Parrots are certified

[SCOTT EVANS]

Adrian
This maybe a little off topic maybe not. I dont totaly have a clear picture of accelorometers. The fellow I was talking about earlier Used them to measure a flight from Boulder Airport and track Roll, pitch, direction of travel and location based on accelerometers. I think he then put the data into another map data base (has terrain data ect.) I think he got the map data from the internet free, or maybe not. (A interesting note: One of the old Ex Commecial pilots said before GPS systems, the airlines used Million doller Accelerometer navigation systems. So accurate,
they would read their taxi speed from them, and keep the Tower guys happy)

Anyway, wouldnt a guy have to enter initial location data? And could you not enter this data into one of those terrain maps and get a visual on a flight in a 3D map. Maybe even radio the data back to a 3D terrain map on the ground? Sorry, just thing out loud sorta.

Scotte

[AdrianParticipant]

This maybe a little off topic maybe not. I dont totaly have a clear picture of accelorometers. The fellow I was talking about earlier Used them to measure a flight from Boulder Airport and track Roll, pitch, direction of travel and location based on accelerometers

I think what you’re describing is an inertial measurement unit, which would contain 3 accelerometers to cover the accelerations in the 3 dimensions, plus 3 gyros to measure rotational rates in the three dimensions. Accelerometers by themselves don’t know which way they are pointing relative to the ground; an axial accelerometer by itself would put out the same readings for a motor burn whether the rocket is pointed up or down.

As an aside, I think I have seen in the club rules that a 3-axis accel might be acceptable for altitude contests. Without 3 axes of gyros, a 3-axis accelerometer would have the same problem detecting weathercocking that a 1-axis accel would.

[SCOTT EVANS]

Inertial Navigation yes, thats what Dad said the old F-4 use to use. A lot more primative when he was in the Airforce then more recent ones like described before that the airlines used. Dad said it would get you close enough within 20-30 miles of the ship (Since the F-4 was originlly a Navy plane) to ride in on a radio beacon.
Gyros, thats your next project Adrian!
😉

[Warren B. MusselmanModerator]

The biggest problem with solid-state gyros (the only kind we can afford as hobbyists) is that they are rate-gyros, not absolute position sensing gyros. They’ll tell you the rate of rotation, but drift is horrendous – like ended up 180 degrees out within a minute or less. For truly stable IMU measurements, you need either a mechanical gyro such as were used in Apollo and most aircraft up until the 70’s or laser ring gyros or their fiber optic descendents.

Another issue with the solid state devices is that they typically have very low g-tolerances and ability to track rates higher than relatively few degrees per second.

Warren

[SCOTT EVANS]

The biggest problem with solid-state gyros (the only kind we can afford as hobbyists) is that they are rate-gyros, not absolute position sensing gyros. They’ll tell you the rate of rotation, but drift is horrendous – like ended up 180 degrees out within a minute or less. For truly stable IMU measurements, you need either a mechanical gyro such as were used in Apollo and most aircraft up until the 70’s or laser ring gyros or their fiber optic descendents.

Another issue with the solid state devices is that they typically have very low g-tolerances and ability to track rates higher than relatively few degrees per second.

Warren

Yea, Im beginning to remember some of the conversation, from the demonstration a couple years ago. The cost of good parts copared to what he was using, and rocket aplications would be way more demanding. Hence the million dollar price tag for the airlines. But if before GPSs it kept you from wandering over USSR or North Korea and attracting a stray missle (it happened) it was worth it.

[Warren B. MusselmanModerator]

Honeywell sells ring-laser gyros and IMU’s based on them for not a huge amount of money – about $11,000.00 for a flight-worthy unit rated sufficient for rocketry.

Warren

[SCOTT EVANS]

Honeywell sells ring-laser gyros and IMU’s based on them for not a huge amount of money – about $11,000.00 for a flight-worthy unit rated sufficient for rocketry.

Warren

Hey Ill run right down and get one!
Where are they located? 😉

[Bruce R. Schaefer]

Adrian, I still think you need to add a voice chip and have the “Parrot” speak the altitude. 😉

[AdrianParticipant]

Yeah, but first you’d have to train it 😉

Actually, Robert deHate (picoalt guy) says he’s made one like that. I don’t know the details, though.

[Bruce R. Schaefer]

Yeah, but first you’d have to train it

And put papers under it! I had an African Grey that lived 26+ years. Miss that bird. 😉 You have a great product, and I’ll get one next year. Already at the just over $200 mark from friends and vendors at the annual meeting. BTW, my launch control talks… though not well, chip is from a clock… 9-9-8-…3-2-1-OH-OH-OH.

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