2024-01-20 Pegasus 4v6 battery Flight Test

Owned by Anthony Luo, created
Last updated: 2024-01-25 by Megan Spee
7 min read

FTC: Make sure to update the Title following the format “2020-01-30 Flight Test”

 Flight Preparation

Requested by:

@Anthony Luo

Required Sub-team integration efforts

Mech
Electrical
EFS
CV
Operation
Sys-Int

Date of Request

Jan 15, 2024

Location and Time

WRESTRC on Saturday Jan 20

Goal Summary

Be awesome & test 4 v 6 battery configurations

Approved?

Yes / Pending / No

 Mandatory Attendees

Name

Phone #

Role

Reason

Name

Phone #

Role

Reason

 @Megan Spee

@Anthony Luo

 

Flight Test Director

  • Creating documentation

  • Booking the test flight

  • Creating a thread in #flight-staging

  • Responsible for coordinating operations from start of brief to end of de-brief

 @Megan Spee @Anthony Luo

 

Pilot in Command

Ground Station Operator

  • Aircraft preparation

  • Filling out documentation

  • Operation of aircraft

  • Coordination between mission plans

 

 

Safety

  • Making sure everyone is safe

  • Bringing Med kit

  • Incident procedure

@Anthony Luo

@Nathan Green

 

(Subsystems integration, Secondary pilot, etc)

 

 Auxilliary Attendees

Name

Role

Name

Role

@Yuchen Lin

Efs support

@Alison Thompson

Mech support

@Anthony Luo

General support

Eugene Hong

Observer

Huan-Yi Shen

Observer

@Conall Kingshott

Handsomeness

@Sam Zhang

Observer

@Georgia Vachon Westerlund

Operations

@Nathan Green

Mech

@Tim Gu

EFS(?)

Drivers & Seat Arrangement

Driver

Vehicle Type

Passengers/cargo

Driver

Vehicle Type

Passengers/cargo

@Anthony Luo

5pass SUV

 

@Megan Spee

5-person liftback

 

Eugene Hong

<(only driving himself)>

 Huan-Yi Shen

@Nathan Green

SDC Grey Dodge Caravan 3-277

 

Goals/Objectives

Objective

Priority

Owner(s)

Objective

Priority

Owner(s)

Evaluate 4 vs 6 battery flight times.

  • Drone will fly sequenced automatic flight, with a failsafe trigger to RTL + autoland when battery reaches minimum voltage (x voltage).

  • Maintains as much consistency as possible, logged data will be used to determine possible flight time.

  • Drone will be set to loiter in circles of (x radius) to remove effects of propwash or possibilities of settling with power.

1

 

 

 

 

Flight Test Timeline

Date/Time

Action

Date/Time

Action

0700

Start battery charging

0900

Briefing @ WARG Bay

0930

Pre-departure loading + organization

1000

Arrival at Flight Test Location

1015

4 battery endurance test → Autopilot to loiter in circles (we want to be in motion when evaluating flight time) until reaching min voltage of 3.3 V

1100

6 battery endurance test → Autopilot to loiter in circles (want to be in motion) until reaching min voltage of 3.3V?

1200

Debrief

 

 

Incident Procedures

Incident

Location

Procedure

Incident

Location

Procedure

Crash

WRESTRC

  • Identify last known location & flight path of the aircraft

  • Divide into teams of 3 and decide on communication protocol

< otherwise >

 

Flyaway

 

See WRESTRC Site Survey for territory around this site. Note if the drone is headed in a direction towards any no-fly zones. Call relevant authorities.

Fire

WRESTRC

  • Designate 911 contact

  • Describe incident (Drone crashed, contains LiPo batteries)

  • Give location of team (Skid pad at the Waterloo Region Emergency Services Training Center)

  • Give best approximation of the location of the drone

< otherwise >

 

Injury

 

  • Apply first aid as required.

  • Call 911 as required.

Property Damage

 

  • Collect insurance details.

Week-Before To-Do List

Drone Registration

Drone Registration Number: C-2316126394 (Vanguard)

Flight test location booked
Pilot scheduled
Test Plan (What we are testing)
This should also include the flight path where applicable
Subteam action items (for flight readiness)
Mechanical: Frame assembled
Mechanical: Motors cleaned + mounted
EFS: Ardupilot failsafes configured
EFS: Motors tested
EFS: Telemetry Tested (RFD900)
EFS: Control Link Tested
EFS: Logging proper & Enabled
EFS: Loiter flight path ready
EE: 4 & 6 battery harness ready
Transportation logistics finalized
Booking SDC vehicles
Assigning drivers
Renting any needed equipment (trailer? generator? etc.)

Day-Before To-Do List

SDC Vehicle key collected (if required)
Batteries Planned for (DON'T LEAVE CHARGING OVERNIGHT)
Drone batteries & spares
Transmitter batteries
Battery tester/indicator
Flight Code Flashed
Ground station Software updated
On-site kit together
First Aid Kit
Ground station / Laptop
Antenna / Receivers
Transmitter
heated blanket (potentially for the batteries)
Airframe assembled
ESCs/flight controller wired
Radio equipment tested
Channel mappings
Flight modes
Motors tested
Wiring secured (Harnessing)
End-to-end test (neglecting props)
Check the center of gravity
All components not on the airframe that are required should be in the flight box (e.g. props & prop nuts)
Airframe payload
Spare parts
Props
Airframe components (landing struts, arms, etc)
wings nuts
prop nuts
any detached components such as angle mount
props for other aircrafts such as Houston
Hardware to assemble these components
Electronics
ESCs
Motors
Flight controllers
Receiver

Pre-Departure Checklist

Take the WREST RC entrance card
Batteries in transport-safe solutions. Team members briefed on incident procedures.
Systems test
Check flight controller orientation
Check motor spin & rotation direction
Check transmitter mappings
Verify communication links (VTX/RX, Controller, Groundstation)
Verify the mission planner + TX16 is logging data
Get snacks
Mission Briefing
Read the flight plan to the team (that was made a week ago)
Purpose of flight
Plan of action + Flightline roles
Success criteria
Safety Briefing
Key flight characteristics to observe
Key system characteristics to observe
Measurements to be made
Ensure everyone is appropriately dressed.

Pre-flight Safety Checklist

Airframe
Motors secure
Electronics secure
Propellers secure
Software Configuration
Telemetry OK

 

couple of batteries 4 milliamps difference

quad X config

LTE, RFD900s for telemetry. LTE working, RFD not. Will figure this out after briefing

flight modes on controller: stabilize, alt hold, loiter, land, circle, RTL.

set drone to face in direction of travel. pitch to change radius, roll to change speed. does ardupilot fix this when it’s in ‘face in direction of travel’? will find out.

6 batt harness exists, no EE reps here at the moment.

Flight Path Plan

Essential Setups

Essential Setups

  1. (Connect laptop to the Pixhawk, then)In the misson planner, please set up the Circle flight mode in the mission planner and map it to one of the Controller flight mode button

  1. In mission planner, go to the parameter list and modify:

During the Flight

During the Flight

  1. Pilot take off in LOITER mode in an even open land. Some one should start record the time.

  1. Flight to an empty space and ensure no obsticle could ever happen when circling

  1. Engage CIRCLE flight mode through controller/mission planner (may called loiter turns in MP, may just called circle)

  1. During flight you can change throttle and yaw under circle mode, pitch and roll won’t work.

  1. With your failsafe procedure and circle flight mode correctly setup, the drone should RTL when it runs out of battery

Post-Flight Checklist

Item

Owner

Item

Owner

Use Flight-Post Mortem to Debrief

ALL MEMBERS PRESENT

Discard of damaged batteries

 

Discharge used batteries for better longevity

 

Flight Test Debrief

Logs: https://uofwaterloo-my.sharepoint.com/:f:/g/personal/uwarg_uwaterloo_ca/EvssRJEfPLZAqbVXcsvuiYIBkdiAjKG-rlY_O-k0nn1iJw?e=bkqjbZ

Media: https://uofwaterloo-my.sharepoint.com/:f:/g/personal/uwarg_uwaterloo_ca/EgIfFsJltkFDs37hU_O3rFQBhfoZatQxOFZzMeIRAET_1Q?e=E8yaq5

Flight Test Timeline

10:15-25 leave the bay

10:45 got all parts to the site, started setting things up

11:15 takeoff - 6 battery combo

fly for ~ 28 minutes. to 11:42. Logging only lasted 23 minutes.

people driving back to pick up more batteries that are charging.

12:23 takeoff - 4 battery combo. 20 mins exactly. to 12:43

 

Analytics (hopefully applicable)

Barometer is not heated

barometer temperature was ~ just below freezing

image-20240120-190339.png
baro temp over 4 battery flight

the temp was oscillating based on the position it was in the circle.

image-20240120-190507.png
baro temp vs latitude, 4 batt

Battery voltage

4 battery

image-20240122-144008.png
Voltage over time, full flight, 4 batteries.

voltage drops from 52-50 V to 49 when it arms. linearly decreases to 43 volts, when we decide to RTL. Recovers to 44.5 V after landing. 3.8 on each cell.

This flight recorded a total mAh used of around 6000? Check the logs again.

Can fly for 40 mins on 4 batteries. 8 m/s.

  • may get more efficient (distance-wise) if it gets slightly faster, according to @Andy Meng .

  • TODO: check this.

6 battery

image-20240122-144148.png
Voltage over time, full flight, 6 batteries

  • Flight was conducted in circle mode, at an average speed of 7m/s.

  • Voltage sagged to ~ 49v when armed, and reached a minimum of ~ 43v after ~ 35 minutes of flight time.

  • Flight recorded a mAh used of around 8000?

voltage vs gps latitude.

image-20240120-190916.png
Voltage & Latitude over time, 4 batt

  • Voltage was shown to be increasing/decreasing within the linear descent.

  • Wind estimation was not enabled, but comparing barometer temperature data to voltage indicates a positive correlation between wind direction, lower temperatures on the barometer, and higher current draw.

    • IE: flying into the wind takes more energy.

Summary

image-20240122-144710.png

Knowing the characteristics of LiPo batteries, the linear voltage/time relation makes sense. This data was taken at -20C , with batteries in a poor condition due to previous use. We can assume that performance from any battery configuration will be at least 30% better in future flights, meaning that a 4-battery configuration should reasonably be able to fly for 50+ minutes.

Flight Test Post Mortem // Final Thoughts // Condensed Summary

  • Drone is physically intact

  • Flew for longer than expecting

  • Didn’t forget anything critical

  • Left reasonably soon (within ~30 mins of projected time)

  • Accomplished most of the goals

  • No control mapping problems with ardupilot

  • Pre-flight couple days went well (well prepared, only needed ~1 hour in the morning of)

  • Heated blankets worked (but not super well)

  • Circle mode worked and operated as predicted

  • LTE Temperature issue

    • RPi shuts off once it becomes too cold.

    • Observed at approx. 22-23 mins @ -12, -18w/wind. Cloudy skies

  • Charging batteries took a while

    • Balance current on our current charger is very slow - took a long time to balance charge.

  • RFD900 didn’t work

  • Pixhawk did not failsafe when the GS disconnected

    • GCS Disconnected (showed on GS)

    • Drone (air) side did not recognize loss of connection - thought it was still connected (still had heartbeat from mavproxy?)

  • Pilot could not fly the drone in the conditions. Gloves removed a ton of dexterity.

  • ELRS Backpack did not work.

TODO:

  • Check ESC’s / Electronics for water/snow damage

“do better next time”:

  • 2 pilots to switch off in the cold

  • weren’t quite sure who was responsible for everything leading up to the FT until @Anthony Luo got there

  • better defined roles for the flight test

    • who is setting up the drone

    • who is taking videos of it

  • mind heavy snow

    • bring a shovel or gravel bag or 2x4s

  • should communicate who needs to be there when on saturday morning

  • timing was ok for people. some people felt it was a bit early and others felt it was alright and could’ve been earlier.

Future tests

  • Future test to check efficiency of batteries @ differing airspeeds (2m/s increments)

  •  

RCA for Red Item

Create a RCA and keep it as a child page.

 

Action Items

Other Resources

Booking WRESTRC Field

WRESTRC