Stub in hooks for Propeller feathering controls and the turbo prop "condition"
lever.
I added a line in FGFDM.cpp to force control properties to exist if they
don't already. This way you can specify anything you want and find them
in the property browser, otherwise no one else may create them and you are
stuck.
In PropEngine::solve() the code original sets _running = true at the
beginning and then sets running = false at the end. I changed this to
save the current value at the start, set to true, solve(), and then
restore the original value at the end. That way if we start off with
_running = true, we don't have to hack up the calc() routine which wasn't
using the value anyway.
Finally I added some very initial support to shut down a turbine engine
(_running = false) when the condition lever goes to zero.
PistonEngine class has grown an "Engine" superclass. Some other stuff
moved around too, and I cleaned up some property naming while I was in
there. This hasn't been tested very thorougly, hopefully I didn't
break anything.
The Propeller class ignored negative RPM but still returned a torque
value, which ratcheted up a higher and higher negative RPM until drag
overwhelmed the aircraft.
In reality, the propeller should windmill at a reasonable postive RPM,
introducing a constant drag on the aircraft -- the propeller should
*not* stop unless the plane is flying very slowly. That's a future
project.
> > Here's a patch to add manual-pitch control to the propeller in YASim. A new
> > control axis "PROPPITCH" is added. Requires "manual-pitch" boolean property
> > in the "propeller" tag.
> >
> > Tags and Properties to add in order to enable:
> >
> > manual-pitch="true"
> >
> > <control-input axis="/controls/engines/engine[0]/propeller-pitch"
> > control="PROPPITCH" src0="0" src1="1" dst0="0.40" dst1="0.80"/>
> >
> > Note that for the time being, excessively low RPM or excessively high RPM is
> > brought undercontrol by a scaling range defined in the control-input tag
> > (see "dst0" and "dst1" properties).
Dynamics (Sim)ulator. Basically, this is a rough, first cut of a "different
take" on FDM design. It's intended to be very simple to use,
producing reasonable results for aircraft of all sorts and sizes,
while maintaining simulation plausibility even in odd flight
conditions like spins and aerobatics. It's at the point now where one
can actually fly the planes around.
