Optimizing Humanoid Motions Using Recursive Dynamics and Lie Groups

In this paper, we present a recursive method for the optimization of humanoid robot motions. The method is based on an efficient dynamics algorithm, which allows the calculation of the gradient function with respect to the control parameters analytically. The algorithm makes use of the theory of Lie groups and Lie algebra. The main objective of this method is to smooth the pre-calculated humanoid motions by minimizing the efforts, and at the same time improving the stability of the humanoid robot during the execution of the planned tasks. Experimental results using HRP-2 platform are provided to validate the proposed method.