Diseño y construcción de un prototipo de sistema impulsor acoplable a sillas de ruedas para personas con discapacidad de miembros inferiores para movilidad en áreas urbanas

Abstract

This project aimed to design and build an electric propulsion system that can be attached to wheelchairs for individuals with lower limb disabilities, enabling mobility in urban areas. Through research and the QFD methodology, data was collected on user experiences to establish design parameters. The most important characteristics considered were mobility, low cost, functionality, safety, and ergonomics. Based on these criteria, three main alternatives were proposed and evaluated using a morphological matrix and the corrected weighted criteria method. The best alternative was selected as a result. Subsequently, the prototype was designed, divided into two parts. The first part involved selecting the control components for the system, while the second part focused on the mechanical design of the prototype structure using CAD software. Finite element analysis (FEA) was performed considering ASTM A36 steel as the primary construction material and ISO 8.8 grade bolts to ensure the prototype's strength. Once the prototype's strength was confirmed, the construction process began, involving various machining tasks and TIG and SMAW welding to assemble the equipment structure. Finally, the electrical components of the prototype were installed. For the control system, a 1000W hub motor, four rechargeable 12V lead-acid batteries, an accelerator, and a 20-ampere controller were selected. Through performance testing, maximum speeds of up to 15 km/h were achieved, with a battery duration of 1.48 hours and a maximum continuous travel distance of 15 km. It was concluded that the propulsion system could smoothly ascend 12% slopes and overcome rugged terrain. It is recommended not to exceed speeds of 12 km/h to avoid potential tipping, and for future projects, the use of lighter materials is suggested.