New fractions of non-histone proteins in spleen cells of mice immunized with various antigens.

Abstract

In order to prevent the humanoid robot TUlip from falling a start has been made with a Zero\nMoment Point (ZMP) based controller. The chosen controller, which is called the Linear Inverted\nPendulum Tracker (LIPT) controller, is based upon a lag between the real and reference ZMP\nand is used in simulations for initial testing.\nTUlip's walking gait is based on the Cart-Table (CT) model based ZMP to keep it stable during\nwalking. However, during simulations and experiments it turned out that TUlip did not remain\nbalanced at all times. Because the gait is based on the ZMP, a ZMP based controller is chosen\nto obtain a stable gait.\nSince the LIPT controller is based on a lag between the real ZMP and the reference ZMP, a\nlag needed to be found. In this report a lag of 0.02 seconds is found between the real ZMP,\nbased on the Center of Pressure (CoP), and the reference ZMP, based on the CT model. A state\nspace representation is derived and implemented in the simulation model. Initial simulations\nshowed a working controller which, given enough time, brought the ZMP back to it's reference\nposition. However, simulations for testing the controller on the robot showed no improvement\nin the stability of the walking gait.\nDuring simulations it was found that the existing ground contact model, developed to prevent\nlarge peak forces when a foot is lifted or put to the ground, was not sti enough. This resulted\nin larger oscillations in the CoP than for the CT model based ZMP, where similar results where\nexpected. Is is recommended to x the ground contact model before continuing the development\nof the ZMP based controller.