Human Factor Engineering

HUMAN FACTORS ENGINEERING BUILD THE JOB TO FIT THE HUMAN

System 

A system is defined as a set of elements which are related by means of the interaction with each other and which collectively act together in order to achieve an objective or purpose

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Biomechanics is the study of mechanics applied to biological systems .It is a sub-discipline of biophysics and biomedical Engineering. It has 3 subdivisions

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Biostatics is the science of the structure of living organization in relation to the forces with which they interact

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Bio-dynamics studies the nature of and determinants of the movement and associated forces of living organisms . Bio-energetics is the study of the energy transformation in living organisms , it includes biothermodynamcis

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Bio engineering is an interdisciplinary engineering field that interfaces engineering with biology . Biostatics , biodynamics , biosenergetics, bioelectrics are the branches of bioengineering

MODEL 

Bio-mathematical modeling is a technique with which the human engineer applies the physical equation of engineering science to describe the human technological system

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Models are conventionally used for inanimate systems Through HFE , we use in human system models too

Types of models      

Deterministic Stochastic Lumped parameter Distributed parameter Discrete Continuous

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All human beings are not alike , human factors engineering models must account for biological variability.

Static’s of Rigid bodies 

Assumption :

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Bodies are considered as rigid There is practically no motion involved rigid body statics

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External forces are completely responsible for the external behavior of the rigid body , we shall consider only the external forces. Internal forces are those inside the rigid body that holds the constituent particles together

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Is our body rigid ?

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No , but for the sake of simplicity , we consider it as a rigid body.

Newton’s law 

Newton’s law - 3 fundamental laws 17 th century

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Is used in the analysis of all bodies from subatomic particles to cosmic systems

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When the resultant forces acting upon the particles is zero , the particles will remain at rest.

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According to first law , a body is said to be in translational equilibrium if the net external forces acting upon it equals to zero

Procedure for analysis of the forces and moments on a rigid body 

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Draw the FBD ( free body diagram ) of the system and indicate all the known and unknown external forces in it . Establish x & y coordinate system . Resolve all external forces into their components along the orthogonal axes.

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For each FBD apply the conditions of static equilibrium and rotational equilibrium Solve the above equations simultaneously for the unknown parameters

Bio-static mechanical model Input : A specific HFE application is stated which requires analysis.

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Modeling and Analysis : A approximate and analytic model of the system is formulated.

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Assessment & interpretation  

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What does the answer mean What useful information does it provide Can we satisfy a system specification Do we need more/different measurement