VR001 Mide Technology Corporation, VR001 Datasheet - Page 12

• Manufacturer Part Number: VR001
• Description: VIBRATION DATA LOGGER
• Manufacturer: Mide Technology Corporation
• Series: Slam Stick™, Volture™r

Specifications of VR001

• Featured Product: Slam Stick™ Vibration Recorder
• Accessory Type: Vibration Characterization Device
• Lead Free Status / Rohs Status: Lead free by exemption / RoHS compliant by exemption
• For Use With/related Products: Volture™ Vibration Energy Harvesters
• For Use With: V25W - PIEZOELECTRIC ENERGY HARVESTERV20W - PIEZOELECTRIC ENERGY HARVESTERV21BL - PIEZOELECTRIC ENERGY HARVESTERV21B - PIEZOELECTRIC ENERGY HARVESTERV22BL - PIEZOELECTRIC ENERGY HARVESTERV22B - PIEZOELECTRIC ENERGY HARVESTER

APPLICATIONS INFORMATION
A series of vibration recordings were taken during a
flight on a commercial jumbo jet. The first was taken
during taxiing; the second taken during active flight. In
each case, the recorder was placed on the floor of the
craft with the button facing upward (Z-axis normal to the
ground). The time-domain result is shown in Figure 2.
Figure 3: 1-D FFT of the time domain data shown in Figure 2.
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10
8
6
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2
0
Vibration v. Frequency
x 10
-3
-0.5
2.5
1.5
0.5
200
-1
2
1
0
Vibration v. Time
400
600
Frequency (Hz)
Figure 2: Time domain response of a commercial jumbo jet during taxiing.
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REVISION N0. 001
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1200
1400
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REVISION DATE: 08-24-2010
Time (s)
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Unsurprisingly, the greatest energy is seen in the Z
direction. The 1-D FFT result for this axis, shown in
Figure 3, shows several features that may be of interest.
The first is a comparatively strong peak at around
920Hz, some extremely low-frequency components
(1.5Hz and 5Hz), and a broad swath centered around
260Hz or so. What’s producing these features, and are
these consistent? Would any of them be useful in an
event triggering or energy harvesting application?
For a more detailed look at the vibration profile, the 2-D
FFT was plotted with a low ceiling value (~ 0.05) in
order to clearly show each feature of interest. For this
Figure, the surface plot was rotated so that it is viewed
directly from the top. Some of the identifiable features
have been labeled.With this image, the contributors
become more clear. The 920Hz peak is extremely
consistent both in time and frequency, most likely
contributed by the aircraft Auxiliary Power Unit (APU).
Although it appears to have the highest amplitude in the
1-D result by far, it is not the highest amplitude signal
after all – those in the 150-375Hz range have higher
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X
Y
Z
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