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ArduPilot / ardupilot

ArduPlane, ArduCopter, ArduRover, ArduSub source
http://ardupilot.org/
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Plane: servos move when Booting with BRD_SAFETYENABLE=0 #7280

Open kd0aij opened 6 years ago

kd0aij commented 6 years ago

Issue details

undesirable servo movements at bootup

Version

master

Platform

[ ] All [ ] AntennaTracker [ ] Copter [ x ] Plane [ ] Rover [ ] Submarine

Airframe type

quadplane_tilttrivec (E-Flite Convergence)

Hardware type

pixracer

Logs

log of servo outputs from Pixracer with BRD_SAFETYENABLE=0 RCOU.Cn are scaled by .01 (scaled range [100,200]) elevons are channels 2,4, starting PWM values are near 1900 vehicle is stationary until about 38 seconds elevons take about 35 seconds to settle down

log_px4_startup

kd0aij commented 6 years ago

another test with the same hardware and slightly different results:

boot

WickedShell commented 6 years ago

@kd0aij any chance that you had AFS enabled? (this can move surfaces during boot, although why it would move a tilt rotor motor is an interesting question)

Naterater commented 5 years ago

What mode are you in on boot? If you boot to a stabilization mode while the gyros are not consistent, you may have "stabilizing" behavior due to bad AHRS. Maybe consider booting in Manual Mode?

kd0aij commented 5 years ago

@Naterater Is it possible to boot into manual mode without setting up manual mode on the RC TX? I suppose I could boot with the TX off...

Naterater commented 5 years ago

Yes it is possible. If so, that would explain this issue and we can close. I don't think anybody else has brought this up, and it's likely because of the EKF settling down after boot. I notice my artificial horizon moves a lot on boot.

kd0aij commented 5 years ago

So what is your power-up sequence? TX-on, then vehicle power up? At what point will it switch from boot mode to the one commanded by RC? It's usually unwise to power up a vehicle with the TX off.

OXINARF commented 5 years ago

Is this still relevant with ChibiOS?

WickedShell commented 5 years ago

I've seen servos get a pulse that looked like a normal PWM while booting exactly once on ChibiOS. Safety was enabled, but it's a different thing to what's described here as this is all before logging starts to be able to log what's happening (and it was only one channel that got a valid shaped pulse).

kd0aij commented 5 years ago

Behavior hasn't changed; elevons and tilt servos are active immediately after bootup. Workaround for tiltrotors is to set INITIAL_MODE to a VTOL mode to avoid having the motors tilt forward. Having the elevons wander around isn't a big deal and does have the advantage of showing the EKF starting up.