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Reaction Wheel: 2022-09-25 Meeting

Reaction Wheel: 2022-09-25 Meeting

Owned by Yevgeniy Gorbachev (RIT Student)
Last updated: Nov 12, 2022

Date

Attendees


Goals

Discussion items

ItemWhoNotes
AdminYevgeniy
  • MARS
    • Launch site is bad
    • Regulations are potentially too strict for reaction wheel flights
  • Rocketry discord
    • Ask around for launch sites near roc
  • Ship it to California so Will tests it
    • Last-er resort than MARS?
PDR Action ItemsYevgeniy
  • Vibration tuning
    • Tune the housing sitting on its own - the vibration level should "look good" to us
      • Hold it in your hand and see how bad it is
    • Preflight (post-installation) check
    • Look into balancing epoxy instead of bolts
      • There exist mathematically optimal approaches to doing this
    • Look into how drone props are balanced
  • Precession
    • Mitigate chance by looking into methods to make sure the wheel isn't canted
    • Preflight (post-installation) check by spinning the rocket manually, check whether L is in line with the rocket
    • (a - g) cross v gives lateral acceleration, might gate that by a threshold
    • Tip-over effects
    • Teams in the SAC discord did failure investigations on inertial roll coupling, investigate how related that is
  • Motor g-rating (esp if we switch to BLDC)
    • Hit it against a table a bunch of times
    • Centrifuge? lots of practical problems
    • Look into hardening
    • Hardening a brushless motor is easier
    • Brushed motor is less susceptible to acceleration effects
    • combat robotics does not use brushed motors
    • Not a lot of experience with BLDC control systems
    • Brushless ESCs would probably give good enough response time anyway
  • How much will the rocket spin?
    • Look at a bunch of flight video
  • Spin effects on recovery
    • Short-closed failure 
      • Heavily mitigated by switch to BLDC
    • Spin after deployment is not considered that bad
    • Watchdogs to watch for spurious outputs
      • Watch for very inconsistent sensor outputs 
      • Shall not spin the motor in the opposite direction of spin
    • Configure controller to ignore too-consistent inputs
  • Spin effects on ground hit
    • Much higher effective velocity
  • Not pursuing fancy stuff this year
  • Steadily spin-down and lock wheel after deployment
  • Lock wheel using ESC braking feature during boost
BLDC options

Action items