Human Engineering in Product Design

Study Notes

Ergonomics, also known as human factors engineering, is the science of designing tasks to fit human capabilities.
It encompasses both human anatomy/physiology/psychology, and engineering sciences like physics and mathematics.
Human factors engineering is crucial in product design for three key reasons:
- Providing adequate space for the operator.
- Considering how humans interpret machine displays.
- Designing controls that humans can effectively operate.

Human bodies convert energy into useful work through the motor system.
Limbs and trunk are heavy compared to the applied forces. This can lead to inefficient movements.
Movements against gravity are less efficient.
Generating force is more effective when movements are directed perpendicular to gravity.
Efficient use of momentum to reduce effort.
Effective muscle contraction, economy, and spread of effort.
Muscles are composed of motor units or bundles of fibres.
More force, or faster movements, involve a greater number of motor units
Isometric force (static) is often best for fine precision, whereas isotonic force (dynamic) aids power and endurance.

Anthropometry is the study of human body dimensions.
Workplace design should initially consider the dimensions of the operators.
Charts and manikins are essential tools for accurate representation of body size and proportions.
Data is typically presented in terms of percentiles (5th, 50th, and 95th) to show population ranges.

A control is a device to change the state of a mechanism, linking the operator to a machine.
Critical for effective operation is the position and type of grip in a control.
Population stereotypes—such as clockwise rotation for increase, etc.—influence the design.

The man-machine interface is the imaginary plane where information exchanges between an operator and a machine occur.
The operator receives information from the display and transmits information through controls.
Information exchange between humans and machines is essential for optimal effectiveness.
The correct allocation of information to each channel (e.g., visual, auditory, tactile) and ensuring that information is sufficiently salient, is needed.

Extract geometric data from a product without CAD drawings, to determine how the component was created.
Provides an efficient solution for products that lack detailed documentation.
Used in various applications (e.g., manufacturing, medical) to generate data and analyze product quality.
Reverse engineering helps speed up product turnaround time and efficiency.