介助者の自律駆動規範モデルを用いた介助用車いすの補助動力制御

関西大

Towards an intelligent wheelchair system for users with cerebral palsy

This paper describes and evaluates an intelligent wheelchair, adapted for users with cognitive disabilities and mobility impairment. The study focuses on patients with cerebral palsy, one of the most common disorders affecting muscle control and coordination, thereby impairing movement. The wheelchair concept is an assistive device that allows the user to select arbitrary local destinations through a tactile screen interface. The device incorporates an automatic navigation system that drives the vehicle, avoiding obstacles even in unknown and dynamic scenarios. It provides the user with a high degree of autonomy, independent from a particular environment, i.e., not restricted to predefined conditions. To evaluate the rehabilitation device, a study was carried out with four subjects with cognitive impairments, between 11 and 16 years of age. They were first trained so as to get acquainted with the tactile interface and then were recruited to drive the wheelchair. Based on the experience with the subjects, an extensive evaluation of the intelligent wheelchair was provided from two perspectives: 1) based on the technical performance of the entire system and its components and 2) based on the behavior of the user (execution analysis, activity analysis, and competence analysis). The results indicated that the intelligent wheelchair effectively provided mobility and autonomy to the target population.Peer ReviewedPostprint (published version

Beach Wheelchair Attachment

This document includes the problem that is under scrutiny, the background research towards finding a solution, the objectives, scope of the project, the planned overall design process, the preliminary design we have produced and analyzed, the critical design we have manufactured, the testing and results, and the final assessment of the produced design. The problem is lack of easy access and movement for wheelchair users on the beach. Other solutions and designs have been logged under background research. With this information, the scope of work was designed to meet all the needs specified and describe how the specifications will be measured. The overall process was undertaken to produce multiple designs which were then refined into a preliminary design to move forward with. A timeline for the project and analysis of the preliminary design have been specified. The critical design and manufacturing plan for the design are mentioned as well. The critical design is a wheel and lever ratchet mechanism that can be easily attached to any manual quick-release axle wheelchair. The design is a three-part assembly: the ratcheting hub and wheels are the first assembly, the second is the lever which attaches to the first assembly, and the third assembly is the separate front wheel ski mechanism to prevent sinking into the sand

Towards Natural Human Control and Navigation of Autonomous Wheelchairs

Approximately 2.2 million people in the United States depend on a wheelchair to assist with their mobility. Often times, the wheelchair user can maneuver around using a conventional joystick. Visually impaired or wheelchair patients with restricted hand mobility, such as stroke, arthritis, limb injury, Parkinson’s, cerebral palsy or multiple sclerosis, prevent them from using traditional joystick controls. The resulting mobility limitations force these patients to rely on caretakers to perform everyday tasks. This minimizes the independence of the wheelchair user. Modern day speech recognition systems can be used to enhance user experiences when using electronic devices. By expanding the motorized wheelchair control interface to include the detection of user speech commands, the independence is given back to the mobility impaired. A speech recognition interface was developed for a smart wheelchair. By integrating navigation commands with a map of the wheelchair’s surroundings, the wheelchair interface is more natural and intuitive to use. Complex speech patterns are interpreted for users to command the smart wheelchair to navigate to specified locations within the map. Pocketsphinx, a speech toolkit, is used to interpret the vocal commands. A language model and dictionary were generated based on a set of possible commands and locations supplied to the speech recognition interface. The commands fall under the categories of speed, directional, or destination commands. Speed commands modify the relative speed of the wheelchair. Directional commands modify the relative direction of the wheelchair. Destination commands require a known location on a map to navigate to. The completion of the speech input processer and the connection between wheelchair components via the Robot Operating System make map navigation possible

Comparison of braking performance between mechanical and dynamic braking for Electric Powered Wheelchair

Braking is the necessary system need to install as the safety feature for moving transportation. Using the mechanical braking only as primary braking system in Electric Transportation (ET) is insufficient due to some issues such as low strength users hand gripping and abruptly tire locking during braking especially on wet surface condition. In this paper, the performance between mechanical and electrical braking which is by using dynamic braking concept is proposed to enhance the braking performance of Electric Powered Wheelchair (EPW). The experiments were conducted during descending on the slope under wet and dry pavements. From the results of slip ratio, the slipping time between mechanical and dynamic braking in dry pavement is recorded 0.9 seconds and 0.7 seconds respectively. Meanwhile, it is observed that tire is fully locked-up for mechanical braking under the wet surface. However, by using the dynamic braking, the wheel does not lock-up and the slipping time was recorded 1.4 seconds. It can be considered that, mechanical and dynamic braking give their own merit. The high braking torque from mechanical braking is suitable to use under the dry pavement for the short stopping distance. The other sides, braking under the wet pavement, dynamic braking is more efficient compare to the mechanical braking in term of short slipping time and does not cause tire to lockup while braking

Climbing and Walking Robots

Nowadays robotics is one of the most dynamic fields of scientific researches. The shift of robotics researches from manufacturing to services applications is clear. During the last decades interest in studying climbing and walking robots has been increased. This increasing interest has been in many areas that most important ones of them are: mechanics, electronics, medical engineering, cybernetics, controls, and computers. Today’s climbing and walking robots are a combination of manipulative, perceptive, communicative, and cognitive abilities and they are capable of performing many tasks in industrial and non- industrial environments. Surveillance, planetary exploration, emergence rescue operations, reconnaissance, petrochemical applications, construction, entertainment, personal services, intervention in severe environments, transportation, medical and etc are some applications from a very diverse application fields of climbing and walking robots. By great progress in this area of robotics it is anticipated that next generation climbing and walking robots will enhance lives and will change the way the human works, thinks and makes decisions. This book presents the state of the art achievments, recent developments, applications and future challenges of climbing and walking robots. These are presented in 24 chapters by authors throughtot the world The book serves as a reference especially for the researchers who are interested in mobile robots. It also is useful for industrial engineers and graduate students in advanced study

Research and Development of an Appropriate Electric Powered Wheelchair for India

The need for assistive technology (AT) extends far outside of the countries where users have the financial capacity to buy them, or there is a social welfare infrastructure to subsidize their purchase. In developing countries, where both technology and financial resources are scarce, AT users face tremendous challenges to find high-quality devices that are affordable. This scenario is in part due to organizations who transfer sub-standard AT to these countries by taking a 'something is better than nothing approach' to a clinically and technologically challenging problem. The goal of this work is to develop and demonstrate AT design and technology transfer strategies that take into consideration the clinical and technological needs of the intended user population. Although other projects have and do take these important user-centered factors into consideration, this work represents the first comprehensive attempt from an academic perspective, where hypotheses are proposed and tested, and design goals are described and evaluated with respect to the final product. The main focus of this work is on mobility devices (wheelchairs, specifically) although many of the protocols and techniques could be extended to address AT design and technology transfer to developing countries in general. The first part of this dissertation (Chapters 1 & 2) focuses on the background literature, and proposes a model describing the important factors influencing the success or failure of a wheelchair technology transfer project. The second part of this dissertation provides a case study in the development of an electric powered wheelchair for users in India. First, an analysis of a commercially available low-cost powered wheelchairs were evaluated (Chapter 3). Second, a study to assess the needs of users in India was performed using a modified ethnographic approach (Chapter 4). Third, the design and evaluation of a novel low-cost electric powered wheelchair for Indian users is described (Chapter 5). The final chapter (Chapter 6) discusses the implication of this work and suggests future directions. The entire drawing-set for the second generation prototype developed here is also included, allowing others to build upon the approach and the design developed here

A Collaborative Wheelchair System

Ph.DDOCTOR OF PHILOSOPH

Ontology of accessibility in the context of wayfinding for people with disabilities.

There is evidence that objects in and of the built environment function as barriers or facilitators to accessibility for people with disabilities. Although there are many existing sources of information about accessibility, they often lack clear criteria to describe accessibility, explanations of barriers and facilitators to mobility, and coverage of multiple physical environments. Researchers have argued that wayfinding services (e.g., Google Maps) can help people with disabilities prepare to travel through the built environment, yet current wayfinding services include little to no information about accessibility. This dissertation aims to study accessibility, in the context of wayfinding, in indoor, outdoor and transitional environments for people who travel in wheelchairs and people with low to no vision. To this end, a qualitative ontological analysis of multiple sources of information regarding accessibility was conducted including analyses of important categories associated with accessible wayfinding; different information providers’ views on accessibility; and specific barriers and facilitators to accessibility. The results indicate that (1) people with low to no vision and people who travel in wheelchairs have different core wayfinding information needs, (2) a gap exists between the information people with disabilities and researchers provide on accessibility and that provided by standard guidelines, and (3) conceptualizing accessibility requires capturing actions performed by people with disabilities during every day travel along with characteristics of environmental objects. The resulting ontology could be leveraged to generate new criteria describing accessibility, new routing algorithms, or to attach provenance to existing accessibility criteria. The findings have implications for people who design wayfinding services and collaborative maps and people collaboratively collecting data on the accessibility of specific places