Just stabilizing a rocket to go straight up and not rolling is anyway outside the philosophy of ITAR and MTCR regulations. But that's a complete other story...
Roll decoupling also helps to minimize the potential adverse roll coupling between canards and stabilizing fins...
Florin
On Tue, Feb 14, 2012 at 3:10 PM, Bernard Davison
<address@hidden> wrote:
Oh I forgot to say before...
The best thing about open source software an hardware (at lease with GPL) is that it is outside of MTCR and ITAR restrictions.
Cheers,
One way to do it is to not attempt any inertial correction during the burn. After the burn out roll/yaw/pitch stabilization can commence. You don't have a high g environment anymore. Also it helps if the rocket is inherently not planned to roll fast...
In this case I could see that an open source autopilot (like paparazzi) could do the task of stabilizing the vehicle.
Florin
On Tue, Feb 14, 2012 at 2:56 PM, Bernard Davison
<address@hidden> wrote:
The nominal burn time for the motors is 0.8-1.25 seconds.
The 3" Sighter and the 5" Zuni motors have pretty similar burn times.
We launch them at an angle of 70 degrees so they always land several kms away from us.
It also helps protect us when the student payloads break off. Which happens from time to time with some of the designs.
Cheers,
Bernie.
Sent from my iPad mini.
How long does the burn take? 2-3 seconds?
Thanks,
Florin
On Tue, Feb 14, 2012 at 2:47 PM, Bernard Davison
<address@hidden> wrote:
The launch is >70G ;-)
The thing goes from a compete standstill to >Mach 2 in 1 second.
The rockets we usually use are surplus defense motors.
We did have a payload once that was going to try and maintain a lock throughout the flight but it got buried. :-(
Cheers,
Bernie.
Sent from my iPad mini.
Hello,
Why doesn't the GPS keep lock during the ascent? I have seen GPS data loggers for high power rocketry that keep lock during the ascent. What type of GPS module do you use?
Best regards,
Florin
On Tue, Feb 14, 2012 at 2:38 PM, Bernard Davison
<address@hidden> wrote:
Yep standard civilian GPSs have been flown. They lose position of course at launch but do acquire solution after the main parachute opens.
Also the MEMS accelerometers have been flown and data logged.
The major problem we've always faced is knowing what went wrong when things don't work and the thing is buried 5m underground and the rocket has turned itself into metal confetti.
We've worked out what we believe Will be a survivable data storage module. Hopefully to be tested in the next year or so.
At the moment were breaking the Lisa/L board up into smaller components and designing them to be rugged. I.e. positive locking connectors isolation on some switches and comms. Etc.
We're also breaking the board into discrete task based "nodes" that can communicate via redundant CAN bus connectors. So in the future it would be possible to have a failure tolerant system. I.e. if you have a failure of a transceiver node, IMU node, flight computer node, CAN bus. Then it could use another node on the network.
Of course that would need the appropriate software to be written for that kind of control.
Cheers,
Bernie.
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Florin Mingireanu
Romanian Space Agency
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_______________________________________________
Paparazzi-devel mailing list
address@hidden
https://lists.nongnu.org/mailman/listinfo/paparazzi-devel
--
Florin Mingireanu
Romanian Space Agency
Str. Mendeleev 21-25, et. 5, sector 1, 010362 Bucuresti, ROMANIA
office tel.
+40-21-316.87.22;
+40-21-316.87.23;
cell:
+40-757-768971 (primary phone)
fax
+40-21-312.88.04address@hidden
http://www.rosa.ro
_______________________________________________
Paparazzi-devel mailing list
address@hidden
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--
Florin Mingireanu
Romanian Space Agency
Str. Mendeleev 21-25, et. 5, sector 1, 010362 Bucuresti, ROMANIA
office tel. +40-21-316.87.22; +40-21-316.87.23;
cell: +40-757-768971 (primary phone)
fax +40-21-312.88.04
address@hiddenhttp://www.rosa.ro