Further Study of a Low-Pressure on-off Pneumatic Servomechanism

This paper compares experimental and theoretical transient and frequency response results for a low-pressure on-off pneumatic servomechanism comprising a polarized relay with dead zone and hysteresis operating a four-way flapper-nozzle valve via a torque-motor. The valve operates a linear pneumatic motor which drives a load in the presence of Coulomb friction and stiction. Position, velocity, and quasi-transient pressure feedback are provided. The effect of dynamic conditions on the valve characteristics is discussed.