Windshield Wiper Assembly Re-design
From DDL Wiki
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Revision as of 13:25, 9 October 2007
Contents |
Executive Summary
Updates since Report 1
Please provide any updates to the wiki report on the analysis of our current product (see report 1 revision assignment)
Research and Observations
Please provide a description of your research and observations. Define the design problem as you understand it, and identify insights and opportunities
Top Design Concepts
Please provide sketches and descriptions of your top three to five design concepts, describing what opportunities have been identified and how they will be addressed.
Compressed Air System
The compressed air system is our most revolutionary idea. This system would get rid of the wipers all together. The basic idea of this design is that we would used compressed air to blow the rain off of the windshield.
Durable
Easy to change
Affordable
Effective for all weather
Percentage of windshield covered
Visibility
Heated Blades
Already been done :-( http://www.blizzardblade.com/Place%20Order.htm
http://www.everblades.com/HEATFLEXX.htm -these guys don't have any 'structure', the rubber just fits the curvature of the windshield.
Back of Envelope Calculations
They use 12 V * 2.5 Amps = 30 Watts. 2 blades = 60 Watts.
Latent Energy of Fusion = energy to melt ice = 80 calories per gram = 334720 joules per kilogram.
An icy windshield is roughly 6 sqr. feet = .56 Meters Square. 1/4 inch thick = 0.003556 M^3 of ice.
Density of ice = .931 gram/cm^3. Icy windshield = 3560 cm^3. Mass of ice = 3.3 KG of ice on windshield.
Need 3.3 * 334720 = 1,104,576 Joules to melt the windshield.
60 joules/second. = 306 minutes to melt the ice. Wow.
Exchangeable Blades/Rubber
Multiple Blades (flap or rotating)
- top design at this time
- keep current rubber blade for rain
- add blade made out of hard plastic for ice/snow/leaves
- wiper blade subassembly will rotate to change to this setting
- Variation: position hard blade so it can flab down into place
- the wiper blade subassembly will not need to rotate
- future decisions: angle of hard blade, how to implement rotation
Design Comparisons
Pugh Chart
| Criteria | Weight | Standard Windshield Wiper | Compressed Air System | Heated Blades | Exchangeable Blades | Multiple Blades |
|---|---|---|---|---|---|---|
| Durable | 1 | 0 | + | - | 0 | - |
| Easy to change | 2 | 0 | - | 0 | ++ | - |
| Affordable | 2 | 0 | -- | - | ++ | - |
| Effective for all weather | 3 | 0 | -- | + | 0 | ++ |
| Percentage of windshield covered | 1 | 0 | ++ | 0 | 0 | 0 |
| Visibility | 3 | 0 | + | + | + | + |
| + | 0 | 6 | 6 | 5 | 9 | |
| 0 | 12 | 0 | 3 | ? | 1 | |
| - | 0 | 12 | 3 | ? | 5 | |
| Net Score | 0 | -6 | 3 | ? | 4 | |
VOA
also, although the client didn't specifically ask for a VOA, I have asked you to provide one as part of your way of communicating the opportunity.
Gandt Chart
In addition, each report should include a Gantt chart or alternative method to map out the team plan for design and prototyping through the remainder of the semester. Be as detailed and specific to your particular project as you can, and assign roles for team members as appropriate.
