1) Pre-takeoff throttle feedback in AltHold, Loiter, PosHold
2) Terrain altitude retrieval from ground station (informational purposes only so far, Pixhawk only)
3) Safety Items:
a) "EKF check" will switch to LAND mode if EKF's compass or velocity variance over 0.6 (configurable with EKFCHECK_THRESH param)
When EKF is not used inertial nav's accelerometer corrections are used as a substitute
b) Barometer glitch protection added. BAROGLTCH_DIST and BAROGLTCH_ACCEL parameters control sensitivity similar to GPSGLITCH protection
When glitching occurs barometer values are temporarily ignored
c) Throttle/radio and battery failsafes now disarm vehicle when landed regardless of pilot's throttle position
d) auto-disarm extended to Drift, Sport and OF_Loiter flight modes
e) APM2 buzzer notification added for arming failure
f) APM2 arming buzz made longer (now matches Pixhawk)
g) do-set-servo commands cannot interfere with motor output
4) Bug Fixes:
a) Drift slow yaw response fixed
b) AC3.2-rc3 failsafe bug resolved. In -rc3 the throttle failsafe could be triggered even when disabled or motors armed (although vehicle would not takeoff)
1) Hybrid mode - position hold mode but with direct response to pilot input during repositioning (JulienD, SandroT)
2) Spline waypoints (created by David Dewey, modified and integrated by Leonard, Randy)
3) Drift mode uses "throttle assist" for altitude control (Jason)
4) Extended Kalman Filter for potentially more reliable attitude and position control (Pixhawk only) (Paul Riseborough). Set AHRS_EKF_USE to 1 to enable or use Ch7/8 switch to enable/disable in flight.
5) Manual flight smoothness:
a) Smoother roll, pitch response using RC_FEEL_RP parameter (100 = crisp, 0 = extremely soft)
b) Adjustable max rotation rate (ATC_RATE_RP_MAX, ATC_RATE_Y_MAX) and acceleration (ATC_ACCEL_RP_MAX, ATC_ACCEL_Y_MAX)
6) Autopilot smoothness:
a) Vertical acceleration in AltHold, Loiter, Hybrid modes can be configured with PILOT_ACCEL_Z parameter (higher = faster acceleration)
b) Maximum roll and pitch angle acceleration in Loiter mode can be configured with WPNAV_LOIT_JERK (higher = more responsive but potentially jerky)
c) Yaw speed can be adjusted with ATC_SLEW_YAW parameter (higher = faster)
d) smoother takeoff with configurable acceleration using WPNAV_ACCEL_Z parameter
e) Twitches removed during guided mode or when entering Loiter or RTL from high speeds
7) Mission improvements:
a) mission will be resumed from last active command when pilot switches out and then back into Auto mode (prev behaviour can be restored by setting MIS_RESTART param to 1)
b) DO_SET_ROI persistent across waypoints. All-zero DO_SET_ROI command restores default yaw behaviour
c) do-jump fixed
d) conditional_distance fixed
e) conditional_delay fixed
f) do-change-speed command takes effect immediately during mission
g) vehicle faces directly at next waypoint (previously it could be about 10deg off)
h) loiter turns fix to ensure it will circle around lat/lon point specified in mission command (previously it could be off by CIRCLE_RADIUS)
8) Safety improvements:
a) After a fence breach, if the pilot re-takes control he/she will be given a minimum of 10 seconds and 20m to recover before the autopilot will invoke RTL or LAND
b) Parachute support including automatic deployment during mechanical failures
9) Other enhancements:
a) V-tail quad support
b) Dual GPS support (secondary GPS output is simply logged, not actually used yet)
c) Electro Permanent Magnet (aka Gripper) support
d) Servo pass through for channels 6 ~ 8 (set RC6_FUNCTION to 1)
e) Remove 80m limit on RTL's return altitude but never let it be above fence's max altitude
10) Other bug fixes:
a) Bug fix for LAND sometimes getting stuck at 10m
b) During missions, vehicle will maintain altitude even if WPNAV_SPEED is set above the vehicle's capabilities
c) when autopilot controls throttle (i.e. Loiter, Auto, etc) vehicle will reach speeds specified in PILOT_VELZ_MAX and WPNAV_SPEED_UP, WPNAV_SPEED_DN parameters
11) CLI removed from APM1/2 to save flash space, critical functions moved to MAVLink:
a) Individual motor tests (see MP's Initial Setup > Optional Hardware > Motor Test)
b) compassmot (see MP's Initial Setup > Optional Hardware > Compass/Motor Calib)
c) parameter reset to factory defautls (see MP's Config/Tuning > Full Parameter List > Reset to Default)
a) support for direct drive tails (uses TAIL_TYPE and TAIL_SPEED parameters)
b) smooth main rotor ramp-up for those without external govenor (RSC_RAMP_TIME)
c) internal estimate of rotor speed configurable with RSC_RUNUP_TIME parameter to ensure rotor at top speed before starting missions
d) LAND_COL_MIN collective position used when landed (reduces chance copter will push too hard into the ground when landing or before starting missions)
e) reduced collective while in stabilize mode (STAB_COL_MIN, STAB_COL_MAX) for more precise throttle control
f) external gyro parameter range changed from 1000~2000 to 0~1000 (more consistent with other parameters)
g) dynamic flight detector switches on/off leaky-i term depending on copter speed
2) SingleCopter airframe support (contribution from Bill King)
3) Drift mode replaces TOY
4) MPU6k SPI bus speed decreased to 500khz after 4 errors
1) GPS Glitch protection - gps positions are compared with the previous gps position. Position accepted if within 10m or copter could have reached the position with max accel of 10m/s/s.
2) Bug fix for pixhawk SPI bus contention that could lead to corrupted accelerometer values on pixhawk resolved
3) Auto Tuning (compile time option only add "#define AUTOTUNE ENABLED" to APM_Config.h and set CH7_Opt or CH8_Opt parameter to 17)
4) CPU Performance improvement when reading from MPU6k for APM
5) SUPER_SIMPLE parameter changed to a bit map to allow some flight modes to use super simpler while others use regular simple (MP release to allow easier selection will go out with AC3.1 official release)
6) Safety changes:
a) safety button must be pushed before arming on pixhawk
b) RGB LED (aka toshiba led) changed so that disarmed flashes, armed is either blue (if no gps lock) or green (if gps lock)
1) Inertial navigation for X & Y axis (Randy/Leonard/Jonathan)
2) 3D waypoint navigation library (Leonard/Randy)
WPNAV_SPEED, WPNAV_SPEED_UP, WPNAV_SPEED_DN control target speeds during missions and RTL
WP_YAW_BEHAVIOR to allow disabling yaw during missions and RTL
3) PX4 support (some features still not available) (Tridge/Pat/PX4Dev Team)
4) Safety improvements:
Tin-can shaped fence (set FENCE_ENABLED to 1 and copter will RTL if alt > 150m or horizontal distance from home > 300m) (Randy/Tridge/Leonard)
GCS failsafe (set FS_GCS_ENABLED to 1 and if you are using a tablet to fly your copter it will RTL and return control to the radio 3 seconds after losing telemetry) (Randy)
pre-arm checks to ensure accelerometer and radio calibration has been performed before arming (Randy)
5) motor interference compensation for compass (Jonathan/Randy)
6) Circle mode improvements:
set CIRCLE_RADIUS to zero to do panorama shots in circle mode (copter does not move in a circle but instead slowly rotates)
CIRCLE_RATE parameter allows controlling direction and speed of rotation in CIRCLE mode and LOITER_TURNS (can also be adjusted in flight from CH6 knob)
7) SONAR_GAIN parameter add to allow reducing the response to objects sensed by sonar (Randy)
8) support for trapezoidal quads (aka V shaped or FPV quads) (Leonard/Craig)
9) performance improvements to dataflash logging (Tridge)
10) bug-fix to analog read which could cause bad sonar reads when using voltage or current monitor (Tridge)
11) bug-fix to motors going to minimum when throttle is low while switching into Loiter, AUTO, RTL, ALT_HOLD (Jason/Randy)
12) bug-fix for auto disarm sometimes disarming shortly after arming (Jason/SirAlex)
- 430 bytes of RAM freed up to resolve APM1 level issue and reduce chance of memory corruption on both APM1 and APM2
Improvements over 2.7.3:
- Improved ACRO mode (Leonard Hall)
- Improved stability patch to reduce "climb-on-yaw" problem (Leonard, Rob Lefebvre, Randy)
- Rate controller targets moved to body frames (yaw control now works properly when copter is inverted) (Leonard/Randy)
- Less bouncy Stabilize yaw control (Leonard)
- OpticalFlow sensor support for APM2.5 (Randy)
- DMP works again by adding "#define DMP_ENABLED ENABLED" to APM_Config.h You can also log DMP vs DCM to the dataflash by adding "#define SECONDARY_DMP_ENABLED ENABLED" (Randy)
- Watch dog added to shutdown motors if main loop feezes for 2 seconds (Randy)
- Thrust curve added to linearize pwm->thrust. Removes deadzone found above 90% throttle in most ESC/motors (Randy)
- More timing improvements (main loop is now tied to MPU6000s interrupt) (Randy)
- GPS NMEA bug fix (Alexey Kozin)
- Logging improvements (log I terms, dump all settings at head of dataflash log) (Jason)
Bug Fixes / Parameter changes:
- fixed skipping of last waypoint (Jason)
- resolved twitching when no GPS attached (Tridge)
- fixed loss of altitude if alt hold is engaged before first GPS lock (Randy/Jason)
- moved Roll-Pitch I terms from Stabilize controllers to Rate controllers
- TILT_COMPENSATION param tuned for TradHeli (Rob)
Code Cleanup:
- HAL changes for platform portability (Pat Hickey)
