Research and Development of a Linear Graph-based MATLAB Toolbox

This paper presents a new MATLAB-based software toolbox, called LGtheory, which provides a robust and automated method of evaluating Linear Graph (LG) models of multi-domain engineering systems for the primary energy domains (electrical, mechanical, hydraulic, and thermal). The necessary background on the major concepts of LG approach is presented along with a description of how the different LG processes are automated using MATLAB software. These processes are demonstrated through the extraction of the state-space model of an example system consisting of a DC motor with an inertial load. The results of this system output by the LGtheory Toolbox are simulated and compared against the same model as constructed in Simulink Simscape. This comparison demonstrates that LGtheory is capable of producing accurate state-space models of multi-domain dynamic systems.