Clean up Transition Flighttask

[MaEtUgR]

Solved Problem

Follow-up to #23731

When looking for flash savings I realized flight task transition now uses 1.5+ kilobytes of flash which is completely useless on flash-constrained boards that do not support VTOLs so I thought about removing the task from flash constrained builds but we don't have a mechanism to enforce that no one will ever build a target with VTOL support but no transition flight task then.

After investigating this I was wondering why the transition task is so big now and cleaned up the logic while going through it.

Solution

First commit should be refactor as in:

• the parameters do not update during a transition anymore
• the fixed-wing parameters not being available gets handled slightly different by the param_get() function
• parameter variables named after the parameter following the convention
• there's no duplicate update of local position with separate evaluation
• the activation is not using an invalid deltatime and applying the initialization values anymore
• use the new AlphaFilter interface from AlphaFilter: set dt during update #24116
• the transition task runs by definition only during a transition so the check for that flag is obsolete
• clear separation of constants
• simplify structure, reducing scope, naming, comments

The only intentional behavior change:

• The maximum deceleration of 2 * VT_B_DEC_MSS is kept also when overshooting the transition target position

Changelog Entry

Bugfix: Keep high deceleration when overshooting transition target position

Test coverage

Honestly I cannot test my changes since I don't know how it should look like. @sfuhrer would you be able to verify it still works as intended?

[github-actions]

🔎 FLASH Analysis

px4_fmu-v5x [Total VM Diff: -424 byte (-0.02 %)]

    FILE SIZE        VM SIZE    
--------------  -------------- 
+0.0%     +65  [ = ]       0    .debug_abbrev
   +11%     +56  [ = ]       0    ../../src/lib/version/version.c
  +0.3%      +9  [ = ]       0    ../../src/modules/flight_mode_manager/tasks/Transition/FlightTaskTransition.cpp
-0.0%     -72  [ = ]       0    .debug_aranges
  -5.0%      -8  [ = ]       0    ../../src/lib/version/version.c
 -20.5%     -64  [ = ]       0    ../../src/modules/flight_mode_manager/tasks/Transition/FlightTaskTransition.cpp
-0.0%    -216  [ = ]       0    .debug_frame
-0.0% -2.57Ki  [ = ]       0    .debug_info
  -0.2%      -4  [ = ]       0    ../../src/lib/version/version.c
  -3.3% -2.56Ki  [ = ]       0    ../../src/modules/flight_mode_manager/tasks/Transition/FlightTaskTransition.cpp
-0.0%   -1005  [ = ]       0    .debug_line
  -1.3%     -25  [ = ]       0    ../../src/lib/version/version.c
 -13.5%    -981  [ = ]       0    ../../src/modules/flight_mode_manager/tasks/Transition/FlightTaskTransition.cpp
  +0.1%      +1  [ = ]       0    task/task_cancelpt.c
-0.0% -2.26Ki  [ = ]       0    .debug_loc
  -0.2%     -15  [ = ]       0    ../../src/modules/flight_mode_manager/FlightModeManager.cpp
  -5.8%    -590  [ = ]       0    ../../src/modules/flight_mode_manager/tasks/Transition/FlightTaskTransition.cpp
  -0.5% -1.65Ki  [ = ]       0    [section .debug_loc]
  -0.1%     -15  [ = ]       0    src/modules/flight_mode_manager/FlightTasks_generated.cpp
-0.0%    -481  [ = ]       0    .debug_ranges
  -2.6%      -8  [ = ]       0    ../../src/lib/version/version.c
  -6.8%    -136  [ = ]       0    ../../src/modules/flight_mode_manager/tasks/Transition/FlightTaskTransition.cpp
  -0.7%    -336  [ = ]       0    [section .debug_ranges]
  -1.5%      -1  [ = ]       0    task/task_cancelpt.c
-0.0%    -590  [ = ]       0    .debug_str
  -0.7%      -8  [ = ]       0    ../../src/modules/commander/level_calibration.cpp
  -0.5%     -14  [ = ]       0    ../../src/modules/flight_mode_manager/tasks/Auto/FlightTaskAuto.cpp
 -35.1%    -568  [ = ]       0    ../../src/modules/flight_mode_manager/tasks/Transition/FlightTaskTransition.cpp
+0.5%      +1  [ = ]       0    .shstrtab
-0.0%    -329  [ = ]       0    .strtab
  -8.1%     -32  [ = ]       0    ../../src/lib/version/version.c
 -45.7%    -329  [ = ]       0    ../../src/modules/flight_mode_manager/tasks/Transition/FlightTaskTransition.cpp
  +0.0%     +32  [ = ]       0    [section .strtab]
-0.0%    -208  [ = ]       0    .symtab
  -7.0%     -64  [ = ]       0    ../../src/lib/version/version.c
 -36.1%    -208  [ = ]       0    ../../src/modules/flight_mode_manager/tasks/Transition/FlightTaskTransition.cpp
  +0.3%     +16  [ = ]       0    ../../src/modules/fw_pos_control/FixedwingPositionControl.cpp
  +0.1%     +48  [ = ]       0    [section .symtab]
+2.6%    +424  [ = ]       0    [Unmapped]
-0.0%    -424  -0.0%    -424    .text
  +0.1%      +4  +0.1%      +4    ../../src/modules/flight_mode_manager/tasks/Auto/FlightTaskAuto.cpp
 -28.5%    -428 -28.5%    -428    ../../src/modules/flight_mode_manager/tasks/Transition/FlightTaskTransition.cpp
-0.0% -7.59Ki  -0.0%    -424    TOTAL

px4_fmu-v6x [Total VM Diff: -408 byte (-0.02 %)]

    FILE SIZE        VM SIZE    
--------------  -------------- 
+0.0%     +65  [ = ]       0    .debug_abbrev
   +11%     +56  [ = ]       0    ../../src/lib/version/version.c
  +0.3%      +9  [ = ]       0    ../../src/modules/flight_mode_manager/tasks/Transition/FlightTaskTransition.cpp
-0.0%     -72  [ = ]       0    .debug_aranges
  -5.0%      -8  [ = ]       0    ../../src/lib/version/version.c
 -20.5%     -64  [ = ]       0    ../../src/modules/flight_mode_manager/tasks/Transition/FlightTaskTransition.cpp
-0.0%    -216  [ = ]       0    .debug_frame
-0.0% -2.57Ki  [ = ]       0    .debug_info
  -0.2%      -4  [ = ]       0    ../../src/lib/version/version.c
  -3.4% -2.56Ki  [ = ]       0    ../../src/modules/flight_mode_manager/tasks/Transition/FlightTaskTransition.cpp
-0.0%   -1005  [ = ]       0    .debug_line
  -1.3%     -25  [ = ]       0    ../../src/lib/version/version.c
 -13.5%    -981  [ = ]       0    ../../src/modules/flight_mode_manager/tasks/Transition/FlightTaskTransition.cpp
  +0.1%      +1  [ = ]       0    task/task_cancelpt.c
-0.0% -2.26Ki  [ = ]       0    .debug_loc
  -0.2%     -15  [ = ]       0    ../../src/modules/flight_mode_manager/FlightModeManager.cpp
  -5.8%    -590  [ = ]       0    ../../src/modules/flight_mode_manager/tasks/Transition/FlightTaskTransition.cpp
  -0.5% -1.65Ki  [ = ]       0    [section .debug_loc]
  -0.1%     -15  [ = ]       0    src/modules/flight_mode_manager/FlightTasks_generated.cpp
-0.0%    -480  [ = ]       0    .debug_ranges
  -2.6%      -8  [ = ]       0    ../../src/lib/version/version.c
  -6.8%    -136  [ = ]       0    ../../src/modules/flight_mode_manager/tasks/Transition/FlightTaskTransition.cpp
  -0.7%    -336  [ = ]       0    [section .debug_ranges]
-0.0%    -607  [ = ]       0    .debug_str
  -0.7%      -8  [ = ]       0    ../../src/modules/commander/level_calibration.cpp
  -0.5%     -14  [ = ]       0    ../../src/modules/flight_mode_manager/tasks/Auto/FlightTaskAuto.cpp
 -35.8%    -585  [ = ]       0    ../../src/modules/flight_mode_manager/tasks/Transition/FlightTaskTransition.cpp
+0.5%      +1  [ = ]       0    .shstrtab
-0.0%    -329  [ = ]       0    .strtab
  -8.1%     -32  [ = ]       0    ../../src/lib/version/version.c
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  -7.0%     -64  [ = ]       0    ../../src/lib/version/version.c
  +2.1%     +16  [ = ]       0    ../../src/modules/flight_mode_manager/tasks/Orbit/FlightTaskOrbit.cpp
 -35.1%    -208  [ = ]       0    ../../src/modules/flight_mode_manager/tasks/Transition/FlightTaskTransition.cpp
  +0.3%     +16  [ = ]       0    ../../src/modules/fw_pos_control/FixedwingPositionControl.cpp
  +0.1%     +48  [ = ]       0    [section .symtab]
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-0.0%    -408  -0.0%    -408    .text
  +0.0%     +13  +0.0%     +13    [section .text]
  +0.1%      +4  +0.1%      +4    ../../src/modules/flight_mode_manager/tasks/Auto/FlightTaskAuto.cpp
  +0.2%      +3  +0.2%      +3    ../../src/systemcmds/ver/ver.cpp
 -28.5%    -428 -28.5%    -428    ../../src/modules/flight_mode_manager/tasks/Transition/FlightTaskTransition.cpp
-0.0% -7.61Ki  -0.0%    -408    TOTAL

Updated: 2024-12-19T14:27:10

[sfuhrer]

Nice cleanup, impressive that that saved 400 bytes.

I only have one comment, and otherwise looked at the code plus tried to break it in simulation without success.

[sfuhrer]

Thanks for the initiative and diligent work!