While most buildings and public campuses are subject to ADA compliance, many wheelchair users still experience difficulty traveling public grounds. One common issue is crossing over elevated curbs. Despite a number of assistive wheelchair technologies to address this problem, many of the solutions are bulky, expensive, or largely inaccessible. Our team aims to design and develop a simple linkage-based device that will allow users to safely and quickly maneuver over curbs and gaps.
The specific aims of this project will be to develop a wheelchair assist mechanism that:
- can lift a wheelchair over an average curb height
- prevents the user from tipping over or being subject to uncomfortable angles
- is mechanically powered
- is not excessively bulky
- provides a complete range of smooth motion
A defining issue to consider for the project is the scale of the final prototype. A life-size scale for a wheelchair presents difficulties in obtaining the required materials for construction and testing, so a 1:4 scale model will be the end goal for the presented prototype. The prototype will encompass the curb scaling mechanism, which will demonstrate translating a model wheelchair from the ground onto an elevated platform. Common curb heights/depths are around 4 to 6 inches and can go up to 12 inches. Because our model will be 1:4, a target curb height of 1.5 inches will be used.
Concepts learned in class such as mechanical advantage will be implemented when designing this mechanism. Positional analysis of the wheelchair and curb scaling mechanism will be important for safety and efficiency reasons. The design will have a strong focus on mapping the location of the CG to prevent tipping as the mechanism will cause the wheelchair to tilt and translate. MATLAB will be used in the position and velocity analysis to aid in determining and finalizing the design of the mechanism.