Board index FlightGear Development Aircraft

Engine wear

Questions and discussion about creating aircraft. Flight dynamics, 3d models, cockpits, systems, animation, textures.

Re: Engine wear

Postby HJ1AN » Sun May 04, 2014 2:52 am

sanhozay wrote in Wed Apr 30, 2014 11:36 am:I've just done the Nasal code behind a Hobbs meter for the Cessna 337, which is not merged yet. It has a class that keeps track of flying time and this can be switched to engine running time (or a metric of your choice) simply by passing a different property tree path into the constructor. Multiple instances could be created for keeping track of the wear/runtime of multiple things. It doesn't have a reset method at the moment but that's trivial to add. It would probably do a lot of the back-end work behind your cockpit clocks -- it's just a different 3D model really.



I totally missed this. That sounds awesome, I'll give the Cessna 337 a try. It looks beautifully detailed
User avatar
HJ1AN
 
Posts: 377
Joined: Sat Jul 25, 2009 4:45 am
Callsign: HJ888
Version: 3.4
OS: OS X

Re: Engine wear

Postby Jabberwocky » Sun May 04, 2014 4:41 am

Hi,

the more I think about it, then please make it the way, the A, B, C, D-checks for the big jets reset the wear or something. Please, make it planable for our virtual airlines in some way and other big jet fans.

J.
Jabberwocky
Retired
 
Posts: 1319
Joined: Sat Mar 22, 2014 7:36 pm
Callsign: JWOCKY
Version: 3.0.0
OS: Ubuntu 14.04

Re: Engine wear

Postby Johan G » Sun May 04, 2014 3:45 pm

I think that for the effects of wear and failures it can cause a good place too look might be incident and accident reports. :wink:
Low-level flying — It's all fun and games till someone looses an engine. (Paraphrased from a YouTube video)
Improving the Dassault Mirage F1 (Wiki, Forum, GitLab. Work in slow progress)
Johan G
Moderator
 
Posts: 5538
Joined: Fri Aug 06, 2010 5:33 pm
Location: Sweden
Callsign: SE-JG
IRC name: Johan_G
Version: 3.0.0
OS: Windows 7, 32 bit

Re: Engine wear

Postby HJ1AN » Mon May 05, 2014 12:01 am

I think wear and failure is separate, although at some point they come together. At this point some planes have comprehensive failure MTBF system... Wear on the other hand is when the effectiveness is not there anymore, ie brakes not as strong, engine not as powerful, flaps not as quick, or they can be warning signs to actual failure. Anyone who has driven 20 year cars will probably be familiar ( I used to drive a 20 year old car)
User avatar
HJ1AN
 
Posts: 377
Joined: Sat Jul 25, 2009 4:45 am
Callsign: HJ888
Version: 3.4
OS: OS X

Re: Engine wear

Postby galvedro » Mon May 05, 2014 6:42 am

The way I was thinking about it is this: The current implementation can fail systems on command, by clicking in the checkbox via GUI or prop tree, or by setting an MTBF/MCBF value. The system will go from "perfect condition" to "failed" instantaneously when the time comes.

The new implementation (in the works) replaces MTBF/MCBF with a trigger system that is more generic. It will be possible to fail a system at a certain altitude or at a certain location, for example. But it will still be a binary condition for now (failed / not failed).

One way to introduce wear I think is to replace the trigger system with an even more generic "wear model", where a "wear model" is a black box that, given certain parameters, provides you with a "level of failure" at a given time. The current triggers can be seen as a wear model that jumps from not failed to failed instantly under certain conditions, but a more elaborate wear model could count usage cycles or running time internally, and provide a failure level according to a curve, for example. The current prototype is not very far from this, actually. The challenge is then pushed to aircraft modelers, who would be responsible for actually implementing this "partial failure" behavior.

Another interesting point of discussion is what would be a convenient way to make the wear status persistent across flights (if that is interesting), and what should they be associated to: aircraft model? immatriculation? just dumped to a file so you can load it at will?
galvedro
 
Posts: 145
Joined: Mon Oct 07, 2013 12:55 pm
Location: Sweden

Re: Engine wear

Postby HJ1AN » Mon May 05, 2014 7:29 am

galvedro wrote in Mon May 05, 2014 6:42 am:Another interesting point of discussion is what would be a convenient way to make the wear status persistent across flights (if that is interesting), and what should they be associated to: aircraft model? immatriculation? just dumped to a file so you can load it at will?


Well I was thinking of saving flights, ie. you can load flights, so that would be part of a dump to file I guess. Once you fly long enough the effects should be seen and you have to deal with it, ie (simulating flying continously for 2 months.. obviously we can't fly it continuously or have the computer on for two months)

Otherwise for those who don't save their flights, or just want to simulate failure, can do the usual checkbox MTBF, and simulate wear & tear optionally ..

perhaps someone has a better idea.
User avatar
HJ1AN
 
Posts: 377
Joined: Sat Jul 25, 2009 4:45 am
Callsign: HJ888
Version: 3.4
OS: OS X

Re: Engine wear

Postby Johan G » Mon May 05, 2014 8:13 am

For me (as a user rather than a developer) it would be enough to have it associated with the aircraft model (pretty much like the aircraft currently using Nasal aircraft.data.add() and aircraft.data.save()). Since II use the same immatriculation I do not need that, but I guess that for those that changes that (does people actually do that?) it might be nice to have that in combination with an aircraft model. I would think that configuring and saving/loading will be helpful in some cases.
Low-level flying — It's all fun and games till someone looses an engine. (Paraphrased from a YouTube video)
Improving the Dassault Mirage F1 (Wiki, Forum, GitLab. Work in slow progress)
Johan G
Moderator
 
Posts: 5538
Joined: Fri Aug 06, 2010 5:33 pm
Location: Sweden
Callsign: SE-JG
IRC name: Johan_G
Version: 3.0.0
OS: Windows 7, 32 bit

Previous

Return to Aircraft

Who is online

Users browsing this forum: No registered users and 1 guest