Abstract
A pneumatic low-pass filter for fluidic systems has been designed. The filter is a combination of channels with different cross sections. This filter has the following remarkable advantages: (1) the design calculation is relatively simple, (2) though no attenuation pole can exist on the imaginary axis, a good characteristic of attenuation band is obtained by increasing the number of cascading unit elements, (3) a filter having the same performance is easily made also from a pipe connection, (4) a pneumatic high-pass filter can be realized by a suitable frequency transformation, etc..
In this study, the characteristic function (Q-function) is determined from given design specifications and the filter is realized on the basis of the reflection coefficient derived from the characteristic function. Using a digital computer, the loss effect due to a pneumatic cascading unit element is compensated for in some filters trially made, and their sizes are successfully reduced.
