What will be the anthropometric concerns and ergonomic studies to determine parameters A, B, C, D, E, α and ф as a design input?
Figure-1
To determine parameter A, It’s better to make an optimized ergonomics approach by choosing %98 anthropometric body type of user population and considering a safety factor (to be used by following generation that will be in the same percentage). The standing height of %98 body type will be the main concern and should be measured and statically located in a bell-shaped curve if there is no existing anthropometric study or standard is suitable or available.
Figure-2
An attempt for direct determination of parameters B and C will possibly cause lots of harsh design requirements and studies. Rather than approaching constant values of B and C, ergonomics analyst should develop more practical inputs for design. At first look, it’s better to lead the designer to an adjustable seat design.
Figure-3
For adjustable seat design, ergonomics analyst should provide seat stoke limits by studying the case with limit body types of population. For horizontal and vertical stroke limits, parameter B and C will be neutral seat position which should be suitable for % 50 population body sizes. For horizontal stroke limits, parameter C‘ where the seat distance to the console is smallest, %3 body size should be considered. Parameter C’‘ where the distance of seat to the console is largest, %98 body type of population should be studied. For vertical stroke limits; B‘ where the seat distance to the bunker floor is largest should be analyzed according to %3 body type , B'‘ where the seat distance to the bunker floor is smallest should be studied according to %98 population size.
Figure-4
Figure-5
For parameter D, ergonomics analyst should just check the reach envelope of the user body type due to adjustable seat design (at stroke limits). There should be also some field tests needed to observe user comfort (keeping in mind that posture of the user will be affected by the stroke limits).
Figure-6
For angular parameters α and ф, ergonomic studies should determine an «eye point», check the parameters if it’s consistent with the standards according to the seat stroke limit positions and contain view area analysis . The term eye point can be defined as the intersection point of normal view line of the user (% 50 body types at neutral seat position) and the screen plane normal lines. After determination of eye point, analyst should check the parameters α and ф is consistent with the standard requirement which declares that the angles between normal view line and screen plane normal should be minimum 45˚. And then with a HMI CAD tool, view of the user body types should be simulated.
Figure-7
Parameter E is the most vital parameter for ergonomic studies because it is related with an emergency application. So human factors analyst must include all the user body dimensions of user population for an achieved crew escape system. This means all users should be able to gain an access to the emergency door and leave the bunker. Precautions like adding a ladder for accessing the emergency exit design should be evaluated by the human factors practice.
Figure-8