Date: 05/17/11 [[BR]]
Location: Tri Valley[[BR]]
Aircraft: Thor[[BR]]
Pilot:  Garrison Hoe & Arion Mangio[[BR]]
Flights: 4 Thor[[BR]]

**Weather**[[BR]]
Sunny, moderate-strong easterly winds winds with some gusts, temps around 50F. [[BR]]
METAR KLVN 171353Z AUTO 10009KT 10SM CLR 11/02 A3010 RMK AO2=

[source:/trunk/FlightData/Control_Laws Link to Flight Data]

We took Thor to Tri Valley today to fly 3 control experiments: a waypoint tracker, a MIMO lateral-directional controller, and an anti-windup protection scheme.  No onboard video this trip.

We completed 4 flights with data. GPS performance was poor. Ticket #22 must be addressed. The flight computer crashed once on the ground at the beginning of the day. No indication as to the cause; performed normally the rest of the day.

Controllers were engaged five times on each flight. 

Software used was /branches/thor_flightcode/ rev 410.

Thor Flight 10: waypoint tracking with LQR inner loop controller (Garrison Hoe). This did not perform well, and never appeared to head to the first waypoint. Very poor GPS performance likely had a significant impact. Bank angle commands were not recorded.

Thor Flight 11: MIMO lateral-directional controller (Andrei Dorobantu). This is an H_inf MIMO lateral-directional roll rate/yaw rate command control law. The lateral and directional axes is completely decoupled. Input the rate command was a 1-2-1 doublet (pulse widths of 0.1 sec) after 5 seconds, 100 deg/sec amplitude. A slow wing leveling controller is also included. Performed as expected with very little directional axis coupling.

Thor Flight 12: Integrator anti-windup protection ON with baseline controller (Jorge Sofrony). This is the baseline controller with artificially low rate limits imposed on the aileron commands. An anti-windup algorithm is used to maintain performance. The command sequence is three 2-second period bank angle doublets of 22 deg amplitude (necessary to hit rate limits) that begins after 4 seconds. Good performance was observed.

Thor Flight 13: Integrator anti-windup protection OFF with baseline controller (Jorge Sofrony). This is the baseline controller with artificially low rate limits imposed on the aileron commands. An anti-windup algorithm here is turned off. The command sequence is three 2-second period bank angle doublets of 22 deg amplitude (necessary to hit rate limits) that begins after 4 seconds. Degraded performance (bank angle overshoots) was observed.

Issues:
1. Observed significant GPS checksum errors. Ticket #22 must be closed out.

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