APX4 2.7.37

What's new

GNSS denied operational enhancements

Added support for operator defined estimator position reset while dead-reckoning. See details at: https://auterion.com/auterion-introduces-new-capabilities-for-efficient-isr-missions-in-gps-denied-conditions/

Fixed-wing performance modeling

New service ceiling parameter:

  • FW_S_CEILING – defines the altitude MSL in standard atmosphere at which the vehicle can still achieve a climb rate of 0.5 m/s at trim airspeed and maximum throttle

New features:

  • Compensate TECS minimum sink speed for weight ratio and air density

  • Compensate TECS maximum climb speed for weight ratio and air density

  • Compensate calibrated trim airspeed for increased load factor due to weight

  • Compensate calibrated minimum airspeed for increased load factor due to weight

The weight ratio is calculated from parameters WEIGHT_BASE and WEIGHT_GROSS.

What improved


  • Bugfix: prevent overflow in UTM global position

  • Handle EKF height reset in terrain estimator

  • Robustify RTK position fix

  • Fix bug in INA238 driver which reset the shunt calibration on an incorrect readback

  • Prevent MAVLink deadlock when calling ‘mavlink status’ via MAVLink shell.

  • Fix erroneously aborting a mission landing when an RTL is triggered with home land approaches being available

  • Prevent a deadlock in MAVLink transmission when using TX DMA on TELEM1

  • Bugfix: only allow GNSS switching while the primary GNSS receiver is unavailable

  • Bugfix: resolve corner case preventing Autotune start

  • Enable use of ADS1115 with analog power modules on FMUv6x


  • Bugfix: ensure multicopter altitude changes are linear between two waypoints

  • Improve land behavior when triggered while moving in Manual Position Mode


  • Fix VTOL takeoff when home position does not coincide with takeoff position

  • Battery estimation improvement: reset current filter when transitioning to fixed-wing flight

  • Bugfix: disallow manual RTL trigger (immediate back-transition for VTOL) while already in mission RTL

  • Limit VTOL tilt-rotor thrust compensation due to non-vertical motors in transition phases

  • Avoid hard banking when overshooting land point during transition

  • Bugfix: handle EKF height resets in quadchute logic

  • Bugfix: refer only to VT_ARSP_TRANS, not FW_AIRSPD_MIN, for transition airspeed threshold

  • Bugfix: disallow Takeoff Mode activation when VTOL takeoff is commanded while in-air

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