Objective of the Activity Index

Apply the power-based modeling metric and model reduction algorithm to 'real-world' systems.

Key ideas

• Use energy flows as an automatic modeling metric.

• Use energy levels to rank the importance of elements.

Motivation for an energy-based metric

• Power(t) = generalized Force(t) x generalized Velocity(t).

• Power can be defined for:

all nonlinear elements,

all types of elements (i.e. C, I, R elements),

all energy domains (mechanical, hydraulics... that give comparable measurements).

• Use the element power to calculate a metric in order to reduce the model complexity.

• The activity measures the total amount of energy that flows in and out of the element.