A REDUCED MODEL FOR A PNEUMATIC TRANSMISSION LINE

A pneumatic transmission line is widely used for measurement and control systems. Therefore it is necessary to calculate dynamic responses of the line. The Brown's model of the pneumatic transmission line gives sufficiently accurate responses, but it needs troublesome calculations including Bessel functions. In this study, a new reduced model is proposed, which is presented by first or second order system and time delay system. So calculatations using the reduced model can be very easily carried out. In experiments, tests of step responses and frequency responses were conducted. The reduced model showed a good agreement with the exact solution and experimental results. The new reduced model is very useful for designing a real control system with pneumatic lines.