Abstract
In a previous paper, pressure response and movement of pneumatic cylinder driven by a pair of pulses were analyzed. In this paper, we study dispersion of piston displacement driven by the same method and consider a method to decrease the dispersion.
The dispersion of displacement is considered mainly to be dependent on the dispersion of friction. Assuming that the dispersion of friction is a normal distribution, the dispersion of displacement is calculated by a strict solution of the basic equation as well as by a linear approximation. They are verified by experimental results.
The theoretical and experimental results show that the coefficient of variation of the piston displacement is almost constant regardless of changing the mean displacement, while the standard deviation increases proportional to the mean displacement. The error of the feedback positioning system is related to the dispersion of piston displacement by the final pair of pulses. It is shown that this dispersion can be decreased by using a higher supply pressure.
