Development of Legless chair with Power Assist for Effort in Standing Action

2002 Fiscal Year Final Research Report Summary

• Project/Area Number: 13650247
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Dynamics/Control
• Research Institution: TOYAMA University
• Principal Investigator: KOIZUMI Kunio TOYAMA Univ. Faculty of Engg. Professor, 工学部, 教授 (60019776)
• Co-Investigator(Kenkyū-buntansha): SASAKI Tohru TOYAMA Univ. Faculty of Engg. Assistant, 工学部, 助手 (00262501) ; SASAKI Motofumi TOYAMA Univ. Faculty of Engg. Assistant Professor, 工学部, 助教授 (00019217)
• Project Period (FY): 2001 – 2002
• Keywords: welfare engineering / welfare for old people / staying home care / assistance / power assist / rehabilitation

Research Abstract

This study deals with the new power assist for standing action, suspends the largest load to the leg in the anti-gravity action, of the old people who the leg function declines. In the case of seating in the floor, the very large load acts to the leg for lining of the waist height level from the floor to the chair. Therefore, the physical burden in Japanese daily life is bigger than the life with chair and bed in Europe and America. Thoughtless utilization of the machine power in the reduction method of the load causes the physical weakness of the leg. As the technical countermeasure in hardware against the difficult problem, the stand assist mechanism for the legless chair was developed to improvement for the natural and easy standing action. In standing action, there is the difficulty of standing in the wide bending of leg joints with transfer of the center of gravity in body weight in lifting of the waist height level from the floor to the chair. The functions of developed mechanism have lifting of the waist height level as the main mechanism action at the low level, and have the bending and extrusion of the body to the front over the height level equal to the chair. The mechanism can be adjusted the seat motion to fit for the individual specificity and the secular change with the only one actuator. And, as the countermeasure in software, the assist algorithm to evaluate the self-help effort for standing was developed to maintain the physical ability remained and rehabilitated.
(1) The power assisted legless chair was developed to follow until self-standing from seating in the floor.
(2) The forces at all joints were analyzed and the required power for the actuator were clarified.
(3) The prototype of the power assist algorithm was developed.
(4) Self- standing power is appropriate as the index of evaluation to effort.
(5) The force acted at elbow hang was clarified to be appropriate as the approximate index.