Tiltrotor: VTOL back-transition: expose tilting time as parameter and reduce overall duration #21760
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This affects how soon after a backtransition the vehicle has the full hover controller running again. Specifically it reduces the duration of the ramp down of the motors prior to tilting them. Signed-off-by: Silvan Fuhrer <silvan@auterion.com>
This reduces the motor ramp up time after a transitions is declared over. Signed-off-by: Silvan Fuhrer <silvan@auterion.com>
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RomanBapst
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Jun 26, 2023
RomanBapst
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Jun 26, 2023
Instead of hard-coding the tilting duration (from FW to MC tilt), expose it as a parameter (VT_BT_TILT_DUR). The default is the same as the hard-coded value previously (1s). Slower tilting mechanisms need a higher value here, while for smaller ones a too high value results in unnecessary delays till the motors are in hover configuration. Signed-off-by: Silvan Fuhrer <silvan@auterion.com>
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This affects how soon after a backtransition the vehicle has the full hover controller running again. Specifically it reduces the duration of the ramp down of the motors prior to tilting them.
Solved Problem
The backtransition logic is split into 4 parts:
The ramp down and the ramp are currently hard-coded to 1s each, as well as the tilting duration. That means that it currently takes 3s from starting the transition to having full MC controller effectiveness. During the first 2s of them purely the FW controller is running and working on stabilizing the system, and then for 1s the MC controller is running but not fully yet. If the vehicle decelerates very fast it can happen that the control surfaces stall already 1s after the back-transition is started, and in that case the vehicle has bad attitude tracking until the 3s when the motors stabilize it again.
Solution
VT_BT_TILT_DURChangelog Entry
For release notes:
Alternatives
Test coverage
SITL tested.