Table of Contents
Working off the precedents set by Team 16007, a Motor Assisted Wheelchair (MAW) prototype has been developed to assist a manual wheelchair move more easily. The MAW is intended to be used in accord with a manual user to physically keep up with and maintain normal, casual conversations with someone walking by their side.
A manual wheelchair alone can leave someone out of breath if they're trying to move at pedestrian paces while talking at the same time. Additionally, inclines may introduce a hazard if the user is incapable of physically pushing their chair up the hill on their own and begin to roll backwards out of control.
A MAW would assist the user with both of these everyday tasks. Furthermore, the transition for someone between a manual wheelchair and an electric wheelchair can be both expensive and lead to unpleasant side effects. As a transitional device, it would delay the effects of upper-body muscle atrophy as well as provide a cost-effective alternative.
The prototype legacy of Team 16007 provides a base model to begin our work. Refined customer requirements and pioneered exploration of materials and engineering lay the foundation for where we need to begin: Cut the costs, cut the weight, and make the device more convenient and universal to deploy.
Team Vision for Problem Definition Phase
During this phase, our team planned to gather the necessary information required to gain a clear and concise understanding of both the customer wants and engineering goals to further improve a prototype that had been previously started by an earlier design group. We planned to reach this goal by:
- Interviewing our customer and asking questions that required thoughtful response
- Identifying stakeholders and recognizing how each impacts the overall project
- Identify customer requirements and understand how they will effect engineering requirements
- Identify engineering requirements and understand how they will effect customer requirements
- Identify and implement common use scenarios into design considerations
- Benchmark parameters and products to effectively compare possible design options
- Identify and consider risk scenarios involving technical, resourceful, and societal risks
During this phase, our team accomplished all of the tasks that we had hoped to complete. We now have a clear understanding of the customer requirements and are beginning to develop potential engineering options to meet each of them. After discussing the design with our customer, we have a list of prioritized requests to implement in our future designs. By understanding the most common use scenarios, we will have the ability to universalize our design to meet the needs of each potential use.
Project Goals and Key DeliverablesThe expected end result of this project is to have a working prototype that utilizes the successful characteristics of the previous design team while improving upon areas that still need further changes. After speaking with our customer, some of these improvements include:
- Reduced weight
- Reduced cost
- Universal application to different wheelchair designs
- Development of a more appealing control system
- Easily removed and stored
- Comfortable and safe
ConstraintsConstraints involved in the development of the motor assisted wheelchair include:
- Obtaining and abiding by financial resources and limits
- Effectively using time during the testing process - limit down time
- Designing to reach portability requirements - detach and store
- Reduce weight
- Long lasting battery life - usable all day
- Weatherproof design
- Design so that the use of a wheelchair during manual operation remains a possibility - both by the user or somebody else pushing the wheelchair
Risk AnalysisSome risk factors related to our project include:
- Motor lacks power - Unable to navigate necessary terrain or inclines
- Assembly is not easily transported - Must be easily detached and stored
- Electrical/Mechanical failure - Communication between electrical and mechanical components must be constant
- Budget consideration - Obtain budgeting and remain within allotted amount
- Testing time - Full days of testing necessary
- Finding correct testing inclines - The incline used to test must be convenient to use whenever necessary
- Emergency stop effectiveness - Must work every time
- Safe speed limitation - Specifically reasonable and safe top end speed
- Tipping when navigating inclines - Weight distribution is important
- Clean power - Easily charged in traditional outlets
- Public interaction in crowds and on sidewalks - Consider regulations regarding motorized equipment in public
- Cost to afford and ease of access - Must be easy to acquire, if desired
Design Review Materials
Customer Interview NotesFull List of Customer Interview Notes
Plans for next phase
Team Vision for Next Phase:
- Develop working knowledge of current prototype to include its strengths, weaknesses, and areas of improvement.
- Resolve customer requirements and engineering requirements to have an expected end-state.
- Utilize benchmarking of other concepts to assist with refinement of device design.
- Assess and mitigate risks associated with the device.
- Calculate theoretical performances for product selection on the system overall.
- Simulate concepts applicable to device refinement.
- Create preliminary BOM and working budget.
- Prototype with available materials for any applicable proof-of-concept refinements.
Individual Plans for Next Phase: Individual plans for next phase