Servo Resolution Of Movement Question

@DJ_Sures I know that you can send a fractional degree to a servo via the Servo() instruction, for example 60.379. But, does the servo really move to 60.379 degrees or is the actual movement rounded down to 60? If it does move to a fractional degree, what is the resolution to which it can be set? Thanks.

PRO
USA
#1

The servo positions are rounded to integers.

#2

@ptp Pretty much what I thought. Thank you very much for your quick reply.

#3

Also note, there are 180 positions, but that may not equal degrees depending on the servo. It is pretty close on the EZ-B servos (I think they actually go a little further but not far), but there are servos with wider ranges. Winch servos (used on r/c sailboats) go 2.5 times around between min and max setting, so each position sent fron ARC would be about 5 degrees (900 degrees divided by 180 positions).

Alan

#4

@WBS00001 If hobby servos had that much resolution you could use them for robotic surgery. I would even be able to get my inMoov to thread a needle LOL .... Stepper motors on the other hand have a very high movement resolution... A 3d printer is a good example of a stepper's hi res capabilities...

PRO
USA
#5

Yes the world is ready for new servos. I have been using the same servo from 30 years ago. They are still noisy and resolution is low. If someone can design the 21st century servo for robots, will have another revolution on the their hands...see what i did there?

#6

I think Dynamixals are a good (if expensive and somewhat quirky) start. Having built in position feedback is probably as or more important than having more incremental positions. Amd in fact, I believe you could get more positions, just ARC mafe the decision to define 180 to closely match the degrees of movement on most servos. If you recall, the V3 had 100 positions across 180 degrees of movement, which lead to a lot of confusion, so I don't think this is so much a technical issue but a usability one.

If we can make a case that we need 1/2 degree resolution, I think that DJ could easily code it (although I am not sure if it would require firmware change or just software), but like everything, it would need to fit in the rest of the wishlist items and I imagine the demand is not very high).

Alan