Download - Engineering 6806

Barriers 1

Engineering 6806: Design Project

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Engineering 6806

Barriers to Success

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Common Barriers

• Team Dynamics• Project Management• Design• Expertise• Construction• Programming• Debugging

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Team Dynamics Barriers• Egos• Animosity• Poor skills mix• Drones• Belicheck

• Smart• Skilled• Character

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Project Management Barriers

• Unrealistic planning• Failure to revise• Integration• Poor use of resources• Lack of contingencies

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Design Barriers

• Poor partitioning• Confusion between functional and

physical• Inadequate definition of interfaces• Failure to analyze• Failure to design• Cut and try

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Design

Read

Experiment

Research

Understanding

Design

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Expertise as a Barrier• Two kinds of knowledge

• Based on understanding (engineering)• Expertise (narrow, detailed, specific)

• Modern subsystems demand expertise• Expertise

• Short half-life• Constant replenishment

• Learn how to acquire it

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Construction Barriers• Poor physical construction

• Lots of wear and tear• Multiple people at work• Time – time – time!

• Technician work – but engineer is responsible

• Wiring• Noise

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Noise• Motors are noisy

• radiation from brush arcing• Hbridges are noisy

• High speed, high power switching• Environment may be noisy• Noise contaminates analog ckts. & sigs• Noise causes errors in digital circuits

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Noise defenses

• Measurement• power and ground lines

• separation• filtering• wiring layout• shielding• immunity/recovery

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Bypass Capacitors

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Bypass CapacitorsSource:

http://www.seattlerobotics.org/encoder/jun97/basics.html

http://www.seattlerobotics.org/encoder/jun97/basics.html

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Wiring

• Neat• Robust• Due regard to noise• http://www.4qd.co.uk/serv/

appnotes/RCWiring.html

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Inefficient Programming

• Embedded processors• constrained in space• constrained in time

• Know your instruction times• Look for efficient algorithms

• boolean ops instead of series of if statements

• look-up tables instead of calculation

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Efficient Programming

• Time budget• Overall control strategy• Interrupts• Don't oversample• Considered embedded assembler

code