Session: MR-5-2: Motion Planning, Dynamics, and Control of Robots

Paper Number: 117042

117042 - Lifting Task Stability Evaluation Based on Balanced State Basins of a Humanoid Robot 

Stability evaluation is a vital aspect of successful balance control and design for humanoid robots. While balance stability has been extensively explored for push recovery during legged locomotion tasks in response to perturbations, less effort has been devoted toward developing a similar understanding for lifting tasks. Lifting involves unique interactions between the robot and lifted object, whose mass can significant alter the center-of-mass of the loaded robot. In addition, the role of upper extremities, which is typically ignored in legged robot balance, is critical when a payload is involved. In this study, the balance stability of a humanoid robot during a lifting task is evaluated with a partition-based approach in the augmented COM-state space. The balanced state boundary is computed through an optimization-based method that incorporates the robot’s and object’s whole-body system properties, such as kinematic and actuation limits, with full-order nonlinear system dynamics in the sagittal plane subject to foot-ground contact interactions and lifting task requirements. The balanced state basins are constructed for different combinations of object masses and lifting trajectories obtained with a ZMP constraint-based pattern generator. Trends in the basins and comparisons between them are used to identify the varying contributions of kinematic and actuation limits; linear and angular momenta regulation; and mass distribution to balance stability under different loading conditions and task parameters.

Presenting Author: Joo H. Kim New York University

Presenting Author Biography: Dr. Joo H. Kim is an Associate Professor of Mechanical Engineering at New York University.

Authors:

Hyunjong Song New York University
William Peng New York University
Joo H. Kim New York University