Author :
Durfee, William K. ; Wall, Matthew B. ; Rowell, Derek ; Abbott, Freeland K.
Author_Institution :
Dept. of Mech. Eng., MIT, Cambridge, MA, USA
Abstract :
A description is given of Lgraph, which is an interactive, graphical software package for creating, modifying, and reducing linear graphs. Linear graphing, a structured method for formulating and representing lumped-element, linear dynamic system models containing connected single-port energy storage, dissipative, and source elements, and two-port transduction elements, is explained through the example of a simplified, quarter-body car suspension. Lgraph enables the user to place elements from several domains in a connected graph, and then computes and displays elemental equations, constraint (loop and node) equations, and state equations for the dynamic system, all in symbolic form. Its operation is described by a second example, the modeling of a DC servomotor drive system. The procedural algorithms are described. The package was implemented using X Windows graphics and runs on Unix-based engineering workstations.<>
Keywords :
digital simulation; engineering computing; engineering graphics; graph theory; interactive systems; software packages; DC servomotor drive system; Lgraph; Unix-based engineering workstations; X Windows graphics; car suspension; connected graph; dynamic system; engineering computing; interactive software; linear graphic; modeling; software package; symbolic form; two-port transduction elements; Computer displays; Energy storage; Equations; Graphics; Modeling; Packaging; Servomotors; Software packages; Software systems; Workstations;
