Kinematic Analysis of an Electric StairClimbing Wheelchair

Kinematic Analysis of an Electric StairClimbing Wheelchair1 Análisis cinemático de una silla de ruedas eléctrica escaladora2 Giuseppe Quaglia3 Walter Franco4 Matteo Nisi5 doi: 10.11144/Javeriana.iyu21-1.kaes How to cite this article: G. Quaglia, W. Franco, and M. Nisi, “Kinematic analysis of an electric stair-climbing wheelchair,” Ing. Univ., vol. 21, no. 1, pp. 27-48, 2017. http://dx.doi.org/10.11144/ Javeriana.iyu21-1.kaes Submitted on: August 17th, 2016. Accepted on: November 16th, 2016. Fecha de recepción: 17 de agosto de 2016. Fecha de aceptación:16 de noviembre de 2016. 2 Fecha de recepción: 17 de agosto de 2016. Fecha de aceptación: 16 de noviembre de 2016. Artículo de investigación científica y tecnológica. 3 Master in Mechanical Engineering, Politecnico di Torino, Italy. PhD in Applied Mechanics, Mechanical System and Structures, Politecnico di Torino. Associate professor at Politecnico di Torino. E-mail: 4 PhD in Applied Mechanics, Politecnico di Torino, Italy. Assistant Professor at Politecnico di Torino. E-mail: 5 Master Degree in Mechanical Engineering, Politecnico di Torino, Italy. PhD student at Politecnico di Torino. E-mail: 1 Ing. Univ. Bogotá (Colombia), 21 (1): 27-48, enero-junio de 2017. ISSN 0123-2126 28 Giuseppe Quaglia, Walter Franco, Matteo Nisi Abstract Resumen Keywords Palabras clave Introduction: This paper presents the functional design and kinematic synthesis of a recent version of an electric stair-climbing wheelchair. Wheelchair.q: The proposed device represents the latest evolution of the ‘Wheelchair.q’ project and introduces several improvements over previous designs. This updated solution has greater stability during stair-climbing operation, and it satisfies the safety requirements introduced by ISO 7176-28:2012, “Requirements and test methods for stair-climbing devices”. The main improvement presented concerns the regularity of the user trajectory during stair-climbing, which ensures a more comfortable perception. This result has been achieved by introducing a cam mechanism between the frame connected to the locomotion unit and the seat frame, which properly manages the seat orientation. With an appropriate cam profile, it is possible to compensate for the oscillations that are introduced on the wheelchair during the climbing sequence and allow the user to obtain a translational trajectory. Results: The proposed design and its working principle are first described and illustrated through schematic and graphic representations. A brief explanation of the procedure for obtaining the cam profile is also given. Two different architectures for the cam mechanism are then compared, and the advantages and disadvantages for each solution are identified. Finally, the kinematic wheelchair performances are tested through a simulation conducted in the MSC-ADAMS multibody environment. Conclusions: The results obtained with the simulation show the effectiveness of the proposed solution. The wheelchair is able to climb a staircase in a safe and regular way. Following studies will complete the design of the wheelchair with the aim to build a prototype for demonstrating the proposed working principle. stair-climbing wheelchair, architectural barriers, cam mechanism, wheelchair.q Introducción: En este trabajo se analiza el comportamiento de una silla de ruedas eléctrica para subir escaleras desde un punto de vista cinemático. Wheelchair.q: El dispositivo propuesto representa la última evolución del proyecto ‘Wheelchair.q’ e introduce varias mejoras con respecto a los diseños anteriores. Esta solución actualizada cuenta con una mayor estabilidad durante la subida de las escaleras, permitiendo llevar a cabo la tarea de una manera segura, cumpliendo la norma ISO 7176-28:2012. Sin embargo, las principales mejoras atañen a la regularidad de la trayectoria del usuario durante la subida de escaleras, lo cual permite obtener una percepción de comodidad mayor. Este resultado se ha logrado mediante la introducción de un mecanismo de leva que gestiona adecuadamente la orientación del asiento en lo que se refiere al bastidor de la silla de ruedas. Con un perfil de leva apropiado, es posible compensar la oscilación introducida en la silla de ruedas durante la secuencia de escalada, para que el usuario pueda obtener una trayectoria de traslación. Resultados: El diseño propuesto y su principio de funcionamiento se describen e ilustran en primer lugar a través de representaciones esquemáticas y gráficas, con una breve explicación sobre los procedimientos para obtener el perfil de leva. A continuación, se comparan las dos diferentes arquitecturas del mecanismo de leva y se identifican las ventajas y desventajas de cada solución. Por último, se prueban las prestaciones de la silla de ruedas cinemática a través de un simulacro en el ambiente de simulación MSC-ADAMS. Conclusiones: Los resultados obtenidos con la simulación muestran la efectividad de la solución propuesta. La silla de ruedas es capaz de subir una escalera de forma segura y regular. Los siguientes estudios completarán el diseño de la silla de ruedas con el objetivo de construir un prototipo para demostrar el principio de trabajo propuesto. subir escaleras, silla de ruedas, barreras arquitectónicas, mecanismo cam Ing. Univ. Bogotá (Colombia), 21 (1): 27-48, enero-junio de 2017 Kinematic analysis of an electric stair-climbing wheelchair 29 Introduction The development of devices that can improve people’s quality of life can be a noteworthy task for engineering researchers. An engineering project aimed at service for humans should begin by identifying a problem that reduces the quality of life of a significant number of people and then seek innovative and ingenious solutions that use the proper theoretical and technical tools for the engineering field, which should provide a feasible answer. In this paper, a particularly novel solution for a stair-climbing wheelchair is proposed. The problem faced in this research is to improve mobility for people with disabilities, particularly with respect to the limits imposed by architectural barriers. It has been estimated that in the U.S. “roughly 30.6 million individuals aged 15 years and older (12.6 percent of U.S. population) had limitations associated with ambulatory activities of the lower body” [1] and, in particular, that “about 3.6 million people (1.5 percent) used a wheelchair” [1] for daily mobility. The percentage increases if only the elderly are considered. Among people over 65 years of age, approximately 2.0 million people used a wheelchair (5.2 percent) [1]. The last point becomes more relevant when considering the aging world population. Based on the actual trend, the percentage of people over 60 years of age will reach 22% of the world population in 2050, but in 2000, it was only 10% [2]. These data highlight that ensuring adequate mobility for people who use wheelchairs will become an important issue in the coming years. In fact, the (...truncated)