Types of simulated systems

Rand Model Designer can be used to create models of multi-component, continuous, discrete and hybrid (continuous-discrete) systems.

The continuous behavior of systems is described by first- and second-order differential-algebraic equations (DAE), written in scalar or matrix forms. A system may be written by the user in “free form”, including equations unresolved with respect to derivatives; Rand Model Designer will automatically detect the underlying mathematical structure.

Behavior charts (B-Charts), which are an extension of UML state chart diagrams without orthogonal states, are used for the description of discrete and hybrid behavior. For Discrete actions of B-Charts (entry, exit, transition) a very simple algorithmic language with well-known basic construction is used.

A system of equations, in free form, is used, for the description of continuous behavior. The free form for planning equations supposes the following possibilities:

input of formally decidable, overdetermined or underdetermined systems;
use of unordered formulas;
use of differential equations, unresolved with respect to derivatives.

Typical applications for Rand Model Designer:

modeling of mechanical systems;
modeling of electric circuits;
modeling of liquid hydraulic systems;
modeling of gas systems;
modeling of control systems;
modeling of macroeconomics.