Accurate altitude data is critical for personnel safety and active buoyancy control.
- Primary Altimeter: Time-of-Flight (ToF) LiDAR for high-precision ground distance (range: 0-100m).
- Secondary Altimeter: High-resolution Barometric pressure sensor (e.g., BMP388) for relative altitude and cross-verification.
- Positioning: Dual GPS (GNSS) modules with RTK capability for precise geofencing and drift monitoring.
Monitoring the mechanical link between the platform and the passenger is a top priority.
- Tension Monitoring: Integrated Strain Gauges on all four harness attachment points.
- Tether Load Cell: Real-time measurement of tether tension to detect "blow-down" or excessive wind force.
- Winch Tension Monitoring: High-frequency monitoring of winch current and line tension to detect snagging or overload.
- IMU Array: Triple-redundant 6-axis Inertial Measurement Units (IMUs) to detect and compensate for unstable oscillations or tipping.
The platform implements automated responses to system failures.
- Fail-Safe Brake: The ATV winch includes an electromagnetic "normally-on" brake that locks the tether position in the event of power loss.
- Power Loss Recovery: The buoyancy system is sized to provide a slow, passive descent if all heating is lost (negative buoyancy bias).
- Emergency "Drogue" Deploy: A small, automated parachute/drogue system for stabilizing the platform during rapid unintended descent.
- ESP32-S3 Watchdog: Hardware and software watchdogs to reset or enter "Safe Mode" (Hold Altitude) if the main control loop hangs.
- Battery Reserve: Dedicated 20% battery reserve strictly for emergency descent buoyancy control.
- Vibration Feedback: Haptic motors in the vest to alert the passenger of geofence boundaries or high-wind warnings.
- Vital Monitoring (Optional): Integration for basic heart-rate/O2 monitoring to detect passenger distress (hypoxia/stress) at higher altitudes.
- Telemetry Stream: Real-time broadcast of all safety metrics to the ground station via LoRa (433MHz).
The control logic (ESP32-S3) prioritizes Platform Leveling and Vertical Stability.
- Leveling Loop: Differential PWM heating to maintain <2° tilt.
- Altitude Loop: PID control mapping LiDAR/Baro data to total buoyancy output.
- Override: Passenger manual controls have a "Safe Envelope" override, preventing manual maneuvers that would exceed stability limits.
Last updated 2026-06-09.