Articulated Spine Mechanisms for Humanoid Robots

Abstract

This PhD thesis addresses the challenge of developing humanoid robots capable of supporting humans in various environments. To operate effectively in unstructured and man-made settings, robots must, among others, exhibit human-like strength, mobility, and size while withstanding impacts. This thesis focuses on the role of the spine in achieving these capabilities. Two distinct approaches are proposed for the torso and neck functionality. For the neck, a continuum mechanism utilizing silicone and tendons is developed to emulate the mechanical robustness and adaptability of the human spine. Multiple prototypes are built, evaluated, and refined to enable roll, pitch, and yaw motions, while ensuring a large workspace. The modular and adaptable design facilitates seamless integration into diverse robotic systems. Regarding the torso which bears significant weight, a stiff-joint approach is adopted. Two mechanical spring mechanisms are employed: a gravitational compensation mechanism for the first two axes and a linear adjustable spring mechanism for the rotational axis. These mechanisms enhance ventral/dorsal, lateral, and rotational motions of the upper body. The developed mechanisms are successfully integrated into the humanoid robot DAVID, a creation of the Institute of Robotics and Mechatronics at DLR. This thesis contributes to the advancement of humanoid robotics by providing innovative solutions for enhancing torso and neck functionality, improving the robot’s ability to support humans in a wide range of scenarios.