The Engineering Design Process

Taken and adapted from Engineering Design Second Edition by Rudolph J. Eggert.

What is Engineering Design?

Engineering design is a set of decision making processes used to determine the form of an object given the functions desired by the customer. Design problems involve consensus building and group decision making such as in determining customer needs and evaluation criteria. A simplified model of the process used to solve design problems will be discussed below.

An overview of the Engineering Design Process we use in our Senior Design Project.

Formulating

Here it is important to understand what the design problem is, and to prepare a plan for its solution.

For example, our problem statement for our project is the following:

The problem with Urban Air Taxi's that are currently being developed is that their controllers have not been proven to be capable of handling failures. Our client (Southern Aerospace Systems and Technology, LLC) desires a way to create a controller that will adaptively handle unknown failures within the motors of the Urban Air Taxi, as well as interface with the "vision" of their Urban Air Taxi that they have created so far (See Figure 1 and Figure 2). Once we established the "problem" we were trying to solve, we were able to figure out a plan for its solution. Sometimes it is important to do background research on the "field of study" your problem falls into in order to understand what your client wants. 

Generating

During this stage brainstorming occurs, and creative alternative design ideas are generated in an attempt to satisfy the customer. Analysis on these design alternatives will be completed later. 

For example, in the beginning of our project we had to sit down and brainstorm various ideas not only for creating the control system, but also for the design of the large scale prototype. Several team members had many ideas and we went through each possibility, combining points from each idea to create a focus of where we wanted to take our project. We did a lot of research in this stage, not only about "Urban Air Taxi's" but also about flying objects (at one point we even considered how a flying squirrel operates).  

Analyzing

This stage includes predicting the performance or behavior of a design candidate. Engineering models will be prepared using knowledge from basic sciences and mathematics, in order to analyze each design solution. If none of the solutions prove to be feasible, a redesign occurs and a loop back to generate alternatives is created.

For example, in this stage we are doing a lot of modeling in CATIA (similar to SolidWorks) and we are doing stress analysis calculations analytically and numerically (hand calculations and Finite Element Analysis in ANSYS). This analysis helps us iterate design solutions in order to figure out what works best for what we need. Sometimes material changes, sizing changes, interface changes might not be considered up front but could cause issues if they weren't caught. 

Evaluating

This stage compares the performance of each feasible design, in order to select which design will be the best alternative. Evaluation criteria can include performance measures (speed, size, reliability) and it is also important to think about optimizing the design methods. 

For example, once we finalize all of our design plans we hope to test the small scale prototype and large scale prototype with the adaptive control system to see if they match the results from the simulation. This will prove if our design solution worked, or if we have to go back to the drawing board. 

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If you are interested in learning more check out the textbook below:

Engineering Design, Second Edition.
Rudolph J. Eggert
Copyright 2010 High Peak Press
ISBN 978-0-615-31938-4

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