Semi-Autonomous Wheelchair Mobility System

Principal Investigator: Richard Simpson, PhD, ATP

Funding Source: The Technology Collaborative

The University of Pittsburgh and AT Sciences are proposing a 12-month project to develop a semi-autonomous mobility aid for individuals who are completely dependent on others for their mobility needs.  The device we are proposing will eliminate the current requirement that a caretaker be present to provide power, guidance, knowledge of the destination and/or communication each time a person desires or needs to move to a different location.  The use of this system will increase the independence of the person and ease the burden on caretakers to constantly be available during times of movement.  

The proposed Semi-Autonomous Wheelchair Mobility System (SAWMS) will target an under-served and rapidly growing market (assisted living facilities and nursing homes for the elderly and disabled) using currently available technologies for visual tracking, object avoidance, and wireless communication, in combination with power assist wheelchair hubs for manual wheelchairs.  The system will have the ability to transport an individual between locations (e.g., room to room or building to building) within a limited environment (e.g., intermediate or long term care facility, nursing home) without total support from a caretaker during the period of movement.

 This research will build on the investigative team's previous experience with navigation assistance for power and manual wheelchairs.  Specifically, the SAWMS will be based on the Smart Power Assistance Module (SPAM) for Manual Wheelchairs.  The SPAM uses sonar, infrared and contact sensors in combination with power assist wheelchair hubs to provide collision-free travel for manual wheelchair users with visual impairments.

The following milestones have been identified for the project:

•  Integrate a color camera and target tracking software into our existing “smart wheelchair” technology;

•  Identify one (or more) materials for use in defining indoor and outdoor tracks;

•  Implement a “target-triggered track following” behavior within the control software of the SAWMS;

•  Implement an “track-guided autonomous navigation” behavior within the control software of the    SAWMS;

•  Implement a wireless, PDA-based interface for caregivers;

•  Design and fabricate simplified power-assist hubs and enclosures for sensors;

•  Evaluate the SAWMS in laboratory and field trials.

•  The project is expected to result in the following deliverables:

•  A functioning prototype of the SAWMS;

•  Designs for simplified power-assist hubs and enclosures for sensors;

•  Hardware and software for integrating multiple sensors with a microprocessor and power-assist wheelchair hubs;

•  Control software that implements target tracking, track following, and track-guided autonomous navigation on non-holonomic vehicles;

•  Software that implements a user interface for the system on a handheld PDA and communicates with the SAWMS via a wireless network;

 The results from initial evaluations conducted both in the laboratory and in a real assisted-living facility.