1,720,970 research outputs found
Carrozzina elettrica innovativa per il superamento delle barriere architettoniche
Full text linkLa 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
Evolution of Wheelchair.q, a Stair-climbing Wheelchair
Full text linkThis 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
CARROZZINA ELETTRICA MONTASCALE CON SISTEMA DI LOCOMOZIONE IBRIDO
No full textLa presente invenzione riguarda una carrozzina montascale (1) comprendente un
telaio (2) provvisto di un sedile (3) destinato ad ospitare un utente (100) da
trasportare e un’unità di locomozione (4) comprendente una coppia di tripodi (40).
La carrozzina (1) comprende inoltre mezzi di appoggio passivi mobili tra una
posizione riposta in cui sono sollevati dal terreno (1a) e una posizione estratta in cui
sono a contatto con il terreno (1a). I mezzi di appoggio passivi comprendono un
cingolo (6) configurato in modo tale che in posizione estratta il telaio (2) appoggia
anteriormente sull’unità di locomozione (4) e posteriormente sul cingolo (6), e la
carrozzina montascale (1) comprende ulteriormente almeno un dispositivo
meccanico collegato tra l’unità di locomozione (4) e il sedile (3) e atto a cooperare con
il cingolo (6) per compensare le oscillazioni del sedile (3) generate dal movimento
della coppia di tripodi (40), l’almeno un dispositivo meccanico essendo configurato
in modo tale da permettere un moto traslatorio del sedile (3) durante l’avanzamento
della carrozzina montascale (1) sulle scale
Kinematic analysis of an electric stair-climbing wheelchair
Full text linkThis paper presents the functional design and kinematic synthesis of a recent version of an electric stair-climbing wheelchair. 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. 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
Wheelchair.q05 final design, an innovative stair-climbing wheelchair
No full textThe presence of architectural barriers in public or private buildings represents an important limit for the mobility of wheelchair users. Although norms promote barriers removal, often a complete accessibility cannot be guaranteed due to economic or technical reasons. In such cases, it is necessary to provide disable people with devices able to autonomously climb architectural barriers or obstacles.
Referring to user needs, some requirements for the wheelchair can be defined. Firstly, the user must use it autonomously. Secondly, it should be easy to use, simple in the mechanical and control systems and with limited weight, dimensions, and cost. Finally, also the appearance of the wheelchair must be adequate to guarantee the user acceptability.
In literature, several solutions of stair-climbing wheelchair are proposed. However, none of these completely satisfies the identified requirements.
In this paper, the Wheelchair.q05, an innovative concept for a stair-climbing wheelchair, is presented. This idea has been developed through several years of researches and functional designs. In detail, this work presents the final design for a constructive and real scale prototype.
The proposed wheelchair, thanks to a smart and hybrid locomotion system, is able to move on flat ground and to climb stairs and sidewalks. A triangular shaped frame with a wheel on each corner, connected through an internal epicyclical transmission system, constitutes the locomotion unit. This system provides the traction both for flat ground and stair motion. Moreover, the wheelchair has an idle track that represents the rear contact point during stair-climbing and guarantees only a stable and regular climbing motion. The wheelchair structure is thus constituted by the following functional elements: two locomotion units, the track, the seat and a couple of pivoting wheels connected to floating arms that represents the rear support during flat ground motion and during sidewalks overcoming.
Through a kinematic synthesis, the optimal layout has been defined and the mechanisms that connect the functional elements with the frame have been designed. These mechanisms allow controlling the wheelchair reconfiguration that is necessary to adapt the vehicle to different working conditions.
Moreover, attention has been paid to the user comfort. Thanks to the introduction of a mechanism that controls the seat orientation, the oscillations generated by the motion on stair are compensated and a regular trajectory is guaranteed for the user center of mass
Design of a self-leveling cam mechanism for a stair climbing wheelchair
Full text linkThis 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
Design and construction of a new version of the Epi.q UGV for monitoring and surveillance tasks
No full textThe paper presents a new member of Epi.q robot family, a series of mobile robots with a wheel-legged locomotion and with the ability to overcome obstacles and move on uneven terrains. The particular feature of this robot family is the ability to switch from a wheel locomotion to a leg locomotion without any external active control but only depending on the dynamic conditions. In particular this work deals with the design of the latest prototype developed, analyzing the design and construction phases. This prototype is more powerful than the previous thanks to the possibility to have four driving units instead of two. The robot architecture has been studied in order to be modular. Several robot configurations can be obtained with the same structure and this allows to test how each component affect the overall robot behavior. Moreover the mechanical design is more accurate and reliable respect to previous versions. A sensing system has been introduced with the aim to evaluate the performances of each robot architecture. Finally an on-board processor has been added. This allows the definition of more complex control logics such as the cooperation between a speed control with a torque control in the four driving units configuration. Moreover it increases the smart tasks that the robot is able to perform such as the developing of a remote autonomous control rather than a manual drive by an operator
Dynamic simulation of an electric stair-climbing wheelchair
Full text linkIn this paper, a novel stair-climbing wheelchair is proposed. This new architecture represents an improvement over previous designs, in particular with regards to stability and safety during stair-climbing operations. The proposed mechanical architecture is hybrid: two locomotion units based on a "rotating leg" system are coupled with an idle track. This structure satisfies many design requirements: small dimensions, reduced weight, and a stable and regular climbing trajectory. In particular, the focus of this study is the design of an actuation system, the choice of suitable control logics, and the dynamic analysis of the proposed solution. The behavior of the wheelchair was tested through multibody simulation. The simulation results show that the proposed device can climb a staircase in a stable and safe manner. Certain smart dynamic features of the wheelchair were also proven. In particular, the efficacy of the cooperative actuation system and the effectiveness of the proposed control logic were analyzed. In conclusion, the simulation results demonstrate the appropriate operation of the proposed device, which will be used to design a working prototype of the stair-climbing wheelchair
IIoT portable laser line profilometer powered by AI for gap and flush measurement in automotive
No full textIn automotive manufacturing, the final assembly of car body parts requires repeated measurements of gap and flush, which are essential not just for aesthetics but also for aerodynamics and noise reduction. This paper initially presents an innovative portable wireless laser line triangulation profilometer for human operators in assembly lines. It then describes how the wireless and ergonomic measurement device exploits embedded AI solutions to improve measurement accuracy. Two semantic segmentation approaches were tested (U-Net vs. LinkNet) to compare their performance in isolating the effective laser line from unwanted reflections, as well as inferring accurate segmentation with short inference times. These approaches were deployed at the edge, requiring pruning and quantization steps to comply with the computational capabilities of the System on Module (SoM) mounted on the device. The LinkNet demonstrated superior accuracy (Dice loss of 0.1127) and faster execution speed (166.77 ms). This approach, particularly with semantic segmentation algorithms implemented on the edge device, paves the way to improve the detection of laser line images on transparent surfaces even in the presence of low contrast and multiple reflections, ensuring precise and efficient measurement of gap and flush, even on front lights
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