Low Energy Failsafe
INDICATIONS
- Uncrew warning message"Caution: Battery Level 30%" and contingency state
- Energy storage device (Battery) Status Indicator in Uncrew or AMC is showing energy storage device below 30%
- AMC indicates Warning: Low battery level, return advised
POSSIBLE CAUSES
- Extended Flight Time
- Battery Degradation
- Cold Weather
- Excessive Load
- Inefficient Flight Conditions
FAILSAFE BEHAVIOR
At 30% remaining energy, the autopilot alerts the RPIC of the low energy threshold being reached. Simultaneously, Uncrew begins the Return to Home process and calculates a new route to the takeoff point. If there is a failure of communication between the Flight Management Unit (FMU) and the Uncrew onboard application on the Skynode, Uncrew triggered failsafes will not be performed and will fallback to PX4 triggered failsafes.
At 11% remaining energy, the autopilot commands the aircraft to land in place, based on the PX4 failsafe, allowing the final 11% of energy to be utilized to execute a controlled landing.
Throughout flight, the aircraft system calculates how much energy is remaining to determine if the remaining flight time is above the estimated flight time it would take to fly back to the takeoff point. If the remaining flight time becomes lower than the estimated time to get to the home point, Uncrew automatically commands the aircraft to reroute to the closest alternate landing zone.
EXPANDED ABNORMAL PROCEDURE
LOW ENERGY ANNOUNCE
The RPIC is to announce the voice comms “Low Energy” once abnormal conditions are identified using the indications information above. The announcement should be made using voice communication devices for all crew members to be situationally aware. Detection of this condition by the RPIC is possible by monitoring for any of the indicators listed above on the RPIC Control Station and RPIC Tablet. Certain indications are exclusively observable on each of the aforementioned AE as noted in the indication information.
If Sufficient Energy for Return to Home:
Telemetry MONITOR
Within the Uncrew Mission Console on the RPIC Control Station, the RPIC is to monitor the energy storage device telemetry to determine if the energy remaining is sufficient for a Return to Home to be executed. If sufficient energy remains, no further actions are required for the completion of this procedure.
If Insufficient Energy for Return to Home:
Uncrew: ALZ SELECT
Select the “ALZ” button within the Uncrew Mission Console on the RPIC Control Station.
Once the button is selected, a popup window will appear requiring RPIC confirmation. This window will remain displayed until “CONFIRM” is selected or exit (“x”) is pressed.
Once the command is confirmed, the aircraft stops performing the mission and begins navigating to an Alternate Landing Zone (ALZ). The aircraft will maintain its altitude at the defined desired altitude. Uncrew navigates the aircraft so that all NFAs and perimeters are avoided. The Aircraft Status shall be Contingency.
At the ALZ, the aircraft will land.