Team Bussin'
Project undertaken in course year 2022-23 with Volkswagen
Project Goal
To design an entryway system for Volkswagen's Classroom on Wheel so that students with and without disabilities are able to use the same entryway to enter and exit the vehicle safely
Project Motivation
As many as 30% of children in rural Brazil are estimated to not be attending school: the Volkswagen "Classroom on Wheels" concept vehicle is under development to propose a solution. Existing school bus vehicles commonly feature separate entrances for wheelchair users and able-bodied students, which promotes a feeling of otherness.
Background
Children in rural Brazil often face long journey times, challenging terrain, and other impediments in traveling to attend school. Decreased school participation has negative impacts on the personal, social and economic development that is so crucial to the largely low-income populations in these areas.
Access for students with mobility impairments - such as wheelchair users or students on the autism spectrum - shows an opportunity for improvement. Brazil is home to an estimated 1.5 million people with an Autism Spectrum Disorder, and an estimated 3.5 million people aged 2 and over use a wheelchair, cane, crutch, walking frame or some prosthesis. UNICEF's research reveals that 21% of students between the ages of 6 and 14 who do not attend school do so on the basis of chronic health conditions.
Conventional school bus designs deployed in Brazil feature separate entryways for persons who require mobility assistance and those who to not; this separation can negatively affect a disabled person's sense of independence, inclusion and personhood, and discourage school participation.
High Priority Requirements
One entryway - entryway must be 36-52 inches wide
No falling off - 2 inch barriers on each side
Easy to enter - Less than 1/4 inch ground to platform gap
Ground to Doorway - system will lift user 30 inches high
Safe to use - System will support >600 lbs with minimal deflection
Ethical Considerations
Design for inclusivity - Safe, welcoming mechanisms and interfaces
Overcome Implicit Bias - conduct user testing and interviews, background research
Solution
A lift-stair hybrid system that deploys, actuates and retracts in the same manner regardless of user capabilities or use case
System solution
Concept sketch showing the final design, as deployed. An able-bodied person can walk up the steps; someone needing assistance moves onto the ramp, and then the actuators pull the ramp up and in to the vehicle; the stairs fold out of the way.
Working prototype
50% scale working prototype, shown in mid-actuation. The wooden structure represents the vehicle, and the aluminum components represent the stair lift system.
Lifting a teammate
Student team demonstrating the device. Linear actuators are sufficiently strong to perform the lift operation, lifting the system and the student riding the device.
2D stairs, open
2-dimensional study demonstrating the stairs in the deployed position. The long horizontal beam on the bottom represents the platform, and; the shorter horizontal beams represent steps.
2D stairs, folded
2-dimensional study demonstrating the stairs having moved into the folded position. The steps are lifted by the platform, which is moved into the appropriate position by the arms. The stairs fold into the vehicle
3D deployment of stairs
View of the stairs being deployed
Arm Stress Analysis
Stress analysis on the lift arms during deployment.
Ramp deflection testing
Testing setup for measuring deflection of the platform
Ramp deflection test results
Test results of platform deflection vs predicted
Other testing conducted
Actuation time
Lift 600 lb
System deflection testing
Stair yield and deflection testing
Student team
Future Work
Make steps out of engineered material (e.g., Aluminum)
Refine stair movement
Have system result in fully "closed" position when stowed
Incorporate handrails
Build and evaluate at full scale
Field research in Brazil
User evaluations