Advanced Energy Vehicle (AEV) Lab 03: AEV Concept Screening and Scoring

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) Several methods are listed above that can assist teams in making decisions throughout the project One (1) method (in bold) will be required to assist in deciding which two (2) of the concepts will be selected to continue with investing up to the Preliminary Design Review

Two Stages to Concept Selection Concept Screening – Screening Matrix A quick method to down-select ideas Use to combine various concepts or parts Sometimes good enough for simple projects 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” These two (2) stages are only part of a design decision construct, and specifically discussed here because of the unbiased structure to categorize and weigh design aspects and screen/score various design concepts. Both will be used for the executive summary, Preliminary Design Review (PDR), and Critical Design Review (CDR).

Concept Screening Matrix Rank each design against every criteria. Rank better, worse, or same as reference. Tally scores to find best designs. Combine and improve to get top several concepts. Continue with next step. As a team develop design Success Criteria (6 minimum are required) Starting with a “reference” design (sample-AEV), rank better (+), worse (-), or same (0) as reference Tally scores, combine design concept components (not mandatory), and rescore (shown on next slide)

Concept Screening Matrix Example Reference Design Night Hawk 3 + Aerodynamics Cost Center of Gravity (Balance) Sum of +’s Sum of 0’s Sum of –’s Net Score - 1 This is an example of the screening matrix comparing the sample AEV to 1 1

Concept Screening Success Criteria Balanced - Minimal blockage + Reference Design A Design B Design C Design D Design E Design F Balanced - Minimal blockage + Center-of-gravity location Maintenance Durability Cost Environmental Sum +’s Sum 0’s Sum –’s 7 2 5 1 4 3 Net Score -1 -2 Continue ? Combine Yes No Revise Four (4) original concepts were screened, compared to the reference design. The reference design should have (0’s) for each design Success Criteria Components of individual designs were combined (Combine) and rescored, and then further revised (Revise)

Concept Scoring Define Success Criteria (rows). Same as before but with perhaps more detail. Add hierarchical breakdown if necessary. Weigh the importance of each criteria (0 – 100% with column adding to 100%). Define Reference and, if necessary or desired, newly revised set of design concepts as results of 1st step. Rate each design for each criteria (0 – 5 with 5 being the best). Calculate ranking by adding weighted scores. Select highest ranked design concepts. Design Scoring provides more detail by weighting each design “Success Criteria” in percentage (total 100%) A reference is selected (either sample-AEV or new reference) Using design concepts, or if necessary and desired, newly revised set of design concepts from the screening process, each concept is rated for each criteria (0-5, with 5 being the best) The weighted rankings are calculated and used to assist in further revising concepts and/or selecting high ranking design concepts This is an iterative process that can continue throughout the design process and the duration of the project

Concept Scoring (Select Final Design Concept) A Reference Old Ref & E Design D Design F+ Success Criteria Weight Rating Weighted Score Balanced 5% 3 0.15 4 0.20 Minimal blockage 15% 0.45 0.60 Center-of-gravity location 10% 2 0.30 5 0.50 Maintenance 25% 0.75 Durability Cost 20% 0.40 Environmental Total Score 2.75 3.45 3.10 3.05 Continue? No Develop The example above shows variation in weights for design Success Criteria, a new selected reference (A Reference) and scoring for three (3) concepts: a combination of components for two (2) concepts (Old Ref and E), an original concept (Design D), and a revised concept (Design F+)

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 Procedure Review the AEV Classroom Track Testing Procedure.pdf in today’s in-lab activities on the EEIC courses website. Follow today’s Concept Screening and Scoring Guidelines & program provided scenario. Demonstrate the balance of the AEV by placing the AEV on the desktop stand. 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? Get an Instructor/TA’s approval prior to running on the test track. Use the large propellers for the track test 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 = Locations of where students should stand Start Here North row – outer north track Next row – inner north track Next row – inner south track South row – outer south rack East Back of classroom

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?