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Engineering 11. Human Factors & Ergonomics. Bruce Mayer, PE Licensed Electrical & Mechanical Engineer BMayer@ChabotCollege.edu. OutLine Human Factors. Human limitations, abilities Human-Machine System Sensory input limitations Decision making limitations Summary.
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Engineering 11 Human Factors& Ergonomics Bruce Mayer, PE Licensed Electrical & Mechanical EngineerBMayer@ChabotCollege.edu
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 Design Formulation Concept Human Factors Preliminary Design Configuration Embodiment Design Parametric Detail
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 Common Customer Requirements
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
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 Considerations in HF Design
Typical S8-0701Ergonomic Measurement • S8 Spec Focuses on • Installer/Disposer • User • Maintainer SEMI S8 GuideLines apply to the design, operation, maintenance, and service of semiconductor manufacturing equipment, as well as, to a limited extent, equipment installation
Human - Machine interface Human-Machine Sensory Limits Makes Decisions Output Muscle force, torque, motion Input Sensory signals Output Performance displays Input Control signals Perform Function(s)
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 interface Human-Machine Decision Limits Makes Decisions Output Muscle force, torque, motion Input Sensory signals Output Performance displays Input Control signals Perform Function(s)
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?) action • e.g. power plant malfunction
Human - Machine interface Human-Machine Output Limits Makes Decisions Output Muscle force, torque, motion Input Sensory signals Output Performance displays Input Control signals Perform Function(s)
Human Mechanics • Forces (e.g. arms, legs, hands, fingers) • Range of motion (Kinematics) • Energy Expenditure • Control - Ability • Size (abilities/limitations)
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
Human - Machine interface Human-Machine System Summary Makes Decisions Output Muscle force, torque, motion Input Sensory signals Output Performance displays Input Control signals Perform Function(s)
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 Visual & Auditory Displays
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 Design 95th PercentileAmerican Male 5th PercentileAsian Female
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) WorkSpace Design
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 SAEAnthropometricData
Engineering 11 Appendix Bruce Mayer, PE Registered Electrical & Mechanical EngineerBMayer@ChabotCollege.edu
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.