APX4 3.0.5

{% hint style="info" %} Please use Auterion Mission Control 1.29 or newer with this version of APX4. {% endhint %}

{% hint style="danger" %} Attention: Default disarmed PWM was changed from 900us to 1000us! See PX4 v1.14 release notes. {% endhint %}

Major changes

• Dynamic control allocation
• Improved preflight failure check reporting
• Improved failsafe handling
• Improved ROS 2 Interface thanks to uXRCE-DDS. This enables the use the Auterion SDK to build advanced flight control capabilities in ROS 2.
• Added helicopter support

APX4 is based on the open-source PX4 release v1.14. See here for detailed release notes for 1.14.

Below are the changes made on top of v1.14.

What's new

General

• Mission feasibility checks: check if mission items fit to the current vehicle type
• Add magnetometer thermal calibration/compensation
• Factory calibration: do not store _PRIO parameters
• Arming checks: disallow arming via parameter
• Commander: add warning for imminent navigation failure
• Enable arbitrary Euler angle for magnetometer rotation
• Battery preflight check: add new battery threshold for arming (COM_ARM_BAT_MIN)
• Add option to configure action when wind limit is exceeded (COM_WIND_MAX_ACT)
• Disarm if battery failure is detected during spool-up
• Add option to enable stick gesture to "kill" vehicle

Sensors / State estimation

• EKF2: new vision attitude error filter
• Add magnetometer inclination check
• Add auxiliary global position fusion option
• Added support to reset vehicle position based on external position. This can be useful in GPS denied conditions where the operator can recognize the current position by looking for landmarks in the video stream.
• Add SF30/D Lightware laser distance sensor

Copter

• Helicopter: add tail servo support
• Coaxial Helicopter Support
• Add "Slow Position Mode" feature. This mode is similar to position mode but allows you to change the speed of the drone. This can be very useful during inspections where the operator wants to make very small maneuvers while inspecting an object.
• Add option for throw launch

Fixed-wing / VTOL

• Tiltrotor VTOL back-transition: expose tilting time as parameter
• Added Performance model for fixed-wing to improve controller stability when flying with varying payload weights or in different altitudes
• Optionally disable SF1xx sensor in VTOL fixed-wing flight phase

Rover

• Add Roboclaw ESC driver
• Differential drive for Rover & Gazebo R1 Rover port

What improved

General

• Micro-XRCE-DDS-Client improvements
• Fix geofence when changing altitude through reposition
• Improvement: Default motor PWM limits minimum 1100 maximum 1900
• Documentation can be found here
• Attention: Default disarmed PWM was changed from 900us to 1000us!
• Geofence: Disable pre-emptive geofence predictor by default
• GNSS-denied workflow: Allow auto modes with local position estimate if global origin is set manually
• Don't allow external reposition commands without a mode switch, and ensure old reposition commands are not erroneously set
• Geofence: if armed, do not allow to upload a fence that would trigger a geofence breach immediately
• Geofence: do not allow to upload a fence that doesn't include Home (to ensure that RTL to Home is always possible)
• Navigator: prevent race condition when receiving multiple commands at once

Sensors / State estimation

• Optical flow: general improvements
• Yaw estimator improvements
• Improve yaw emergency estimator convergence
• Yaw estimator: use gyro bias from EKF2 if at rest
• Magnetometer preflight check: report strength and inclination values in case of failure
• EKF2: improve resilience against incorrect magnetometer data
• Robustify range finder kinematic consistency check
• Terrain estimator: handle EKF2 height reset
• Improve EKF2 stability by switching to an error-state Kalman filter
• Sensors: add parameter to silence IMU clipping (SENS_IMU_CLPNOTI)
• Multi GNSS fallback improvements

Copter

• Respect spool-up time in Stabilized mode and have zero throttle while still landed
• Fix helicopter actuator saturation logic
• Fix multicopter altitude change sometimes not linear between two waypoints
• Fix FlightTaskAuto: harden line following logic (only do line following if previous and current setpoints are not equal).
• Yaw handling improvements/simplifications, e.g. remove waypoint yaw acceptance requirement if weather vane is enabled
• Beginner/tuning friendly Acro mode defaults

Fixed-wing / VTOL

• Replace old implementation of "uncommanded descend quad-chute" (VT_QC_ALT_LOSS and VT_QC_T_ALT_LOSS)
• Fixed-wing: Always establish loiter around current position when switching into Hold mode
• VTOL: scale transition airspeed threshold with configured vehicle weight and air density
• Fixed-wing/VTOL: High wind controller hardening
• Rework figure eight joining logic
• Add guidance fallback for corner cases without valid wind estimates
• Make airspeed sensor configuration easier and consistent with other sensors
• VTOL Tailsitter: add automatic pitch ramps in transition also in Stabilized mode
• TECS throttle gains renames and defaults reduction
• VTOL: treat Descend mode like Land mode for pusher/tilt assist
• Fixed wing autotune improvements

Parameter Changes Compared to APX4 2.7

Removed Parameters

| Parameter name | Affecting | Reason | | ------------------------------------------------------------------------------------------------------------------------------------------------------------- | --------- | ---------------------------------------------------------------------- | | CBRK_RATE_CTRL | All | Deemed not necessary anymore. | | CBRK_VELPOSERR | All | Deemed not necessary anymore. | | COM_ARM_ARSP_EN | VTOL, FW | Deemed not necessary anymore after airspeed preflight check changes. | | COM_ARM_WO_OBLOG | All | Allow arming without onboard logger being enabled and in ready state. | | COM_OBL_ACT | All | Commander state machine rewrite. | | COM_RC_DARM_A_H | All | Disarm gesture rework. | | EKF2_REQ_MAG_H | All | Required mag health time rework. | | FD_BAT_EN | All | State machine rewrite: now battery health is always checked. | | FW_ECO_AD_THRLD, FW_ECO_ALT_ERR_O, FW_ECO_ALT_ERR_U, FW_ECO_ALT_MIN FW_THR_MAX_E FW_T_ALT_TC_E FW_T_CLMB_R_SP_E FW_T_SPDWEIGHT_E | VTOL, FW | Removal of ECO flight mode (deemed not necessary anymore). | | FW_L1_DAMPING FW_L1_PERIOD FW_L1_R_SLEW_MAX FW_USE_NPFG | VTOL, FW | Replace L1 guidance with NPFG, deprecate L1. | | FW_T_SPD_OMEGA FW_T_TAS_R_TC | VTOL, FW | TECS rework, params not required anymore. | | GF_ALTMODE GF_COUNT | All | Remove outdated features during a general geofence rework. | | LNDMC_ALT_MAX | MC, VTOL | Not deemed necessary anymore. | | MAV_ODOM_LP | All | EKF2: EV overhaul and position fusion | | MIS_DIST_WPS | All | Deemed not necessary anymore. | | MNT_MAV_SYSID | All | Mavlink System ID of the mount: not needed anymore | | PWM_AUX_RATE PWM_MAIN_RATE SYS_CTRL_ALLOC VT_FW_MOT_OFFID VT_IDLE_PWM_MC VT_MC_ON_FMU VT_MOT_ID MOT_ORDERING | All | Deprecated with switch from static mixing to control allocation. | | TF_TERRAIN_EN | All | Removed feature (terrain follower in RTL). | | VT_B_DEC_FF | VTOL | Not needed functionality, P gain is enough. | | VT_B_REV_DEL VT_B_REV_OUT | VTOL | Not needed functionality, not implemented with new control allocation. | | RTL_HDG_MD | MC | Deemed not necessary anymore. | | SYS_USE_IO | All | Not needed anymore. |

New Parameters

| Parameter name | Affecting | About | | ----------------------------------------------------------------------------------------- | --------- | ------------------------------------------------------------ | | CAL_MAGx_ROLL/PITCH/YAW | All | Enable arbitrary Euler angle for Mag rotation. | | COM_ARMABLE | All | Disallow arming via a parameter. | | COM_ARM_ODID | All | Enable Drone ID system detection and health check | | COM_THROW_EN COM_THROW_SPEED | MC | MC throw launch | | EKF2_AGP_CTRL, EKF2_AGP_DELAY, EKF2_AGP_GATE, EKF2_AGP_NOISE | All | Aux global position (AGP) sensor aiding. | | EKF2_GRAV_NOISE | All | Gravity observation. | | EKF2_GYR_B_LIM | All | Gyro bias limit | | EKF2_OF_QMIN_GND | All | Optical flow data quality metric threshold. | | FW_ACRO_YAW_EN | FW, VTOL | Parameter to enable yaw rate controller in Acro | | FW_AT_MAN_AUX | FW, VTOL | Enable/disable auto tuning using an RC AUX input | | FW_MAN_YR_MAX | FW, VTOL | FW attitude controller: add option to disable yaw rate input | |

FW_PR_D,
FW_RR_D,
FW_YR_D

| FW, VTOL | D gains for fixed-wing rate controller. | | FW_T_SPD_DEV_STD, FW_T_SPD_PRC_STD, FW_T_SPD_STD | FW, VTOL | TECS rework | | IMU_GYRO_DNF_MIN | All | IMU gyro dynamic notch filter minimum frequency | | MAN_KILL_GEST_T | ALl | Stick gesture to kill | | MPC_YAWRAUTO_ACC | MC | Heading acceleration. Only applies to Goto Setpoints atm. | | MPC_LAND_RADIUS | MC, VTOL | Landing nudging radius | | RTL_APPR_FORCE | VTOL | RTL force approach landing | | SENS_IMU_CLPNOTI | All | IMU notify clipping | | UXRCE_DDS_DOM_ID UXRCE_DDS_KEY UXRCE_DDS_PTCFG UXRCE_DDS_SYNCC UXRCE_DDS_SYNCT | All | Micro XRCE-DDS configuration |

Features with Renamed Parameters

Old name	New name	Related feature	Auto translation
COM_DR_EPH	COM_POS_LOW_EPH	GNSS-denied navigation (feature has been re-worked)	No
EKF2_HGT_MODE EKF2_BARO_B_EN	EKF2_HGT_REF	EKF2 multiple height sources fusion	No
EKF2_RNG_AID	EKF2_RNG_CTRL	EKF2 multiple height sources fusion	No
EKF2_AID_MASK	EKF2_DRAG_CTRL EKF2_OF_CTRL EKF2_GPS_CTRL EKF2_IMU_CTRL EKF2_EV_CTRL	EKF2 multiple height sources fusion	Yes
FW_DTRIM_P_FLPS FW_DTRIM_P_SPOIL FW_DTRIM_R_FLPS	CA_SV_CS${i}_FLAP CA_SV_CS${i}_SPOIL	Flap & Spoiler Handling rework	No
FW_L1_PERIOD	NPFG_PERIOD	Replacement of L1 by NPFG	No
FW_L1_R_SLEW_MAX	FW_PN_R_SLEW_MAX	Replacement of L1 by NPFG	Yes
POSSLOW_DEF_HVEL POSSLOW_DEF_VVEL POSSLOW_DEF_YAWR POSSLOW_MAP_HVEL POSSLOW_MAP_VVEL POSSLOW_MAP_YAWR POSSLOW_MIN_HVEL POSSLOW_MIN_VVEL POSSLOW_MIN_YAWR	MC_SLOW_DEF_HVEL MC_SLOW_DEF_VVEL MC_SLOW_DEF_YAWR MC_SLOW_MAP_HVEL MC_SLOW_MAP_VVEL MC_SLOW_MAP_YAWR MC_SLOW_MIN_HVEL MC_SLOW_MIN_VVEL MC_SLOW_MIN_YAWR	Rework of MC slow mode	No
RWTO_L1_PERIOD	RWTO_NPFG_PERIOD	FW runway takeoff	No
VT_FW_DIFTHR_SC	VT_FW_DIFTHR_S_P VT_FW_DIFTHR_S_R VT_FW_DIFTHR_S_Y	VTOL differential thrust in FW	No
VT_PSHER_RMP_DT	VT_PSHER_SLEW	Pusher throttle ramp up slew rate	Yes
VT_QC_HR_ERROR_I	VT_QC_ALT_LOSS	Quad-chute uncommanded descent threshold	Yes
COM_RCL_ACT_T COM_BAT_ACT_T	COM_FAIL_ACT_T	Commander state machine rewrite	No
NAV_FT_ALT_M NAV_FT_DST NAV_FT_FS NAV_FT_RS NAV_MIN_FT_HT	FLW_TGT_ALT_M, FLW_TGT_DST, FLW_TGT_FA, FLW_TGT_HT, FLW_TGT_MAX_VEL, FLW_TGT_RS	Rewrite of flight task follow target	No
COM_PREARM_ODID	COM_ARM_ODID	Open Drone ID	Yes
FW_ARSP_MODE	FW_USE_AIRSPD	Rework airspeed configuration	Yes
CBRK_AIRSPD_CHK	SYS_HAS_NUM_ASPD	Rework airspeed configuration	Yes
FW_T_THR_DAMP	FW_T_THR_DAMPING	TECS rework	No
FW_T_I_GAIN_THR	FW_T_THR_INTEG	TECS rework	No

Parameters with Changed Defaults

Parameter name	Old value	New value	About
COM_ARM_HFLT_CHK	0	1	Enable hardfault log check
COM_ARM_MAG_ANG	45	60	Relax threshold for magnetic field inconsistency between units that will allow arming
COM_LOW_BAT_ACT	0	2	Automatic return/land in battery empty case
COM_RC_STICK_OV	12	30	Increase threshold for stick override
EKF2_EVA_NOISE	0.05	0.1	Increase measurement noise for vision angle observations
EKF2_MAG_YAWLIM	0.25	0.2	Reduce yaw rate threshold for 3D magnetometer fusion
EKF2_WIND_NSD	0.02	0.05	Increase wind process noise
FW_AIRSPD_MAX	20	25	Increase max airspeed limit
FW_WR_IMAX	1	0.4	Reduce max integrator value of wheel controller
GF_PREDICT	1	0	Disable predictive geofence feature
MC_ACRO_EXPO MC_ACRO_EXPO_Y	0.7	0	Disable Acro stick expo
MC_ACRO_P_MAX MC_ACRO_R_MAX	720	100	Reduce max Acro roll/pitching rate
MC_ACRO_SUPEXPO MC_ACRO_SUPEXPOY	0.7	0	Disable Acro stick super expo
MC_ACRO_Y_MAX	540	100	Reduce max Acro yawing rate
MPC_ALT_MODE	0	2	Set default to terrain following
SENS_GPS_MASK	0	7	Use speed, hpos and vpos accuracy for multi GPS blending logic
SENS_MAG_AUTOCAL	0	1	Automatically initialize magnetometer calibration from bias estimate
SENS_MAG_MODE	0	1	Publish primary magnetometer
VT_B_TRANS_DUR	8	10	Increase max VTOL backtransition duration