Design of a self-leveling cam mechanism for a stair climbing wheelchair. (June 2017)

• Record Type: Journal Article
• Authors: Quaglia, Giuseppe; Nisi, Matteo
• Is Part Of: Mechanism and machine theory. Volume 112(2017:Jun.)
• Page Start: 84
• Page End: 104
• Publication Date: 2017-06
• Subjects: Stair-climbing wheelchair -- Triple-wheels -- Cam mechanism -- Mechanism design -- Architectural barriers -- Disable; Machine theory -- Periodicals; Machinery -- Periodicals; Machines -- Périodiques; Génie mécanique -- Périodiques; Machine theory; Machinery; Periodicals; 621.81
• DOI: 10.1016/j.mechmachtheory.2017.02.003
• Languages: English
• ISSNs: 0094-114X

Abstract

Highlights: A new version of an electric stair-climbing wheelchair is proposed. The performances in term of static stability and user comfort have been improved. A cam mechanism has been introduced to cancel the seat oscillation. A parametric analysis on the cam mechanism has been conducted. Abstract: This paper presents a new version of Wheelchair.q, a wheelchair with stair climbing ability. The wheelchair is able to climb single obstacles or staircases thanks to a hybrid wheel-leg locomotion unit with a triple-wheels cluster architecture. The new concept presented in this work represents an improvement respect to previous versions. Through a different arrangement of functional elements, the wheelchair performances in terms of stability and regularity during movement on stair have been increased. In particular, attention has been paid to ensure a regular and comfortable motion for the user during stair climbing operation. For this reason, a cam mechanism has been introduced and designed with the aim to compensate the oscillation generated on the wheelchair frame by the locomotion unit rotation. A design methodology for the cam profile is presented. Moreover, a parametric analysis on the cam profile and on the mechanism dimensions has been conducted with the aim to find a cam profile with suitable dimensions and performances in terms of pressure angle and radius of curvature. Graphical abstract: