Jesse Frey and I just spend the last hour digging through ao_flight and ao_kalman to learn how the apogee lockout works and also how ao_speed is calculated for a flight like this with a pressure/height error.
The apogee lockout code looks solid - except that it has to be used with caution because it looks like it’ll take a while for the Kalman filter to unwind (because ao_speed gets errors fed to it from other than just the pressure sensor in the case of a TeleMetrum). In the case of my flight, I’ll have over 15 seconds after it goes subsonic before apogee. So I’m going to set the apogee lockout to about 2 seconds before the sim apogee…and all will be right with the world. ;) I’d LOVE for my flight data tomorrow to be run through the ground sim to see what it would have done without the apogee lockout. So, if you get that working again Keith, I’d love to be a test case. Thanks! Bryan > On May 28, 2022, at 3:14 PM, Bryan Duke <br...@thedukes.org> wrote: > > Thanks Keith. No need to run the ground sim with my data - I’ll be on my way > back to Tennessee as soon as this Alamosa launch is over on Monday. > > I’m doing some avbay leak cleanup & backup rocket prep today and plan to fly > again in the morning. > > Sooo, I think I want to go against your manual’s recommendations and set an > apogee lockout. There is a warning against using it for versions prior to > 1.8.6, but that seems to be only for multi-stage flights. My sim data show > about a 26.5 second apogee. The flight data looks a tiny bit better than the > sim data, so as long as the launch goes ok, apogee should be in the 26-27 > second range. Is my thinking right that a ~23 second apogee lockout would > give me a huge margin away from the supersonic issues I’m seeing and still be > enough pad before apogee for the TeleMetrum to detect it correctly? > > -Bryan > >> On May 28, 2022, at 3:01 PM, Keith Packard <kei...@keithp.com> wrote: >> >> Bryan Duke <br...@thedukes.org> writes: >> >>> The static ports are about 2” behind the nosecone. For 38mm rockets, >>> this has worked well for me before. That said, this nosecone isn’t a >>> super tight fit with the coupler. Since I have the coupler attached to >>> my airframe and the avionics share the same air as the nosecone >>> (baffled, but not sealed between the avionics in the coupler and the >>> chute in the nosecone), maybe that increased nosecone-to-coupler gap >>> is causing some vacuum. Maybe there’s a shock forming at the nosecone >>> joint and that’s causing trouble. >> >> Hrm. Nothing in this seems obviously troublesome to me. >> >>> I’m still running 1.8.5 on it. It worked for me before, so I didn’t >>> want to change anything. Just to make sure - 1.8.5 is fine to run, >>> right? >> >> I don't see anything beyond 1.8.5 that you need. What I can do is run >> your eeprom file through a ground simulation using the latest code and >> see if it does the same thing. That's currently broken due to some other >> changes, so it'll be a few days. >> >> -- >> -keith > > _______________________________________________ > altusmetrum mailing list -- altusmetrum@lists.gag.com > To unsubscribe send an email to altusmetrum-le...@lists.gag.com _______________________________________________ altusmetrum mailing list -- altusmetrum@lists.gag.com To unsubscribe send an email to altusmetrum-le...@lists.gag.com
