Tennis racket wheelchair attachment
This was the second engineering design project I did during my first year at Rice University. Throughout the semester, we took the project from a low level prototype to a complete instruction manual on assembly and operation of a pneumatic tennis racket attachment for wheelchairs. In our group of four engineers, I was in charge of coding, wiring, and housing the electronic components.
Since we were unable to assemble the final product, we delivered a detailed instruction manual of how to assemble and operate it. This gave me key experience in complete project documentation and accounting for ease of assembly in the design process.
Client
Individual
Year
2020
Background Context
Our client wanted to play tennis despite having spastic quadraplegic cerebral palsy. We aimed to build an attachment for his wheelchair that, using pneumatics, would hit the ball with little muscular effort. In a previous course, another group had made a low fidelity prototype with strong potential to meet the users needs. Our goal was to progress the design to be robust enough for user testing.
Design Concept
In every iteration, the low fidelity prototypes had used a button to control the racket. I asked our client if buttons were his preferred method of activation. He said he didn’t know, so I devised a test to see what he liked the best.
My box (figures 3 and 4 below) contained six activation methods, each of which would flash a light.
During testing, we timed the client’s reaction speed using each method as we observed him.
Through my client interview, I learned that though he was fastest with the accelerometer, it was less controllable than his favorite method, the flex sensor.
Ideation
Ideation
Prototyping & Experimentation
1. CAD for the electronics box (SolidWorks)
2. CAD for the mechanical arm movement
3. Prototype box for testing activation methods
4. User testing session
5. Cross section of the PVC pipe