Motion Capture with MATLAB and a Webcam

Last semester, I had a class project where we had to develop a model for a car or truck’s suspension.  We used a half car model and had 2 people stand over the rear axel of a truck and jump out, then analyzed the reposnse to find the parameters of the model.  Most groups just held a tape measure up against the car and videotaped it, which we also did as a backup, but I also wrote a quick MATLAB script to capture the response of the system.

Basically we just drapped a darkish sheet across the truck, with a while shape pinned onto it.  The script captures all of the frames using a webcam, at 30fps.  After the video is all captured, their contrast it upped, they are converted to black and white, and the centriod of the whitespace is found.   Once a baseline conversion from pixels to meters is found, it is pretty simple to take the height over time and find a generic model.

All of the code can be found here:

https://github.com/wdm0006/MoCapSuspensionModel