Multi-Axis Positioning Control for Pneumatic Isolation Table by Using On-Off Valves

A vibration suppression control problem by using on-off valves for a pneumatic isolation table is considered. In this system, positioning control is difficult because the system possesses a non-linear quantizer essentially. As a result, positioning error is remained in general. To overcome this problem, we have proposed a method considering the common multiple constraint, which is the appropriate relationship between the number of inhalation times and the number of exhalation times. By using this method, high convergence performance can be obtained without any offset. However, only vibration in the vertical direction is considered. Thus, we propose a method of suppressing the vibration of the two-axis direction by generalizing the previous method. The effectiveness of the control method is verified by numerical simulation.