Hi Matteo, can't you mark one of the spokes or the wheel and setup the camera in a distance so that a blob tracker can cope with it? Then, it's fairly easy to measure something like the zero-crossing rate along one dimension x or y. gr~~~
Am 02.09.2010 um 17:54 schrieb Matteo Sisti Sette: > Hi, > > I need to measure the rotation speed of a spoked wheel. > > As an alternative to a suitable sensor + arduino, I was considering using a > webcam placed very close to the wheel and counting the frequency at which the > spokes pass in front of the webcam. > > Has any of you tried anything similar? Do you have any suggestions? > > > My naïf idea is that if a (natural or artificial) source of light is placed > in front of the webcam, when the spoke passes in front of it, it will reduce > considerably the brightness of the whole frame or of a big portion of it. > > I'm looking for something simple: if this eventually leads to a complicated > artificial vision task, or if a good calibration is difficult to achieve, > then I would rather go for a tachometer and an arduino... > > > Thanks in advance > m. > > _______________________________________________ > Pd-list@iem.at mailing list > UNSUBSCRIBE and account-management -> > http://lists.puredata.info/listinfo/pd-list _______________________________________________ Pd-list@iem.at mailing list UNSUBSCRIBE and account-management -> http://lists.puredata.info/listinfo/pd-list
