On the inertially decoupled structure of the floating base robot dynamics★ ★

In this paper a coordinate transformation is proposed that provides an inertially decoupled structure for the equations of motion of a floating base robot. As the center of mass (CoM) has been used both for locomotion and balancing of legged robots because of its decoupled dynamics from the rest of the system, we expect to benefit from our coordinate transformation since it allows to separate the linear and angular centroidal dynamics from the joint dynamics. Gaining insights about the model, simpler and more effective control laws can be developed. As an example of application, the proposed transformation is used in the derivation of a humanoid balance controller.