In some relation with Kevin's work with InMoov kinematics I finally managed to create a python script that calculates the x,y,z position of the palms and the head in realation to the body's midcenter rotation point and set's the neck and rothead servo to point the eyes at the hand.

The video:  

The script:  https://drive.google.com/file/d/0BzHOAcGHjhpTSnYxVTVuRzViYW8/view?usp=sharing

Of course it would be nice to have it as a built-in function in MRL but I doubt I could do that without a very patient advisor ...

 

kwatters

8 years 9 months ago

That's amazing.  I saw the script, did you work out all of the DH parameters for the other parts?!  How accurate do you think they are?  It looks like it's working, so the models must be reasonably close!

Wow, this video makes me very happy! Great job.  If you're happy with those DH models,  I'm happy to add them in to the InMoov service as the default models.  It would be an excellent contribution!  and VERY VERY welcome!

-Kevin

 

GroG

8 years 9 months ago

Juerg !  You Rock !..

Ya this should be Borg'd !  ... I suppose a defautl DH model service for InMoov would be very helpful.

Really nice work Juerg !

I am overwhelmed by your comments - thanks masters!

@Kevin - as you recommended I used the "Robotic Arm Kinematic GUI" of MRPT. It was a bit tricky for me to understand the working of the parameters - much trial and error - but it helped a lot to compare the positions of all the single steps with my own script. In addition I tried to verify the result with a "sweden meter" (maybe this is not a correct translation :-)) and am rather happy with the result.

Currently I have tried to come up with the parameters from the lower body rotation point to the palms and head. Fingers will be rather impossible without a feedback from the joints. Thinking about this - what about a "finger calibration routine", InMoov looks at the open hand while it stepwise closes each finger. From the pictures the angles of the finger parts might be identified? We could build a lookup table for each finger and it would be individualised for each InMoov to account for the building differences?

Would also like to better understand and experiment how to reach a defined position and to avoid collisions - so lots of stuff to go for!

@Grog - as I have quite a lot of time available to play with my baby - maybe you can guide me to build this "lookatHand" into MRL or make it even a constantly updating "watchHand"?

 Juerg

Getting Started