This is the multi-page printable view of this section. Click here to print.

Return to the regular view of this page.

Sensors

Sensors carried by WII5 buoys — power, navigation, motion, environment, imaging.

The sensor catalog. Not every buoy variant carries every sensor — see the buoy types for which sensors ship with which build.

  • MPPT — solar charging.
  • GPS — position and directional heading.
  • Kistler — high-precision accelerometer.
  • IMU — inertial measurement.
  • Temperature — water and internal temperature sensors.
  • Anemometer — wind speed and direction.
  • Cameras — visual deployment / surface imaging.

1 - MPPT

Solar charging via MPPT — maximum power point tracking. Custom-designed for the small batteries used in solar WII buoys, because nothing off-the-shelf fit.
mppt.jpg

MPPT (maximum power point tracking) charge controller for the solar input that keeps the battery pack alive between sunny windows.

Why we designed our own

At the small battery sizes used in solar WII buoys, no off-the-shelf MPPT existed that was a good fit — commercial MPPT controllers were designed back then for vehicle, off-grid, or marine packs at least an order of magnitude larger than what a buoy carries. The available options were either too lossy at low currents, drew too much quiescent power, or had input/output ranges that didn’t match a small solar panel + lithium-pack combination.

So we built our own. The result is an MPPT optimised for:

  • Small battery capacity — sized for the buoy pack, not a vehicle.
  • Low quiescent draw — the controller itself can’t be a meaningful fraction of the buoy’s deep-sleep current budget.
  • Small panel — input range matches the panels we can fit on a buoy enclosure top, with anti-slide spikes and antenna clearance around them.
  • Cold operation — has to keep working at the Antarctic temperature range, where commercial controllers often spec out.

Status: placeholder. Schematic, board layout, efficiency curves, and deep-sleep current measurements to follow.

2 - GPS

GPS — position, time, and directional heading.

GPS provides position, timing, and where supported, directional heading used in the directional wave-spectrum analysis.

Status: placeholder.

3 - Kistler

Kistler high-precision accelerometer for wave-motion measurement.

Kistler high-precision accelerometer. Used where the IMU’s MEMS accelerometer doesn’t have enough resolution for the wave-motion calculations.

Status: placeholder.

4 - IMU

Inertial measurement unit — accelerometer, gyroscope, magnetometer.

The IMU provides 9-axis motion data: accelerometer, gyroscope, and magnetometer, used for orientation and motion estimation alongside the Kistler.

Status: placeholder.

5 - Temperature

Water and internal temperature sensing.

Temperature sensors for water (where the buoy enclosure permits) and internal electronics monitoring.

Status: placeholder.

6 - Anemometer

Wind speed and direction sensor.

Anemometer for wind speed and direction. Carried on variants intended for combined sea-state and atmospheric observation.

Status: placeholder.

7 - Cameras

Visual deployment and surface-imaging cameras.

Cameras carried by some variants for visual deployment confirmation and surface imaging during operation.

Status: placeholder.