Research on Test Conditions of Sealed-Relay Remainders Based on High-Speed Video Technology - Intelligent Computing for Sustainable Energy and Environment - page 513

b) The speed of remainders and test objects is very low while a m is low, which is
disadvantageous for detection.
c) If other conditions are fixed, there is a threshold in the acceleration peak value, if
a m is lower than the threshold, increasing a m can improve y average significantly; if a m is
higher than the threshold, the effect of increasing a m is significantly reduced. In the
table, the thresholds and corresponding y average are recorded in italic.

It should be noted that remainders may be confined inside the relay for a number of
reasons. If a m is very low, it may not activate remainders [16].

3.2 The Improved Test Conditions for Relays with a Transparent Shell

Test conditions were also researched for relays with a transparent shell. Bearing Steel
balls were selected as remainders, r are 1.5mm and 1mm respectively and the sizes of
two relays are 30mm × 30mm × 40mm and 20mm × 20mm × 20mm. Remainders
were put in relays and tested with varying frequency and acceleration conditions; and
likewise, 50 images were selected.
According to the experimental results and analysis, it is recommended that the test
conditions of PIND for sealed relay could be improved if the following principles are
adopted:

a) The test frequency range should be between 20Hz and 90Hz.
b) The step value should be reduced in the low frequency range (20Hz-40Hz), and
more tests within this frequency range should be attempted.
c) In order to overcome the binding, a m higher than the standard ones should be
used if the test objects are not damaged.
d) For the test objects with large height dimension, a m higher than the standard ones
or f lower than standard ones should be used to improve the success rate of detection.

4 Conclusions

Test conditions of sealed-relay remainders have been studied based on high-speed
video technology. The main conclusions are as follows:
a) A movement-analysis method of remainders based on high-speed video
technology have been developed; corresponding image processing algorithms and
motion parameters extraction algorithms have been designed. The motion parameters
of remainders and test objects can be extracted automatically using this method.
b) Based on the method, it is found that the detection effectiveness is inversely
proportional to the test frequency, and proportional to the acceleration peak value; the
phenomenon of approximate periodic collision vibration of remainders and thresholds
in the test acceleration peak value are found.
c) According to the experimental results, suggestions for improvement of PIND test
conditions have been proposed, which can improve the success rate of detection of
remainders in sealed relays.