Saturday, September 19, 2009

Flying Lessons - How Not to Fly

Every one likes videos, so here are some examples of how not to fly:

Things learned include:
  • Center of Gravity! (Specially when the plane has taken some damage already. Nose heavy will cause it to stall, tail heavy will cause it to turn over when turning using rudder)
  • Different trim values required for flying with motor on or gliding with motor off (flying straight when motor on, will cause it to turn slightly right when gliding with motor off)
  • Perception! (Plane flying towards or away. Successfully stabilize the plane first, attempt maneuvers later)
  • Taking in to account speed gains when dropping plane. Also speed losses when climbing.
  • Trees! (Sometimes getting the plane down damages it more then the crash itself
  • Response delay introduced by various elements (crosswinds, momentum, servo delay ...)

On a side note, the plane was named post usable service as AVI@TOR 01 (Aerial Vehicle Intended @(Academic Testing) Or Research).

Friday, September 11, 2009

Flight No. 10 - Data Analysis

One more flight with interesting data, now visualized for better understanding.

Flight video, which unfortunately ended in a tree:

The raw sensors data was smoothened using GNU Octave (language for numerical computations) Data Smoothing Package to clean the raw telemetry of noise (vibrations, sensor deviation, ...) and then the smoothened values plotted against raw values.

Orientometer data with smoothed and raw values:

Accelerometer data with smoothed and raw values:

Next the smoothened data was visualized and animated (using Octave and imageMagick) for better perspective and to be checked against the flight video to see how it matched.

Orimetometer data visualized and animated:

Accelerometer data visualized and animated:

Next step in sensor telemetry would be to implement the real time data smoothing in to the sensor software.

Thursday, September 10, 2009

Flight No. 9 - Sensor Telemetry

With the "Crash O Meter" app loaded it was time for almost fully equip test flight.

First two small "jumps", to shake the sensors and get some baseline readings, then a short flight with a violent landing:

Accompanied accelerometer data:

Accompanied orientometer data:

And since the plane was still flyable one more try with SonyEricsson C702 phone, just for fun:

Sensors App - Crash O Meter

No denying it, the "landings" are still hard, so this would be a good time to finally use the sensors on G1 and get some data:

After figuring out Services on Android, a quick app named Crash O Meter was hacked up to record onboard sensor data in to a coma separated file (CSV).

Flight No. 8 - Where all Things Come to Die

Was actually a huge success!

A whole training circle completed before a mistake related to perception (plane facing toward the pilot would perform left banking maneuver with aileron control pushed to the right), resulting in almost total destruction:

At this stage the cockpit is composed mostly of glue.

Wednesday, September 09, 2009

Flight No. 7 - Training Wheels

Some thing felt strange, so to test them out the plane was "pimped" with some training wheels for "on the ground" training.

Good thing too, since it lead to the discovery that the elevator was wired reversed and with that the ailerons might actually be useful for roll correction.

Wednesday, September 02, 2009

Flight No. 2,3,4,5&6 - Beginers Mistaks

A few quick Throw -> Crash -> Glue sequences to get some experience.

Unfortunately one of them ended misfortunately:

Resulting in a broken plane, broken glasses, scraped elbow and broken transmitter antenna.

But there was also a very important lesson learned! A plane carrying three quarters over designed weight requires some work on launching technique, namely with 951g (where's recommended weight being 650g) a lot faster starting speed is necessary to swing it in to stable flight.

On a plus side, there was a cool looping performed before the last crash.