Introduction

• Follow up to 2024-08-28 Houston Atrium Cleaning

  • Identical safety plan

  • Same flight time, 9pm to 10pm, but on 2024-08-30

• Attendees

  • @Hardy Yu

  • @Daniel Puratich

• Online Support throughout the day

  • @Nathan Green

  • @Smile Khatri

  • @Yuchen Lin

• Improvements/Changes

  • Better Pixhawk Mount

    • Pixhawk is now solidly bolted to the frame on a 3d printed adapter instead of sticky taped

  • Optical Flow Sensor Mounted

    • Hoping this would improve GPS denied position hold stability

  • Notch Filter, Quicktune, & Autotune completed

    • Hoping this would improve stability

  • Attempted to mount Rangefinder

    • We did not succeed in this.

    • The rangefinder we have seems to be RS-485 only and doesn’t support CAN

    • We have a new one coming intended for another aircraft we may be able to use in the future once it arrives.

    • The rangefinder was not mounted for the indoor flights, we just played with in the bay for the past two days.

Debrief

Media

• Videos and Photos: 2024-08-30 Houston Field & E7

• Pixhawk Ardupilot Logs

  • Tuning Part of Flight Test: 2024-08-30 Tuning

  • E7 Atrium Cleaning: 2024-08-30 E7 Atrium

• Some smaller media and conversations were posted in discord thread here.

• We took some more photos of our outdoor test on the nice camera which we didn’t upload yet. All indoor media was captured on cell phones.

Flights

• Tuning Outdoor Flight

  • takeoff flight test with flying in stabilize, loiter mode

  • Proceed optical flow sensor calibration

  • Proceed quick tune, and succeed quickly

  • Did autotune, each axis at a time. Each axis cost us one battery

    • Autotune aggressiveness is set to 0.1 (strong)

    • The batteries we have right now are pretty old, new ones are coming in

  • Tried flying in FlowHold flight mode without GPS

• Indoor Flight 1

  • notch filer set to in-flight FFT

  • all indoor flight test is done in flowHold

• Indoor Flight 2

  • notch filer set to in-flight FFT

• Indoor Flight 3

  • notch filter set to static

• Indoor Flight 4

  • notch filter set to throttle

Wins

• Started up top and was able to make some tangible progress at cleaning.

• Got more pilot practice.

• Did not crash.

Issues

Oscillation Issue

• Drone oscillation was visually worse than the previous indoor test

  • See media videos as evidence

• Possible Causes

  • Autotune aggressiveness being set too high resulted in a poor tune. We really just want a very stable tune (lots of phase margin in all axes) so low aggressiveness may be best.

IMU Drift

• Same issue as last time

• See videos to show how offset it was when pilot landed or let go of the sticks

• Unsure if this is solvable without scanning Lidar

• Flowhold flight mode seemingly did not help

• Pilot experience is helping a bunch here

Cornered & Large Paper Airplanes

• We were not able to blow the larger airplanes

• Videos show this but airplanes trapped in the corners were tough to get

• A piece of debris has a heavy weight with a long streamer

  • there is a large concern of getting it in the propeller and we should continue to be careful

• Possible solutions

  • Increase the weight of aircraft

    • increases the downforce the drone produces

    • would require retuning (though we probably need to do this anyways)

  • there are many other more complicated ideas floating around