3 UNITS, SYSTEMS, AND REFERENCE PLANES

Both the information required to perform an analysis with Ergoniza Intelligent and the resulting output use the International System of Units, apart from specific exceptions. Forces are expressed in newtons (N), distances in meters (m), and moments in newton-meters (N·m). Angles are generally displayed in degrees (°), and time may be expressed in seconds or minutes depending on the type of analysis.

To make certain data easier to enter and read, the interface also uses centimeters (cm) for some distances and kilograms (kg) for the mass of handled loads. When a mass entered in kilograms must be incorporated into the calculations as a weight force, Ergoniza Intelligent uses a standard gravitational acceleration of 9.81 m/s².

Ergoniza Intelligent uses two main reference systems to express position, forces, moments, and other vector quantities: the Global Reference System and the Model Reference System, shown in Figure 2.

Ergoniza Intelligent also uses multiple internal reference systems that are not displayed to the user. Many of them are used in calculations and are associated with the model's different body segments.

Figure 2: Global and model reference systems.

The reference-system axes are represented using the standard color convention: X in red, Y in green, and Z in blue.