Transcript EENG 1920 Chapter 1 - UNT College of Engineering

EENG 1920 Chapter 1
The Engineering Design Process
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Chapter 1 Homework
1.1, 1.2, 1.3, 1.5
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Chapter Objectives
• By the end of this chapter, you should:
– Understand what is meant by engineering design.
– Understand the phases of the engineering design process.
– Be familiar with the attributes of successful engineers.
– Understand the objectives of this course
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Engineering Design
• The process of devising a system, component, or
process to meet desired needs.
• It is a decision-making process (often iterative), in
which the basic sciences, mathematics, and
engineering sciences are applied to convert
resources optimally to meet a stated objective.
• Among the fundamental elements of the design
process are the establishment of objectives and
criteria, synthesis, analysis, construction, testing,
and evaluation.
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General Types of Design Processes
• Prescriptive
– Prescribe an exact sequence of steps and decisions for
realizing a design.
– Often algorithmic in nature
– Expressed on flow charts with decision logic
• Descriptive
– Describes general steps needed to achieve a design
– Does not explicitly layout steps to achieve a design
– Less formal than prescriptive process
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A Prescriptive Process
Identify Problem
& Needs
Do
requirements
satisfy needs?
Determine
Requirements
Yes
No
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A Descriptive Process
(Elements of the Design Process)
Problem
Identification
Maintenance
and
Upgrade
Research
Delivery
and
Acceptance
Requirements
Specification
System
Test
Concept
Generation
System
Integration
Design
Prototype
and
Construct
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Elements of the Design Process
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•
•
•
•
•
•
•
•
Problem Identification
Research Phase
Requirements Specification
Concept Generation
Design Phase
Prototyping and Construction Phase
System Integration
System Test
Maintenance Phase
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Problem Identification
• First phase
– Correctly Identify the problem or
– Correctly Identify the customer’s needs
• Failure to correctly identify needs results in
– Negative ramifications for entire project
– Abandonment of the project
– Costly redesigns
Cost to
implement
changes
Project lifetime
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Research Phase
• Research team conducts research on
– Basic engineering and scientific principles
– Related technologies
– Existing solutions
• Become an expert on the problem
– Do not reinvent the wheel
– Develop new and innovative solutions
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Requirements Specification
• Mission statement that guides the entire project
• Articulates what the system must do to be:
– successful
– accepted by the customer
• Focuses on what the system must do
– Engineers tend to focus on solutions and propose
early implementation of solutions
– Most Engineering education focuses on solving
problems instead of specifying them
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Concept Generation
• Many possible solutions to the problem
• Develop the best one that satisfies requirements
Design Phase
• Team develops a technical solution
• Produces a detail system design
– Describes all major systems and subsystems
– Depends upon the particular technology being used
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Prototyping and Construction Phase
• Elements of The prototype system are constructed.
– The objective of building a prototype system is to model
some aspect of the system.
– Prototype model may not work: Testing is needed.
System Integration
• All subsystems are combined to produce a complete
production model system.
– Challenging and time-consuming
– Teams must work together
– Production model may not work: Testing is needed.
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System Integration
• All subsystems are combined to produce a complete
system.
– Challenging and time-consuming
– Teams must work together
• Production model OT&E
– Installed on-site: system delivery
– Perform operational tests
– Evaluate test results
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System Test
• Prototype operation testing and evaluation (OT&E)
– Demonstrate the prototype meets requirements
– Prototype may be discarded or modified
• Production model OT&E
–
–
–
–
Tested in-house first
Installed on-site: system delivery
Perform operational tests
Evaluate test results
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Maintenance Phase
• Design problems are corrected.
• Maintenance is performed.
• System up-grades are made.
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Successful Engineers
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Aware of the world: alert to market opportunities
Solidly grounded: Thoroughly trained
Technically broad: Conversant in several disciplines
Effective in group operations:
– Willing to seek and use expert advice
– Cooperative with group members
– Effective in written and oral communication
• Versatile: innovative in the development of products and services
• Customer oriented: satisfied customers guarantees business
success
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Technical Design Tools
• LABVIEW
– Laboratory Virtual Instrumentation Engineering Workbench
(LABVIEW) is a graphical programming environment based on
the concept of data flow programming.
– Widely adopted by industry, academia, and research
laboratories around the world as the standard for data
acquisition and instrument control.
• MATLAB
– Matrix Laboratory (MATLAB) is a numerical computational software for
engineering and scientific calculations.
– Primarily a tool for matrix calculations
– Has a rich set of plotting capabilities
– Has a large collection of toolboxes
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Technical Design Tools
• VHDL
– VHSIC Hardware Descriptive Language (VHDL) is an industrystandard language for PLD design.
• VHSIC : Very High Speed integrated Circuit
• PLD: Programmable Logic Device
• Programmed in Xilinx software program
• PSPICE
– Simulation Program with Integrated Circuit Emphasis (SPICE) is
a simulation program that enables you to design a circuit and
then simulate the design on a computer.
– PSPICE is a SPICE program produced by the OrCAD company.
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VLSI System Design Process
• VLSI – Very Large Scale Integration
– System specification is used to develop the system
architecture.
– System architecture is composed of major functional unit
– Functional units designed at the
• Gate logic level
• Circuit level
• Circuit elements laid out on a silicon chip
Specification
System
Architecture
Logic Design
Circuit Design
Layout
Is this prescriptive or descriptive?
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Embedded System Design Process
• Embedded systems are combined
hardware/software embedded in
a large system to perform dedicate
application-specific operations.
• Employed in automobiles,
DVD players, and digital cameras
Descriptive or
Prescriptive?
Software Design
 Application
 Operating System
 Compiler
Requirements
Analysis
Specifications
System
Architecture
Interface Design
 Software Drivers
 Hardware Drivers
Hardware Design
 Architecture
 Synthesis
 Compiler
Integration
and Test
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Waterfall Software Development
While the waterfall methodology offers an
orderly structure for software development,
demands for reduced time-to-market make
its series steps inappropriate.
Requirements
Analysis
Specification
Development
Software Design
Test and
Verification
Descriptive or
Prescriptive?
Maintenance
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Spiral Methodology
The spiral methodology reflects the relationship of tasks with rapid
prototyping, increased parallelism, and concurrency in design and build
activities. The spiral method should still be planned methodically, with
tasks and deliverables identified for each step in the spiral.
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Success In Executing The Engineering
Design Process
• Understanding of the design process
• Able to use strong technical design tools
• Professional skills
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Course Objectives
• Understand a project’s life cycle.
• Gain proficiency with LABVIEW,
MATLAB, VHDL and PSpice software.
• Know project report procedures.
• Appreciate oral presentations
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