Camera vs. Shimmer

Below is a graph of the distance (in pixels) that a ball travels following a strike from the cue vs. the strength exerted by the player on the cue.I recorded myself for about 10 minutes striking a red ball down the table (red for good contrast against the blue surface) at different strengths, some soft some hard. The shimmer was attached to the cue and reacted to a strike by a sudden spike in its data values, particularly on the y axis. The data was then processed by cutting before and after images of each shot out of the video and measuring the distance between the ball's positions, the shimmer data was exported to Excel (this resulted in approx 42,000 rows X 3 columns (x,y,z axes)). With Excel, by plotting graphs I identified the shots. While experimenting, to serve as a divider between each shot, I shook the cue vigorously. Once I identified the shots,I took the difference between the max and min values of y axis and plotted this vs. the distance calculated.

The following graphs illustrates this:


Shake

Shot

Final 4 weeks!

Well since the last time I wrote on this, midterm presentations are finished and we are now entering into the final 4 weeks of the programme!

The camera and shimmer are working well together and I've got some experimental results on distance and the force on the cue........finally!

I've just started to write some sections of my report so as not to leave it all to the last minute!

I hope to have a good working demo by the end of the next four weeks even though alot of work has to be done in the meantime!

What this demo will actually be is yet to be determined.....it'll be a surprise..... :)

Update (03.07.2009)

Update..........

I have the camera set-up and pool table in position! I've finally had some success with the shimmer - I can now use it to calculate the angle of the cue to the table and it's also giving me some visual output, so now I know how the striking of a ball appears via the shimmer.

Distance can be measured (in pixels) by using the mouse to click on the two points you want to measure between. With some experimentation, 1 pixel is equivalent to approximatly 0.61cm. However, this is useless for measuring the distance the ball travelled, so camera tracking is now my main priority. Not only is it the best way to measure the distance the ball travelled on the table, it will also be essential when dealing with angles later,so it is a key ingredient to the success of the project.

Following this Fridays meeting with Benoit, we decided on trying to use matlab for camera tracking, if this is unsuccesful or taking too long, to look into using some other ways and output data we need to matlab such as distance & angle.

Fingers crossed......