Design and performance analysis of a 3-RRR spherical parallel manipulator for hip exoskeleton applications

Abstract

This paper presents the design and performance analysis and experimental study of a 3- R RR spherical parallel manipulator in the context of hip exoskeleton applications. First, the mechanism’s inverse kinematics analysis and Jacobian matrix development are revisited. Manipulability, dexterity, and rotational sensitivity indices are then evaluated for two different methods of attachment to the human body. The superior attachment method in terms of these performance measures is indicated, and an experimental study based on the selected method is conducted; the experiment involves testing the capability of a 3- R RR manipulator’s end-effector in tracking the motions experienced by a human hip joint during normal gait cycles. Finally, the results of the experimental study indicate that the manipulator represents a feasible hip exoskeleton solution providing total kinematic compliance with the human hip joint’s 3-degree-of-freedom motion capabilities.

Topological Analysis of a Novel Compact Omnidirectional Three-Legged Robot with Parallel Hip Structures Regarding Locomotion Capability and Load Distribution

“…In [14,16], a manipulator for precise and high-speed orientation of a camera-the Agile Eye-was built. In [17][18][19] the manipulator was utilized as an device for surgery applications and in [20] in a human hip exoskeleton context. In combination with the knee joint, each leg of the robot is a serial-parallel-manipulator on its own, which is connected by the central torso part.…”

A Spherical Active Joint for Humanoids and Humans

“…Parallel joints are, on the contrary, less considered in humanoid and prosthetic applications due to the complexity of their structures. The 3-dof spherical 3D agile eye, developed by Gosselin et al in [12] for camera orientation, was adopted in [13] for a hip exoskeleton application. The 3D agile eye presents singularities in the 3 rotational directions of the mobile platform [14].…”

Motion Generation of a Wearable Hip Exoskeleton Robot Using Machine Learning-Based Estimation of Ground Reaction Forces and Moments

“…In the Assistive Robotic Systems Lab at Simon Fraser University, a hip exoskeleton robot has been developed [34,35]. It has the advantage of using a parallel mechanism called "Agile Eye" [36] in its structure which has the benefit of providing a full range of motion.…”

“…In the second scenario, the robot is moving based on the user's body and robot link follows user's upper thigh based on the inverse kinematics developed in [35]. One of the randomly chosen walking step's result is provided in Figure 5.6.…”