70 Engineering Fundamentals
other designs and make possible adjustments to
their selected approach. Redesign is critical to
engineering design and must be available at all
stages to reach the optimal solution.
Once the fi nal design is selected, engineers
develop more detailed sketches for use in commu-
nicating their ideas and as a way to advance to the
design, modeling, and analysis steps discussed in
the next chapters. To accomplish these detailed
sketches, engineers develop refi ned sketches. The
refi ned sketches combine all the components of the
fi nal design, which may be a combination of differ-
ent ideas. The refi ned sketches have much more
detail than rough sketches and are used as a frame-
work for further development. Refi ned sketches
are usually a series of sketches detailing all of the
different systems in the engineered design.
For example, a rough sketch for a new bicy-
cle design could be one sketch of the overall
bicycle with little information about each system
included. Once you select your idea, refi ned
sketches include drawings of each system, such
as gearing, pedals, and steering, and may be a
series of drawings. These drawings, while still
created by hand, will have a new level of detail
needed to begin modeling the solution.
Going Green
• 1916–1917—Two hybrid vehicles are introduced
by Baker and Woods. Both vehicles work but do
not have as much power as vehicles powered by
an internal combustion engine.
• 1970s—Victor Wouk, an electrical engineer,
researches and develops models for hybrid
vehicles including a prototype based on a Buick
Skylark.
• 1989—Audi introduces the Audi Duo, a vehicle
that uses an internal combustion engine and an
electric generator to power the automobile.
• 1997— Toyota introduces the Toyota Prius, the
first widely available hybrid vehicle, Figure A.
Figure A.
Jose Gil/Shutterstock.com
Hybrid Vehicles
Engineers are constantly trying to develop solu-
tions to problems encountered on a daily basis. As
we discovered in this chapter, engineers must be
dedicated to using many different forms of research
to find potential solutions. Solutions are developed
by using different types of research over a long
period of time. Much of the research currently being
conducted is focused on redeveloping more environ-
mentally friendly solutions to existing problems.
One example of this type of innovation through
research is the hybrid vehicle. The following is a brief
time line of the development of hybrid vehicles:
• 1839—First electric car is developed by Robert
Anderson of Aberdeen.
• Late 1800s—Battery technology is drastically
improved by many researchers and engineers.
• 1900—The Ferdinand Porsche Company develops
a vehicle that uses an internal combustion engine
to power a generator to recharge batteries making
it the first hybrid vehicle. The vehicle travels 40
miles on the battery alone.