In the paper, based on "contactless" sensing technology and taking advantage of high-speed, high-resolution camera motion to seize image of operation driving part in the operation of HVCB, we proposed a method of image analysis and trajectory tracking technology to obtain the variable components, according to travel-time curve of circuit breaker to calculate the moving contact observation travel, (open) close time and velocity, and so forth.
Mechanical parameters of circuit breaker can be calculated by travel-time curve.
The increase of velocity with depth may usually be reliably excluded, if there is a larger number of points on the travel-time curve and these display linear dependence of time on distance.
By measuring the travel time over several distances between the source and receiver a linear travel-time curve can be obtained.
The velocity was determined from the slope of the differential travel-time curve.
In identifying the S-wave arrival times, mutual comparison of the separate travel-time curves was found to be of principal importance and, therefore, it was necessary to have the possibility of changing from displaying the data on one travel-time curve to displaying the data on another travel-time curve.
In particular, the Wichert-Herglotz method requires a smoothed travel-time curve
with monotonous derivatives, which the DSS data usually do not satisfy.
By reducing their positions to correspond to a single travel-time curve
, it was possible to determine the velocity by fitting a straight line to all 24 times on the reduced travel-time curve
The smoothed travel-time curve
in the form (1) was then interpreted by the Wiechert-Herglotz method.
In order to obtain a long travel-time curve
, we have joined data from separate plutons.
This method is based on the averaging of group velocities for each period from all travel-time curves
1980, Partial derivatives of travel-time curves
of reflected waves in a layered medium.