Design and Development of Assistive Robots for Close Interaction with People with Disabilities

People with mobility and manipulation impairments wish to live and perform tasks as independently as possible; however, for many tasks, compensatory technology does not exist, to do so. Assistive robots have the potential to address this need. This work describes various aspects of the development of three novel assistive robots: the Personal Mobility and Manipulation Appliance (PerMMA), the Robotic Assisted Transfer Device (RATD), and the Mobility Enhancement Robotic Wheelchair (MEBot). PerMMA integrates mobility with advanced bi-manual manipulation to assist people with both upper and lower extremity impairments. The RATD is a wheelchair mounted robotic arm that can lift higher payloads and its primary aim is to assist caregivers of people who cannot independently transfer from their electric powered wheelchair to other surfaces such as a shower bench or toilet. MEBot is a wheeled robot that has highly reconfigurable kinematics, which allow it to negotiate challenging terrain, such as steep ramps, gravel, or stairs. A risk analysis was performed on all three robots which included a Fault Tree Analysis (FTA) and a Failure Mode Effect Analysis (FMEA) to identify potential risks and inform strategies to mitigate them. Identified risks or PerMMA include dropping sharp or hot objects. Critical risks identified for RATD included tip over, crush hazard, and getting stranded mid-transfer, and risks for MEBot include getting stranded on obstacles and tip over. Lastly, several critical factors, such as early involvement of people with disabilities, to guide future assistive robot design are presented

Effort reduction and collision avoidance for powered wheelchairs : SCAD assistive mobility system

The new research described in this dissertation created systems and methods to assist wheelchair users and provide them with new realistic and interesting driving opportunities. The work also created and applied novel effort reduction and collision avoidance systems and some new electronic interactive devices. A Scanning Collision Avoidance Device (SCAD) was created that attached to standard powered wheelchairs to help prevent children from driving into things. Initially, mechanical bumpers were used but they made many wheelchairs unwieldy, so a novel system that rotated a single ultra-sonic transducer was created. The SCAD provided wheelchair guidance and assisted with steering. Optical side object detectors were included to cover blind spots and also assist with doorway navigation. A steering lockout mode was also included for training, which stopped the wheelchair from driving towards a detected object. Some drivers did not have sufficient manual dexterity to operate a reverse control. A reverse turn manoeuvring mode was added that applied a sequential reverse and turn function, enabling a driver to escape from a confined situation by operating a single turn control. A new generation of Proportional SCAD was created that operated with proportional control inputs rather than switches and new systems were created to reduce veer, including effort reduction systems. New variable switches were created that provided variable speed control in place of standard digital switches and all that research reduced the number of control actions required by a driver. Finally, some new systems were created to motivate individuals to try new activities. These included a track guided train and an adventure playground that including new interactive systems. The research was initially inspired by the needs of young people at Chailey Heritage, the novel systems provided new and more autonomous driving opportunities for many powered wheelchair users in less structured environments.EThOS - Electronic Theses Online ServiceGBUnited Kingdo