Work in the Time of Covid-19: Actuators and Sensors for Rehabilitation Robotics

Ronnapee Chaichaowarat, Satoshi Nishimura, Takahiro Nozaki, Hermano Igo Krebs

研究成果: Article査読

1 被引用数 (Scopus)

抄録

This paper reports on our work conducted during 2020 in the development of actuation and sensing techniques and devices. In gait rehabilitation, active body weight support systems are often needed to guarantee the safety of patients. These support systems are required to operate at two distinct operation points: A high-force operating mode to hold a patient and prevent falls and, conversely, a "transparent mode"that reduces the mechanical impedance of high-force actuators to enable patients, even those who are weak or paralyzed, to easily express movement. However, the ability to deliver high forces and easily manipulate robots is a key challenge in improving the force-based interaction control. Force feedback is an effective approach to reduce the inertia and friction of robots, but stability is paramount particularly when interacting with humans. By modeling the environment as a second-order spring-mass-damper system and considering the phase response, we derived the control parameter gains required to guarantee a stable human-robot interaction. The design of actuators with intrinsically adjustable mechanical properties is a complementary strategy. For instance, the stiffness of actuators can be modulated by adjusting the unsupported length of a cantilever leaf spring. To model the spring stiffness under deflection, an ideal cantilever support model cannot be assumed for a conventional design of a slider with dual roller pairs, particularly with a soft spring. We proposed a beam deflection model considering the non-zero slopes at the contact points between the rollers and spring. The spring parameters were determined to attain the desired range of stiffness with a short traveling distance of the adjuster. For a single degree-offreedom (DOF) linear motion, we investigated a macro-mini actuation concept using an electrorheological-fluid brake. Balancing these conflicting requirements between the driving force generated from the non-backdrivable high-force unit and the low-inertia and low-friction unit was achieved by controlling the electrical field affecting the fluid yield stress between the rotor and stator electrodes of the brake. One of the limitations of the feedback control scheme was noisy force sensors. We discuss our novel proximity and force sensor using optical techniques and conclude with a description of low-profile 3-DOF flat motor.

本文言語English
ページ(範囲)256-265
ページ数10
ジャーナルIEEJ Journal of Industry Applications
11
2
DOI
出版ステータスPublished - 2022

ASJC Scopus subject areas

  • 自動車工学
  • エネルギー工学および電力技術
  • 機械工学
  • 産業および生産工学
  • 電子工学および電気工学

フィンガープリント

「Work in the Time of Covid-19: Actuators and Sensors for Rehabilitation Robotics」の研究トピックを掘り下げます。これらがまとまってユニークなフィンガープリントを構成します。

引用スタイル