Re: [Electronics_101] Re: More moto ECU tricks
- On Mon, Jan 28, 2013 at 5:13 PM, rtstofer <rstofer@...> wrote:
> **The pot/butterflies are calibrated to be certain values at full open /
> --- In Electronics_101@yahoogroups.com, Aaron Turner wrote:
> > One thing that probably simplifies things a bit is that based on the
> > information I have, I don't think the motor is PWM driven- it's just
> > a solid 12V in either direction. I just ordered a Rigol 1052E, so I'll
> > be able to find out soon.
> You might be able to find out if PWM is in use if you can force a small
> position error by manually pushing on the mechanism. For a small and
> unsustained error, the output of the PID -> PWM would be a series of narrow
> pulses getting wider as the error remains longer.
> As the error gets larger or remains longer, the pulse width will increase.
> As the error goes to zero, the pulses will get narrower and eventually
> At least that my current guess - knowing, as I do, absolutely NOTHING
> about ECUs.
> Lacking limit switches, I wonder how the ECU knows when the throttle has
> reached the end of its mechanical motion. If it is based on the value of
> the potentiometer, that implies that the ECU knows a LOT about how the pot
> is rigged to the mechanism. Perhaps it just jams the motor in one direction
> until the pot quits moving and calls that one end. Then it tries the other
> end. Perhaps it is guaranteed to run out of potentiometer before it runs
> out of mechanical space.
closed. From what I've seen, it just jams the motor in one direction when
the pot is disconnected.
> Do these throttle plates modulate as the engine is running under load? DoOverride? yes and no. there are two sets of butterflies in series. So if
> they override the grip throttle? Boy, I would hate to have a disagreement
> with the computer when I was laid over in a corner. I learned something new
> about shaft drive the first time I got in too deep and then backed off the
> throttle. OOPS!
I was giving full throttle and the ECU decided 0%, it could close it's
butterflies and the effective airflow would be 0% throttle. My
understanding is that the ECU controlled butterflies are only used in low
RPM situations so the risk is a lot lower for bad things to happen. Either
way, there's really no reason for them to be installed on a race bike and
since they're in the way, off they go!
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