Ergonomics and Aesthetic Ergonomics and Aesthetic designdesign

Definition…Definition…

Ergonomics is the scientific discipline Ergonomics is the scientific discipline concerned with the understanding of concerned with the understanding of interactions among humans and other interactions among humans and other elements of a system and the profession elements of a system and the profession that applies theory , principle data, and that applies theory , principle data, and design methods in order to optimize design methods in order to optimize human well being and overall system human well being and overall system performance .performance .

Overview…Overview…

Ergonomics is a science concerned with Ergonomics is a science concerned with the ‘fit’ between people and their work. It the ‘fit’ between people and their work. It takes account of the worker's capabilities takes account of the worker's capabilities and limitations in seeking to ensure that and limitations in seeking to ensure that tasks, equipment, information and the tasks, equipment, information and the environment suit each worker. environment suit each worker.

Five aspects of ergonomics Five aspects of ergonomics

There are five aspects of ergonomics: There are five aspects of ergonomics: Safety Safety Comfort Comfort Ease of use Ease of use Productivity/performance Productivity/performance Aesthetics Aesthetics

DomainsDomains

The International Ergonomics Association (IEA) divides The International Ergonomics Association (IEA) divides ergonomics broadly into three domains :ergonomics broadly into three domains :

Physical ergonomics :Physical ergonomics : is concerned with human anatomical, physiological and is concerned with human anatomical, physiological and

biomechanical characteristics as they relate to physical biomechanical characteristics as they relate to physical activity. (Relevant topics include working postures, activity. (Relevant topics include working postures, materials handling, repetitive movements, work related materials handling, repetitive movements, work related musculoskeletal disorders, workplace layout, safety and musculoskeletal disorders, workplace layout, safety and health.) health.)

Cognitive ergonomics :Cognitive ergonomics : is concerned with mental processes, is concerned with mental processes, such as perception, memory, reasoning, and motor response, such as perception, memory, reasoning, and motor response, as they affect interactions among humans and other elements as they affect interactions among humans and other elements of a system. (Relevant topics include mental workload, of a system. (Relevant topics include mental workload, decision-making, skilled performance, human-computer decision-making, skilled performance, human-computer interaction, human reliability, work stress and training as these interaction, human reliability, work stress and training as these may relate to human-system design.) may relate to human-system design.)

Organizational ergonomics:Organizational ergonomics: is concerned with the optimization of sociotechnical systems, is concerned with the optimization of sociotechnical systems,

including their organizational structures, policies, and including their organizational structures, policies, and processes. .(Relevant topics include communication, crew processes. .(Relevant topics include communication, crew resource management, work design, design of working times, resource management, work design, design of working times, teamwork, participatory design, community ergonomics, teamwork, participatory design, community ergonomics, cooperative work, new work paradigms, virtual organizations, cooperative work, new work paradigms, virtual organizations, telework, and quality management.) telework, and quality management.)

PACKAGING AND ENCLOSURESPACKAGING AND ENCLOSURES EPDEPD

PACKAGING INFLUENCE AND PACKAGING INFLUENCE AND ITS FACTORSITS FACTORS

Drives the design for most electronic instruments.Drives the design for most electronic instruments. Involves considerations like,Involves considerations like,

CostCost Size Size ShapeShape WeightWeight MechanismsMechanisms FinishesFinishes AppearanceAppearance ServiceabilityServiceability ReliabilityReliability Regulations and StandardsRegulations and Standards

An exampleAn example Medical market requires rugged but safe Medical market requires rugged but safe

instruments .Military devices have to work under instruments .Military devices have to work under rugged conditions and provide good performancerugged conditions and provide good performance..

MilitaryMilitary electronicselectronics often have to operate at ambient often have to operate at ambient temperatures between -55temperatures between -55o o CC and +125 and +125o o C while C while industrial equipments has to operate between -40industrial equipments has to operate between -40oo C C and +85and +85oo C. C.

DESIGN FOR DESIGN FOR MANUFACTURE,ASSEMBLY AND MANUFACTURE,ASSEMBLY AND

DISASSEMBLYDISASSEMBLY

Some ways to reduce the cost of both assembly Some ways to reduce the cost of both assembly and production are:and production are:

Simple or automated assemblySimple or automated assembly Reduction of adjustments and calibrationsReduction of adjustments and calibrations Interchangeable partsInterchangeable parts Minimum inventory and parts handling Minimum inventory and parts handling Adaptation of existing manufacturing Adaptation of existing manufacturing

capabilitiescapabilities Minimum vendor count Minimum vendor count

WIRINGWIRING

Has many applications and complex variations Has many applications and complex variations based on current carrying capacity, mechanical based on current carrying capacity, mechanical strength, insulation properties and shielding.strength, insulation properties and shielding.

Design consideration includes the following:Design consideration includes the following: Vibration,Vibration, abrasion and shockabrasion and shock Types of connectorsTypes of connectors EMI emissionEMI emission Wire routingWire routing ServicingServicing Temperature ,humidity and fungusTemperature ,humidity and fungus

CONNECTORSCONNECTORS Connectors raise the following issues:Connectors raise the following issues:

Contact force and resistanceContact force and resistance Gastight fitGastight fit CorrosionCorrosion Life cycle, wear and fatigueLife cycle, wear and fatigue Keying Keying

TEMPERATURETEMPERATURE

Mismatch between temperature coefficients of Mismatch between temperature coefficients of thermal expansion during temperature changes put thermal expansion during temperature changes put stress on mechanical joints and accelerate failure.stress on mechanical joints and accelerate failure.

Hence ,a possible way out is by using cooling Hence ,a possible way out is by using cooling systems.systems.

It will help the designer to minimize thermal It will help the designer to minimize thermal transients and gradients in circuits. transients and gradients in circuits.

VIBRATION AND SHOCKVIBRATION AND SHOCK

Problem areas include the following:Problem areas include the following: Cables and connectorsCables and connectors Flexure stress at junction of lead and component bodyFlexure stress at junction of lead and component body Component shaking looseComponent shaking loose Transformers ,batteries, large capacitorsTransformers ,batteries, large capacitors Mechanical relays chattering above 10g and 500 HzMechanical relays chattering above 10g and 500 Hz

Some guidelines to reduce the problems in vibrations are:Some guidelines to reduce the problems in vibrations are: Mechanically damp heavy or large structures.Mechanically damp heavy or large structures. Firmly anchor large massesFirmly anchor large masses Add support to long, flexible circuit boardsAdd support to long, flexible circuit boards Clamp large componentsClamp large components Use short component leads Use short component leads Avoid sliding jointsAvoid sliding joints

VIBRATION AND SHOCKVIBRATION AND SHOCK

a) Leads should remain short to add stiffness

b) Components mounted on the posts should have a strain relief loop

c) Large components should be strapped or clamped down

d) Heavy components should be mounted near mechanical supports

OTHER MECHANICAL ISSUESOTHER MECHANICAL ISSUES Size, Weight and VolumeSize, Weight and Volume

Fire and Flood SurvivalFire and Flood Survival

MaterialsMaterials

SafetySafety