P16007: Motor-Assisted Wheelchair/public/
Team Vision for System-Level Design PhaseDuring this phase we sought to:
- Finalize Engineering Requirements
- Generate different concepts and evaluate them in order to:
- Generate a system design, including deciding on the type of power source and how it will act on the wheel chair
- Create initial test plan including each spending a day in a manual wheelchair.
- Calculate performance limitations
- Assess skills and resources needed
- Continue risk management
During this phase we managed to:
- Finalize Engineering Requirements and create preliminary test plans to see if those requirements are achieved.
- Each member spent a day in the wheelchair to get first hand experience
- Generate five serious concepts and select one to move forward with.
- Decide upon using an electric power source and addition of another wheel to actually provide the wheelchair assistance.
- Benchmark against existing solutions and components to ensure proposed system design is feasible.
- Find existing CAD drawings of wheelchairs to help better visualize and prepare for future phases
- Revise and update risks.
Concept Development and Morphological Chart
Concept 5Combination of concept 1 and 3, generated after two rounds of Pugh Analysis.
Concept Selection Criteria
- Weight of addition
- Able to be designed and built within 2 semesters
- Easy to transport & store
- Usable for a long period of time without needing to stop to replenish energy source
- Level of speed control available
- Independence level granted to the end user
- Impact on the overall dimensions of the wheelchair when the addition is added
- Allows the user to walk with friends
- Assists user going up an incline
Summary of Pugh Analysis with Concept 1 as Datum
Summary of Pugh Analysis with Concept 2 as Datum
SelectionConcept 5 was selected as it had the most positives with the least negatives. This makes sense as it was generated as a composite between one and three, combining the good features found within each of those concepts while eliminating some of the not so good features and then submitted to the same pugh analysis. It is believed by the group that this concept will best meet the end goals of this project.
Overall Solution Benchmarking
Designs and Flowcharts
CAD DrawingsCAD Files for Non-Modified Wheelchair Rendition
Preliminary Test Plans
User Interface Scale
Design Review Materials
Plans for next phase
Team Vision for Next Phase
- Decide on specific solutions for each subsystem and
how those subsystems will interface.
- Mechanical - motor selection, wheel selection/placement/mounting mechanism on the existing wheelchair
- Electrical - battery selection, user interface
- Perform feasibility analysis of each solution
selected to ensure that it will be able to achieve
- Specifically ensure that sensors are available to achieve the functionality desired
- Ensure omniwheel selection will work on outdoor pavement and have a long lasting life
- Ensure the motor provides the output required to meet the speed and incline engineering requirements.
- Determine the wear on the motor when it is in "idle" operation (attached but not turned on while user uses chair manually).
- Ensure the battery will provide the power levels required and last for the lengths specified in the engineering requirements.
- Create high level drawings of each subsystem to show how the components in each subsystem interface with one another.
- Start creating CAD drawings of each component and placing them on the system
- Begin generating a preliminary bill of materials.
- Continue updating risks.
- Further develop test plans.
- Work better as a team to ensure tasks are completed in a timely manner and not left until the last second.