Backward Looking Summary
During the Design Concepts: Screening and Scoring lab last week, the primary goals were to develop critical decision making skills, practice developing and evaluating design concepts, develop a sample program for the AEV to complete a specified objective, and conduct a concept screening and scoring of the teams AEV designs by comparing them to the first AEV that was made at the beginning of the course, which will be referred to later as the base line. Doing this type of concept screening and scoring is important to the overall AEV design choice and team dynamics because it removes personal bias to one AEV design over another by categorically comparing the design and scoring them. The AEV that has the best overall score at the end of this process is going to be the design that the team implements.
During this lab an AEV test run was conducted on the test track using the given code scenario in this lab. At the very start of the run there is a slight delay before the AEV turns on after the start button has been initiated. The AEV design that was used had a good balance on the straight track and banked to the outside of the curve, as it was moving through the curve. This is due the centripetal force on the AEV at that point and not a design flaw. Overall the design used looked very promising.
Concept Screening Score Sheet
| Success Criteria | Reference | Design A | Design B | Design C |
| Balanced in turn | 0 | 0 | – | 0 |
| Minimal blockage | 0 | + | 0 | – |
| Center of gravity | 0 | – | – | + |
| Maintenance | 0 | + | – | – |
| Durability | 0 | + | – | – |
| Cost | 0 | 0 | – | – |
| Environmental | 0 | 0 | 0 | 0 |
| Sum +’s | 0 | 4 | 0 | 1 |
| Sum 0’s | 0 | 2 | 3 | 2 |
| Sum –‘s | 0 | 1 | 5 | 4 |
| Net Score | 0 | +3 | -5 | -3 |
| Continue? | No | Yes | No | No |
From this screening score sheet we found that Design A was the best fit design.
The criteria choices came from the lab manual. This spreadsheet represents the design that is most conceptually favorable.
Concept Scoring Matrix
| Reference | Reference | Design A | Design A | Design B | Design B | Design C | Design C | ||
| Success Criteria | Weight % | Rating | Weighted Score | Rating | Weighted Score | Rating | Weighted Score | Rating | Weighted Score |
| Balanced | 25 | 3 | 0.75 | 3 | 0.75 | 2 | 0.5 | 3 | 0.75 |
| Minimal Blockage | 5 | 2 | 0.10 | 4 | 0.20 | 2 | 0.1 | 1 | 0.05 |
| Center/Gravity | 30 | 2 | 0.60 | 1 | 0.30 | 1 | 0.3 | 3 | 0.9 |
| Maintenance | 15 | 3 | 0.45 | 4 | 0.60 | 2 | 0.3 | 2 | 0.3 |
| Durability | 15 | 2 | 0.30 | 3 | 0.45 | 1 | 0.15 | 1 | 0.15 |
| Cost | 5 | 3 | 0.15 | 3 | 0.15 | 2 | 0.1 | 2 | 0.1 |
| Environmental | 5 | 3 | 0.15 | 3 | 0.15 | 3 | 0.15 | 3 | 0.15 |
| Total Score | 100 | 2.50 | 2.60 | 1.6 | 2.4 | ||||
| Continue? | No | Develop | No | No |
This concept-scoring matrix confirmed the results of the concept screening. We used the same criteria in both. Design A was better than the reference in the areas of blockage, maintenance, durability, and cost. This is because this design does not require any additional parts that were not included in the AEV Kit, but its center of gravity was not as good as the reference. Using these evaluation techniques we will proceed with design A. Takeaway from this lab is not to fall behind and not to procrastinate, if these happen it is easy to have late work. Design A was David’s design, design B was Clara’s design, and design C was Michael’s design. See attached pdf. File for design sketches.
Forward Looking Summary
We expect to use design A and program code that will be able to complete the track requirements in the near future. Next week there should be a test and the week after that there should be a oral presentation.
Code used:
motorSpeed(1,30);
motorSpeed(2,20);
goToAbsolutePosition(166);
brake(4);
Goals of next week:
| Monday | Tuesday | Wednesday | Thursday | Friday |
| Work on Portfolio | Meeting in lab | Lab 6, delegate assignments | Compile data | Team collaboration via phone |
Team Meeting Notes:
– After all make up has been delegated evenly, we are now caught up on late assignments.
– Work on PDR will start