Premium stability test

[FabinovX]

Hi,
the newbie is back.
Since i received my Bioloid premium, i tried to do lots of little soft to feel it.
i tried to do a stabilization soft using torque feedback and it works quite well but ax12+ feedback is quite noisy and the robot is always dancing.
so tonight i tried to do the same thing using the difference between present and goal position.
the soft is really short as compared to the torque feedback version, and finally the result is better.
excuse me for the bad quality of the video (size about 4Mo):
http://fabinovx.free.fr/Divers/stability_test.avi

cu all

[billyzelsnack]

Nice.

I don't understand exactly what you are doing. You take the difference in the present and goal position and push the goal position in the opposite direction?

(ps. Please get a youtube account! )

[UncleBob]

i been trying to do the same. Any sample code ?

[FabinovX]

to billyzelsnack :
you're right, that's exactly what i do.
i really apology for the poor video quality.
next time i will use my camera instead of my webcam and i will register youtube too.

to unclebob :
i'm at my office's.
no problem, i will give you the code as soon as i can.
But i don't use the gyro in this software.
Actually, i think it will be interesting to implement the gyro
in my code in order to manage really fast motion.
the gyro can't be use with slow motion as you can see here because acceleration is nearly 0.

[UncleBob]

I have used current position with motion offset but still get chicken dance

[FabinovX]

that's normal.
you have to deal with.
to do so, i create a deadzone parameter while capturing.
if capture < deadzone then capture =0
the first time you have to adjust deadzone value.
create a parameter for front/back deadzone and another for left/right deadzone.

[FabinovX]

here is the code :
http://robosavvy.com/Builders/FabinovX/stabily_test_delta-position.zip

in order to filter the AX12 feedback you can also make a loop :
for i=1~10
capture=capture+value
next i

value= value/10
gyro value are obtained this way in original code.

but you will loose a lot of time.
actually i just take the value from 2 AX12 check if they are or not >deadzone value.
then i add the two value and then /2.
you can also try to check deadzone with the result value after the last step upon.
activate the debug lines and watch for the value in each case in order to find the better way to obtain what you want.
I will be happy if it helps you because i'm really a beginner in robotics.

i will try to add gyro to this code in order to manage low rate and high rate moves.

cheers
FabinovX

[FabinovX]

No news from you unclebob.
well, i've just finished coding a new appli including gyro and using motion page.
it works quite well even better than the other basic code.
motion page 227 in my code is a copy/paste of standard motion 31 with
softness at 6 for id 18,17,16,15,10,9 and time at 0.28.
if you want to try it, it's here :
http://robosavvy.com/Builders/FabinovX/stabily_test_delta-position+gyro.zip
remember i've a type A premium, so may have to adapt the code.

cheers.
FabinovX

[FabinovX]

Ok, i come back with a new video (i followed billyzelsnack advice )

phpBB [media]

here is the sample code :

http://robosavvy.com/Builders/FabinovX/ ... y_Test.rar

the .tsk is the same as i already shared (just add U and D events to deactivate or activate the gyro) so i've deleted the previous shared files.
Some softness in the .mtn file have been changed in order to improve response.

cheers
FabinovX.

[UncleBob]

Hey thanks dude. I didn't see your reply til now. Letme give that piece of code a try.

[UncleBob]

I get this any idea ?

[Invalid Page Read:00E3][Invalid Page Read:00E3][Invalid Page Read:00E3][Invalid Page Read:00E3][Invalid Page Read:00E3][Invalid Page Read:00E3][Invalid Page Read:00E3][Invalid Page Read:00E3][Invalid Page Read:00E3][Invalid Page Read:00E3][Invalid Page Read:00E3]

[FabinovX]

the tsk file uses motion page 227 which is a standard 31 with some special softness values.
you can find it in the mnt given in the archive.
copy this page to your own robot mnt or save your robot whole mnt and download the one given in the archive.
Don't forget i have a type A so the code may need some adaptation to run with your type C.
i think front/back will be ok, but left/right may need some modification.
i will try to make a type C compatible version.

[FabinovX]

Ok UncleBoB, try this with your type C, it should work fine :

http://robosavvy.com/Builders/FabinovX/ ... Type_C.rar

please, tell me if it really does or not.

File updated (i forgot to invert gyro offset with 9 and 10)

[UncleBob]

thkx but still not working. I am wondering if because I don't have a gyro or something else. I remove my gyro and put in the balancer.

[FabinovX]

LOL that's right you're the lucky one
i just finish to write a new code, i will post a video tomorrow and share the code.
well if you want to adapt the code to the balancer it is quite easy.
you just have to change the port3 to dynamixel custom ID 105 adress 38 and port4 to dynamixel custom ID 105 adress 40 (according to your video).
you then may have to adjust the scaled value according to AX-S20 gyro value, but they are maybe the same range that are those of the basic gyro.

I need this balancer (please robotis, sell it or send it but do something )