Planning for Humanoid (Atlas)

[teguhSL]

I would like to plan the whole body motion of a humanoid robot (Atlas) using trajopt. I follow the example in drc_walk, and it works well.

However, I realize that when I use press_button_request() to plan the motion, only the upper body is moving (the leg remains exactly at the same position). This is strange to me because the constraints only specify that the poses of the feet has to remain the same, but not the joint angles. The joint angles of the leg should be able to move, as long as it still keeps the feet at the same locations. The robot should be able to lower its knee if it tries to grab something below, as long as this still statisfies the ZMP constraint. Instead. all the planning show that the legs remain at the same position.

This is the same when I try to do step-forward: only the leg is moving but all the upper body part remains stationary.

Does anyone have any idea how I can make the whole body move together? Thank you!