Plane: tiltrotors: allow vectored yaw motor tilt when disarmed

[kd0aij]

Useful for checking the vectored yaw tilt direction and range when setting up tilt SERVO MAX/MIN and Q_TILT_YAW_ANGLE

[IamPete1]

I'm don't think this is more intuitive than yawing the plane and seeing the yaw tilt motor move to counteract. That is what I think it does now?

[kd0aij]

It does nothing when disarmed, and I've never seen the tilt servos react to yaw without the props spinning.
This also lets you check for binding at the extremes of yaw tilt.

[IamPete1]

Its been a long time since I have played with VTOL stuff IRL. I thinking again your correct, in that case I think this makes sense. The only possible issue is that in arming it will do a full yaw. On some vehicles this might make the props hit the ground. Is there a options bitmask parameter somewhere we could put this in?

[kd0aij]

Yes, this has the potential disadvantage that rudder arm/disarm results in maximum yaw tilt.
But vectored yaw uses a relatively small amount of tilt on normal tiltrotors,

And when you put a Convergence or a TVBS into FBWA the motors promptly tilt all the way forward, even when disarmed, which pretty much guarantees that props will scrape the ground.
So we have a precedent :)

I don't think there are any existing params which could be exploited to turn this on and off.

[tridge]

this could spin up while tilted

[kd0aij]

Demo with Q_M_SPIN_ARM and Q_M_SPIN_MIN set to 0.15. Note that on arming with rudder, motors return to vertical during the warning beep and before spooling up. But on rudder disarm, the motors tilt while coasting down.
https://photos.app.goo.gl/NJYhPQwg4jmgnv6w5

added 3 second delay from disarm to tilt

[kd0aij]

Copter's ARMING_DELAY is not implemented in quadplane. Commit 51e204c adds a const expression: ARMING_DELAY_MS = 2000; and delays spoolup in motors_output for that length of time. This also allows time for the motor tilt to return to vertical on rudder arming.

[IamPete1]

You could put the this and the delay as a bit on this param

ardupilot/ArduPlane/quadplane.cpp

Line 333 in 36ea023

AP_GROUPINFO("OPTIONS", 58, QuadPlane, options, 0),

So by default there is no change, if you enable the bit you get the tilting and the delay

[kd0aij]

Cool... Question is whether this is a safety issue that was overlooked in quadplane. In Copter (and PX4) there is an intentional delay between arming (and the start of the arming tone) and the motors spinning up. Gives you time to move your fingers out of the way :)
Probably should be a separate PR...

[IamPete1]

you could always give them a bit each ;)

[kd0aij]

put disarmed tilt on a q_option bit and only do the delays if it is enabled
The spool-up delay is always applied if OPTION_DISARMED_TILT is set, to allow motors to return to vertical before spinning.
If OPTION_DELAY_ARMING is set, the spool-up delay is always applied.

[kd0aij]

@tridge I think this is acceptable now...

[kd0aij]

rebased and tested on miniConvergence with mRoX21

[kd0aij]

@tridge added the missing parentheses and squashed; ready to merge if it passes CI

[tridge]

I don't think this belongs at the hal level, it creates a dependency on ARMING_DELAY_MS in the hal

[kd0aij]

OK, won't consider consolidating the arming delay with copter

[kd0aij]

@tridge moved arming_delay from HAL to quadplane

[kd0aij]

moving arming_delay logic to AP_Arming_Plane gives better localization and simplifies the logic in quadplane.cpp

SITL test:

QSTABILIZE> arm throttle
10859: set delay_arming
APM: Throttle armed
Got COMMAND_ACK: COMPONENT_ARM_DISARM: ACCEPTED
10866: delaying spoolup
ARMED
Arming checks disabled
11866: delaying spoolup
12859: reset delay_arming
APM: EKF yaw reset -0.44
APM: EKF2 IMU0 origin set
APM: EKF2 IMU1 origin set
QSTABILIZE> disarm
APM: Throttle disarmed
Got COMMAND_ACK: COMPONENT_ARM_DISARM: ACCEPTED
27264: delaying tilt
DISARMED
28264: delaying tilt
29264: delaying tilt

[kd0aij]

demonstration of disarmed motor tilt and rudder arm/disarm with spoolup delayed till end of alarm tone
https://youtu.be/2q72UJIULIg