Re: [Flightgear-devel] Autopilot: NAV/Localiser
It works, but the behaviour is unexpected, or I got it wrong about VOR navigation. Sounds like it could be a faulty config file ,,, but the proper way to do a VOR navigation is : Set your (VOR/LOC) frequency set your desired course / radial. Set your heading bug to intercept the course ... most autopilots ive been studying go into heading hold automatically if your outside the capture range ... then NAV engages when your in range of the course (not the station). The only way I can describe it is imagine the course as a road and your driving parallel , off the road . you turn on the autopilot and point the car towards the road ... when your close enough to the road the autopilot takes over and pulls you onto the road ... And now I'm off to design an autopilot for my car ;) Cheers -- The Planet: dedicated and managed hosting, cloud storage, colocation Stay online with enterprise data centers and the best network in the business Choose flexible plans and management services without long-term contracts Personal 24x7 support from experience hosting pros just a phone call away. http://p.sf.net/sfu/theplanet-com___ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel
Re: [Flightgear-devel] Autopilot: NAV/Localiser
On Tue, Jan 26, 2010 at 2:36 AM, syd adams wrote: It works, but the behaviour is unexpected, or I got it wrong about VOR navigation. Sounds like it could be a faulty config file ,,, but the proper way to do a VOR navigation is : Set your (VOR/LOC) frequency set your desired course / radial. Set your heading bug to intercept the course ... most autopilots ive been studying go into heading hold automatically if your outside the capture range ... then NAV engages when your in range of the course (not the station). I would say be a little careful about what config file you use as an example. There is some slightly goofy stuff that has crept into some autopilots over the years. There are some stages that could easily be P only, but are written as PID which leads to more hunting and oscillations or long term errors than otherwise would be necessary. Regards, Curt. -- Curtis Olson: http://baron.flightgear.org/~curt/ -- The Planet: dedicated and managed hosting, cloud storage, colocation Stay online with enterprise data centers and the best network in the business Choose flexible plans and management services without long-term contracts Personal 24x7 support from experience hosting pros just a phone call away. http://p.sf.net/sfu/theplanet-com___ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel
Re: [Flightgear-devel] Autopilot: NAV/Localiser
Curtis Olson wrote: On Tue, Jan 26, 2010 at 2:36 AM, syd adams wrote: It works, but the behaviour is unexpected, or I got it wrong about VOR navigation. Sounds like it could be a faulty config file ,,, but the proper way to do a VOR navigation is : Set your (VOR/LOC) frequency set your desired course / radial. Set your heading bug to intercept the course ... most autopilots ive been studying go into heading hold automatically if your outside the capture range ... then NAV engages when your in range of the course (not the station). I would say be a little careful about what config file you use as an example. There is some slightly goofy stuff that has crept into some autopilots over the years. There are some stages that could easily be P only, but are written as PID which leads to more hunting and oscillations or long term errors than otherwise would be necessary I fixed the ocillations on a couple of aircraft, however all the aircraft have this NAV1/VOR slow correcting error which is completely unrealistic imho, such as following a SID or STAR as the aircraft doesnt really get on course until near the VOR station. (red in the image below). http://imgur.com/LL6b9 What this implies is that say I am 100nm away from a VOR, and just within the 30 degree correction, then it would take 100nm to correct that final 30 degree. Is there a way to sort this with a PID. And as Syd pointed out with the car and road analogy, then the car would be in the ditch most of the time ! pete -- The Planet: dedicated and managed hosting, cloud storage, colocation Stay online with enterprise data centers and the best network in the business Choose flexible plans and management services without long-term contracts Personal 24x7 support from experience hosting pros just a phone call away. http://p.sf.net/sfu/theplanet-com ___ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel
[Flightgear-devel] Autopilot: NAV/Localiser
Am trying to get the autopilot to follow a NAV1 course, correctly. It works, but the behaviour is unexpected, or I got it wrong about VOR navigation. Please have a look at the image link below as I am not good at explaining. http://imgur.com/LL6b9 Approaching a VOR, from say 50nm away, just off the track, then (see red on image) * the aircraft will turn toward the VOR at a maximum of 30 degree correction, * then at some point even 40 nm away it will start to slowly turn toward the VOR very very slowly and gradually correct until passing over the VOR at correct heading (where then aircraft them wobbles). * The aircraft also never seems to establish on the localiser runway center line where the error is even more critical, although I need to research more. The expected behaviour would be for the aircraft to continue at 30 and then turn directly into the radial at correct course (Blue on image) I've tried messing about with the pid, by adding gain, etc but getting nowhere. Can anyone offer some advice. TIA regards Pete -- The Planet: dedicated and managed hosting, cloud storage, colocation Stay online with enterprise data centers and the best network in the business Choose flexible plans and management services without long-term contracts Personal 24x7 support from experience hosting pros just a phone call away. http://p.sf.net/sfu/theplanet-com ___ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel
