ZMP-Based Humanoid Walking Engine with Arms Movement and Stabilization
Marcos R. O. A. Maximo1; Carlos H. C. Ribeiro1
1 Instituto Tecnológico de Aeronáutica
Resumo
In this paper, we present an omnidirectional walking engine for a humanoid robot. Our approach is based on the Zero Moment Point (ZMP) concept, which provides an useful criterion for biped stability. To avoid dealing directly with the complex dynamics of a high degrees of freedom humanoid robot, we used the 3D Linear Inverted Pendulum Model (3D-LIPM) to approximate the robot dynamics. 3D-LIPM dictates that the center of mass (CoM) and ZMP dynamics are related by uncoupled second order ordinary differential equations. Thus, we may compute a suitable CoM trajectory to maintain the robot balance by solving a boundary value problem analytically. Furthermore, we employed strategies to improve the walking robustness, namely, we make the robot move its arms in order to compensate the yaw moment induced by the legs and we developed a feedback controller that uses the torso angular velocities to stabilize the walk. Simulated and real experiments on a custom enhanced Bioloid robot are shown to validate the proposed methods.
Palavras-chave: Robotics; Biped Locomotion; Humanoid Robots