Jörg Demtröder wrote:
> I am looking for information about the reliability of the RT sheduler.
> E.g. How many task can run and how precise I can organize the task to
> each other. The plan is to use this this system for flight simulation.
The stable releases of RT-Linux are really stable :-)
I have it installed on my workstation for more than half a year now
(24/7). It schedules dummy RT-Tasks in background all the time.
Never had a crashes caused by RT-Linux (ok, had crashes while trying ggi
and so on - but that has nothing to do with RTL)
Timing accuracy for (periodic)task-switching is about 10 microseconds.
Interrupt responce is better than 35 microseconds (surely better,
but only tried with a 35 microsecond deadline, yet).
In another laboratory at the TUM, some scientists use RT-Linux for controlling
a 4-link robot-arm. The PID-servo control algorithm has rather
timing-critical differential parts ... they never had problems!
My experience: RTL is very reliable, stable and accurate, but hardware-
drivers are missing. But anyway: as you can't expect Ethernet and SCSI
to be hard-RT-save, that is not really a loss!
And as you have the source-code: if something is unclear, you can RTFSC.
With commercial products, you have to rely on its' documentation and it
is very likely, that it will not be supportes any more in five years.
I read about a company for elevators that uses Linux now, because they
have long-time running systems. And even when there is the unlikly
case, that Linux is not anymore supported by newsgroups, mailing lists or
commercial companies, they still have the source code an can make changes)
When you want to use RT-Linux for data aquisition or control systems
with task periodicity at about 1 KHz (or even up to 10KHz), then RT-Linux is
a good choice, as you can use the same system for data visualization or
other user-space applications.
What kind of flight-simulator is that? With hydraulics and so on?
A real big one for two persons (Airbus: Debis/Daimler/DASA)?
It would need some more details on the sensors and actors used,
but it is very likely that rt-linux can manage it (with some
HW-driver development efforts of course)
You may contact me for furthe details ...
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