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Criteria

Weighting

4-Wheel

Tadpole

Notes

Suspension

0.5

0

This criteria is broken up into the design, manufacturability, and assembly of the front and rear suspension. Both will be factored into the final decision.

Front

0

Design

1

0

Manufacturability

2

0

Assembly

1.5

0

Rear

0

Design

1

0

Manufacturability

2

0

Assembly

1.5

0

Steering

1

0

This criteria is broken up into the design, manufacturability and assembly of front, rear, or all-wheel steering. In this case, we will use the best scoring implementation of the three steering types. Consider this a child decision matrix.

Front

0

These are virtually the same because they're both 2 wheels at the front - Malcolm

Design

1

0

0

Manufacturability

2

0

0

Assembly

1.5

0

0

Rear

0

NOTE: I really struggled to find anything on rear-wheel exclusive steering, because most info is for all wheel so a lot if this info is based on intuition and my opinion. Here's a link for a couple things I could find about exclusive rear wheel steering Rear wheel steering Research -Malcolm

Design

1

0

1

Tadpole benefits from only having one wheel, don't have to consider Ackermann steering or anything like that -Malcolm

Manufacturability

2

0

1

Most rear-wheel steering systems that I could find were controlled electronically and not manually (http://imperialjournal.com/wp-content/uploads/2019/06/Vol-3-Issue-1-5.pdf), so it seems like they’d have similar implementation, although the 4-wheel system would need to consider different wheel alignments for turning, so Tadpole wins here again due to its simplicity -Malcolm

Assembly

1.5

0

0

Tadpole has an advantage due to its compact shape and simplicity, but loses points due to the overall surface area/interior area of the car being smaller than that of a 4 wheeler -Malcolm

All-Wheel

0

Design

1

0

Manufacturability

2

0

Assembly

1.5

0

Brakes

1

0

With the assumption that the implementation of brakes will be relatively equal between different wheel allocations (only front, only back, all wheels), we will only look at the over arching difficulty. Brake wheel allocations is being worked on by Ayush.

Design

1

0

Manufacturability

2

0

Assembly

1.5

0

Stability

2

0

Min is researching the stability. 3 Wheel Vehicle

Handling

2

0

Chassis

1

0

Aerobody

1

0.50

1

Connor Hawkins left a comment on the 3- vs. 4-Wheel Car co-op task page which would be another consideration for this criteria.

Smaller shape = more aerodynamic, and less holes in the car (spots for wheels) also makes it more aerodynamic, hence Tadpole -Malcolm

Battery Box

1

0

Motor Allocations

0

Typically, for tadpole design the vehicle is rear wheel drive - Evan Dodd

Consider the number of motors and if a differential would be required https://www.youtube.com/watch?v=gIGvhvOhLHU&t=282s

Weight Allocation Flexebility

1

0

-1

From Jens’ CG bounding box cad files, 4-wheel has more flexibility with CG placement -Malcolm

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