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Design Requirements

Concept

WE SHOULD NOT BLAME THE RIDER FOR A SUDDEN UNPREDICTABLE CUTOFF OF THE EUC.

  • Foolproof, weatherproof
  • Impossible to fry electronics by riding hard
  • Impossible to damage battery by riding too cold (leanback and emergency before)
  • Leanback angle calculation is central point, function of:
    • Temperatures
    • Voltages
    • Currents
    • As a consequence:
      • Speed

        To maintain a given guaranteed minimum torque

  • Make it perform strict self-tests
  • Error states:
    • Warning: Just so you know
    • Alert: Gradual limits that affect the performance when balancing. Affects leanback
      • Battery overheating, overvoltage, or undervoltage. All will limit the speed. Overheating may limit it to 0.
    • Emergency: STOP. Hard leanback. Safety measures

      For molicel p42a pack: <8.4A, <4.2V, >0ºC, <45ºC. Gradual transfer curve when getting close to these limits, that results in gradual predictable leanback

Hardware

  • The charger will be built into the EUC, with a small vacuum cleaner style cable.
  • Crimped connectors? > Not just soldered when there's so much vibration.
  • Bolts: Positive locking mechanism

    • cotter pin, safety wiring, [nylon, prevailing torque, jet, K] lock nuts, tab washers or locking plates.

  • Several wires in parallel for redundancy (motor and battery wiring), while being able to detect a single one disconnecting? > Maybe unnecessarily complex
  • Battery disconnect loop key? (actionable from the outside.)

Firmware

  • Include emergency modes that get triggered for many reasons
  • Dynamic calculation of max speed based on battery level, temperature, and other factors.

  • Gradual tiltback that asympotically grows in intensity as the max speed is reached.

  • State machine?

    • OFF (Not balancing, when put sideways)
    • Balancing (Normal, affected by alerts)
    • Charging
    • Emergency (Balancing but with hard leanback, to speed 0)