Human-like compliant locomotion: state of the art of robotic implementations

Abstract

This review paper provides a synthetic yet critical overview of the key biomechanical principles of human bipedal walking and their current implementation in robotic platforms. We describe the functional role of human joints, addressing in particular the relevance of the compliant properties of the different degrees of freedom throughout the gait cycle. We focused on three basic functional units involved in locomotion, i.e. the ankle-foot complex, the knee, and the hip-pelvis complex, and their relevance to whole-body performance. We present an extensive review of the current implementations of these mechanisms into robotic platforms, discussing their potentialities and limitations from the functional and energetic perspectives. We specifically targeted humanoid robots, but also revised evidence from the field of lower-limb prosthetics, which presents innovative solutions still unexploited in the current humanoids. Finally, we identified the main critical aspects of the process of translating human principles into actual machines, providing a number of relevant challenges that should be addressed in future research.

Head and trunk kinematics and kinetics in normal and cerebral palsy gait: a systematic review

“…Children with CP show altered movements such as decreased head and trunk stability [4]. Typical gait comprises the movements of various body segments but gait in a developing CP child is a complex process [5].…”

Plantar Tactile Feedback for Biped Balance and Locomotion on Unknown Terrain

“…With the addition of contact or pressure sensors on the sole, walking algorithms have been extended to handle unknown terrain conditions 8,19,26 without complex compliant mechanic designs 27 or fast reactive motions. 28 Furthermore, even for point feet robots, the detection of premature contacts on a step trajectory can be used to reset the phase of a Central Pattern Generator (CPG).…”

Construction and Control of the Bipedal Walking Robot

“…The ankle joint is the last one necessary for proper movement, thanks to which bending and straightening movements are possible, as well as small movements allowing the body to deflect in the frontal plane. [12].…”