Date: 10/7/10 [[BR]]
Location: Tri Valley [[BR]]
Aircraft: Odin, Loki, & FASER [[BR]]
Pilot: Garrison Hoe, Arion Mangio [[BR]]
Flights: 4 Odin, 1 Loki, 1 FASER [[BR]]

[source:/trunk/FlightData/2010_10_07 Link to Flight Data]

Gary, Garrison, Arion, and myself went to Tri Valley with both Ultra Sticks and FASER. Weather was perfect; sunny, light west winds.

The test objectives were:

   1. Test new microbotics airdata system, with code fix for resolution.
   2. Get additional data on the fault detection filter flown last week.
   3. Get additional data on the ASDX pressure sensors.
   4. Test the MicroNav air data with revised pressure zero procedure.
   5. Run multi-sine PID inputs.
   6. Fly FASER with new motor/prop combination.

We completed 6 flights and met all objectives; notes as follows for each flight number:

Odin Flight 14: MicroNav, MB air data system (ADS), LQR controller, multi-sine PID input. This program would use the LQR controller to fly straight and level for 4 seconds, hold the controller positions and inject a 10-second PID input, and then resume the controller. The ADS worked well, although it appears there is some filtering being applied to the airspeed and altitude, as there was virtually no noise whatsoever, and changes were very smooth. The PID input often would drift to the left or right and pitch down. I think the strategy of holding the last controller command is not adequate. A better option may be to use an expected trim value. The amplitudes of the PID input was 1 deg on each surface. Qualitatively, this looks OK for the elevator, but too small for the aileron, and perhaps too small for the rudder. 

We attempted a second flight with the MicroNav aircraft, but were not able to get GPS lock on the ground. We decided to switch to the new avionics and let the MicroNav cool down. While starting programs for the new avionics, we were not getting "GPS DATA". Inspected the connections, found them OK. Tried all programs, found one that worked, and proceeded with flight 2.

Loki Flight 06: New avionics, LQR controller, multi-sine PID input. Noted soon after takeoff that the "IMU DATA" indicator was OFF. However, the HUD was functioning normally, so clearly IMU data was being received. Review of the data showed that the "imu_status" flag was zero the entire flight, but IMU data was present the whole time. This flight also included some high and low speed flight to exercise the ASDX pressure sensors. Several GPS checksum errors were noted in the data. Initially, several "data invalid" flags were noted. Once GPS lock was obtained, it remained solid through the flight.

Odin Flight 15: MicroNav, baseline controller, doublets; The standard program. The purpose here was to check the air data zero procedure (see ticket:12). Airspeeds were normal (20-25mps). GPS lock was intermittent at first, but improved.

Odin Flight 16: MicroNav, LQR controller, FDI: Fault detection repeat. Nominal flight, flap fault handled fine.

Odin Flight 17: MicroNav, baseline controller, FDI: Fault detection repeat. Nominal flight, flap fault handled fine.

FASER Flight: The new motor and folding prop combination runs much higher RPMs, but seems to have plenty of thrust. Shortly after takeoff, the left wheel detached from the axle. We continued to fly for several minutes and discussed landing strategy. We decided the best course of action was to land on the asphalt rather than grass to keep the gear from snagging and causing a cartwheel. On the landing pass, Arion got the airplane as slow as possible, touched down on the right wheel and applied right roll to keep off the left gear as long as possible. Once the gear did touch, it simply scraped along, and the aircraft remained under control. No damage (other than minor scraping on the gear) occurred. Good flying!!  Check out the video (bad camerawork, sorry): http://www.youtube.com/watch?v=a3RNpNSq9bU


Actions & notes:

1. FASER: File a flat spot on the axles so wheel collar set screws can hold securely. Apply thread locker to the set screws. (ticket:23). Done.
2. Increase the throttle setting from 60% to 70% in the flight programs. (ticket:24) Done.
3. Determine why imu_status was zero on Loki Flight 06. Looked at past data, and this has always been the case for the new avionics. (ticket:26)
4. Determine why some flight programs didn't show GPS DATA. Tested ok in the lab. Not sure what was happening here. UPDATE: possibly loose solder connections.

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