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Unable to find variable [stabalizer.roll]

Posted: Thu May 09, 2013 11:54 am
by panguitou
Hi everybody !

I have got the following message in the console :

Code: Select all

WARNING:cflib.crazyflie.toc:Unable to find variable [stabalizer.roll]
WARNING:cflib.crazyflie.log:Log: stabalizer.roll not in TOC, this block cannot be used!
I'm wondering if this as something to do with my stability problem : the CF does not stay stable when hovering but drift one side or the other randomly.
The red led blinks at 2hz and it seems pretty well balanced.. is there something to try with the PID settings ?

Thanks in advance

Re: Unable to find variable [stabalizer.roll]

Posted: Thu May 09, 2013 12:03 pm
by marcus
Hi Jean-Marie,

No, this has no effect at all. It's a misspelling of stabilizer in the file conf/log/stabalizer.json and this will result in the plot tab not working correctly. Since the plot tab doesn't work very well anyways then this won't really affect anything.

It's hard to get the Crazyflie to stay perfectly still when hovering but you could try changing the Trim roll/pitch settings in the UI to make it better.

Edit: I've created an issue for this here.

/Marcus

Re: Unable to find variable [stabalizer.roll]

Posted: Thu May 09, 2013 1:39 pm
by panguitou
marcus wrote: Edit: I've created an issue for this here.
/Marcus
Thank you Marcus,
I have noticed that the stability is much better when the battery is fully charged, it's degrading a lot when the current is too low...
I have also increased the Slew limit at 50% and decrease the Slew rate to 10%, I find it's easier to control the height and the CF is not falling down as a stone any more ;)

Keep on the good job :

Re: Unable to find variable [stabalizer.roll]

Posted: Thu May 09, 2013 2:18 pm
by marcus
panguitou wrote: I have noticed that the stability is much better when the battery is fully charged, it's degrading a lot when the current is too low...
This can be seen when the red LED is fully lit (or shortly before it get's fully lit). Since the voltage from the battery is low it will be hard to compensate by increasing the thrust on some motors and this will cause some instability. Do you notice this even as the red LED is only blinking?
panguitou wrote: I have also increased the Slew limit at 50% and decrease the Slew rate to 10%, I find it's easier to control the height and the CF is not falling down as a stone any more ;)
Thanks for the tip. I tried it just now and it works a lot better than the current settings :D The only issue is if you happen to crash (which I did..), the the motors will not turn off. But for this you should map the Emergency stop button. When pressed it will stop the motors until you press the button again. You could also pull the throttle down and it will momentarily turn off the motors (but once you release it they will go back on).

/Marcus

Re: Unable to find variable [stabalizer.roll]

Posted: Thu May 09, 2013 2:31 pm
by panguitou
marcus wrote: This can be seen when the red LED is fully lit (or shortly before it get's fully lit). Since the voltage from the battery is low it will be hard to compensate by increasing the thrust on some motors and this will cause some instability. Do you notice this even as the red LED is only blinking?
I reckon you are rather speaking of the green LED, aren't you ?

Re: Unable to find variable [stabalizer.roll]

Posted: Thu May 09, 2013 2:40 pm
by marcus
Ah, my explanation was a bit off... :oops: It's till the red LED but the 2 Hz blinking is the heartbeat. When it's steadily lit it's an indication that the battery voltage is low (see led indications). The green LED will blink when a packet is received.

/Marcus

Re: Unable to find variable [stabalizer.roll]

Posted: Thu May 09, 2013 3:04 pm
by panguitou
marcus wrote:Ah, my explanation was a bit off... :oops: It's till the red LED but the 2 Hz blinking is the heartbeat. When it's steadily lit it's an indication that the battery voltage is low (see led indications). The green LED will blink when a packet is received.
/Marcus
Thank you, then I was misunderstanding, I'll pay a special attention to that in my next 'flights' !