Employing a Novel Gait Pattern Generator on a Social Humanoid Robot

Document Type: Article

Authors

1 Social & Cognitive Robotics Laboratory, Center of Excellence in Design, Robotics, and Automation (CEDRA), School of Mechanical Engineering, Sharif University of Technology, Tehran, IRAN

2 School of Mechanical Engineering, Sharif University of Technology, Tehran, Iran

Abstract

This paper presents a novel Gait Pattern Generator developed for the “Alice” social humanoid robot which
up to now lacked an appropriate walking pattern. Due to the limitations of this robot, the proposed gate
pattern generator was formulated based on a nine-mass model to decrease the modeling errors; and the
inverse kinematics of the whole lower-body was solved in such a way that the robot remains statically
stable during the movements. The main challenge of this work was to solve the inverse kinematics of a
7-link chain with 12 degrees-of-freedom. For this purpose, a new graphical-numerical technique has been
provided using the definition of the kinematic equations of the robot joints’ Cartesian coordinates. This
method resulted in a significant increase in the calculations’ solution rate. Finally, a novel algorithm was
developed for step-by-step displacement of the robot towards a desired destination in a two-dimensional
space. Performance of the proposed gate pattern generator was evaluated both with a model of the robot in
a MATLAB Simulink environment and in real experiments with the Alice humanoid robot.

Keywords