A Performance Analysis System for the Sport of Bowling

3.8 SUMMARY - MASTER ANALYSIS
The SMARTDOT concept was predicated on the assumption that the action of a bowling
ball could be captured by sampling and recording the ambient light level at a single point
on the ball as the ball rolls down the lane. This concept was developed in two stages:
first, by building an in-situ sensor module that captures and uploads the waveform; and
second, by deriving and implementing a set of algorithms that filter, analyze, and display
the captured waveform.
It was assumed that the digitized waveform would be sinusoidal in nature, with the peaks
and valleys of the waveform occurring at 0° and 180° of rotation, respectively. In
actuality, the digitized waveform required some "massaging" through adaptive digital
filtering before the analysis process could be automated. Further, the discrete rows of
overhead fluorescent lights imprint a Doppler-like effect on the filtered waveform,
resulting in apparent oscillations in the angular velocity of the ball, especially on the first
half of the lane (closest to the foul line).
A polynomial curve-fitting scheme was used to smooth out the angular velocity
waveform, and the linear velocity of the ball was recovered through energy conservation
techniques, combined with certain assumptions about the effects of friction. From the
linear velocity, it was possible to find the distance the ball was lofted at release, and the
location of each revolution of the ball relative to the foul line. A method for finding the
coefficient of friction between the ball and the lane was also derived, although this
technique has not yet been implemented.
Another problem that arose from the analysis was that of "phase shift", where the pin
deck light overpowers the ceiling lights and imposes a sudden phase shift on the
waveform immediately before the ball hits the pins. This phase shift occurs in the last
revolution of the ball, and can drastically affect the resulting analysis. The effects of the
phase shift can be removed by excluding from the data passed to the digital filter the 50-
75 msecs (6-9 samples) of the waveform immediately preceding impact. Before
proceeding with the remainder of the analysis algorithms, the filtered waveform is
extrapolated back into the samples that were previously excluded.
It is important to note that all of the waveforms used for development of the MASTER
algorithms have originated from the author's use of the SMARTDOT system. As such,
testing of the SMARTDOT system with a wider range of users is mandated, and further
refinement of the algorithms will most likely result. Ultimately, the results of the
MASTER analysis algorithms must be verified and validated with formal testing. That
testing could also be used to reveal which algorithms are the most applicable to the
SMARTDOT system.
Admittedly, there is much development, verification, and validation yet to be done.
However, this phase of the project has shown that the SMARTDOT system, as described,
is a feasible and viable method for quantifying and assessing a bowler's level of
execution and performance.
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