Dissertations / Theses on the topic 'Electric wheelchairs'

While the active dynamic stability of automobiles has increased over the past 17 years there have been very few similar advances made with electrically powered wheelchairs. This lack of improvement has led to a long standing acceptance of less-than-optimal stability and control of these wheelchairs. Accidents due to loss of stability are well documented. Hence, the healthcare industry has made several efforts for improved control of electric powered wheelchairs (EPWs) to provide enhanced comfort, safety and manoeuvrability at a lower cost. In response, an area of stability control was identified that could benefit from a feedback control system using solid state sensors. To design an effective closed–loop feedback controller with optimal performance to overcome instabilities, an accurate model of wheelchair dynamics needed to be created. Such a model can be employed to test various controllers quickly and repeatedly, without the difficulties of physically setting a wheelchair up for each test. This task was one central goal of this research. A wireless test-bed of a front wheel drive (FWD) wheelchair was also developed to validate a dynamic wheelchair model. It integrates sensors, a data control system, an embedded controller, and the motorised mechanical system. The wireless communication ensures the integrity of sensor data collected and control signals sent. The test-bed developed not only facilitates the development of feedback controllers of motorised wheelchairs, but the collected data can also be used to confirm theories of causes of dynamic instabilities. The prototype test-bed performed the required tasks to satisfaction as defined by the sponsor. Data collected from live tests in which the test-bed followed set patterns, was processed and analysed. The patterns were designed to induce instability. The analysis revealed that an occupied wheelchair is more stable than an unoccupied wheelchair, disproving an initial instability theory proposed in this research. However, a proximal theory explaining over-steer is confirmed. Two models of the FWD test-bed were created. First, a dynamic model inherited from prior research, based on equations of motion was tested and enhanced based on measured data. However, even with alterations to correct parameter values and variables in the equations, a complete model validation was not possible. Second, a kinematic model was created with a factor to compensate for dynamics not normally accounted in kinematic models. The kinematic model was partially validated versus the measured data. Although, still highly accurate, there is room for improvement in this model. Both models contained a sub-system drive motor model, to account for input forces to the FWD wheelchair system model, which is fully validated.

Le fauteuil roulant électrique constitue un moyen efficace permettant de retrouver une certaine mobilité pour de nombreuses personnes dans le monde. Malheureusement, certaines personnes en situation de handicap moteur et atteintes d’une perte de force musculaire peuvent avoir du mal à utiliser un fauteuil roulant électrique à cause de difficultés liées au maniement du joystick, dispositif usuel de pilotage du fauteuil. Cette thèse vise à proposer explorer une alternative au joystick pour des personnes atteintes de maladies neuromusculaires. Le travail de cette thèse s’intéresse plus particulièrement à l’interaction tactile. L’hypothèse est que l’interaction tactile peut offrir un pilotage fiable avec un niveau d’effort physique qui est tolérable par des personnes atteintes de maladies neuromusculaires. Dans cette perspective, nous avons développé une interface sur smartphone de pilotage de fauteuil roulant électrique qui offre de nombreuses possibilités de paramétrage permettant de la personnaliser selon le besoin de la personne. Cette interface a été conçue dans une démarche itérative centrée utilisateur. Dans chaque itération, différentes personnes souffrant d’une perte de mobilité ont pu tester l’interface de pilotage. Leurs retours alimentent les améliorations à apporter à l’interface dans l’itération d’après. Lors de la dernière itération dans le cadre de cette thèse, Une étude a été menée avec des utilisateurs atteints de maladies neuromusculaires au SSR le Brasset, avec l’aide de l’AFM Théléton. Ces participants ont pu s’approprier l’interface tactile et l’utiliser pour piloter leurs fauteuils roulants. Nous avons également comparé les performances de pilotage en utilisant l’interface tactile et le joystick dans différentes tâches quotidiennes (virage, slalom...). Les performances de ces patients avec l’interface tactile sont proches de celles du joystick. Par ailleurs, les remarques récoltées suggèrent que l’interface tactile exige moins d’effort physique que le joystick
The power wheelchair is an effective way to regain mobility for many people around the world. Unfortunately, some people with motor disabilities who also suffer from loss of muscle strength may find it difficult to use a power wheelchair. The reason is that they can experience difficulties related to the handling of a joystick, the standard wheelchair control device. This thesis aims to propose exploring an alternative to the joystick for people with neuromuscular diseases. The work of this thesis is particularly interested in tactile interaction. The hypothesis is that the tactile interaction can offer a reliable control with a level of physical effort which is tolerable by people suffering from neuromuscular diseases. In this perspective, we developed a wheelchair steering interface on smartphone. It offers many configuration possibilities allowing the customization according to the user's needs. This interface was designed in a user-centered, iterative approach. In each iteration, different people suffering from a loss of mobility were able to test the piloting interface. Their feedback feeds into improvements to the interface in the next iteration. During the last iteration as part of this thesis, a study was carried out with users suffering from neuromuscular diseases at the SSR Le Brasset, with the help of the AFM Théléton. These participants were able to take appropriate the use of the touch interface and use it to control their wheelchairs. We also compared the driving performance using the touch interface and the joystick in different daily tasks (cornering, slalom ...). The performance of these patients with the touch interface is close to that of the joystick. In addition, the comments collected suggest that the touch interface requires less physical effort than the joystick

A sedentary lifestyle can induce health related problems including pressure ulcers. Pro­longed sitting inadequacies constitute a risk for pressure ulcer to many individuals, in particular people with disabilities and re­duced mobility. The measurement of distributed pressure and detection of irregular sitting postures are essential in prevention of the risk of developing pres­sure ulcers. In this thesis, a screen-printed pressure sensor for a large area is presented, with the objective of measuring the distributed pressure of a seated per­son in a wheelchair. The conductors and interdigital patterns are printed with silver-based ink. A blend of a non-conductive and a low resis­tive ink is used for customized resistance for an optimal sensing range of the pressure sensor. The effect of moisture and temper­ature are realized in an environment chamber. For characterization, other key performance tests such as repeatability, drift and flexibility are carried out. The surface morphology is carried out for structural analysis of printed samples. The sensor data is acquired and processed using an 8-bit ATmega-2560 micro­controller and wirelessly transmitted to a PC for post-processing, storage and analysis. For real-time data presentation of dis­tributed pressure points, a GUI has been developed to display the values ob­tained from the large area sensor. The detection of four sit­ting pos­tures; forward leaning, backward leaning, left leaning and right leaning along with a normal sitting posture is attained. An analysis for stretchable printed tracks has been conducted to investigate the changes in electrical resistance using elon­ga­tion tests, surface morphology and EDS. The optimal curing time and tem­per­ature were investigated to manufacture stretchable conductive tracks. In summary, the contributions in this thesis provides an effective approach regarding pressure distribution measurement and recognizing irregular sitting postures for wheelchair users.

Vid tidpunkten för framläggningen av avhandlingen var följande delarbete opublicerat: delarbete 3 (accepterat).

At the time of the defence the following paper was unpublished: paper 3 (accepted).

Thesis (MTech( Electrical Engineering)) -- Cape Peninsula University of Technology, 2012
Due to the complex design of existing electric mobility vehicles in South Africa and their imported parts, make them unaffordable to the majority of disabled people in South Africa. The traditional electric units are also not practical for use in rural areas due to the heavy, bulky design. The scope of this study was to investigate various designs using existing wheelchair frame designs, low cost three phase hub motors and various electronic techniques to achieve the desired functionality. An attempt was be made to remove inefficient and expensive DC brush motors and the gear boxes associated with the traditional design of wheelchairs, while still allowing the unit to fold like the traditional manual chair design. One of the aims for this electric wheelchair was to utilise existing large radius wheels, typical of manual wheelchairs and a modified traditional frame design, providing the clearance often necessary to overcome rough terrain whilst enabling the chair to be used as a manual wheelchair should the battery fail. One of the primary aims of the project was to develop a method for an electric assist feature built into the modified electric wheelchair, whereby the force applied to the manual pushrims on the wheels would be measured and the electric component would proportionally assist the user. This option suits the users who are weak but not physically disabled. One of the many focal points here would be on HIV/AIDS patients, which is prevalent in South Africa, who may require a wheelchair when debilitated with this disease. The electric assist portion of the design would act similarly to a wireless self-powered torque sensor, allowing for an array of applications besides the electric assist portion of this project. A recent survey by National Government indicated that over 85% of wheelchair users only generated an income of between R0 – R500 per month. Low state disability grants and wage figures for disabled and HIV/AIDS patients mean that electric mobility vehicles have become a luxury rather than an essential commodity in South Africa. The need for cheap electric wheelchairs that could cope with the rural terrain and could be fitted onto existing manual wheelchairs offering the full manual operation should the batteries go flat, was clearly apparent. The cost of an electric wheelchair ranges from R18 000 with more advanced models escalating in price to well over R150 000. These prices were typically the result of the complexity of the unit and local wheelchair manufacturers having to import 80% of their parts from abroad. The largest local manufacturer is CE Mobility which is the dominant mobility vehicle supplier in Southern Africa and has the only SABS approved units for sale. Our complete redesigned wheelchair including the manual frame supplied by an existing supplier would only cost R9 000. A prototype demonstrated that is was possible to build a wheelchair that meets all these criteria. A cost effective unit could provide a solution to assist and enable economically challenged and disabled people in rural areas of Southern Africa.

Thesis (Ph.D)--Bioengineering, Georgia Institute of Technology, 2010.
Committee Chair: Sprigle, Stephen; Committee Member: Brani Vidakovic; Committee Member: Charlie Lachenbruch; Committee Member: John L. Lin; Committee Member: Rudy Gleason. Part of the SMARTech Electronic Thesis and Dissertation Collection.

A quick-connect wheelchair power add-on unit (PAU) has been developed at the Human Factors Engineering Center of Virginia Tech. The objective of the new invention is to provide an inexpensive, highly portable product which can quickly convert a manual wheelchair into a power-operated wheelchair. This dissertation details the three year research and design effort to develop the new wheelchair PAU. Results are presented from a series of evaluations conducted to identify performance and user-interaction characteristics of the PAU. Interpretation of the results provides a prioritized list of identified design deficiencies along with wheelchair expert and design team suggestions for the next generation of design alterations. The three evaluations conducted with the second generation PAU prototype include a series of wheelchair expert interviews, a PAU performance evaluation, and a usability evaluation which utilized wheelchair operators as subjects. Also included in the dissertation is an explanation of the need for a new PAU, a description of the most recent design iteration, a literature review containing information about the history of wheelchairs, the condition of the current PAU market, and an analysis of wheelchair PAU consumers. The new invention was conceived and patented by Dr. John G. Casali of the Industrial and Systems Engineering (ISE) Department at Virginia Tech. This research was supported jointly by Southwestern Applied Technologies, L. C., of Roanoke, Virginia and Virginia's Center for Innovative Technology in Herndon, Virginia.
Ph. D.

Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2010.
This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
Cataloged from student submitted PDF version of thesis.
Includes bibliographical references (p. 79-81).
This work addresses the fundamental problem of how a robot acquires local knowledge about its environment. The domain that we are concerned with is a speech-commandable robotic wheelchair operating in a home/special care environment, capable of navigating autonomously to a verbally-specified location in the environment. We address this problem by incorporating a narrated guided tour following capability into the autonomous wheelchair. In our method, a human gives a narrated guided tour through the environment, while the wheelchair follows. The guide carries out a continuous dialogue with the wheelchair, describing the names of the salient locations in and around his/her immediate vicinity. The wheelchair constructs a metrical map of the environment, and based on the spatial structure and the locations of the described places, segments the map into a topological representation with corresponding tagged locations. This representation of the environment allows the wheelchair to interpret and implement high-level navigation commands issued by the user. To achieve this capability, our system consists of an autonomous wheelchair, a person- following module allowing the wheelchair to track and follow the tour guide as s/he conducts the tour, a simultaneous localization and mapping module to construct the metric gridmap, a spoken dialogue manager to acquire semantic information about the environment, a map segmentation module to bind the metrical and topological representations and to relate tagged locations to relevant nodes, and a navigation module to utilize these representations to provide speech-commandable autonomous navigation.
by Sachithra Madhawa Hemachandra.
S.M.

The Emotiv Insight is a commercially available, low-cost, mobile EEG device that is commonly overshadowed by its costlier counterpart, the Emotiv EPOC. The purpose of this report is to investigate if the Emotiv Insight is a suitable headset to be used as a controlling factor in conjunction with an Arduino microcontroller and various electrical components that are used towards the development of an open-sourced, affordable electric wheelchair with the primary goal of providing those who either do not have the financial resources or the physical capability to operate a traditional wheelchair due to their disability a viable option to improve their quality of life. All of the C++ code, STL files used to fabricate the 3d-printed components are uploaded to a GitHub repository as open sourced files to allow individuals with access to a 3d-printer to either build the open sourced wheelchair for their personal use, or refine the design to suit their needs.

Diploma thesis deals with design of electric wheelchair. Final product is standing on the bases from the designer and technical analysis. The main goal is to create electric wheelchair with a charakteristic appearance, that will respect user health condition and ergonomic and technical parameters as well.

A power assisted wheelchair combines human power, which is delivered by the arms through the pushrims, with electrical motors, which are powered by a battery. Today’s electric power assisted wheelchairs use force sensors to measure the torque exerted on the pushrims by the user. The force sensors in the pushrims are rather expensive and this approach also makes the wheels a little bit clumsy. The objective with this project is to find a new, better and cheaper solution that does not use expensive force sensors in the pushrims. The new power assisted wheelchair will instead only rely on its velocity, which is measured with rotational encoders, as feedback signal and thereby the project name “Torque Sensor Free Power Assisted Wheelchair”.

The project consisted of two main parts; an extensive construction part, where an ordinary joystick controlled motorized wheelchair has been rebuild to the new power assisted wheelchair without torque sensors and a development part, where different torque sensor free controllers has been designed, simulated, programmed and tested.

The project resulted in a torque sensor free power assisted wheelchair, where the final implemented design is a proportional derivative controller, which gives a very good assisting system that is robust and insensitive to measurement noise. The proportional derivative control design gives two adjustable parameters, which can be tuned to fit a certain user; one parameter is used to adjust the amplification of the user’s force and the other one is used to change the lasting time of the propulsion influence.

Since the new assisting control system only relies on the velocity, the torque sensor free power assisted wheelchair will besides giving the user assisting power also give an assistant, which pushes the wheelchair, additional power. This is a big advantage compared to the pushrim activated one, where this benefit for the assistant is not possible.

In the design of autonomous mobile robots, databases have been used mainly to store information on the environment in which the device is to operate. For most of the models and ready systems, the database when used, is not a stand alone component in the system, rather it is only intended to keep static information on the disposition and properties of objects on the map.

The goal of this diploma thesis is design of the electric wheelchair. The purpose is designed with knowledge of historic and todays devices for handicapped people. The design respects aesthetic, ergonomic and technical requirements. The electric wheelchair would go over the usual obstacles, would be solution of long sitting problems and also have an interesting and modern feel.

This graduation theses is engaged in design of additional module to wheelchair. The project should bring new solution of shape of the equipment, but at the same time keep the original frame. Final solution has sporty look and it results from inner construction and stifles sanitary sterility.

Orientador: Franco Giuseppe Dedini
Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecânica
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Resumo: Neste trabalho foi estudada a modelagem do contato roda-piso e a teoria de controle de uma cadeira de rodas. Logo, para complementar os testes e estudos, foi desenvolvido um laboratório virtual objetivando o estudo da dinâmica veicular e da modelagem do contato roda-piso. Esse laboratório, criado em programas multicorpos como o Working Model 2D ® e o MSC Adams?, foi usado para a visualização do comportamento dinâmico de uma cadeira de rodas em diversas situações. Nesta aplicação, observa-se que as características dos pneus são alguns dos parâmetros mais importantes da modelagem do contato roda-piso de um veículo. Deste modo, para a obtenção desses parâmetros foi construída uma bancada experimental. Esta bancada experimental é constituída basicamente de uma mesa fixada por células de cargas e uma estrutura onde a roda é presa. Vários testes experimentais foram propostos e os parâmetros, ou seja, as características do pneu foram levantados, implementados e comparados entre si, através de imagens e gráficos. Para o estudo da teoria de controle, foi construído um protótipo funcional de uma cadeira de rodas motorizada no qual o principal objetivo é seguir uma linha desenhada no chão. A utilização de sensores, microcontroladores e estratégias de controle foram necessárias a fim de atingir este alvo. Diferentes tipos de controle robusto foram simulados levando em consideração as características do pneu e o controlador PID foi implementado no protótipo funcional apresentando resultado satisfatórios ao seguir uma trilha desenhada no chão
Abstract: In this work was studied the model of the contact between the tire and the ground and the control theory of a wheelchair. Thus, for the tests and studies was developed a virtual laboratory for the dynamic vehicle and the contact between tire and ground model. This laboratory was created in a multibody program as Working Model 2D® and MSC Adams®, also was used to visualize the dynamic behavior of a wheelchair in various situations. The characteristics of tires are the most important parameters of the contact between ground and tire, so for that an experimental device was built. This test rig consists basically of a table fixed by the load cells and a structure where the wheel is attached. Several experimental tests have been proposed and the parameters or the characteristics of a tire were investigated, compared and implemented with each other by images and graphs. For the control theory was built a prototype of a electric wheelchair in which the main objective is to follow a path drawn on the floor. For this goal was necessary to use sensors, microcontrollers and control strategies as a PID
Doutorado
Mecanica dos Sólidos e Projeto Mecanico
Doutor em Engenharia Mecânica

Tato diplomová práce představuje koncept elektrického invalidního vozíku ovládaného lidskou myslí. Tento koncept je určen pro osoby, které elektrický invalidní vozík nemohou ovládat klasickými způsoby, jakým je například joystick. V práci jsou popsány čtyři hlavní komponenty konceptu: elektroencefalograf, brain-computer interface (rozhraní mozek-počítač), systém sdílené kontroly a samotný elektrický invalidní vozík. V textu je představena použitá metodologie a výsledky provedených experimentů. V závěru jsou nastíněna doporučení pro budoucí vývoj.

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CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
Currently, diverse existing training environments help new users of electric powered wheelchairs (EPW) learn how to drive, acquaint and improve their abilities with these assistive devices. Several authors are developing such environments, and most of them use virtually simulated wheelchairs. Despite the similarities between virtual and real wheelchairs, it is easier to drive the real device because representation of the wheelchair physical behavior is still a problem for virtual simulated environments. Concerning the driving methods, most of them are based on a joystick, which does not give the opportunity for users to test, practice and acquaint themselves with new technologies, such as driving through eye movements. This work implements and tests a more realistic approach for a training environment dedicated to new users of EPW. The proposed system is based on a real EPW controlled by teleoperation, and it is flexible enough to attend to multiple driving methods. An architecture that allows a user to send command messages to control a real EPW through the Internet was implemented to validate the system. The implemented driving methods were conventional joystick, eye-tracker and a generic human-machine interface. For the system’s evaluation, scenarios were created considering the implemented driving methods, and also scenarios considering a long distance teleoperation. The experimental results suggest that new users can practice safely using a real EPW through the Internet, even in a situation with a communication delay of 130.2 ms (average). Furthermore, the proposed system showed potential for attending new EPW users with different types of disabilities and to be a low-cost approach that could be applied in developing countries.
Atualmente, diversos ambientes de treinamento existentes ajudam novos usuários de cadeira de rodas motorizada (CRM) a aprender a comandar, se familiarizar e aprimorar suas habilidades. Vários autores estão desenvolvendo esses ambientes, e a maioria deles está usando CRM virtualmente simulada. Apesar das semelhanças entre a CRM virtual e a real, observouse que é mais fácil comandar o dispositivo real. Isso ocorre porque nesses ambientes virtuais, a representação do comportamento físico da CRM ainda é um problema. Outro aspecto observado, foi a respeito dos métodos de condução, onde a maioria dos trabalhos utiliza apenas o joystick. Porém, esse método não oferece a oportunidade a usuários com deficiência severa de aprender a comandar a partir de novas tecnologias, como por exemplo, o rastreamento ocular. Para superar essas dificuldades, este trabalho propõe, implementa e valida uma abordagem mais realista, a qual é baseada em treinamento por teleoperação e por múltiplos métodos de condução. Foi implementada uma arquitetura que permite ao usuário enviar comandos remotamente para comandar uma CRM real a longas distâncias. Os métodos de condução implementados foram por joystick, eye-tracker e por meio de uma interface humanomáquina genérica. Para a avaliação do sistema, foram criados cenários considerando diferentes configurações. Os resultados experimentais sugerem que novos usuários podem praticar com segurança utilizando uma CRM real através da Internet, mesmo em uma situação com delay de 130,2 ms (média). O sistema proposto mostrou potencial em atender novos usuários de CRM com diferentes tipos de deficiência, bem como de ser uma abordagem de baixo custo com possibilidade de ser aplicada em países em desenvolvimento.

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O presente trabalho de pesquisa consiste na concepção de um veículo motorizado elétrico modular de acoplamento universal em qualquer modelo de cadeira de rodas mecanomanual. Trata-se de um equipamento eletro-mecânico, disponibilizado em forma de acessório, com estrutura física simplificada e alta tecnologia eletrônica aplicada capaz de proporcionar ao cadeirante maior liberdade de movimentação sem desgastes físicos. A aliança entre o design inclusivo e a área médica pode se relevar um passo importante na obtenção de produtos direcionados para as necessidades reais de pessoas com condições físicas e psíquicas particulares, melhorando o seu bem-estar e capacidade de execução de atividades no dia a dia. Desta forma, o presente trabalho é direcionado pelos fundamentos do design inclusivo com o principal ponto focal no usuário, mas que apresenta outros dois importantes pilares adotados em sua metodologia de desenvolvimento, sendo eles, o benchmarkig e o estudo de Normas Técnicas aplicadas no desenvolvimento de equipamentos assistivos. São apresentadas as etapas de desenvolvimento, ensaios com base em Normas Técnicas e teste de usabilidade. Busca-se evidenciar todo o processo de design de equipamento, assim como o estudo teórico de estabilidade e montagem do protótipo funcional. Os ensaios baseados na Norma Técnica ABNT NBR ISO 7176 permitem o entendimento do comportamento dinâmico e funcional do protótipo em termos de estabilidade estática, eficácia dos freios, consumo de energia, velocidade máxima, aceleração, desaceleração e capacidade de transposição de obstáculos. Por fim, discute-se a análise de resultados dos ensaios junto aos resultados teóricos calculados e pré-requisitos estabelecidos.
The thesis consists in the conception of a modular electric motor vehicle that can be attached in any model of standard wheelchair. It is an electro-mechanical equipment, available as an accessory, with a simplified physical structure and high applied electronic technology capable of giving the wheelchair greater freedom of movement without physical wear and tear. The union between inclusive design and the medical field can be an important step in obtaining products aimed at the real needs of people with particular physical and psychological conditions, improving their well-being and ability to do their daily activities. In this way, the thesis is guided by the fundamentals of inclusive design with the main focal point in the user, by the way presents two other important pillars adopted in its development methodology, being the benchmarkig and the study of Technical Standards applied in the development of Assistive devices. The stages of development are presented, tests based on Technical Standards and usability testing. The aim of this work is to demonstrate the whole process of equipment design, as well as the theoretical study of stability and assembly of the functional prototype. The tests based on the Technical Standard ABNT NBR ISO 7176 allow the understanding of the dynamic and functional behavior of the prototype in terms of static stability, brake efficiency, power consumption, maximum speed, acceleration, deceleration and obstacle transposition capacity. Finally, we discuss the analysis of the results of the tests together with the calculated theoretical results and established prerequisites.

Nowadays, oil resources start to decrease, therefore it is necessary to think about alternative sources of energy. The result of this semester project is a basic overview of the current development of electric and hybrid cars, with potential application in normal operation and the proximity of their main characteristics, such as mileage, price and service when traveling. The energy required to operate the electric stored in batteries are recharged using the power stations, which is also devoted part of the work. The thesis focuses on the design and calculation of power consumption for a defined route of four-wheel electric wheelchair. The conclusion of the thesis deals with the future development of hybrid and electric vehicles, and with the expected trends in the field of power electronics and motors and with the propagation of hybrid vehicles to the customers.

L’objectif du travail de cette thèse est la contribution au développement de nouvelles techniques dans le domaine dessystèmes de détection sans marqueur pour une utilisation dans trois domaines vitaux de la santé en utilisant des capteursinnovants et peu coûteux. Pour la réalisation de nos objectifs nous avons eu recours principalement à de l’électroniqueembarquées et du traitement du signal en utilisant le capteur Kinect. Des résultats encourageants ont été obtenus et sontprésentés tout au long de cette thèse. Dans la première partie de ce travail, nous présentons un nouveau système desurveillance visuelle sans marqueur en temps réel pour détecter et suivre les personnes âgées et surveiller leurs activitésdans leur environnement intérieur en utilisant un réseau de capteurs Kinect. Le système identifie également l’événementde chute des personnes âgées sous surveillance. Dans la deuxième partie nous utilisons également le capteur Kinectmais cette fois ci pour la détection sans marqueur des mouvements de la tête d’un patient lors d’un examen utilisant LaTomographie par Emission de Positons (CT/PET) du cerveau. Ce travail est basé sur la compensation de la dégradationde l’image TEP due aux mouvements de la tête du patient. Pour nos essais un cobaye dit « fantôme » a été réalisé,les résultats sur le fantôme sont prometteur ce qui a donné lieu à un test sur un vrai patient volontaire. Les résultatsfinaux montrent l’efficacité de ce nouveau système. La troisième partie du travail présente la mise en oeuvre d’un nouveausystème intelligent pour contrôler un fauteuil roulant électrique par des mouvements spéciaux de la tête toujours sansmarqueur. Un algorithme adapté est conçu pour détecter en continu les degrés des mouvements du visage en utilisant lecapteur Kinect. Fautes de fauteuil roulant électrique, le système a été testé sur un véhicule radio commandé
The objective of the work of this thesis is the contribution in developing novel technical methods in the field of marker-lesssensing systems for use in three vital health areas by using new inexpensive sensors. Several scientific areas are involvedin achieving our objective such as; electronics and signal processing by using the Kinect sensor. Encouraging results wereachieved as presented throughout this thesis. In the first part of this work we present a new real-time marker-less visualsurveillance system for detecting and tracking seniors and monitoring their activities in the indoor environment by usingnetwork of Kinect sensors. The system also identifies the fall event with the elderly. In the second part, we present anew approach for a marker-less movement detection system for influential head movements in the brain Positron EmissionTomography imaging (CT/PET) by employing the Kinect sensor. This work addresses the compensation of the PET imagedegradation due to subject’s head movements. A developed particular phantom and volunteer studies were carried out.The experimental results show the effectiveness of this new system. The third part of the work presents the design andimplementation of a new smart system for controlling an electric wheelchair by special mark-less head movements. Anadaptable algorithm is designed to continuously detect the rotation degrees of the face pose using the Kinect sensor inreal-time that are interpreted as controlling signals through a hardware interface for the electric wheelchair actuators

by Hon Nin Chow.
Thesis (M.Phil.)--Chinese University of Hong Kong, 2003.
Includes bibliographical references (leaves 79-84).
Abstracts in English and Chinese.
Chapter 1 --- Introduction --- p.1
Chapter 1.1 --- Motivation --- p.1
Chapter 1.2 --- Organization of the Thesis --- p.3
Chapter 2 --- Literature Survey --- p.6
Chapter 2.1 --- Learning-by-Demonstration --- p.6
Chapter 2.2 --- Neural Networks --- p.7
Chapter 2.3 --- Navigation Learning --- p.8
Chapter 2.4 --- Localization --- p.9
Chapter 2.5 --- Robotic Wheelchair --- p.10
Chapter 3 --- System Implementation --- p.12
Chapter 3.1 --- Hardware Platform --- p.12
Chapter 3.2 --- Software Platform --- p.14
Chapter 3.3 --- Basic Functionality --- p.15
Chapter 3.3.1 --- Collision Avoidance --- p.15
Chapter 3.3.2 --- Wearable Eye-jaw Control Interface --- p.16
Chapter 4 --- Learning Human Navigational Skill --- p.22
Chapter 4.1 --- Introduction --- p.22
Chapter 4.2 --- Problem Formulation --- p.23
Chapter 4.3 --- Approach --- p.23
Chapter 4.4 --- Experimental Study --- p.26
Chapter 4.4.1 --- Settings --- p.26
Chapter 4.4.2 --- Results --- p.30
Chapter 4.5 --- Discussions --- p.31
Chapter 5 --- Learning from Multi-phase Demonstrations --- p.33
Chapter 5.1 --- Introduction --- p.33
Chapter 5.2 --- Problem Formulation --- p.34
Chapter 5.3 --- Approach --- p.35
Chapter 5.4 --- Experimental Study --- p.35
Chapter 5.4.1 --- Settings --- p.35
Chapter 5.4.2 --- Results --- p.37
Chapter 5.5 --- Evaluation of Learning Performance --- p.37
Chapter 5.6 --- Discussions --- p.43
Chapter 6 --- Localization Learning --- p.44
Chapter 6.1 --- Introduction --- p.44
Chapter 6.2 --- Problem Formulation --- p.45
Chapter 6.3 --- Approach --- p.45
Chapter 6.4 --- Experimental Study --- p.46
Chapter 6.4.1 --- Settings --- p.46
Chapter 6.4.2 --- Result 1: Localization Performance --- p.47
Chapter 6.4.3 --- Result 2: Similar Sensor Patterns in Various Configurations . --- p.53
Chapter 6.4.4 --- Result 3: Small Variations in Major Dimensions of Environ- mental Feature along the Route --- p.53
Chapter 6.5 --- Discussions --- p.59
Chapter 6.5.1 --- Accuracy --- p.59
Chapter 6.5.2 --- Choices of Sensor-Configuration Mappings --- p.60
Chapter 7 --- Conclusion --- p.62
Chapter 7.1 --- Contributions --- p.62
Chapter 7.2 --- Future Work --- p.65
Chapter A --- Cascade Neural Network --- p.67
Chapter B --- Trajectories for the Navigation Learning in Chapter 4 --- p.69
Chapter C --- Publications Resulted from the Study --- p.78

碩士
國立交通大學
電機學院電機與控制學程
102
A Gesture Recognition and control system is developed in this paper. The system is applied to control remote electric wheelchairs with natural gestures. The way users control remote electric wheelchairs is similar with the way users control general wheelchairs. Gesture Recondition dependents on motion of hands and open-closed hands detection, then the system generates command according to gestures. The motion of hands bases on particle filter tracking which selects proper features to tolerate shape change. While hands tracking, the system has specific handling methods to avoid hands interference and overcome tracking fail due to environment lighting change. The experiment results show that the system is suitable to control remote electric wheelchairs. It also has good performance in efficiency, accuracy and the ability to resist interferences in different events.

The use of a commercial powered wheelchair during daily activities by people with motor limitations provides autonomy, increasing quality of life. For people with more severe restrictions, specifically reduced handling, the use of the powered wheelchair may be compromised as they cannot control the joystick with the required ability. This work is intended to give these people the ability to drive comfortably and safely their electric wheelchair. This proposal for adapting a commercial powered wheelchair has essentially two main objectives. The first one is to allow people who cannot drive a conventional powered wheelchair because they have muscle weakness in their upper limbs to do so. So, and to facilitate the wheelchair navigation, three modes of operation are proposed. Therefore, the adapted wheelchair controller must able translate the new impulses provided by the joystick, depending of the user abilities, in direction commands. Driving the powered wheelchair continuously can quickly become a stressor. Thus, the second goal is to ensure that during the powered wheelchair driving, its user always remains in a calm state, avoiding harming their well-being and their health. It is thus proposed to insert a system for monitoring the emotional state of the wheelchair user. The primary purpose of this system is to alert its user when he reached critical emotional levels, which makes it impossible to continue driving safely. In this situation the wheelchair controller becomes responsible for the wheelchair command. The implementation of the stress detection system was based in the galvanic skin response and heart rate sensors. With the acquired information, it was defined the user’s emotional profile and evaluated several algorithms classification to predict new emotional states. This system was tested by two users groups. The first group consisted of drivers driving cars and the second group consisted of tetraplegic people driving their powered wheelchair. For people without disabilities, it was confirmed through biometric signals that each person reacts differently to the same situations. This difference is most striking in the response of skin conductivity. For tetraplegic people, we concluded and confirmed, that the sympathetic nervous system response cannot be measured by galvanic skin response. Several classification algorithms were trained for stress detection in realtime. For each user, the best classifying model was found. We conclude that the best models vary from person to person and also depend on the number and type of predictors used. This work results from the collaboration of the University of Aveiro and the Centro de Reabilitação e Medicina da Região Centro - Rovisco Pais.
O uso de uma cadeira de rodas elétrica durante as atividades do quotidiano por pessoas com limitações motoras proporciona autonomia, aumentando qualidade de vida. No caso de pessoas com limitações mais severas, nomeadamente com manipulação reduzida, a utilização da cadeira de rodas elétricas pode estar comprometida, pois não conseguem controlar o joystick com a destreza necessária. Este trabalho pretende proporcionar a essas pessoas a possibilidade de conduzir a sua cadeira de rodas elétrica de uma forma confortável e segura. Esta proposta de adaptação de uma cadeira de rodas elétrica tem essencialmente dois grandes objetivos. O primeiro é permitir a pessoas que não conseguem conduzir uma cadeira de rodas elétrica convencional por sofrerem de fraqueza muscular nos membros superiores, o comecem a fazer. Assim, para facilitar a condução da cadeira, propõem-se três modos de operação. Além disso, o controlador da cadeira adptada vai ter que ter a capacidade de interpretar os novos impulsos dados no joystick, que dependem das capacidades de manipulação de cada utilizador, em comandos de direção. A condução da cadeira de forma consecutiva pode-se tornar rapidamente um fator de stress. Assim, o segundo objetivo ´e garantir que, enquanto a pessoa conduz a cadeira se mantenha sempre num estado calmo, evitando prejudicar o seu bem-estar e consecutivamente, a sua saúde. E assim proposto a integração de um sistema de monitorização do seu estado emocional durante a condução da cadeira. Este sistema tem como principal objetivo alertar o utilizador que este atingiu níveis emocionais críticos que inviabilizam a continuação da condução em segurança. Nesta situação, quem passa a ficar responsável pelo comando da cadeira é o próprio controlador da cadeira. A implementação do sistema baseou-se no uso de sensores de resposta galvânica e de batimento cardíaco. Com a informação adquirida por estes sensores, definiu-se o conceito de perfil emocional do utilizador e foram avaliados algoritmos de classificação de stress capazes de prever diferentes estados emocionais. Este sistema foi testado por dois grupos de utilizadores. O primeiro grupo foi composto por condutores a conduzirem automóveis e o segundo grupo foi composto por pessoas tetraplégicas, a conduzirem as cadeiras de rodas elétrica pessoais. Para pessoas sem deficiência confirmou-se, através dos sinais biométricos, que cada pessoa reage de forma diferente perante as mesmas situações. Esta diferença é mais flagrante na resposta da condutividade da pele. No que diz às pessoas tetraplégicas, confirmou-se que a resposta do sistema nervoso simpático não pode ser medida através da resposta galvânica da pele. Para a implementação da deteção de stress em tempo real foram usados diversos algoritmos de classificação. Para cada utilizador, foi encontrado o melhor modelo de classificação. Conclui-se que os melhores modelos variam de pessoa para pessoa e que também dependem do número e tipo de preditores utilizados. Este trabalho resulta da colaboração entre a Universidade de Aveiro e o Centro de Medicina de Reabilitação da Região Centro - Rovisco Pais.
Programa Doutoral em Engenharia Eletrotécnica

M. Tech. Electrical Engineering.
Modelizes, simulate and analyse the behaviour of an ordinary manual propelled wheelchair (MPW) when equipped with a mechatronic drive module. This serves as a preliminary study towards investigating whether a suitable mechatronic drive module could be designed and easily plugged on an ordinary MPW without any difficulties to obtain full propulsion of the chair with the use of a joystick for navigation purposes. For modelling purposes, a dynamic systems modelling method called Bond Graph was used.

M. Tech. Electrical Engineering.
Wheeled Mobile Platforms have considerable acceptance and dominance in the field of transportation. While most of these platforms have been designed for able users, very few special designs are available for the physically disabled persons. With increasing numbers of disabled peoples around the world, accommodative and safer displacement means are called for. A normal wheelchair platform with two front castor wheel and two independently driven rear wheels is therefore considered in this study for modelling and control. Based on the nature of persons using wheelchairs, better and much easy to control wheelchair platforms are necessitated. To achieve such objective, this research is focused on two main threads: dynamic modelling and control. In modelling, the aim is to present a dynamic model of wheelchair platform that takes into account slipping parameters and frictional/traction forces experienced on motion. It also intends to account for the effects of gravitational forces that would be experienced by the wheelchair and its effect on the platforms during uphill and downhill movements. Lagrange formalism is utilised in the design of this dynamic model. In control, the objective is to ensure that the platform tracks the reference linear velocity and the reference angular orientation as desired. With such control commands, a simple access device may be employed to ensure that people with severe disability also have a chance of controlling the wheelchair. Since no zero dynamics arise with linear velocity and angular orientation as the platforms outputs, standard input-output feedback linearisation is considered and applied in the linearisation of the model and in the development of the control law. Successfully simulated results demonstrating the performance of the proposed dynamic model and control law are presented for verification. The entire dynamic model and the controller are simulated in a software tool MATLAB and SIMULINK.

M. Tech. Electrical Engineering
Determines whether Hidden Markov models (HMM) can be used to classify steady state visual evoked electroencephalogram signals in a BCI system. This is for the purpose of aiding disabled people in driving a wheelchair.

M. Tech. Electrical Engineering.
Discusses how to develop the kinematic and dynamic model and the controller for the 2-DOf motion platform used in an augmented reality environment for wheelchair driving. This comes as a motivation to help to train disabled and elderly people to drive wheelchairs.. With accurate inverse dynamic model, it is possible to achieve high performance control algorithms of robots and direct dynamic model is required for their simulation. The other part of this research was to model and control the roller for the feedback of the wheelchair wheels.

碩士
國立高雄大學
國際高階經營管理碩士在職專班(IEMBA)
107
In the face of rising global trade disputes, frequent changes in central banks' monetary policies, and rising international energy and raw material prices and so on, electric wheelchairs and electric scooters are under great pressure. In addition, the industry players are faced with the situation of domestic demand market saturation and international price cut competition, and the industry is mostly foundry, lacking in design and development capabilities and lack of access to further development of the channel model, resulting in inevitable vicious competition. This industry has faced great competitive pressures and must develop more differentiated marketing strategies. This study is mainly to explore how the electric wheelchairs and electric scooters industry players should examine their own strengths and weaknesses and opportunities, threats, grasp market opportunities and continue to create profit for the company. Therefore, taking W company as an example, using semi-structured interviews to collect data, conduct SWOT analysis, understand the advantages, disadvantages, opportunities and threats of case company, and propose strategies such as attack, protection and reinforcement through cross-analysis. In addition, this study also uses the buyer's benefit matrix analysis as a basis for assessing the business model of a case-raising company in the future, and proposes to strengthen the competitiveness of the case company. After analysis of this case study, it is found that although the case company has a unique profit model, in the face of changes in the big environment, the old profit model is not enough to resist external threats, and it is necessary to develop a new state service model. Combining the soft powers of marketing, design, and APP application development, we will achieve the goal of sustainable development and long-term success.

D. Tech. Electrical Engineering.
Developes a wheelchair motion platform whereby its user may be introduced into a simulated world. This simulated world is then required to be closely related to real world spaces that will be encountered by a disabled person using a wheelchair as a mobility aid. The wheelchair to be accommodated in the simulation environment may have multiple mechanical construct possibilities. The wheelchair used on the simulation platform needs to be driven by a combination of two wheels, as is generally found on manual and electric wheelchairs. The final objective was to design the simulation as closely as possible to the real world in order to use the VS-1 motion platform for architectural evaluations, possible training and general research in the field of simulators used in an enabled environment.

M. Tech. Electrical Engineering.
Investigates a new approach of wheelchair control, based on the user behaviour recognition. This objective involves two steps in the resolution of the problem. The first step is to determine the action the user initiates. Therefore, the present study will mostly refer to literatures on car driver behaviour modelling, as several studies have been conducted in that domain. The proposed model of user's behaviour presented here is based on probabilistic graphical model, for instance, Bayesian network. The second step is the generation of an assistive control signal that will compensate the user input, depending on the driving task inferred by the Bayesian network.Experiments have been conducted on a virtual environment model developed in Matlab and several users participated to the experiments. The results show a great potential of Bayesian Network model to infer on human behaviour and also a satisfying output from the ANFIS model as it delivers signals following the user's behaviour.

D. Tech. Electrical Engineering.
Proposes a vision-based solution for intention recognition of a person from the motions of the head and the hand This solution is intended to be applied in the context of wheelchair bound individuals whose intentions of interest are the wheelchairs direction and speed variation indicated by a rotation and a vertical motion respectively. Both head-based and hand-based solutions are proposed as an alternative to solutions using joysticks pneumatic switches, etc.

M. Tech. Electrical Engineering.
The hypothesis states that a closed loop control system could be applied to a mechatronic system consisting of a mechanical device(s) to be fitted onto the user, and other relevant periphery mechanical devices, appropriately actuated to provide powered movement to assist the wheelchair-bound individual securely attain a standing position.The premise upon which the hypothesis was to be tested relates to the control system's ability to facilitate the upward movement proposed and its degree of stability when simulating the system, thus re-creating the anticipated functionality.

碩士
大葉大學
車輛工程學系碩士班
96
Due to the aging of our society, the electric powered wheelchairs become more and more needed. However, the electric powered wheelchairs on the market currently are bulky, heavy, and costly. The present thesis focuses on the feasibility of converting a self-propelled wheelchair into a lightweight electric powered wheelchair by adding a hub motor to one of its rear wheels. The commercial code ADAMS was used to predict the motion of the wheelchair and a lightweight electric powered wheelchair was fabricated to perform the road test. The results show that the outcomes of simulations and road tests are in good agreement and this lightweight electric powered wheelchair is feasible and deserves further development and commercialization

碩士
國立成功大學
電機工程學系
102
1.SUMMARY Based on the technology of high-efficiency dual-core embedded systems, the authors propose an integrated electric-powered wheelchair system that integrates related hardware peripherals and sensors such as Wi-Fi adapters, electric wheelchair motors, linear actuators and wireless video transmissions. To transmit video immediately and effectively, a JPEG image is compressed and encoded on a dual-core embedded system platform using a codec engine software architecture approach. The hardware configuration technology uses shared memory to transfer ARM and DSP data and employs fixed-point calculation on the fixed-point DSP to increase its efficiency of calculation. The advantages of dual-core embedded system platform features and design multithreading achieve the effect of parallel processing. In terms of safety for electric wheelchairs, the system uses the proportional-integral-derivative (PID) control strategy to improve deficiencies in going straight because the dynamic characteristics of left and right wheel speed are different. Furthermore, real-time image transfer allows the images from a wheelchair’s blind side to be transferred to the user’s tablet PC, thus increasing safety. 2.INTRODUCTION In the face of an aging society, many people are experiencing age-caused diseases and gradually losing the ability to move, which means they must rely on electric-powered wheelchairs for independent movement. Currently, the most common type of input device for electric-powered wheelchairs is the joystick, yet people whose hands cannot operate normally are unable to use such a device. Therefore, current research is aimed at finding better input devices for electric-powered wheelchairs. Action identification achieved through voice control [4] and head movement with the use of a webcam [9] are some of the ideas that have been discussed. But these input devices are often designed for a specific disease and are not available for common use among people with all kinds of severe disabilities. Furthermore, the hardware design of these new devices use fixed sets of input, so if there is ever a need to replace other input methods, a lot of effort and time must be spent. In the past, the development of electric-powered wheelchairs mostly focussed on the mechanism—such as the folded vs. the reclining wheelchair—and the integration of the joystick for control was taken for granted. The joystick device is mostly presented as a part of the hardware rather than, weakly, the software. Yet, if an electric-powered wheelchair is assisted by software, integrated with the necessary hardware and updated with an improved mechanism and technique, future electric-powered wheelchairs—whether using external controls or auxiliary interactive features—will match the demands of many different physically challenged groups. With vigorous technology developments, a large number of embedded systems have recently been used in mobile phones, digital cameras, network equipment and even high-level home appliances; smart phones and tablet PCs are becoming more common—almost everyone has one. If we use these devices as a user interface and use Wi-Fi to transmit relevant signals to a microcomputer and the drive circuits associated with electric-powered wheelchairs, then tablet PCs can communicate directly with electric-powered wheelchairs. In this way, tablet PCs may be applied to assist users with control operation and interaction. Moreover, regarding version control, software and firmware can easily be updated in this way. However, people who have lost mental and physical abilities cannot control tablet PCs without specific help. So, we use the Morse code converter [1], [2], [5] (which was developed by our laboratory) as an input device. This device simulates the mouse and keyboard for tablet PCs. People with disabilities can take advantage of various different input switches—for example, mouth control, foot control and head control—and can pass the signal through the Morse code converter to the tablet PC application to manipulate electric-powered wheelchairs. With the assistance of a high-performance micro-controller, we integrate the control circuit with real-time video transmission in addition to other necessary control items (electric wheelchair motor, linear actuator or optical encoder). This transmission will have direct communication with the user’s tablet PC or mobile phone and enable interaction with the user to increase driving safety, thus meeting user’s needs and providing a smart electric-powered wheelchair for users with severe disabilities. 3.MATERIALS AND METHODS Embedded auxiliary within the proposed interactive system for electric wheelchairs allows people with severe physical or mental disabilities to control their electric-powered wheelchairs and is also interactive and multi-functional. Morse code is input through a mouse-controlled switch via a Morse code converter, which converts various signals into signals for mouse or keyboards, thus operating applications in tablet PCs. Then, through PC applications, the electric wheelchair is controlled using Wi-Fi technology and electronic control systems that allow electric wheelchairs to communicate with each other. Among the electronic control systems in this electric-powered wheelchair, two microprocessors are used for system integration—namely, BeagleBoard-xM and STM32F407. The main microprocessor is BeagleBoard-xM, which serves as the main core of the entire electronic control system and is in charge of every peripheral’s state information. Communication between the electric-powered wheelchair and the user’s tablet PC goes through BeagleBoard-xM first; therefore, we use a USB Wi-Fi adapter for two-way communication with the user’s tablet PC. In addition, to allow users to watch ground images from the electric-powered wheelchair, a webcam is added to BeagleBoard-xM to transmit images to the user’s tablet PC in real time. Regarding image transmission, codec engine technology is used to call the BeagleBoard-xM DSP core to take complex calculations to the DSP core and to reach communications between DSP and ARM. The secondary microprocessor is STM32F407, which is developed and designed specially for control; therefore, it plays the role of directly communicating with peripheral control such as motor controllers for the electric-powered wheelchair, linear actuators and rotary encoders. BeagleBoard-xM and STM32F407 are in a master–slave relationship using UART signals for serial transmission. The mobile app we developed allows a graphic interface to use the commercial tablet computer or smartphone as a user control panel using Wi-Fi transmission with SoftAP technology to realise communication with electric-powered wheelchair systems. Moving information and conditions can provide feedback to the user in real time, thus providing guidance assistance and interaction. Graphics interface is available on the tablet computer or smartphone in the market as the user control panel with the mobile app we developed using Wi-Fi transmission with SoftAP technology to realise communication with electric power wheelchair systems. Moving information and condition can provide feedback to the user in real-time and reach its assistance and interaction effects in the way of guiding. 4.RESULTS AND DISCUSSION Experimental results show that this system can effectively transmit images from electric-powered wheelchair systems to tablet PCs or smartphones for display using Wi-Fi wireless transmission. For instance, taking a resolution of 320 × 240 as an example, the executive speed of the electric-powered wheelchair system can handle approximately 29.4 frames per second, while the receiving end of the user’s tablet PC can receive 27.6 frames per second. The control system of an electric-powered wheelchair uses a PID controller to adjust appropriate parameters and obtain stability; this is achieved after two rounds. In one experiment, subjects with body weights of 74 and 81 kg, respectively, used the electric-powered wheelchair system to move a distance of two meters; in both cases, the system had to adjust suitable PID parameters and remain steady and stable without any offset in linear motion. In the case of the 74 kg subject, the average error for two wheels was 0.65 cm; in the case of the 81 kg subject, it was 0.41 cm. 5.CONCLUSION This study combines high-order embedded systems with electric-powered wheelchairs. Considering the popularity of smart phones and tablet PCs, this study proposes a system architecture for smart electric-powered wheelchairs. Wheelchair users benefit from a good user interface and interaction, and caregivers may also use their own smartphones or tablet PCs to view their patient’s operational situation and images in real time. Two microprocessors (i.e. BeagleBoard-xM and STM32F407) are used in the electric-powered wheelchair’s hardware to constitute the entire electrical control system. The more powerful functions and complex work (image transmission, Wi-Fi SoftAP, etc.) are in the charge of BeagleBoard-xM, while STM32F407 is responsible for the control systems of peripherals (wheelchair motor drives, rotary encoders, PID feedback, etc.). With the electric-powered wheelchair user control interface, participants can use their smartphone/tablet system and make use of Wi-Fi transmission to control the wheelchair. The interface application is Android-based, designed in a lightweight software to achieve the best operating effect and to reduce the burden of application resources.

碩士
國立臺灣大學
機械工程學系
85
This research develops an electrical differential for electrical wheelchairs with two motors instead of mechanical differential. The steering function is achieved by the control of differential speed between two motors, whose comm- ands are generated by a simplified differential formula. A digital full- bridge PWM (Pulse Width Modulation) motor driver and a single board controller with the PI control law is designed and implemented with the motorized wheelchair. The performance of the electrical wheelchair is tested successfully with simu- lations and experiments.

碩士
臺灣大學
機械工程學研究所
96
General electric wheelchairs are driven by a high speed motor with reduction gears and differential gears. The design poses several disadvantages because the wheel-chairs are inevitably heavy, big, and less efficient. In this study, a direct-drive brush-less DC rim motor is designed to produce enough torque without other mechanical de-vices. In this way, the electric wheelchair’s functions are enhanced with light weight. The dimensions of the motor are determined by optimal analysis, so the motor is designed with the least cost. The optimal sizes are simulated and verified by finite element analysis. Furthermore, the geometry is modified to reduce the cogging torque and torque ripple. The experiment results show that the performance of the whole wheelchair system is developed, meeting the standards set by this study.

碩士
明志科技大學
工程技術研究所
93
The demand for electric wheelchairs and their performance has increased because the aging of population has become a more serious problem gradually and nearly thirty percent of the elderly have difficulty in walking. Therefore, research and development of advanced control techniques and production of better drive systems become critical in order to improve the performance of electric wheelchairs in motion and provide better driving features such as comfort, safety, and operation functions. VisSim/Embedded Controls Developer was used in this project and digital processor eZdspTM320LF2407 A was made as control core. The design included current feedback and speed feedback to provide perfect speed and torsion for electric wheelchairs. Thus, an integral high performance drive system was created and a field test was conducted.

碩士
南開科技大學
車輛與機電產業研究所
101
Wheelchairs are widely used in the silver-haired and limbs in recent years on aids for people with disabilities, to improve their mobile dexterity, this study design and manufacture a multidirectional movement, four wheel independent suspension and automatically maintain the level of seat's electric wheelchair, enhance the convenience of wheelchair moves and ride comfort. Which can omnidirectional mobile of mechanism, is to four group innovation radiation shaped 12 Group side to free round composed of round group, mix micro-controller manipulation movement policy, and reached with operation who command and to any direction side moved or leads; four round independent shock absorbers part, with wheelchair chassis installed connecting rod and buffer structure, reached with terrain changes and themselves adjustment posted to effect; another seat level keep way, is chassis and seat design two group guide screw Rod institutions, Ground angle, adjust the seat front and rear or left angle in real time, to seat level, its control by means of three-axis accelerometers capture signals, via the micro-controller and A/D module processing, achieve a seat automatically balance. Study on mechanical structure and appearance is based on SolidWorks3D software design, and, after a full action simulation, parts production and Assembly.

碩士
國立虎尾科技大學
光電工程系光電與材料科技碩士班
107
This paper uses mobile phone with LinkIt 7697 to control electric wheelchair, write a mobile app program using app Inventor 2, this program has Bluetooth connection, mobile phone positioning, mobile phone Orientation-sensor direction sensor and other functions, after the user opens the app and opens the remote control function, with the rotation of the left and right of the phone, the directional sensor transmits the current posture of the phone to LinkIt 7697, the servo motor driver is then controlled by LinkIt 7697, servo motor mounted on front wheel of electric wheelchair, after receiving the instructions of the drive, you can achieve the action of controlling the front wheel around the phone. The rear wheel of an electric wheelchair is controlled by a dc24v DC motor, transmit the boot signal to the DC motor driver through the mobile app's instructions for moving forward back to LinkIt 7697, mobile phones can control the advance and retreat of wheelchairs, the mobile app also has the speed to control the travel of a wheelchair, divided into five levels from slow to fast. MCS (MediaTek Cloud Sandbox) cloud platform developed by MediaTek, with LinkIt 7697, the current information of the electric wheelchair is transmitted to the MCS through WiFi, use the monitor's mobile app to learn remotely about the status of your current electric wheelchair.

碩士
國立臺灣科技大學
機械工程系
99
The objective of this paper is to develop innovative wheels for the powered wheelchair. This wheelchair’s chassis is equipped with two types of wheel modules. The main function of the front wheel modules is turning, and that of the rear wheel modules is moving forward or sideways so as to overcome the small interior space constraints and to increase the mobility of the wheelchair. Two generations of the rear wheel modules were developed. They both use one motor to achieve two-degree-of-freedom motion by taking the advantage of the one-way bearing. Compared to the traditional omni-wheel design, the wheel module developed in this research is energy-saving and easy to control.