Neuro-sliding mode multivariable control of a powered wheelchair.

This paper proposes a neuro-sliding mode multivariable control approach for the control of a powered wheelchair system. In the first stage, a systematic decoupling technique is applied to the wheelchair system in order to reduce the multivariable control problem into two independent scalar control problems. Then two Neuro-Sliding Mode Controllers (NSMCs) are designed for these independent subsystems to guarantee system robustness under model uncertainties and unknown external disturbances. Both off-line and on-line trainings are involved in the second stage. Real-time experimental results confirm that robust performance for this multivariable wheelchair control system under model uncertainties and unknown external disturbances can indeed be achieved

Non-Metrical Navigation Through Visual Path Control

We describe a new method for wide-area, non-metrical robot navigationwhich enables useful, purposeful motion indoors. Our method has twophases: a training phase, in which a human user directs a wheeledrobot with an attached camera through an environment while occasionallysupplying textual place names; and a navigation phase in which theuser specifies goal place names (again as text), and the robot issueslow-level motion control in order to move to the specified place. We show thatdifferences in the visual-field locations and scales of features matched acrosstraining and navigation can be used to construct a simple and robust controlrule that guides the robot onto and along the training motion path.Our method uses an omnidirectional camera, requires approximateintrinsic and extrinsic camera calibration, and is capable of effective motioncontrol within an extended, minimally-prepared building environment floorplan.We give results for deployment within a single building floor with 7 rooms, 6corridor segments, and 15 distinct place names

Autonomous wheelchair with a smart driving mode and a Wi-Fi positioning system

Wheelchairs are an important aid that enhances the mobility of people with several types of disabilities. Therefore, there has been considerable research and development on wheelchairs to meet the needs of the disabled. Since the early manual wheelchairs to their more recent electric powered counterparts, advancements have focused on improving autonomy in mobility. Other developments, such as Internet advancements, have developed the concept of the Internet of Things (IoT). This is a promising area that has been studied to enhance the independent operation of the electrical wheelchairs by enabling autonomous navigation and obstacle avoidance. This dissertation describes shortly the design of an autonomous wheelchair of the IPL/IT (Instituto Politécnico de Leiria/Instituto de Telecomunicações) with smart driving features for persons with visual impairments. The objective is to improve the prototype of an intelligent wheelchair. The first prototype of the wheelchair was built to control it by voice, ocular movements, and GPS (Global Positioning System). Furthermore, the IPL/IT wheelchair acquired a remote control feature which could prove useful for persons with low levels of visual impairment. This tele-assistance mode will be helpful to the family of the wheelchair user or, simply, to a health care assistant. Indoor and outdoor positioning systems, with printed directional Wi-Fi antennas, have been deployed to enable a precise location of our wheelchair. The underlying framework for the wheelchair system is the IPL/IT low cost autonomous wheelchair prototype that is based on IoT technology for improved affordability

Application of human machine interface research in powered wheelchair

Orientador: Franco Giuseppe DediniDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia MecanicaResumo: Há uma parcela da população que, por possuir severas limitações físicas e motoras, é inapta a utilizar cadeiras de rodas convencionais, manuais ou elétricas, bem como dispositivos de interface que não consideram as suas características particulares. Deste modo, este trabalho possui foco no desenvolvimento de interfaces e sistemas de navegação para cadeiras de rodas, provendo soluções para a inclusão deste grupo de usuários. Para isto, a revisão bibliográfica envolve três aspectos: as interfaces para usuários, os sistemas de navegação e a integração entre ambos. Primeiramente localiza-se a interface como parte da relação entre usuário e tarefa, para posteriormente restringir-se a interfaces para portadores de severas limitações físicas. Reconhecendo que determinados tipos de limitações de usuários demandam sistemas de navegação, estes são descritos na forma de exemplos de implementações. A revisão bibliográfica conclui com a descrição de métodos para a integração entre interface, navegação e controle da cadeira de rodas. Com base nesta pesquisa bibliográfica, desenvolveu-se um protocolo de integração e três tipos interfaces: controle de voz, filtragem do sinal de joystick para usuários com dificuldade em posicionar a mão, e controle por contrações musculares. A interface de reconhecimento de voz permitiu obter dois protótipos: um primeiro que utiliza um software comercial e um segundo em microcontrolador. A interface de filtragem do sinal do joystick foi prototipada virtualmente, demonstrando a resposta deste filtro a diferentes distúrbios. A interface que utiliza controle por contrações musculares foi implementada em protótipo funcional, por meio de um microcontrolador, e modularizada por meio do protocolo de integração desenvolvido. Este protocolo de integração foi testado em um kit de motorização com os módulos joystick, interface por contrações musculares e sonar, permitindo alternar, remover e inserir módulos sem a necessidade de reprogramaçãoAbstract: There is a part of population, with physical impairment, that cannot use conventional manual or powered wheelchair and kinds of interface with do not consider they own characteristics. To solve this problem, this work does a bibliographic review on wheelchair interfaces and navigation support, alloying development on solutions for inclusion of this users group. The bibliographic review embraces three aspects: interfaces and users, navigation support systems, and integration between navigation and interfaces. The first chapter, interfaces and users, localizes the interface as an medium between user and task, allowing to be more focused on next chapter: interfaces for wheelchair uses with severe impairment level. Recognizing about in some kind¿s of user impairment levels an adequate interface is not enough, navigation support systems are described. The bibliographic review concludes with a description about integration methods for interfaces, navigation support and wheelchair control. Based on this bibliographic review, an integration protocol and three interfaces have developed: voice control, joystick filtering for users with difficult on hand positioning, and muscular contraction control. The voice recognition interface allows creating two prototypes: one with commercial software, and a second using embedded microcontroller on wheelchair. The joystick filtering interface was virtually prototyped allowing response tests for different noisy sources. The muscular contraction interface has implemented as functional prototyping, by a microcontroller, and modularized by the developed modularization protocol. This protocol has tested in a wheelchair motorization kit with joystick, muscular contraction interface and auxiliary sonar modules, allowing inserting or removing then without any reprogramming needsMestradoMecanica dos Sólidos e Projeto MecanicoMestre em Engenharia Mecânic

Robotização de uma Cadeira de Rodas

Neste trabalho foi desenvolvido um sistema de controle de baixo nível para uma cadeira de rodas robotizada controlada por sinais biológicos, incluindo hardware (Placa de Acionamento dos motores) e software (firmware executado em microcontrolador). O objetivo é dar suporte para um sistema de controle de alto nível que captura, processa e interpreta sinais biológicos a fim de controlar uma cadeira de rodas robótica. Neste trabalho foi dado um especial foco à eletrônica, ao sistema operacional de tempo real aplicado a cadeira de rodas robótica e ao controlador de baixo nível também aplicado a esta. A eletrônica de controle da cadeira de rodas utilizou uma rede de comunicação industrial, a rede CAN, para suportar toda a aplicação e algoritmos de controle. Todas as tarefas implementadas são geridas por um sistema operacional de tempo real. O controlador de baixo nível implementado é capaz de controlar de forma independente as velocidades angular e linear da cadeira de rodas. Para alcançar o objetivo proposto neste trabalho fez-se necessário manipular dispositivos de eletrônica de potência, programação, algoritmos de controle e instrumentação, rede CAN, sistema de tempo real, armazenamento de dados e controle automático

Designed Interface For Users Of Powered Wheelchair With Arms Or Hands Deficiency

Actually, wheelchair users with impairment or total lost of movements in arms or hands have many difficult to operate conventional motorized wheelchair. This project develop and integrate support systems having focus in a friendly user interface, like voice recognition, filters in joysticks, sonar for collision avoidance and motor drivers, all integrated by a hierarchic control architecture. Voice recognition was developed in two different architectures and implementations methods: the first by using commercial voice recognition software and the second by a microcontroller firmware, allowing a significant cost and weight reduction. For wheelchair user with hands or arms impairment like repetitive strain injuries or muscular dystrophy a joystick filter must to be used to interpret the movements where oscillate around a desired position. Since different kinds of interfaces and inputs are used, a consistent integration is necessary between them. The integration system uses a hierarchical logic, meaning that are some inputs are predominant than others when used, and stays in an idle condition until an event occurs. Hierarchical logic can be used for input management or obstacle avoidance, when an unsafe command is performed, like to drive to close of a wall, when the navigation system will disable some movement's directions. To evaluate this project, a prototype was built in reduced scale, but conserving all sensors and navigation architecture characteristics. Copyright © 2007 SAE International.Bourhis, G., Agostini, Y., The Vahm Robotized Wheelchair: System Architecture and Human-Machine Interaction (1998) Journal of Intelligent and Robotic Systems: Theory and Applications, 22 (1), pp. 39-50Shaw, R., Crisman, E., Loomis, A., Laszewski, Z., The eye wink control interface: Using the Computer to Provide the Severely Disabled with Increased Flexibility and Comfort (1990) IEEE, pp. 105-111. , http://ieeexplore.ieee.org/iel2/483/3324/00109386.pdf?arnumber=109386, on-line, available inLaw, C.K.H., Leung, M.Y.Y., Xu, Y., Tso, S.K., A cap as interface for wheelchair control (2002) IEEE International Conference on Intelligent Robots and Systems, 2, pp. 1439-1444Min, J.W., Kyoobin, L., Lim, S.C., Kwon, D.S., Human-friendly interfaces of wheelchair robotic system for handicapped persons (2002) IEEE/RSJ Out, pp. 1505-1510. , http://ieeexplore.ieee.org/iel5/8071/22356/01043968.pdf, on-line, available in. Access 23 AprJacob, R.J.K., The Use of Eye Movements in Human-Computer Interaction Techniques:What You Look at Is What You Get (1991) ACM Transactions on Information, pp. 152-169Yanco, H.A., Wheelesley: A Robotic Wheelchair System: Indoor Navigation and User Interface (1998) Assistive Technology and AI, pp. 256-268. , http://www.cs.uml.edu/~holly/papers/ai-at-yanco.pdf, on-line, available inTaylor, P.B., Nguyen, H.T., Performance of a Head-Movement Interface for Wheelchair Control (2003) IEEE EMBS, Set, pp. 1590-1593. , http://ieeexplore.ieee.org/iel5/9009/28599/01279669.pdf, on-line, available inGips, J., (1998) On Building Intelligence into EagleEyes, pp. 50-58. , http://www.springerlink.com/index/LLC1PMYUCQ4NHVTJ.pdf, Computer Science Department Boston College Chestnut Hill, on-line, available in. Access 18 Apr. 2007Yanco, H.A., Gips, J., Preliminary Investigation of a Semi-Autonomous Robotic Wheelchair Directed Through Electrodes (1997) Proceedings of the Rehabilition Engineering Society of North America Annual Conference, pp. 414-416. , http://www.cs.uml.edu/~holly/papers/yanco-gips-esna97.pdf, Jun. on-line, available inBourhis, G., Agostini, Y., Man-machine Cooperation for the Control of an Intelligent Powered Wheelchair (1998) Journal of Intelligent and Robotic Systems: Theory and Applications, 22 (3-4), pp. 269-287Rasmussen Jens, Skills, rules and knowledgesignals, signs and symbols, and other distinctions in human performance models (1983) IEEE Transactions on Systems, Man and Cybernetics, SMC-13 (3), pp. 257-266Keates, S., Clarkson, P.J., Robinson, P., (2007) Developing A Methodology for the Design of Accessible Interfaces, , http://ui4all.ics.forth.gr/UI4ALL-98/keates.pdf, online,- available in. Access 23 mayEngdahl, T., (2000) Powering Microphones, , http://www.epanorama.net/circuits/microphone_powering.html, 5 December 200