A Performance Analysis System for the Sport of Bowling

3.6.1 Implementation and Performance
There are several performance issues with the current version of the MASTER software
that are currently being addressed.
• The coefficient of friction calculations from Section 3.4.3 have not yet been
incorporated. Instead, a command-line argument specifies the percentage of the
change in angular momentum that is lost due to friction. For this paper, frictional
losses were set at 10%.
• A somewhat less accurate method for deriving the linear velocities than that
described in Section 3.3 is currently implemented. This method derives the
average linear momentum from the average linear velocity of the ball, and
calculates the average angular momentum from the angular velocities for each
revolution. Although this yields the proper shape for the waveform, it
misrepresents the magnitude of the linear velocities. See vCalcVelocityData in
Figure 3-8 for more detail.
• The current linear velocity extraction algorithm does not check for roll out of the
ball (that the angular velocity is decreasing). Therefore, under the constant
energy assumption, when the angular velocity begins to decrease, the calculated
linear velocity increases. The graph in Figure 3-9 demonstrates this phenomenon.
Figure 3-9: Effects of Roll Out, "Analysis" Screen Capture
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