Introduction
Summary
We are taking on a short term project to remove the paper airplanes from the E7 atrium ledges this term.
We will not be removing the dust.
Project is being taken on with significant coordination from Professor Rayside
This test will be to validate our engineering solution in a low stakes area.
Our solution is blowing the planes away with prop wash from Houston.
This is the simplest solution we got and works well on the ground in the SDC.
There will be a subsequent flight test (not covered by this document) with a different flight plan in which will involve closing off the north section of E7 in addition to the south section to clean the area.
Aircraft Information
We will be flying a https://uwarg-docs.atlassian.net/wiki/spaces/ARCHS22/pages/2194702345/HOUSTON+Class+Quadcopters?search_id=98b548d4-d439-4470-b8c8-fe02477501af.
Lidar and rangefinder depopulated.
While the readings my be useful these add weight and cost to the system.
Weight is just above 1kg w/ battery.
Measured at 1.3kg with the prop guards and all
GPS will not function due to being indoors and pilots have practiced GPS denied flight.
GPS was manually disabled in ardupilot
the GPS module was still fitted on the drone so we could use it’s internal compass
Flight mode Stabilize or AltHold decided by pilots discretion.
Sub 250 gram drones may be used as well in this testing if this is deemed as the only permissible option.
This was not done.
Known Rules & Regulations
Transport Canada rules do not apply because flight is indoors.
In the SDC only Graeme & Teertstra have informed us tethered flight is permissible without a need to request approval for a specific flight plan.
This was discussed a while ago and will be discussed again during F24 term.
Date
We want to do it before the start of F24.
We cannot do it on the weekend as plantops is not present.
Evenings are preferred as E7 will be mostly depopulated.
Date and time must be approved so this document will remain ambiguous
Members
Participating
Confirmed Unavailable
Unavailable until the first day of F24 term.
Further Information
See our internal conversation at this discord thread.
Further context can be found within the WARG https://uwarg-docs.atlassian.net/wiki/spaces/AD/pages/2311618600/Email?search_id=3d75d9f9-68ad-4211-91f4-cf02c14388df.
Flight Test Plan
Timing
Late in the evening or early in the morning is preferred as E7 will be mostly depopulated.
Testing window should be ~ an hour in length.
Targeting 30 minutes of setup time and 30 minutes of flight time max.
Location
Floorplans
The flight area will be above the 2472 area of E7
E7 2472 is commonly known as the E7 event space and is depicted below on the floorplan in red.
See the below drawing. We will be flying above the pink/red exclusion zone for this test flight.
The area in green can be blocked off or have WARGians nearby to advise people not to enter.
Flight test team will stand above the drone at all times
Flight team will be on a stairway, landing, or bridge in E7/E5 at a higher altitude than the drone at all times.
This is both for safety concerns and also to maintain visual contact with the drone for flight control.
It’s alright if there are spectators around the pilots during the flight.
Concerns
Safety Controls
Referring to https://www.ccohs.ca/oshanswers/hsprograms/hazard/hierarchy_controls.html
People will be prevented from going close to the drone.
This flight plan involves perimeter control to ensure there are no members of the general public / university community in the flight area so nets and tethers will not be employed.
Pilots will maintain line of sight with the aircraft at all time.
Liability Controls
The 7th floor administration is assuming responsibility if the unlikely case of a propeller strike.
Debrief
Media
Hardy recorded on his phone.
Will be uploaded to our https://uwarg-docs.atlassian.net/wiki/spaces/AD/pages/2241790526/Media+Folders+Photos+Videos#%F0%9F%93%9D-Media-Ingest-Folder .
Most flights were not recorded, but a few were particularly to document our issues.
There are some images we took on the ops camera. Won’t bother downloading just yet.
Daniel took some photos on his phone as well
mostly not during flight as was busy piloting
Timeline
started setting up around 8:50 and finished at around 10pm
First we went to the stairs between the second and third floor starting the first flight
We did not need to do accelerometer or megnetometer calibration in flight.
Althold flight mode first, noticed some altitude instability during flight
This was somewhat predicted due to barometer error and similar behavior was observed outside.
Notably the barometer is temperature sensitive.
Changed to Stabilize flight mode for the rest of the flights
eliminated the altitude instability and was controllable due to pilot practice with this more manual throttle mode.
Disabled compass 1 and enabled compass 2 for determining heading when using 2nd battery
The IMU error didn’t get mitigated at all, more compass error noticed after making this change
it turns out this magnetometer change doesn’t play an important role in this game
Noticed IMU drifts after a period of flight, have to land every 5 mins to reset it
Sometimes it would automatically reset, we have videos showing this
Sometimes a power cycle was required. This was very time consuming with only two people on the flight line.
Ended up consuming all three batteries
Each battery can last for estimably 15 mins of flight time
Wins
No crashes
Prop guards never contacted the wall
Cleared some debris
Yaw was very stable
Throttle was very stable in stabilize flight mode
Issues
IMU Issue
What was the issue:
The drone’s definition of level would drift over time.
Resulted in
Pilotting became more difficult over time as pilot would have to hold a constant stick input to maintain level flight
We landed on the ledges accidentally twice when the drone was harder to control .
Lots of time having to land on the ground over and over again so the drone could reset it’s definition of level flight
Possible Solutions (we can test these and may brainstorm more)
Installing optical flow sensor.
We have these sensors.
Was mentionned as a solution in https://discuss.ardupilot.org/t/indoor-flight-horizontal-position-shift-drift-using-only-imu-sensors/94877 .
Being able to use controller trim during flight may be able to resolve the issue without landing.
Disabling all compasses may help.
Changing IMU settings may help.
Why we didn’t catch this sooner
All our other tests were outside and away from large metal obstacles so this condition did not arise as severely as it did.
What caused it:
Flying near the metal walls seemed to cause the center drift to become much more severe.
Doing sharp stick inputs when in the middle of the event space did not cause any problems.
Flying near the concrete didn’t cause much problems either it seemed.
We have videos showing this, maybe review those and don’t trust us so much.
Debris Removal Issue
Resulted in:
The paper airplanes get stuck under the metal piece on the edge of the wall and it means even though we’re blowing them up a bit the nose tip remains still stuck in the crevice.
hard to clean the paper airplane on the corner/beside the wall
sometimes we blow the paper airplane to those spots as well
Possible Solutions (we can test these and may brainstorm more of course)
propeller direction config such that it sucks objects instead of blow them away?
A different approach.
Why we didn’t catch this sooner
This was our simplest possible approach and we weren’t too sure how it would go
that is why we have this test flight !!
What caused it:
the propellers blows the stuff outwards
It’s tough to get close to the wall to avoid blowing stuff closer to the wall
Next Steps
Look into issues.
Email Derek & Dennis to update them of our status.
Try again on Friday evening for another test flight.