The commonly offered ordinary wheel chairs do not utilize any techniques of automation or artificial intelligence to help out the consumer. This is a significant disadvantage to the relentlessly disabled persons. Extensive research work carried out in this regard must pick up the pace to meet the increasing necessitation for the Wheel Chair Mini Project. In 2000, there were an estimated 1. 7 million full-time wheelchair bound Americans. Approximately 55% of them were over the age of 65. With an increasing aging
population and life expectancy, these numbers will only grow in the next twenty years. As such, there will be a dramatic need for assistive technology that does not rely exclusively on human caretakers for operation. While the use of powered wheel chairs has become common-place for many handicapped people, the severely handicapped do not have many options. Their limited dexterity usually means that a caretaker must be present at all times to ensure that the occupant is not injured or damage anything in the environment.
The current state of the art in robotics can help this situation by augmenting the wheel chair user’s senses and reaction time. This will require multiple aspects of artificial intelligence, vision processing, and sensor fusion to name a few. (Micire 2006) Design: Earlier mobility-enhancing robotic tools: The progress of a robotically amplified walker poses uncommon confronts not seen in either more tightly or loosely coupled assistive mobility systems.
Some of them are peculiar to the elderly users who constitute the majority of the user population and may be visually or cognitively impaired in addition to having impaired mobility and/or balance. Some others are specific to the role and function of the device. Wheelchair systems, such as NavChair, SIAMO, or the Bremen Autonomous Wheelchair, focus on obstacle avoidance and user modeling, modular design and versatility, or robust obstacle avoidance plus the refinement of the shared control model, among other goals.
In contrast to walkers or canes, the user interface for assistive wheelchairs generally relies on a joystick or similar device. The user’s intended direction is interpreted as explicit, accurate, and discrete based on the signal from this device, making the design of a shared control paradigm based on discrete device and user modes much easier, for a comprehensive review of robotically enhanced wheelchair developments. Walker-based systems must be more concerned with balance and gentle, intuitive shared control than wheelchair-based systems.
Walker users are not simply riding a mobile robot platform and can be seriously injured by the system’s failure to consider this. Yet the guidance supplied by a robotic walker cannot be as laissez-faire as that of Wheel chair mini project 3 Borenstein & Ulrich’s GuideCane or similar devices engineered for those who have limited sight but are otherwise physically and cognitively fit. The Guido system, which evolved from Lacey & MacNamara’s PAM-AID, addresses this dichotomous challenge by relying on significant weight to lend stability to the system.
This itself is a design tradeoff since lightweight and/or foldable walkers have generally been preferred for their portability and ability to be carried up or down stairs. PAM-AID, however, was designed with the goal of facilitating exercise for the visually impaired elderly and thus focuses on wall or corridor following in level environments, such as would be found in an assistive living facility. Dubowksy et al’s PAMM (Personal Aid for Mobility and Monitoring, distinct from PAM-AID) project focuses specifically on the needs of users in an eldercare facility, in particular health monitoring and global navigation.
A non-holonomic cane has been developed that relies on ceiling “signposts” for location feedback and communicates wirelessly with local facilities to exchange user health monitoring data, schedules, and maps. Its shared control system for obstacle avoidance follows the model of but proposes moving to the VFH+ model proposed by. The cane has the ability to lead users along pre-determined paths at fixed or user-determined speeds, a functionality we do not envision for the Nursebot walker.
A walker-based device, the Smart Walker, has also been constructed as the next step of the PAMM project due to observations that users of the cane-based PAMM would be benefited by additional support. It extends the functionality of the smart cane to a more stable platform. The holonomic four-wheeled platform comprising the Smart Walker’s form factor is designed to handle uneven terrain, carpets, and dirty environments, and is powered for up to an estimated 1500m of travel.
Wasson & Gunderson, in their previous development of robotically enhanced wheeled walkers, emphasize that the walker’s role as a balance aid significantly distinguishes it from a wheelchair. Onboard control systems must take into account the more collaborative and loosely coupled relationship between a walker and user. Failure to do so means that errors may rapidly compound, resulting in a fall. The design of Wasson & Gunderson’s walkers rely on the user’s motive force to propel the devices.
Several layers of control systems have been developed for these walkers, from simple warning sounds (and no corrective action) to corrective action that consists of a combination of braking and steering away from obstacles, to path planning that gently keeps the user “on track” even when no obstacles are present. This last level is achieved with correction times that are long enough and corrective forces that are subtle enough to give the user the impression of full control rather than the feeling of being steered by the device.
The exact degree of these parameters is currently being subjected to estimation and experimental verification. None of these systems, however, address the safety issue brought up in the introduction to this paper; that is, the potential for falls or other mishaps while the user is coupling or uncoupling from the system. Unless the user is to remain permanently attached to his or her assistive device, such situations will inevitably occur. Hence, building on the vision of Nursebot participants, we seek to deal with the advance dimension of mobility-assisting instrumental consumption in a patient’s life.