitive A 1/cyle impulse of sufficient amplitude was found A Boolean formula combines two booleans into a single result
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