Introduction To EngineeringCamera Lab - 0 Introduction to the Design Process

Agenda Presentation on reverse engineering

Let’s begin with a simple question:

What is engineering??

One possible answer, from the Oxford English Dictionary:Engineering is:i) “the application of science for directly

useful purposes…” ii) “the action of working artfully to bring

something about…”

Which raises some other questions:

Is engineering just “applied science”?Is the engineer’s job the same as the

scientist’s? Engineers and scientists both solve problems, right?

If that’s the case, why are we in separate colleges at OSU?

If engineers are just “problem solvers”, then how are we different from physicists, stock brokers, or mathematicians?

And while we’re on the subject, aren’t engineers famous for creating as many problems as they solve?

More Questions

Is there anything essential about what engineers do that would clearly separate us from every other profession?

The Real Question

An Answer

Yes, there is: engineers generally are interested in creating something new and different, based on what we know (or think we know) to be true about the physical world.

The word that gets used a lot in this context is design.

A working definition of engineering:

Engineering is design performed in the presence of limiting factors and conditions.”

Design is the key: as engineers, we’re about creating new things, based on our understanding of the physical world.

What kinds of things do we design?

A new bridge (CE, WE);A racing bicycle (ME, MSE, ISE, ChemE)A fuel cell for NASA (Aero, ChemE, EE)A new operating system (EE, CSE)

The key point: in every case, it’s new and somehow different than what came before.

However, it’s almost never the case that our ideas are totally new. Almost every engineered object is an improvement or a refinement of someone else’s bright idea.

A few “for instances”…

What does NEW mean?

“Smart” Car

A two-passenger car for over-populated cities…

Planetary Explorer

How about a robot explorer for a neighboring planet?

An improved exercise watch...

A new look at PCs

• A totally new take on a venerable product:

Good engineers and designers constantly look around to see what other smart folks have done, before they begin to work.

This avoids the problem of “reinventing the wheel”. (This technique is called “reverse engineering”.)

An Initial Step

When we talk about figuring out how the world works, we use the word, analysis.

Engineers spend a lot of time learning to analyze problems, situations, designs, and ideas.

Analysis

Analysis is crucial to engineering: without our tools for doing analysis, we’re not really engineering. We’re just guessing.

One thing that sets engineers apart from other people is our penchant for attaching numbers to things… and we have a lot of ways to do that…

More on Analysis

However, analysis all by itself isn’t engineering. It’s science – usually physics or chemistry.

(Warning: this is one professor’s view.)It’s when we use analysis to help us

create something new, that we’re actually engaged in the other side of engineering, synthesis.

What is analysis without design?

Synthesis

A five-dollar professor-word for “design”.It’s what we do when we put our

analytic skills and our ideas to work creating something new.

It’s what sets us apart from most of the rest of the world...

How about limiting factors?

Usually we think of natural laws, but often the really severe limits are imposed by our fellow humans.

We call these limiting factors constraints, because they constrain our designs in some way.

Sometimes we see them ahead of time, sometimes we don’t…

A famous example: the Hubble Space Telescope

Some typical kinds of constraints:

Performance weight speed rigidity

CostMaterialManufacturing

Aluminum Cans

A design constrained by manufacturing

Some questions to ask about any design:

What were the constraints?How well did the designers deal with

them? Did they overlook any? What tradeoffs did they make?How could we design it better?

Kodak Single Use Camera:

What constrains this design?PerformanceEconomicsMaterialsManufacturing???

How does the design constrain the manufacturing process?

The camera has to be: Lightweight Rugged Light-tight

The parts themselves must be: Cheap to produce Easy to assemble Very complex

This means we need a production process that can:

Make complex partsUse strong, lightweight materialsCan produce lots of components very

quickly and cheaply

This leads us to injection molding… which you’ll get to see in a few weeks (Lab 5)

But first, we need to get a sense of how the camera works, and how it’s used.

First we’ll take some photos.We’ll use the photos to estimate the

shutter speed.The we’ll use the photos to look at the

optics of the camera. You’ll learn how the flash circuit works.Finally, you’ll see how the camera is

manufactured.