Field Test 5.28.15

Flight Test-Along Power Lines in the Field

Date: 5.28.15

Time: 6:28 PM (needed about 20 min. to set everything up)

Wind Speed S 10 mph

Visibility 10.00 mi

Temp 79°F (26°C)

Location: Spring Coulee, Genoa

Very informative field test tonight. We wanted to test the UAV in a rural area along real power lines. From the start the UAV had problems getting a GPS lock which is required for Auto Missions and some of the other modes such as Loiter and RTL. It would get a signal and then

sometimes lose the signal between arming the UAV and it even lost the GPS signal in flight which caused it to emergency land. This flight test was very short as a result of that loss of signal, but a lot was learned from it.

The in flight loss of signal is one we worry about. If the UAV loses a  signal during a mission it is set to land immediately. We felt this was the safest setting for our use. The problem with that setting, is it lands way too fast..borderline crash. When we had the loss of GPS signal occur the UAV immediately landed as it was calibrated to do. Fortunately it kept upright and buried its legs in the soft grass. No apparent damage to the UAV at this point.

We checked a handheld GPS unit and found in this rural area 4 sats could be found with only 3 strong signals the 4th was very weak. By comparison on the practice fields at Logan HS we can get 11 sats, however, as we walk closer to the school that diminishes down to 7 sats. The recommendation is to have at least 5 sat signals. That way if you lose one, you have 4 others that can still provide guidance.

Recommendations as a result of the field flight test:

1. GPS lock is essential for auto missions. In coulees and valleys around the area, GPS signals can be sporadic because they may lack a "clear view of the sky". A loss of signal could result in damage to the UAV or property if it lands immediately. GPS units do not work well in cities with tall buildings, valleys, canyons, heavy tree canopy, etc... The GPS unit on our UAV uses more sophisticated algorithms that a GPS used in a car so we found out it is essential for it to acquire at least 5 sats before takeoff.

2. Change loss of GPS signal setting on UAV to "AltHold" instead of "Land" this will allow the UAV to stay in the air hovering where it lost the signal until the pilot can switch to "Stabilze" mode and take over the flight manually.

3. Improve the quality of the GPS system to find satellites. This would allow for more confidence in Auto Missions.

4. Improve the quality of the camera. That way the UAV can fly higher to keep out of valleys and use the camera to zoom in on the power lines. It would also keep it out of the trees or other vegetation along the power lines.

*Update5.29.15*

After getting the UAV back to school the morning of the 29th, we put a meter on the battery to check the voltage. It registered at 8 volts (14.8 V when fully charged). This was very low and probably contributed to why the UAV landed as such a high rate of speed. Not sure what caused the battery to drain that fast as the time in the air was minimal.