Subsystem Build & Test
Table of Contents
Team Vision for Subsystem Level Build & Test Phase
During the second phase of MSD II we plan to test the 4th revision of the top cart and the first revision of the bottom cart. During the same testing meeting, we plan on discussing our end vision with Karla to make sure that everything is viewed the same way by both parties and needs and expectations are being met. We also plan on having the front and rear harness modifications complete so that testing can go smoothly. Our stretch goal for this phase is to leave a cart with Karla to begin our long-term testing; we are unsure if this can yet be accomplished at this phase.
Testing metrics and methods
Testing with Trey and Delilah occurred on February 12th with the intention of determining the effectiveness of 'Top Frame' cart design for both cats. At the time of testing, we were still attempting to determine if unique specialized designs would be the best approach for meeting our customer requirements. It was determined that the 'Bottom Frame' design would be too narrow for the cat's current size and it was not used during testing.
Each subject was examined using predefined testing metrics using a testing form. Metrics were evaluated on a scale between 1 and 5, with 1 being the least ideal and 5 being most ideal. This scaling was defined through the use of the testing metrics rubric, as seen below.
Results and testing notes
Overall, the test can be considered a success. There was a notable improvement to cat mobility and the balance of the cart with the 4th iteration design. Both cats were able to briefly walk unassisted in the cart and the overall balance of the cart greatly improved. This can in part be attributed to changes made within the frame and improvements to the harnessing system used. Creation of a custom harness fixtures allowed for greater control of cart balance and a reduction in undesired movement within the cart.
There were several key problems that will need to be addressed in the next iteration of the design. First, the cart's height was too large for the for both subjects, resulting in forward imbalance which made movement more difficult and caused discomfort for the cat. Cart clips on the front harness used for both cats were too low, which added to the forward imbalance observed in both cats. During testing, Delilah was able to gain enough leverage to escape both the front and rear harness entirely, leaving both still attached to the cart.
To address these problems we will be making the following improvements during the design of the 5th iteration top frame design.
- Adding adjustability within the cart to account for slight differences in height between subjects and to better match height requirements for each cat.
- Front harness clips will be relocated to a higher point on the harness.
- Front and rear harness will be tightened, around the chest and waist respectively, to prevent the cat from gaining the necessary leverage to escape.
- The bottom frame will be reevaluated to determine viability as a design.
Testing documentsTrey's Testing Form
Risk and Problem Tracking
Plans for next phase
Team Plan for Week 8 Integrated System Build & Test
- Determine practicality of bottom frame design
- Refine design of top frame (rev. 5)
- Complete CAD design
- 3D print joints
- Fabricate and attach front harness
- Fabricate and attach rear harness support
- Create two carts
- Brainstorm and solidify long-term testing plans
- Discuss and improve testing metrics form
- Discuss and improve test plan sheet
- Test top frame rev. 5 at Karla’s on March 5th,
2017 utilizing testing metrics form and test plans
- S6, S7, S8, S11, S12, S13, S14 Test Plan – Rating Form Metrics
- S9, S10 Test Plan – Time Attaching or Releasing Cat
- S19 Test Plan – Cart Usage Per Day
- Submit Imagine RIT proposal (at the latest on March 20th but likely sooner)
Individual PlanColin Lemen week 8 individual plan
Imagine RIT ProposalCat Cart: A Feline Mobility Assistive Device
Description: Some of our furry friends need a bit more help than others. This was the case for two local cats born with some degree of paralysis in their rear legs. Our senior design team was granted the task of creating a cart for each cat to improve their mobility and quality of life. The carts are a low cost and do-it-yourself initiative whose designs may be freely distributed to help disabled cats everywhere. Stop by our exhibit to see our client’s, Trey and Delilah, in action using their carts!