| The objective of this thesis is introduce a new method for obtaining rational polynomial transfer function approximations for the dynamics of fluid transmission lines. In addition to the requirement to achieve accurate approximations over a frequency range from zero to a specified maximum value, emphasis has been placed on obtaining results that can be directly introduced into a total fluid system simulation diagram for time domain analysis of the effects of the line dynamics on the performance of the total system. A least squares error minimization approach in MATLAB is used to generate the approximations. To simplify the formulation of simulation diagrams, subsystem block sets for lines and other fluid components are formulated and added as SIMULINK library elements. Model formulation and simulation results are presented for three typical fluid systems operating with hydraulic fluid. The examples are repeated with air as the fluid. |
