Multi-objective optimization of structural parameters design of vacuum cylinder

Air pressure control methods consist of constant volume control method and variable volume control method. The constant volume control method under a lower vacuum circumstance has problems with a low pumping capacity of vacuum pump, intensified leakage of servo valve, and dynamic characteristics of connecting pipelines, which result in poor pressure control effects. This article proposes a variable volume control method with a pressure generator. The pressure generator is built by a symmetrical vacuum cylinder. Friction and natural frequency are two key factors of the vacuum cylinder affected by the cylinder structural parameters. The mathematical model of the cylinder with friction is presented. A multi-objective optimization method of the cylinder structural parameters is provided to improve the friction performance and the natural frequency. The influence of both the vacuum cylinder piston diameter and the single chamber width on the friction and the natural frequency is investigated. The results show that the pressure range of the developed vacuum cylinder is 1 ~ 100 kPa.