# manipulability measure calculation with KDL::Jacobian

 Submitted by threelight on Mon, 2008-09-29 13:07

I've written a function which should calculate the manipulability measure of my KDL::Chain. For this purpose I create a JntToJacSolver an execute the JntToJac-function with the current joint values as input.
So I get the resulting jacobian for the manipulability measure. Now my question is: leads this way to create a Jacobian to a correct manipulability measure sqrt(det(JJ^t))?

I have always values between 15000 and 20000 during a trajectory. Is this correct?

### manipulability measure calculation with KDL::Jacobian

On Mon, 29 Sep 2008, manuelbirlo [..] ... wrote:

> I've written a function which should calculate the manipulability measure of
> my KDL::Chain. For this purpose I create a JntToJacSolver an execute the
> JntToJac-function with the current joint values as input. So I get the
> resulting jacobian for the manipulability measure. Now my question is: leads
> this way to create a Jacobian to a correct manipulability measure
> sqrt(det(JJ^t))?
If you do the calculation for the matrix multiplication, the determinant
and the sqrt correctly, yes! :-)

> I have always values between 15000 and 20000 during a trajectory. Is this
> correct?
No idea! This depends on so many things: chosen units, chosen reference
frames, actual configuration, ...

For example:

@Article{ doty-etal-itra95,
author = {Doty, Keith L. and Melchiorri, Claudio and Schwartz,
Eric
M. and Bonivento, Claudio},
title = {Robot manipulability},
journal = {IEEE Trans. Robotics and Automation},
year = {1995},
volume = {11},
number = {3},
pages = {462--468}
}

Herman

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### manipulability measure calculation with KDL::Jacobian

I've found this paper (Robot manipulability) but I have no access to view it: