Three-dimensional Limit Cycle Walking with joint actuation

Abstract

This paper describes 3D biped walking generation and control based on Limit Cycle Walking. In our study, we use the simplest possible 3D biped model with three DOFs, incorporating roll and pitch motions in the frontal/sagittal planes, respectively. Our approach dynamically decouples these two motions, stabilizes pitch motion in the sagittal plane via the Limit Cycle Walking approach, introduces robustness for this motion using energy feedback control, and robustness for roll motion based on reference trajectory feedback tracking control. The roll reference trajectory is generated via analysis of the impact dynamics. Performance is verified via simulations.

Joint friction estimation for walking bipeds

“…However in bipeds, joint friction compensation is generally neglected. [53][54][55][56] The reported studies that considered the joint friction are few. They are either model-based or model-free.…”

“…The parameters values of the friction model (56) for each joint of the leg are listed in Table I. The corresponding generated true friction is shown Fig.…”

"The Spherical Inverted Pendulum with Pelvis Width in Polar Coordinates for Humanoid Walking Design"

“…The approach is in the realm of passive walkers and of hybrid zero dynamics [6,7]. In particular, a similar model, with finite-width between the legs, was discussed previously in [8] and [9][10][11]. However, here the dynamics is simpler, and the progression of the walk is not obtained with a sloped ground, but with appropriate increments of the rotational velocities after the foot collision.…”