Kinematics and performance analysis of a serial hip assistive mechanism

Abstract

A serial assistive mechanism was proposed for the hip adduction/abduction and flexion/extension motion assistance, which is kinematically compatible with human hip complex. As the mechanism is connected to the wearer, a 2-degree-offreedom human-robot closed chain is formed. The closed-form position solution of the assistive mechanism was investigated, the Jacobian matrixes which map the velocity and force from the active joint space of the assistive mechanism to hip joint space were derived, and five new indices for performance evaluation of the assistive mechanism were defined. On the basis of the presented position solution and evaluation indices, the performances of the assistive mechanism during a human gait cycle, such as the human-robot motion offset, the motion and force assistive characteristics, were analyzed through the examples with seven wearing error models. The results show that the assistive mechanism has several distinct advantages including small human-robot motion offset, favorable motion assistive isotropy, and high force assistive efficiency. The proposed indices can evaluate the assistive feature adequately, and the serial assistive mechanism is applicable to the 2-degree-of-freedom hip adduction/abduction and flexion/extension motion assistance.

Effect of Common Pavements on Interjoint Coordination of Walking with and without Robotic Exoskeleton

“…To increase walking efficiency of humans, it needs to reduce impact on the natural walking gait by minimizing changes in kinematics [5]. In addition, the appropriate assistive strategies constitute the human-robot motion, which benefits the assistive isotropy of the motion, and improves the assistive efficiency of the force [6]. Matching the assistance pattern of exoskeleton with the individual also needs to maximize the advantage of the device and minimize the human energy cost during walking [7].…”

Manipulability Inclusive Principle for Assistive Result Evaluation of Assistive Mechanism

“…And especially, the design and optimization should also keep the assistive mechanism not only have better kinematical performance on symmetry, isotropy etc., but also be able to provide better assistance for human. In recent research studies, the research in [ 30 ] uses the Jacobian matrices to analyze the assistive isotropy and assistive efficiency; researchers in [ 31 ] use the global performance index to represent the dexterity, and the manipulability ellipsoids for the 4-DOF assistive robot is obtained in [ 32 ]. However, the research studies shown in [ 30 – 32 ] have not considered the influence of the motions of the human limb.…”

“…In recent research studies, the research in [ 30 ] uses the Jacobian matrices to analyze the assistive isotropy and assistive efficiency; researchers in [ 31 ] use the global performance index to represent the dexterity, and the manipulability ellipsoids for the 4-DOF assistive robot is obtained in [ 32 ]. However, the research studies shown in [ 30 – 32 ] have not considered the influence of the motions of the human limb. For example, the problem of assistive feasibility should compare the manipulability between the assistive mechanism and the human limb.…”

“…For example, the problem of assistive feasibility should compare the manipulability between the assistive mechanism and the human limb. Additionally, compared to [ 30 – 32 ], this paper will show more systemic research on optimization problem including assistive feasibility and assistive efficiency.…”

Projeto De Mecanismo, Análise Cinemática E Dinâmica De Um Manipulador Robótico Acionado Por Junta Cardânica Ativa Com Três Graus De Liberdade

“…Muitas vezes, o movimento do manipulador pode ser integrado ao movimento humano, no caso de tecnologia assistiva, conforme estudado por Li et al (2018), que projetaram um mecanismo de assistência humana, que é conectado ao usuário e forma uma cadeia fechada de dois graus de liberdade humano-robô (LI, SHEN, et al, 2018). Outro caso de tecnologia assistiva foi estudado por Bellman et al(2008), que desenvolveram uma junta passiva protética para o tornozelo com dois graus de liberdade, sendo que um dos graus de liberdade é regenerativo por possuir molas e amortecedores que tendem a manter a posição da junta (BELLMAN, HOLGATE e SUGAR, 2008).…”