bruce mayer, pe licensed electrical & mechanical engineer bmayer@chabotcollege

[email protected] • ENGR-11_Lec-05_Chp8_ParaMetric_Design.ppt1

Bruce Mayer, PE Engineering-11: Engineering Design

Bruce Mayer, PELicensed Electrical & Mechanical Engineer

[email protected]

Engineering 11

Human Factors

& Ergonomics



OutLine Human Factors Human limitations, abilities Human-Machine System Sensory input limitations Decision making limitations Summary



Definition Human Factors What is Human Factors Engineering

(a.k.a. Human Factors)? The Design for the abilities,

limitations, and other physiological or behavioral characteristics of humans which affect the use & operation of tools, machines, systems, tasks, jobs, and environments.



Consider HF Early in the DesignHum

an FactorsFormulation

Detail

Parametric

Configuration

Concept

Embodiment Design

Preliminary Design



Common Customer Requirements Typical Human Functional

Requirements• User-Friendliness• Convenience• Effectiveness• Efficiency • Increased productivity

Typical Human Values Requirements• Improved safety • Reduced worker

fatigue or stress • Increased comfort • Greater user

acceptance • Increased job

satisfaction • Improved quality of

life



Starting Pt Activity Analysis Human Factors Design often begins

with an Activity, or InterAction, Analysis for the Types of People Who will Interact with the Designed Product in some form.

Interaction Type examples• People who BUILD the Product• People who USE the Product• People who DISPOSE of the Product



Example Bike USER (Rider) Activity Analysis for a BiCycle Rider

• removes the bicycle from storage, • climbs onto the bike and pedals down the street,• pushes the handle bar to steer around a dog in the street,• slows down by grasping handbrake lever and squeezing,• steers to the side of the road to let car pass by, • pushes the shift lever to a lower gear decreasing pedal

force to climb hill,• squeezes brake lever to stop at the top of the hill,

dismounts, • walks the bike to roadside and enjoys the view.



Rider↔Bike InterActions Use eyes to see Hands/Arms to pick up Foot and Leg to climb up onto seat Hand(s) for braking Feet and Legs to provide propulsion Ears to Hear traffic or dogs Fingers to shift gears Inner Ear/Balance to stay upright



Considerations in HF Design Types of People

who Interact with a Machine• Builder/Maker

– person who produces the product

• Shipper/Installer• User• Maintainer (repair

persons)• Disposer

Basic Machine Operation• Takes INPUTS• Performs a

Productive FUNCTION

• Produces OUTPUTS– Value-Added

OutPut (Desired)– ByProducts

(Not Desired)May be

nonBenign



Typical S8-0701Ergonomic Measurement

S8 Spec Focuses on• Installer/Disposer• User• Maintainer

SEMI S8 GuideLinesapply to the design, operation, maintenance, and service of semiconductor manufacturing equipment, as well as, to a limited extent, equipment installation



SEMI S8 A

ctivity A

nalysis &

Conform

ance Review



Human-Machine Sensory Limits

Makes Decisions

Perform Function(s)

InputSensory signals

OutputMuscle force,

torque, motion

InputControl signals

OutputPerformance

displays

Human - Machine interface



Sensory input limitations Sight Hearing Smell Taste Touch

• Kinesthetic (People can get a “Feel” for a good Tennis Stroke)

• Vestibular (Response to whole-body Accelerations)



Sight Limitations Near/Far focusing Speed (persistence of vision) Night vision/illumination “perceive” (optical illusions,

psychological?) Color blindness



Hearing Limitations Frequencies Amplitude “perceive” (hear, but not

know what caused…) Understand (language) Masking by ambient/environmental

noise



Touch • Kinesthetic • Vestibular Tactile stimulation of skin

• Sharp, hot, smooth, electrically charged Radiation (heat) Kinesthetically feel joint/muscle

movement• “Good” golf/tennis swing, skiing, PoleVault

Vestibular (inner ear) • Sense of balance



Sensory OverLoad Too much input, too fast Confusing Sensory

Fatigue



Human-Machine Decision Limits

Makes Decisions

Perform Function(s)


OutputMuscle force,

torque, motion


OutputPerformance

displays




Decision making limitations DECISION RAMIFICATIONS InputInfo → MakeDecision → TakeAction

• Action Taken is often called the “OutPut”

Example• Input: See politician in the road• Decision: Decide to hit or avoid?• Output (TakeAction): Steer Around OR

Brake OR Accelerate



ReAction Times Fast & Slow SIMPLE reaction time

• one stimulus, same response– i.e. “knee jerk”, trained response

e.g.; See Dog Run into Road Hit Brakes!!!

CHOICE reaction time• several stimuli, different responses

– i.e., process multiple, and possibly conflicting, signals; then Take “some” (wrong?) actione.g. power plant malfunction



Human-Machine Output Limits

Makes Decisions

Perform Function(s)


OutputMuscle force,

torque, motion


OutputPerformance

displays




Human Mechanics Forces (e.g. arms, legs, hands,

fingers) Range of motion (Kinematics) Energy Expenditure Control - Ability Size

(abilities/limitations)



Force Mechanics



Range of M

otion



Energy/Power Expenditure

Table 11.2 Mean value energy expenditure per day for various occupations (adapted from Sanders and McCormick, 1993)

Energy Expended Occupation (kcal/day) Construction worker (male) 3000 Steel worker (male) 3280 Coal miner (male) 3660 Housewives 2090 University males/females 2930/2290



Human Sizes The study of Anthropometrics (human

measurement) is concerned with the physical sizes and shapes of humans.

Of particular interest are the differences between and among different populations (men vs. women, Northern Europeans vs. Japanese, etc.)• Most typical “Boundary Conditions”

– 5th %-tile Asian Female– 95th %-tile American Male



95th %-tile American Male

5th %-tile Asian Female



Anthropom

etricsA

merican W

oman



Control-Ability



Human-Machine System Summary

Makes Decisions

Perform Function(s)


OutputMuscle force,

torque, motion


OutputPerformance

displays




Visual & Auditory Displays Visual Display Types

• indicator lights • continuous readout gages • digital counters • graphical panels

Audible Display Types• bells• buzzers• horns• Sirens• tones, and • electronic devices that speak



Display GuideLines Conspicuity – The display should be

conspicuous in that it should be prominently located, novel and relevant.

Emphasis – Important words should be visually emphasized.

Legibility – Character fonts, size and contrast should be exploited.



Display GuideLines Intelligibility – Succinctly tell the

operator what the hazard is and how to fix it.

Visibility – The display should be visible in all lighting conditions including day or night.

Maintainability – The display should resist aging, wear and vandalism.

Standardization – Standard words and symbols



Design For Fit Gold Standard Design to

Accommodate Human Interaction for

5th Percentile Asian Femaleto

95th Percentile American Male

Use anthropometric data



Example Ergonomic Design95th PercentileAmerican Male

5th PercentileAsian Female



WorkSpace Design Climate

• air temperature, humidity• airborne particulates• odors and harmful vapors

Illumination • light intensity, color content• glare/ reflection

Noise • sound level, frequency, duration, • fluctuations in level or frequency

Motion • whole body vib., freq. and intensity• head motions (motion sickness)



Summary ErgoNomics Customer requirements include HF Sensory input limitations Decision making limitations Human muscle output limitations

• Forces, range of motion, energy, Anthropometrics Design for fit Workspace guidelines



All Done for Today

Formula SAEAnthropometric

Data



Bruce Mayer, PERegistered Electrical & Mechanical Engineer

[email protected]

Engineering 11

Appendix



SEMI S8 Goals These guidelines provide ergonomics design principles and

considerations for semiconductor manufacturing equipment. The purpose of these guidelines is to promote compatibility

between the user and the equipment in the IC manufacturing environment. The following general principles are integral to the ergonomics design and evaluation of equipment: • The equipment should be designed to optimize safety by distributing

tasks. Tasks should be distributed among hardware, software, and users to make the best use of their respective capabilities and to minimize limitations and hazards. Appropriate distribution of tasks will also optimize performance.

• Equipment should be designed to minimize potential for errors and mishaps, by conforming to users' expectations.

• The equipment design should reduce fatigue and injury by fitting the equipment to the expected body size, strength, and range of motion characteristics of the user population. Such design will also facilitate task performance.



Human Machine InterAction

bruce mayer, pe licensed electrical & mechanical engineer bmayer@chabotcollege

Documents

pe engineering

human abilities

human characteristics

human factors ergonomics

n s j o h n s o n c

design of equipment

shift lever

handbrake lever