Team Nathan Suspension

Nathan Cooper is an 8-year old boy with Spinal Muscular Atrophy (SMA). SMA has affected Nathan’s muscle development and requires him to use the Standing Dani™ mobility device. The Standing Dani is a motorized standing wheelchair, or Wheelstand. Nathan controls and uses it to get around. Though the Standing Dani performs well for most functions, it has some distinct issues. The primary issue that this project addresses is its lack of suspension and the discomfort that Nathan feels as a result. After talking with our client, we developed several specifications generally related to geometry, safety, vehicle dynamics, and reliability. Many possible suspension solutions were developed using three methods of idea generation. A rear trailing arm suspension paired with pneumatic casters in the front was chosen as the final concept. From this concept, we designed a system that was made up of four basic components: front casters, frame, trailing arm linkages, and a spring-shock assembly. The final design is supported with hand calculations involving the static system and a dynamic analysis of the suspension behavior using MATLAB®. The manufacturing and testing portions of the final design were completed in the final three months of the project. We are confident that the design that has been developed will suit the needs of Nathan and make his daily activities all the more enjoyable