This adds four-way auto-hover to Flightgear's Harrier-GR3. This allows automated control of vertical, forwards and lateral speeds, plus heading rotation speed.
The diff/bundle below is dated 2019-03-31, and is relative to fgaddon:Aircraft/Harrier-GR3 svn r3850 / git-svn:Aircraft/Harrier-GR3 id 22e4bd0d9b05: "Harrier-GR3: restore the CoG.".
harrier-auto-hover.diff: raw diff.
harrier-auto-hover.bundle: git bundle.
Control in vertical plain is slightly different from the original vertical-only auto-hover patch.
As of 2019-03-31:
Usage is described in aircraft help:
Alt-Page up
Auto-hover vertical: increment target vertical speed
Alt-Page down
Auto-hover vertical: decrement target vertical speed
Alt-0
Auto-hover vertical: set target vertical speed to zero
Alt--
Auto-hover vertical: maintain current height
Alt-v
Auto-hover vertical: off
Alt-.
Auto-hover horizontal: Set target forwards/sideways speeds to zero
Alt-up
Auto-hover horizontal: Increment target forwards speed
Alt-down
Auto-hover horizontal: Decrement target forwards speed
Alt-right
Auto-hover horizontal: Increment target rightwards speed
Alt-left
Auto-hover horizontal: Decrement target rightwards speed
Alt-a
Auto-hover horizontal: control air speed
Alt-g
Auto-hover horizontal: control ground speed (default)
Alt-h
Auto-hover horizontal: off
Alt-4
Auto-hover rotation: increment target rotation speed to left
Alt-5
Auto-hover rotation: set target heading to current heading
Alt-6
Auto-hover rotation: increment target rotation speed to right
Alt-r
Auto-hover rotation: off
=== Auto-hover vertical ===
Uses throttle to control vertical height/speed.
=== Auto-hover horizontal ===
Uses pitch and roll to control forwards/sideways speed.
=== Auto-hover rotation ===
Uses rudder to control rotation speed or heading.
Auto-hover currently uses crude on-screen text to show what it is doing.
The system is pretty unsophisticated and forwards/sideways in particular will go wrong if the aircraft is not stable. So it's best to have nozzles at standard hover setting (Alt-m) and manually get the aircraft stable and slow in the horizontal plain before engaging forwards/sideways auto-hover.
Here's a brief description of the changes:
Harrier-GR3-keyboard.xml:
New, included by Harrier-GR3-set.xml. Contains keyboard
short-cuts previously in Harrier-GR3-set.xml, and new auto-hover
keyboard short-cuts.
Harrier-GR3-mice.xml:
New, empty, but included by Harrier-GR3-set.xml. [Auto-hover was
originally controlled by mouse, which required this separately
included file, but i subsequently switched to keyboard control
instead.]
Harrier-GR3-set.xml:
Include Harrier-GR3-keyboard.xml and Harrier-GR3-mice.xml
instead of inline. Added help for auto-hover. Added namespace
for Nasal/Controls.nas.
Nasal/Controls.nas:
Added implementation of auto-hover. Implementation uses nasal
callbacks which modify throttle, elevator and ailerones in order
to track target x, y, z and heading speeds.
Systems/Autopilot.xml:
Some experimental code to implement auto-hover using fg's
standard pid support; doesn't work very well so far.