Several accessories have been developed to aid the wheelchair-confined individual in retaining their social independence. However, after a comprehensive study it was determined that a device, which would automatically extend the immediate reach of the handicapped individual, could not be easily added to such currently existing wheelchairs. We proposed a device that could easily be attached to the back of the electric wheelchair. This unit contains all necessary hardware to support the movement of an actuating arm whose intent is to automatically deliver and retrieve objects outside the person’s immediate reach. In addition, the unit does not significantly exceed the dimensions of the chair so as to not obstruct its normal use. To maximize our efforts, we re-evaluated the creativity of its construction: This was done to optimize its durability, reliability, and ultimately lower its construction cost. The ease of its manufacturing supports our intent for a universal application so that all handicapped individuals could benefit from this device as an after-market electric wheelchair accessory.
Achieving these types of functions required the development of two pneumatic telescoping arms that can match and overcome its maximum load of 15 lb., and an electrical control system that both develops arid defines all object motions. A comprehensive static and dynamic analysis was performed to, determine the forces governing the motion of the arm as well as to predict its operating speed and direction. This analysis also tests the boundaries of our control system. This information allowed us to determine the range and limitations that defined the electrical as well as mechanical components of this system.