links to our projects:
http://www.sourceforge.net/projects/aion/
http://www.sourceforge.net/projects/firmataplus/
http://www.dataczar.com/
Today we spent some time building the new turret and worked on auto-calibration for our playeratat software.
We're creating the new turret using DC motors with optical encoders to increase power and prevent the step-skipping we've been getting with the stepper motors on the current turret implementation. The step-skipping has forced us to slow the motors down considerably from what they should be. By switching to DC we should be able to dump as much power as we want into the motors without worrying about loss of accuracy.
Since the previous competition we increased the size of the stepper motors on the original turret and we added a color camera to the base to enable auto-calibration (not yet implemented). The increased motor size allowed us to increase the speed because the skipping "stall" threshold was reduced, however we are still limiting the speed considerably to prevent skipping. Skipping must be prevented because in the absense of sensors to indicate the turret position, it is impossible to know the position of the turret if a skip occurs.
The new implementation turret includes optical encoders to feedback motor position information. DC optical motor controllers are on order for the new turret. We have Player (http://playerstage.sourceforge.net/) drivers integrated for the current stepper-motor implementation. When the new motor drivers are received we'll probably need to create custom Player drivers for them as well.
