Signal Shaping of Fluid Transmission Lines Using Parallel Branching

The dynamic characteristics of fluid transmission lines with a parallel branching line are analyzed in both time and frequency domains using modal approximation techniques which enable us to use linear system theory. For hydraulic blocked lines, root loci of dominant modes as functions of parallel line length ratio, branching location and line characteristic parameters are obtained, and also unit step and frequency responses are illustrated for various parallel line configurations. By properly adding a parallel branching line, shaping of frequency response and control of fluid transients can be accomplished in various advantageous ways, i.e., shifting the resonant frequencies, improving the resonant quality, suppressing the frequency response for particular bands of frequencies including the resonance regions, phase leading. The steady state conditions are derived in an exact manner and a modal bond graph model is presented.