[bb]UPDATE - TERO is running IONI Pro HC - 9 Dec 2015[/b]
Hey All,
Just had a nice email from Tero.
During this past weekend, Tero and Aki had a first test-run of their MMos DIY wheel - yeay, lots of good things to come!!
They were so eager, fitted a wheel-rim, albeit on a very nice hub Aki has quickly done on the inhouse machinery. The hardware is based on the Disco board, MMos FW and IONI Pro HC. The servo has a Sin/Cos encoder and a is a scary 36 Nm (peak) motor.
Tero very quickly prototyped few ideas in firmware level (I can see a lot more of this coming very soon, I will follow up with another post, hopefully tonight, about recent discussions we had in Finland)
-Encoder output from IONI GPO pins routed to the Disco, this could give sin/cos resolution advantage to the Disco. However the first implementation has too much jitter in quadrature output which is pretty much negating the benefits - more work on this will be done
-Effects (spring, friction, damping, inertia) calculation ported to IONI. This immediately made an improvement over MMos, and will be fine-tuned
Tero is still not fully familiar with MMos' filter principles, but at least it's friction and inertia effects seemed a bit odd, he feels. Friction looks like "viscous damping" and inertia effect is very weird: at slow wheel speeds it resists movement, and at any higher speed it boosts it. However it may be, Tero will implement those functions directly to IONI to reduce latencies on those filters.
See Tero's video where he is testing his version, implemented directly on IONI:
https://youtu.be/KRt6gOg8Z3U
The reason why a lot of these effects and functions will move over to the IONI itself: If the simulator update rate is 60 or 120 Hz and all post processing is done on the IONI controller hardware, there should be no need for going above that update rate from USB. It should not make any difference in sending setpoints at 1kHz if it would just repeat same setpoint many times before the simulator gives a new value.
The above scenario of course only applies directly to the IONI. Of course, this is the fun-part of DIY DD FFB: We have a great drive-controller developer working very closely with the community, to improve and implement sim-specific functions directly onto the controller, to reduce latencies.
Tero will implement and test many things after our recent discussions, some will work, others won't, but the end result will be a very good and stable, low-cost powerful motor controller, which will allow you to select the motor of your choosing.
This here is a watershed moment for us, and we can expect rapid progress in this arena.
Will keep you posted with more.
Cheers,
Beano