Evolution of Wheelchair.q, a Stair-climbing Wheelchair

This paper presents a solution for a stair-climbing wheelchair that can climb single steps or entire staircases. This device was designed in order to ensure greater autonomy for people with reduced mobility . The main component of the wheelchair structure is a three-wheel locomotion unit that allows obstacle climbing thanks to an epicycloidal transmission. The other characteristic element is an idle track that behaves like a second foothold giving static stability during stair-climbing. Another important feature concerned with this design is a reconfiguration mechanism that makes the wheelchair suitable both for stair-climbing and for moving on flat ground. This feature allows performances and overall dimensions comparable to traditional electric wheelchairs. The choice and design of the mechanisms for the reconfiguration phase are the main topics discussed in this article and represent the principal innovations of this wheelchair compared to earlier versions

Design of a self-leveling cam mechanism for a stair climbing wheelchair

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

Locomotion system for ground mobile robots in uneven and unstructured environments

One of the technology domains with the greatest growth rates nowadays is service robots. The extensive use of ground mobile robots in environments that are unstructured or structured for humans is a promising challenge for the coming years, even though Automated Guided Vehicles (AGV) moving on flat and compact grounds are already commercially available and widely utilized to move components and products inside indoor industrial buildings. Agriculture, planetary exploration, military operations, demining, intervention in case of terrorist attacks, surveillance, and reconnaissance in hazardous conditions are important application domains. Due to the fact that it integrates the disciplines of locomotion, vision, cognition, and navigation, the design of a ground mobile robot is extremely interdisciplinary. In terms of mechanics, ground mobile robots, with the exception of those designed for particular surroundings and surfaces (such as slithering or sticky robots), can move on wheels (W), legs (L), tracks (T), or hybrids of these concepts (LW, LT, WT, LWT). In terms of maximum speed, obstacle crossing ability, step/stair climbing ability, slope climbing ability, walking capability on soft terrain, walking capability on uneven terrain, energy efficiency, mechanical complexity, control complexity, and technology readiness, a systematic comparison of these locomotion systems is provided in [1]. Based on the above-mentioned classification, in this thesis, we first introduce a small-scale hybrid locomotion robot for surveillance and inspection, WheTLHLoc, with two tracks, two revolving legs, two active wheels, and two passive omni wheels. The robot can move in several different ways, including using wheels on the flat, compact ground,[1] tracks on soft, yielding terrain, and a combination of tracks, legs, and wheels to navigate obstacles. In particular, static stability and non-slipping characteristics are considered while analyzing the process of climbing steps and stairs. The experimental test on the first prototype has proven the planned climbing maneuver’s efficacy and the WheTLHLoc robot's operational flexibility. Later we present another development of WheTLHLoc and introduce WheTLHLoc 2.0 with newly designed legs, enabling the robot to deal with bigger obstacles. Subsequently, a single-track bio-inspired ground mobile robot's conceptual and embodiment designs are presented. This robot is called SnakeTrack. It is designed for surveillance and inspection activities in unstructured environments with constrained areas. The vertebral column has two end modules and a variable number of vertebrae linked by compliant joints, and the surrounding track is its essential component. Four motors drive the robot: two control the track motion and two regulate the lateral flexion of the vertebral column for steering. The compliant joints enable limited passive torsion and retroflection of the vertebral column, which the robot can use to adapt to uneven terrain and increase traction. Eventually, the new version of SnakeTrack, called 'Porcospino', is introduced with the aim of allowing the robot to move in a wider variety of terrains. The novelty of this thesis lies in the development and presentation of three novel designs of small-scale mobile robots for surveillance and inspection in unstructured environments, and they employ hybrid locomotion systems that allow them to traverse a variety of terrains, including soft, yielding terrain and high obstacles. This thesis contributes to the field of mobile robotics by introducing new design concepts for hybrid locomotion systems that enable robots to navigate challenging environments. The robots presented in this thesis employ modular designs that allow their lengths to be adapted to suit specific tasks, and they are capable of restoring their correct position after falling over, making them highly adaptable and versatile. Furthermore, this thesis presents a detailed analysis of the robots' capabilities, including their step-climbing and motion planning abilities. In this thesis we also discuss possible refinements for the robots' designs to improve their performance and reliability. Overall, this thesis's contributions lie in the design and development of innovative mobile robots that address the challenges of surveillance and inspection in unstructured environments, and the analysis and evaluation of these robots' capabilities. The research presented in this thesis provides a foundation for further work in this field, and it may be of interest to researchers and practitioners in the areas of robotics, automation, and inspection. As a general note, the first robot, WheTLHLoc, is a hybrid locomotion robot capable of combining tracked locomotion on soft terrains, wheeled locomotion on flat and compact grounds, and high obstacle crossing capability. The second robot, SnakeTrack, is a small-size mono-track robot with a modular structure composed of a vertebral column and a single peripherical track revolving around it. The third robot, Porcospino, is an evolution of SnakeTrack and includes flexible spines on the track modules for improved traction on uneven but firm terrains, and refinements of the shape of the track guidance system. This thesis provides detailed descriptions of the design and prototyping of these robots and presents analytical and experimental results to verify their capabilities

Carrozzina elettrica innovativa per il superamento delle barriere architettoniche

La presenza di barriere architettoniche in ambienti pubblici o privati rappresenta una forte limitazione per la mobilità di persone che utilizzano una carrozzina per gli spostamenti quotidiani. Nonostante l’introduzione di normative con lo scopo di promuovere l’abbattimento di queste barriere, non sempre la loro completa eliminazione è realizzata o realizzabile. In queste situazioni è necessario poter fornire all’utente disabile un ausilio in grado di superare autonomamente barriere architettoniche od ostacoli. Tale dispositivo dovrebbe poter essere utilizzato in autonomia, essere trasportabile ed integrato nella struttura della carrozzina, in maniera da essere attivabile all’occorrenza. L’obiettivo di questo lavoro di tesi è quindi l’ideazione di una carrozzina montascale che integri in un unico oggetto le abilità e le funzionalità di una tradizionale carrozzina elettrica e di un montascale. Attualmente, vista le complessità dell’obiettivo, esistono pochi dispositivi di questo tipo disponibili in commercio, mentre un numero più ampio di soluzioni è stato individuato nello stato dell’arte delle ricerche e dei brevetti. In ogni caso le soluzioni individuate presentano forti limitazioni per la diffusione della tecnologia, in quanto in generale risultano ingombranti, complesse, costose e non sembrano rispondere a criteri di accettabilità personale dell’utente. Per questi motivi la tesi di dottorato è stata indirizzata allo sviluppo di un’idea innovativa di carrozzina montascale, con l’obiettivo di ottenere prestazioni superiori rispetto alle soluzioni presentate nello stato dell’arte. In particolare, si è progettato un dispositivo in grado di superare con sicurezza e regolarità rampe di scale e singoli scalini, limitando però allo stesso tempo il peso, l’ingombro e la complessità del veicolo. Particolare attenzione è stata inoltre posta nel garantire un moto su scala con minime oscillazioni percepite dall’utente e nell’ottenere un dispositivo gradevole oltre che funzionale. Caratteristica principale della carrozzina è l’architettura ibrida del sistema di locomozione, composto da una coppia di unità di locomozione motorizzate poste anteriormente e da un cingolo non motorizzato né frenato che costituisce il punto di appoggio posteriore. Le unità di locomozione a zampe rotanti sono costituite da un telaio con tre bracci, ciascuno dei quali porta una ruota all’estremità. Le tre ruote sono ulteriormente collegate tra loro attraverso un rotismo epicicloidale interno all’unità. Questa architettura permette di gestire in maniera semplice e funzionale sia la marcia in piano che la marcia su scale, permettendo inoltre un’agevole transizione tra le due condizioni di impiego. Nel lavoro di tesi proposto verrà analizzata la progettazione cinematica e dinamica del dispositivo, analizzandone il comportamento e le prestazioni di funzionamento. I risultati ottenuti dimostrano l’efficacia della carrozzina proposta nel superare ostacoli in maniera sicura, regolare, adeguata agli obiettivi di progetto richiesti e in grado di rispondere ai requisiti di sicurezza imposti dalla normativa (ad esempio ISO 7176-28:2012, “Requirements and test methods for stair-climbing devices”). La soluzione proposta risulta quindi idonea per essere ulteriormente sviluppata attraverso la realizzazione di un prototipo in grado di validare attraverso una campagna di prove sperimentali l’efficacia dell’architettura di carrozzina montascale descritta in questo lavoro di tesi

Análisis cinemático en el diseño conceptual de un mecanismo tipo clúster para el desarrollo de una silla de ruedas eléctrica con capacidad de ascenso en escaleras rectas

Este trabajo de tesis consistió en el análisis cinemático en el diseño conceptual de un mecanismo de seis grados de libertad tipo clúster para el desarrollo de una silla de ruedas eléctrica con capacidad de ascenso en escaleras rectas. Se consideró el diseño de un nuevo concepto por las dificultades en ascenso y descenso de escaleras que mantienen aún las personas con discapacidad limitadas de forma permanente para caminar hoy en día. El diseño conceptual propuesto cumplió con las normativas de edificación para una escalera recta sin descansos y de escalones uniformes, y consideró como usuarios a personas adultas de hasta 80 kg con capacidad de controlar el vehículo de manera autónoma. El análisis cinemático se estudió según unas transiciones planificadas entre estados que mantienen su estabilidad y que van desde el inicio del cambio a la modalidad para ascender sobre una escalera de 5 escalones rectos, hasta el final del cambio a la modalidad de silla de ruedas una vez ya ascendido. Los resultados almacenados de su simulación por medio de una herramienta de software matemático (Matlab), y según entradas a velocidad constante, mostraron que al sistema le tomará un total aproximado de 4 minutos y medio realizar todo el proceso mencionado. Asimiso, las posiciones almacenadas, la propuesta de masas y centros de masa, y Matlab permitieron simular análisis estáticos para aproximar cargas en la estructura del vehículo. Seguidamente, se estimaron factores de seguridad de sus componentes a partir del análisis de resistencia de sus materiales con ayuda de un software de ingeniería asistido por compuratoda (SolidWorks Simulation). Luego, las selecciones de actuadores, sensores, elementos de interacción hombre-máquina relevantes, y fuentes de alimentación eléctrica se efectuaron para satisfacer con los requerimientos cinemáticos en cada transición. Por último, se estimó que la batería puede proveer aproximadamente 29 minutos de autonomía para tareas de ascenso, mientras que para desplazamiento en superficies planas la autonomía puede alcanzar las 5 horas.Tesi

Library buildings around the world

"Library Buildings around the World" is a survey based on researches of several years. The objective was to gather library buildings on an international level starting with 1990