[Ipopt] convergence with specific constraints

[lengagne sebastien]

Dear all

I am working on the motion generation for humanoid robots and I use 
IPOPT to solve motion planning problemcon.

I have some troubles with the convergence of the algorithm due to the 
properties of my problem.
To plan a motion, I implement constraint on the body position and also 
on the contact forces. But the contact forces have a physical meaning 
only when the body are at the contact location.

So, I would like to know if it is possible to not take into account some 
constraints (on the contact forces) only when some other constraints (on 
the body position) are satisfied ?

thank you

-- 
Sébastien LENGAGNE, Ph.D
CNRS-AIST JRL(Joint Robotics Laboratory), UMI3218/CRT
INTELLIGENT SYSTEMS RESEARCH INSTITUTE (IS), AIST
AIST Central 2, 1-1-1 Umezono, Tsukuba, 305-8568 JAPAN
tel : +81-29-8626508
fax : +81-29-8626507
mail : sebastien.lengagne at aist.go.jp