September 4, 2014

ENGR B47Intro. to Egr. & Design

Lab #2

The Design Process &The Book Light

Today’s Agenda

• Design Process example 1: HPH• Design Process example 2: IDEO• Start a project of our own

– Info on LEDs– Info on building a circuit– Divide into teams– Define project specifically– Start drawing up designs

The Design Process

Imagine it.

Design it.

Build it.

Improve it.

- Landis p.39

• Specifics in 2.2 - 2.3• Walk through case study

Design ProcessCase study: Human-Powered Helicopter

Step 1: Customer Need or Business Opportunity• Different than business route

– Design prize offered by The American Helicopter Society (AHS)

– “Isn’t about creating a practical machine. It is an engineering challenge to the vertical flight technical community. This is a multi-disciplinary project that harnesses technical skills and teamwork to overcome what many have said for three decades was an impossible challenge”

• Open up new possibilities• First offered in 1980, $25k payout

From AHS website, accessed 2014-09-01

Design ProcessCase study: Human-Powered Helicopter

Step 2: Specifications and Constraints• Set by rules Human-Powered Helicopter competition• Rotary wing• Capable of VTOL• Flight time: 60 seconds• Altitude: must exceed 3 meters momentarily• Drift: stays within 10 meter square*• Energy storage: not permitted• Lighter than air gasses: not permitted

... and others

From AHS website, accessed 2014-09-01

Design ProcessCase study: Human-Powered Helicopter

• What was not said– Use 6061-grade aluminum– The four blades should have a teardrop profile– The hand-crank should should be positioned above the

pilot

• We don’t care how it works, we care that it works

If AHS knew how to build the best HPH, they’d have done it already!

From AHS website, accessed 2014-09-01

Design ProcessCase study: Human-Powered Helicopter

Step 3: Data and Information Collection

Step 4: Development of Alternative Designs

Step 5: Evaluation of Design /

Selection of Optimal Design

Step 6: Implementation of Optimal Design

Step 7: Test and Evaluation

Step 8: Redesign! (“fail fast”)

From AHS website, accessed 2014-09-01

Design Process

• Book tracks those of U. of Maryland Team– Gamera I– Gamera II

• “Whether the Gamera team (or any other team) will have won the Sikorsky Prize by the time you read this is anybody’s guess”...

Sikorsky Prize Winner!

• Set on June 13, 2013• Completed by AeroVelo• $250,000 cash prize

Image from Popular Mechanics article posted July 11, 2013

Sikorsky Prize Winner!

Video available on AeroVelo website:

http://www.aerovelo.com/projects/helicopter/intro/

Example #2: IDEO’s Shopping Cart

• Video from 1999 (don’t laugh!)• Follows a premier design company - IDEO• Watch the process in action• Video available on YouTube:

https://www.youtube.com/playlist?list=PL23EB9F0658CEDF6A

The Book Light Project

Searched common online marketplace for “Book Light” about nine hours ago (link)

What Tools Do We Need?

• Light source is LED– Info here is paraphrased from Georgia State

University “HyperPhysics” website

http://tinyurl.com/LEDinfo4BC

• How is it different from light sources we know?

• How does it work?

Knowledge of Basic Circuits

• Wires are like electron superhighways– Idealized as resistance of 0.000 Ω– Never any electron traffic jams

• Battery is like electron elevator(pretty bad metaphor but the best I

can do)– Low energy electrons come in– High energy electrons go out

• Will add in a switch– “Open” means you’ve put up a roadblock– “Closed” means you’ve re-opened the superhighway

Time to Make Teams

• Ideally...– Everyone gets a person familiar with circuits– Everyone gets a person with soldering experience

• If not?– Welcome to real life– Be prepared to learn– Don’t fake it - ask some questions

Design Criteria

A device that gives off LED illumination when “clipped” to a book (off otherwise)

Has construction sturdy enough to withstand everyday use

Is visually appealing to the user

Constraints

• Materials– Chip clip (various)– LED– Wire– Battery holder– AAA batteries– SPST NO switch– Electrical tape– Other components, decorations, paint (not supplied)

Tentative Schedule

• Week 1: Preliminary Designs• Week 2: Finalize Design, Wiring• Week 3: Aesthetics, Ergonomics, Refinement• Week 4 (Sept 25): Evaluation / Presentations