fix(boards/fmu-v6xrt): Enable usage of all three on-board IMUs on FMU-V6XRT by default

[abhijithcv]

fix(boards/px4_fmu-v6xrt): enables all on-board IMUs by default

FMU-V6XRT Pixhawk standard boards have 3 on-board IMUs. It is ideal behaviour for all 3 to be enabled by default. This is done with default parameters SENS_IMU_MODE set to 0, and EKF2_MULTI_IMU set to 3.

[PetervdPerk-NXP]

Maybe it would be better to set it on chip-level and match the STM32H7
https://github.com/PX4/PX4-Autopilot/blob/45659d36aaabb1ca82179aa9a11bee3de0f3179c/platforms/nuttx/init/stm32h7/rc.board_arch_defaults

https://github.com/PX4/PX4-Autopilot/blob/45659d36aaabb1ca82179aa9a11bee3de0f3179c/platforms/nuttx/init/imxrt/rc.board_arch_defaults

[abhijithcv]

Maybe it would be better to set it on chip-level and match the STM32H7 https://github.com/PX4/PX4-Autopilot/blob/45659d36aaabb1ca82179aa9a11bee3de0f3179c/platforms/nuttx/init/stm32h7/rc.board_arch_defaults

https://github.com/PX4/PX4-Autopilot/blob/45659d36aaabb1ca82179aa9a11bee3de0f3179c/platforms/nuttx/init/imxrt/rc.board_arch_defaults

Fixed with #456b2b4

[PetervdPerk-NXP]

Can you just fully match it? i.e.

# Multi-EKF
param set-default -s EKF2_MULTI_IMU 3
param set-default SENS_IMU_MODE 0

param set-default -s IMU_GYRO_FFT_EN 1

param set-default -s MC_AT_EN 1

param set-default -s UAVCAN_ENABLE 2

set LOGGER_BUF 64

Also can you share a flight log with these defaults?

[abhijithcv]

Can you just fully match it? i.e.

# Multi-EKF
param set-default -s EKF2_MULTI_IMU 3
param set-default SENS_IMU_MODE 0

param set-default -s IMU_GYRO_FFT_EN 1

param set-default -s MC_AT_EN 1

param set-default -s UAVCAN_ENABLE 2

set LOGGER_BUF 64

Also can you share a flight log with these defaults?

https://logs.px4.io/plot_app?log=5522ccf7-3b35-4f78-bdb6-05785824529a

The autopilot was hard-mounted on to the copter

[dk7xe]

related testing with 1.17RC2 #26271 (comment)
Observation is that vibrations seems to be much lower with multi EKF2 IMU enabled

[PetervdPerk-NXP]

LGTM

[dakejahl]

I'm not sure I would recommend this. Multi-EKF is not well tested and there has been a history of problems with EKF lane switching. See #27013 as an example

[PetervdPerk-NXP]

I'm not sure I would recommend this. Multi-EKF is not well tested and there has been a history of problems with EKF lane switching. See #27013 as an example

Thank you sharing, I think for 1.17.0 we're fine because there the default is still disabled.
Although this PR was more to sync default behavior between V6X and V6X-RT, since on V6X multi-ekf is enabled by default. What would be best to proceed on main disable multi ekf for both?

[dakejahl]

What would be best to proceed on main disable multi ekf for both?

I would disable multi-ekf as default for all boards until there is a stakeholder who is regularly testing it, so that we have confidence it actually works reliably.

[PetervdPerk-NXP]

What would be best to proceed on main disable multi ekf for both?

I would disable multi-ekf as default for all boards until there is a stakeholder who is regularly testing it, so that we have confidence it actually works reliably.

Sounds fair, I would support it, enabling by default gives a wrong impression.