VVV10 HandSome

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Revision as of 13:56, 26 July 2010 by Vvv10 (talk | contribs) (Proposed Demo)
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"Hand"Some

We would like to implement impedance behaviours coupling both the hands, hence the bad pun on the name. We would work under the Force Control group and share tools and code with everyone.

You are more than welcome to hack with Us! :D So far, we are YARP and iCub Noobs so any assistance the Wise Ones can give is greatly appreciated.


Technical Background

e would like to replicate some of the behaviours demonstrated [here]. For more visual demo check this [video] especially the part from 1:57 into it.


Members

Participants (so far) :

   * Naveen Kuppuswamy (Naveenone)
   * Cristiano Alessandro (!Alessandro) 
   * Arne Nordmann (North-Man the superhero)
   * Gauss Lee (Gauss-Man the Maths superhero)
   * Paolo Tommasino (Pa"O"lo)
   * Jiuguang Wang (G1)

Proposed Demo

We believe that the ideal impressive demo should always involve alcohol service, and thus we would like to demonstrate some simple two handed grasp and user directed manipulation of trays with drinks or individual alcohol bottles. Additional tricks can be manipulating objects of various sizes and compliance by playing around with the coupling stiffnes or even adding a cartesian impedance constraint to fit service robot scenarios like serving drinks (keeping bottle upright in cartesian space to compensate for user drunkenness).


  • Update *
Demo has been scaled down to accomodate for our procrastination. It would involve something like multi-arm coordinated holding of an object like a box

Components and Task Distribution

Upon realising the theoritical and practical difficulties in this task we have decided to eat a bit of humble pie and appraoch the task conservatively. We have decided to partition the task as follows :

Phase 1 : Approach of Object (Arne + Gauss) An assumed object in front of the robot is approached using Joint Impedance Position Control

Phase 2 : Cartesian Impedance Control : Fake and Real (Naveenone + Paulo + Cristiano) Object is held by arms using Cartesian Spatial Impedance. This is done is 2 ways:

a. 'Real' Cartesian Impedance Control (Paulo + Naveen) A Virtual spring assumption is made which generates desired Forces at end effector, and this is converted to desired joint level torques.

b. 'Fake' Cartesial Impedance Control (Cristiano) A imaginary line is taken between the arms and the Arms are commanded to maintain their end effectors on this virtual line exerting pressure on a virtual region smaller than the object. This is then sent to a joint level Impedance position control scheme.

To test Phase 2 we will focus on single arm experiments first, wherein, an imaginary point is assumed to be the target of the desired impedance and that is used to test the arm control.