Lab 03: AEV Concept Screening and ScoringAdvanced Energy Vehicle (AEV)

Learning Objectives Become familiar with techniques for

design decision making

Become familiar with a structured method to screen and score design concepts

Observe a sample AEV operation

Using the sample AEV as a reference, practice concept screening and scoring methods with AEV design concepts.

Types of Decision Methods External Decision – Customer, client, end user

Product champion – influential team member

Intuition – gut feel

Multi-voting – popular demand

Pros and cons – evaluate strengths/weaknesses

Prototype and test – trial and error

Decision matrices – selection criteria(weigh against prioritized requirements)

Two Stages to Concept Selection1. Concept Screening – Screening Matrix• A quick method to down-select ideas• Use to combine various concepts or parts• Sometimes good enough for simple projects

2. Concept Selection – Scoring Matrix• Provides better resolution than screening• May have better definition of concepts at this point• May want to refine or create hierarchy of

“Selection Criteria”

Concept Screening Matrix1.Rank each design against every criteria.

2.Rank better, worse, or same as reference.

3.Tally scores to find best designs.

4.Combine and improve to get top several concepts.

5.Continue with next step.

Concept Screening Matrix Example

0

0

0

0

3

0

0

Reference Design

Night Hawk Aerodynamics

Cost

Center of Gravity (Balance)

Sum of +’s

Sum of 0’s

Sum of –’s

Net Score

+-

0

0

1

1

1

Concept ScreeningSuccess Criteria Reference Design A Design B Design C Design D Design E Design F

Balanced 0 0 0 - 0 - -

Minimal blockage 0 0 - - 0 + 0

Center-of-gravity location

0 0 0 + + 0 +

Maintenance 0 0 0 0 - 0 0

Durability 0 0 0 0 0 + 0

Cost 0 + - - 0 - 0

Environmental 0 + + 0 + 0 0

Sum +’sSum 0’sSum –’s

070

250

142

133

241

232

151

Net Score 0 2 -1 -2 1 0 0

Continue ? Combine Yes No No Yes Combine Revise

Concept Scoring1. Define Success Criteria (rows).• Same as before but with perhaps more detail. Add hierarchical

breakdown if necessary.

2. Weigh the importance of each criteria (0 – 100% with column adding to 100%).

3. Define Reference and, if necessary or desired, newly revised set of design concepts as results of 1st step.

4. Rate each design for each criteria (0 – 5 with 5 being the best).

5. Calculate ranking by adding weighted scores.

6. Select highest ranked design concepts.

Concept Scoring(Select Final Design Concept)

A Reference Old Ref & E Design D Design F+

Success Criteria Weight Rating Weighted Score

Rating Weighted Score

Rating Weighted Score

Rating Weighted Score

Balanced 5% 3 0.15 3 0.15 4 0.20 4 0.20

Minimal blockage 15% 3 0.45 4 0.60 4 0.60 3 0.45

Center-of-gravity location

10% 2 0.20 3 0.30 5 0.50 5 0.50

Maintenance 25% 3 0.75 3 0.75 2 0.50 3 0.75

Durability 15% 2 0.30 5 0.75 4 0.60 3 0.45

Cost 20% 3 0.60 3 0.60 2 0.40 2 0.40

Environmental 10% 3 0.30 3 0.30 3 0.30 3 0.30

Total Score 2.75 3.45 3.10 3.05

Continue? No Develop No No

Making the Sample AEV

Build the Sample AEV as shown in the 3D PDF (in Lab 1).

MAKE SURE THE ARDUINO DOES NOT TOUCH THE METAL BRACKETS!!!!!

Classroom Track Testing Procedure1. Review the AEV Classroom Track Testing Procedure.pdf in today’s in-lab activities on the

EEIC courses website.

2. Follow today’s Concept Screening and Scoring Guidelines & program provided scenario.

3. Demonstrate the balance of the AEV by placing the AEV on the desktop stand.

4. Run the AEV statically to ensure the code is working the way the team intended.• Are the propellers spinning the correct way?• Is the AEV running the correct length of time?

5. Get an Instructor/TA’s approval prior to running on the test track.

6. Use the large propellers for the track test

7. Caution: Before running on the test track, verify that the body of your AEV is PARALLEL to the track. Carefully tighten the attaching screws to assure the alignment does not change.

Test Track Safety Procedure

Entrance Gate (Station #2)

North

EastBack of classroom

Start Here

= Locations of where students

should stand

Preliminary Design Review (PDR) The PDR demonstrates that the preliminary design meets

all system requirements with acceptable risk and within the cost and schedule constraints and establishes the basis for proceeding with detailed design.

• These first eight labs will help build a foundation in creating an energy efficient vehicle that will meet all the criteria stated in the Mission Concept Review (MCR)

• PDR is due at the beginning of Lab 10B with more details of the PDR outlined in Lab 8

Questions?