Quadrupedal Human-Assistive Robotic Platform (Q-HARP): Design, Control, and Preliminary Testing

Abstract

With the rapid expansion of older adult populations around the world, mobility impairment is becoming an increasingly challenging issue. For the assistance of individuals with mobility impairments, there are two major types of tools in the current practice, including the passive (unpowered) walking aids (canes, walkers, rollators, etc.) and wheelchairs (powered and unpowered). Despite their extensive use, there are significant weaknesses that affect their effectiveness in daily use, especially when challenging uneven terrains are encountered. To address these issues, the authors developed a novel robotic platform intended for the assistance of mobility-challenged individuals. Unlike the existing assistive robots serving similar purposes, the proposed robot, namely Quadrupedal Human-Assistive Robotic Platform (Q-HARP), utilizes legged locomotion to provide an unprecedented potential to adapt to a wide variety of challenging terrains, many of which are common in people's daily life (e.g., roadside curbs and the few steps leading to a front door). In this paper, the design of the robot is presented, including the overall structure of the robot and the design details of the actuated robotic leg joints. For the motion control of the robot, a joint trajectory generator is formulated, with the purpose of generating a stable walking gait to provide reliable support to its human user in the robot's future application. The Q-HARP robot and its control system were experimentally tested, and the results demonstrated that the robot was able to provide a smooth gait during walking.

Kinematic Interactions between a Human Musculoskeletal Model and a Lower Limb Exoskeleton

“…Font-Llagunes et al have developed a prototype that consists of two modular robotic orthoses, which are powered by a motor-harmonic drive actuation system that controls knee flexion-extension [8]. A quadrupedal human-assistive robotic platform that can adapt to various terrains has been introduced by Shen et al [9]. A dynamic model for a hydraulically actuated lower limb exoskeleton that estimates the forces and moments required by the exoskeleton based on the desired kinematics and time of movements has been presented by Glowinski et al [10].…”