2024-02-10 Pegasus + Houston Flight Test

Owned by Megan Spee
Last updated: 2024-02-13 by Anthony Luo
9 min read

Sections for requesting team to fill out:

  • Admin preparation

  • Test Cards / Test Plan

  • Mandatory Attendees

Sections for flight test coordinator to fill out:

  • Flightline team

  • Location

  • Status

  • Drone

Sections for flightline team to fill out:

  • EFS to fill out flight test cards

Admin Preparation

Requested By

@Megan Spee

Sub-Team Review

(To be checked once reviewed by sub-team representative)

Mechanical
Electrical
EFS
Autonomy
Operations

Date of Request

2024-01-30

Goal Summary

  • Pegasus Video transmission (1.3GHz VTX - new)

  • verification of systems at full speed missions on Pegasus

  • Gemini on Houston

  • Obstacle avoidance on Houston

  • Tracking antenna tests on Pegasus + Houston

Status?

Waiting for Sub-Team Review

Desired Airframe

Houston / Pegasus

Location + Time

WrestRC

Testplan - to be filled out by requesting team

Note: This should include the tracking antenna used on Sundayā€™s ground testing. (Discord - Group Chat Thatā€™s All Fun & Games )

Should also ideally include video muxing with at least 2 cameras.

Pink controller INOP as primary until arm/disarm logic proven working.

Test #1: Pegasus VTX, LOS low speed & hover performance

Procedure

Goals / Objectives

Knockoff criteria

  1. Takeoff manually in Loiter, verify that video is stable during takeoff.

  • Ensure that video signal is maintained during close-range takeoffs.

  • Ensure hover doesnā€™t negatively impact video switching

  • Ensure OSD elements are correct

Loss of Video Transmission

  • Stop drone movement, attempt to re-establish video link.

Loss of Control

  • Land the drone as soon as possible

Loss of Orientation

  • RTL

Battery

  • Land, RTL if possible.

  1. Attempt switching video sources

  1. IF CONFIGURED: attempt switching OSD screens.

  1. Fly slow passes at varying altitudes / distances (pilot discretion) from the ground station

  • Ensure that video signal is maintained during different maneuvers

  • Ensure that different video sources are functional during different passes

  1. Land normally

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Test #2: Pegasus VTX, FPV performance & Landing Accuracy

Procedure

Goals / Objectives

Knockoff criteria

  1. Takeoff manually in Loiter, verify that video is stable during takeoff.

  • Ensure that video signal is maintained during close-range takeoffs.

  • Ensure hover doesnā€™t negatively impact video switching

  • Ensure OSD elements are correct

Loss of Video Transmission

  • Stop drone movement, attempt to re-establish video link.

  • Pilot hand-over to LOS pilot if necessary.

Loss of Control

  • Land the drone as soon as possible

Loss of Orientation

  • RTL

Battery

  • Land, RTL if possible.

  1. Attempt switching video sources

  1. IF CONFIGURED: attempt switching OSD screens.

  1. Fly slow passes at varying altitudes / distances (pilot discretion) from the ground station

  • Ensure that video signal is maintained during different maneuvers

  • Ensure that different video sources are functional during different passes

  1. Attempt landing on a landing pad FPV

  • Evaluating FPV camera placement, ability to maintain orientation/reference during fpv landing

Loss of orientation

  • Push altitude, handover if necessary.

FOD / risk of rotorstrike

  • Push altitude, handover if necessary.

Test #3: Pegasus VTX, High load perf.

Procedure

Goals / Objectives

Knockoff criteria

  1. Takeoff manually in Loiter, verify that video is stable during takeoff.

  • Ensure that video signal is maintained during close-range takeoffs.

  • Ensure hover doesnā€™t negatively impact video switching

  • Ensure OSD elements are correct

Loss of Video Transmission

  • Stop drone movement, attempt to re-establish video link.

Loss of Control

  • Land the drone as soon as possible

Loss of Orientation

  • RTL

Battery

  • Land, RTL if possible.

  1. Attempt switching video sources

  1. IF CONFIGURED: attempt switching OSD screens.

  1. Enter Attitude / Stabilize mode.

  • Ensure that video signal is maintained.

  1. Attempt to ā€œloadā€ batteries by changing direction rapidly / accelerating / decelerating.

  • Ensure that video signal integrity is maintained.

Loss of orientation / Obstacles nearby

  • Switch to Loiter, handover if drone is in sight.

Test #4: Pegasus VTX, Long dist perf.

Procedure

Goals / Objectives

Knockoff criteria

  1. Fly Card 2 as normal

  • Ensure video link is maintained as the drone flies further away.

follow card 2 knockoff criteria

  1. Evaluate Video perf. during card 2 maneuvers

  1. Push card #2 distance from home if necessary

Note: This should also include tracking antenna testing.

Test #1:

Procedure

Goals / Objectives

Knockoff Criteria

  1. Configure waypoint mission incl. one long straight (at least 500m), a wide 180 degree turn, and subsequent return.
    Set WPNAV speed to 20m/s (max)

Ensure that there is sufficient straight line distance for Pegasus to reach max target speed.

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  1. Set Pegasus to Auto Mode (Mode 5)

Enable auto mission

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  1. Arm, and allow Pegasus to fly the mision

Determine maximum speed reached by Pegasus

Lost Link

  • Follow lost link protocols. Pegasus should automatically RTL if link is lost.

Battery failure / low voltage

  • pilot takeover

  • Land drone as soon as possible.

Instability in drone / vibe / ekf failure

  • Pilot takeover

  • Fly drone back to launch at slow speed.

  • Land & Analyze logs.

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Note: This flight test can be Gemini + OA at the same time.

General Gemini Procedure:

  • Enable logging on TX16.

Preface: https://ardupilot.org/copter/docs/parameters.html#avoid-parameters , we want to determine if:

  • Avoid backup_spd

  • Avoid accel_max

  • Avoid backup_dz

Has impacts on handling ā€œpredictabilityā€ near obstacles.

Test #1: Default OA setting characteristic handling

Procedure

Goals / Objectives

Knockoff criteria

  1. Ensure base parameters are set to defaults

AVOID_MARGIN = 2m

AVOID_ACCEL_MAX = default

AVOID_BACKUP_DZ = default

AVOID_BACKUP_SPD = default

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  1. Pilot #1 takeoff, attempt to fly towards obstacle @ varying speeds (of comfort)

  • Understanding handling characteristics of the drone

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Impact w/obstacle

  • Visually inspect airframe

  • Perform control checks pre RTS

Loss of orientation

  • RTL the drone, or land and disarm immediately.

Loss of control

  • Land and disarm if possible.

OA failure

  • Re-attempt at slower speed. Note timestamp.

  1. Pilot #2 takeoff, attempt to fly towards obstacle @ varying speeds of comfort

Test #2: Modified OA Setting handling

Procedure

Goals / Objectives

Knockoff criteria

  1. Remove avoid accel limits and repeat Card3 Test#1 steps 2-3

  • Looking to understand controllability of the system.

Impact w/obstacle

  • Visually inspect airframe

  • Perform control checks pre RTS

Loss of orientation

  • RTL the drone, or land and disarm immediately.

Loss of control

  • Land and disarm if possible.

OA failure

  • Re-attempt at slower speed. Note timestamp.

  1. Adjust backup_dz/backup_spd and repeat Card3 Test#1 steps2-3

Note: There must be * some * amount of wind.

Test #1: Hover Weathervane

Procedure

Goals / Objectives

Knockoff criteria

  1. Takeoff manually in Loiter, hover in place.

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Loss of control

  • Land, restart systems, re-attempt

  1. Toggle weathervane high (enabled)

  • Determine if the drone will weathervane

  1. Toggle weather vane low (disabled)

  • Determine if the drone will remain in place

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Test #2: Auto mission Weathervane

Procedure

Goals / Objectives

Knockoff criteria

  1. Enable weathervaning

  • Determine if the drone will automatically weathervane when in loiter to reduce itā€™s cross-section into the wind

Loss of control

  • Pilot takeover

  • establish system characteristics, restart if possible.

Loss of telemetry

  • Pilot takeover to RTL (should happen automatically as well)

Battery failsafes

  • land immediately

  1. Fly auto mission in a few directions w/straight lines at angle to the wind

  1. Land & evaluate?

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Necessary Preparation

Mechanical

Pegasus cleared to fly (mechanically)
sensor mount ready
Motors + frame rigid
Houston cleared to fly (mechanically)
sensor mount attached
arms + plates rigid

Electrical

Pegasus cleared to fly (electrically)
harnessing secure
Houston cleared to fly
Video System harnessed & Checked

Embedded Flight Software

Autonomy

Attendees

Name

Phone # (opt)

Sub-team

Driving

Role

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Name

Phone # (opt)

Sub-team

Driving

Role

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@Megan Spee

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Director

toyota prius

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@Anthony Luo

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Director

5-pass sedan (smol)

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@Maxwell Lou ?

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Mech

Caravan

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@Jerry Tian

6472074122

electrical

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checking harness & debug Gemini if needed

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@Yuchen Lin

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EFS

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flight test coord

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@Ayoung Eun

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EFS

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@Andy Meng

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@Ayush Ganguly

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EFS

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Testing OSD and VTX

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Flightline Team

Name

Phone #

Role

Reason

Name

Phone #

Role

Reason

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Pre-Flight Preparation

Checklists

  • Motors Tested (directions)

  • Propellers Checked

  • VTX System E2E Checked on Pegasus

    • VTX system works

    • Camera switching works

    • Ground station relay works

    • All monitors & Goggles Work

    • Ā 

Incident Procedures

Weather

image-20240210-141256.png

Light chance of rain, sunny, and above 0.

image-20240210-141405.png

Potential chance of steady wind & gusts up to 30+km/h.

Flight Test Timeline

Date/Time

Action

Notes

Date/Time

Action

Notes

0700

Start charging batteries

4x 6s 5000mah (pegasus)

3x 3s 4000mah (houston)

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0930

Final flight inspections

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1000

Briefing @ WARG Bay

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1015

Begin loading vehicles

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1030

Arrival at Flight Test Location

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Card 1-1

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Card 1-2

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Card 1-3

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Card 1-4

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Card 2-1

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Card 3-1

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Card 3-2

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Packup

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Debrief

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0200

We outta here bois

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11:40

Flight test plan (Pegasus) Misson 2 - Arm & take off time

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11:43

landing

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11:48

Mission 3: arm and take off

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11:52

disarm and land

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12:09

Mission 4 (Test VTX and OSD): arm and take off

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12:11

disarm and land

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12:19

Houston flight test mission 1: arm and take off

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12:21

disarm and land

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12:22

Mission 2: Testing with box obstruction: arm and take off

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12:22

disarm and land

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12:23

Mission 3: arm and take off

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12:25

crashed into obstacle and disarm

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12:28

Mission 4 (increased distance) : arm and take off

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12:29

disarm and land

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DEBRIEF

Logs: https://uofwaterloo-my.sharepoint.com/:f:/g/personal/uwarg_uwaterloo_ca/EprwSfOtGeZOom-fAK63e0gBZ2c94HDJ8xIIYBWXcJXheg?e=hJEmC2

Media Ingest: https://uofwaterloo-my.sharepoint.com/:f:/g/personal/uwarg_uwaterloo_ca/EqjTFLI7eSZHil5CgZ13PYMBk9KPlNMFPESkOseTALivzg?e=tapYW3

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Action items

  • Get the max weight of houston to mechanical for new landing gear design

    • more stable to avoid tipping

  • Update angle limit and re-run max speed

  • try landing on landing pads with current FPV setup: need mux harness and second camera harness prior

  • VTX range test

  • configure OSD better

    • change from icarus config

    • fix the ā€˜turning on and off in the airā€™ problem

  • get link stats between gemini and the drone forwarded to logs somewhere

  • buying pre crimped wires to build a proper VTX harness

  • Weathervaning

  • figure out obstacle avoidance parameters/setup on houston

  • get new batteries

    • hit 70 amp current draw at one point

    • indicates battery health bad

  • document OA parameters and how it translates to behavior. @Anthony Luo to look at this

  • clean up harnessing on pegasus:

    • shorten all the cross wires

    • clean up all little wires too

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Analysis

  • logs are uploaded, donā€™t need much analysis on them

Vibe

Pegasus generally shows good vibration means, near 10 in all axis. (where 10 is essentially perfect). Comparing against vanguard shows worse vibe performance in some instances, but not to a significant degree.

Houston showed incredibly bad vibration, likely due to chipped propellers.

Attitude Control

Wind was estimated to be around 20-40km/h, the highest winds weā€™ve flown Pegasus in to-date. Attitude control performance on roll and pitch axis are excellent, even given the higher vibe.

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Current Draw

During card 2 - 1, multiple missions were run. On average, when flying at full speed forward, we were limited by our MAX_LEAN_ANGLE of 30 degrees. At this angle, our average current draw is visually observed to be around 80Amps.

Efficiency

Snipping from sections where Pegasus was at maximum or near-maximum forward velocity, we are able to calculate efficiency in mah/km using the following formula:

BAT.Curr[A] * 1000. [mA/A] / GPS.Spd [m/s] * (3600[s/h] / 1000 [m/km] ) --> Eff[mAh/km]

Average efficiency at high-speed shows somewhere between 700-1000 mah/km

Assuming battery capacity of 2*6000 = 12000 mah, this means we expect to be able to run 12km at 15m/s = 55km/h, giving us ~ 4 laps in ~26minutes. This is perfect assuming we get a 30 minute flight windowā€¦.