Interchanging of Roll and Pitch inputs in mid flight

ArduCopter Copter 4.3
1

Hello,

I had an weird experience with my hexa drone today. I took off in AltHold mode, and everything was going smoothly. However, when I switched to Loiter mode during mid-flight, I observed a strange behavior. It seems that when I pitched forward, the roll was changing, and when I rolled, the pitch was changing. This unexpected interchange of roll and pitch controls in mid-flight.

I made a mistake while trying to change it to RTL, accidentally triggering the motor emergency stop which resulted in a crash. Please don’t mind that part… However, I’m more concerned about understanding why the controls seemed to interchange during the flight.

Log Link

Has anyone else experienced a similar issue or can shed some light on what might have caused this behavior?
Your insights and suggestions would be greatly appreciated.

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2

This is usualy caused by the pilot confusing where the front of the vehicle is.

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3

Or they entered Super Simple mode and don’t understand how it works.
We have seen this often enough because of those checkboxes next to the modes in Mission Planner. Those should be eliminated and Simple Mode and SS mode selected with an Aux chan.

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Good point, yes that might also be it.

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5

You have two RC channels set to RTL and two set to Sprayer, and Throttle is also set to Save Waypoint - that’s not good!

Set SIMPLE,0 to avoid that strange behaviour.
You had it set to -1 which in bitmask speak is 254 (I think) which is equivalent to “everything” in this particular case - apply Simple to every possible flight mode!

Set these:

ARMING_CHECK,1
BATT_ARM_VOLT,44.30
BATT_CRT_VOLT,42.00
BATT_LOW_VOLT,43.20
FENCE_ENABLE,1
INS_ACCEL_FILTER,10
INS_LOG_BAT_MASK,1
INS_LOG_BAT_OPT,4
MOT_BAT_VOLT_MAX,50.40
MOT_BAT_VOLT_MIN,39.60

Check and fix your BATT2 and BATT3, there is duplication. Probably check BATT4 too.
Disable any you dont really need.

Conduct a test flight, configure the harmonic notch filter then advance to tuning.
Dont mess around with safety related parameters, use everything available - they are more important than most people realise.

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@dkemxr Is there a option available in updated autocopter firmware or is it still in development phase to activate Super simple or simple mode in flight.

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I gave you the parameter to change.
Even if you did want to use Simple or Super-Simple it was configured wrong and you should use a transmitter switch to enable it - so you can also disable it at any time.

Simple and Super-Simple modes only apply to GPS-assisted modes such as Loiter which is why you only noticed once you changed into Loiter mode.

3 Likes
8

Hi @amilcarlucas @dkemxr,

Thank you for the reply. After reviewing the flight logs, I’ve determined that the UAV’s heading was correct relative to the pilot’s position. I also examined the correlation between stick inputs, and it appears that when inputting for pitch, roll is occurring. This suggests that the pilot wasn’t confused about the orientation.

As @dkemxr mentioned, the Simple or Super Simple mode might be the issue. I’m not very familiar with how it works, so I’ll need to investigate further and conduct another flight test.

Thanks again to all of you for your replies

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Hi @xfacta ,

Thank you for your reply, and thank you for pointing out a couple of important issues. You’re absolutely right, and I’ve discovered that there are multiple switches mapped to the same mode, which is something that needs immediate attention. Also, I wasn’t aware that throttle is mapped to ‘Save waypoint,’ so thank you for bringing this to my attention.

As you and @dkemxr have mentioned, this could indeed be related to the Simple or Super Simple mode settings. I’m not well-versed in these modes and how they function, so I plan to delve deeper into these settings to gain a better understanding. Additionally, you mentioned notch filtering, and it’s clear that tuning needs to be done on this UAV. Once again, thank you for your input and support.

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It was definitely related to Simple mode.
The bitmask sets which of your flight modes that Simple will apply to - and you had “11111110” (seven positions) and we only have 6 flight mode positions available.
Normally you would set the bitmask to point to just one of your flight mode positions.

Simple and SuperSimple seem very cool, but better to learn to orientate the craft yourself and work the “stick” appropriately, because you will need that ability.
Simple mode is handy for passing the controls to a first time user, the pitch stick become “come here / go away” and the roll stick becomes “left / right” regardless of which way the copter nose (yaw) is pointed.

Just be aware this is an issue if the copter goes behind you :slight_smile:

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