Braxton Kyle Bensel

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For my Decision Matrix, I used five different qualities to rank the three concepts I discussed in Assignment 3. I looked at

Cost

The cost evaluates how much each concept will cost. Concept 1 is the most expensive, requiring a drivebase, linear slide, and unique control system. Concepts 2 and 3 are still not cheap but comparitively are much cheaper. Concept 2 will be moderately expensive due to the advanced sensors required. Concept 3 requires a lot of bulk material, but much less electronics.

Ease of Use

Ease of Use evaluates how simple it is for the user to use the concept. This mostly relates to how the concept will operate within ones household or how it will need to be installed. Concept 1 is a gigantic moving robot which will liekly be very hectic, giving it a very low score. Concept 2 takes away the size of concept 1, but keeps the danger in terms of a moving object that isn't constrained. Concept 3 is isolated to a rail, so it is fairly user friendly once it's been assembled.

Ease of Assembly

Ease of Assembly looks at how difficult the design will be to create. Concepts 1 and 2 are incredibly complex (as they'll require some considerable electro-mechanical setup that I'm not quite familiar with. Concept 3 has some electromechanical input but it doesn't need to sense and understand its own surroundings to the same degree as the first two concepts.

Coolness

Coolness looks at how much I like the module and how cool I think it is. Like last time, coolness is an important factor, but I don't think it's nearly as important this time around. Concept 1 is really freaking awesome, but Concept 2 and 3 are also pretty sweet. Overall, I'm happy with any of them.

Manufacturing Required

Manufacturing Required looks at how much manufacturing the parts themselves require to make. This is different from Ease of Assembly as this dictates how hard it will be to create and aquire the parts that will then be assembled. Concept 1 will require complex machining, while 2 only needs a moderate amount (but does require a lot of fine tuning). Concept 3 requires a lot of machining, but it's not particularly complex.

With this Decision Matrix, it is clear that the right decision is Concept 3.

A cart system that utilizes a singuilar connection piece to keep the rollers engaged with the track.

Functional Requirements	Design Parameters	Analysis	References	Risks	Countermeasures
Able to connect to rail	Singular Fixed-Distance Rod	By having a fixed distance, the distance between both rollers will be constant and will always adhere to the rail.	My knowledge :)	May be difficult to assemble, will require manual adjusting when assembling.	Try to make the segment as easy to connect as possible.
	Singular Spring Connection	By having a spring connection, we get the advantage of the fixed-distance connection but with a small amount of flexure to help the cart deal with real-world situations.	My knowledge :)	The spring may result in the cart potentially dropping off if the spring force is not enough.	Apply a rigorous safety factor to the design of the spring connection.
	Singular Rubber Band Connection	Similar to the spring connection, rubber bands are simply an easier connection to create than a string.	My knowledge :)	The rubber bands may be even less secure than the spring connection.	Apply an even more rigorous safety factor if rubber bands are selected.
Able to slide along rail	Traditional Bearings	Friction force = Coefficient of Friction * Normal Force	Statics	Downwards force from gravity may cause the bearings to be inefficient.	Experiment with downwards load. If it is an issue, use other option.
	Custom Delrin Piece	Friction force = Coefficient of Friction * Normal Force	Statics	Will require additional machining and inaccuracies may result in failure to slide.	Have considerate amounts of care taken when manufacturing custom delrin blocks.
	V Groove Bearing	Friction force = Coefficient of Friction * Normal Force	Statics	Similarly to traditional bearings, downwards force from gravity may cause the bearings to be inefficient.	Experiment with downwards load. If it is an issue, use other option.
Ability to house all electronics and sanitizer	Upper-Mounted Roller Arms	Shear Stress = F/A	2144 Materials	Having Upper-Mounted Roller Arms results in the base plate having less effective room. This could prevent all required electronics from fitting.	Make sure base plate is large enough to account for loss of room due to upper-mounted roller arms.
	Lower-Mounted Roller Arms	Shear Stress = F/A	2144 Materials	Having Lower-Mounted Rollers results in the base plate being closer to the bottom of the rail. This could result in potential collisions.	Carefully design hex shaft length to ensure there is enough room on base plate.

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