Mechanism and Validation of a Long-Stroke Ultraprecision Atmospheric Pressure Driven Actuator

This article presents an innovative atmospheric pressure driven actuator (APDA) that achieves precise control by utilizing a giant magnetostrictive actuator valve (GMAV). The actuator operates via fluid transmission and requires offline charging. A constant and stable energy supply is available throughout the actuation process, resulting in quasi-static characteristics. Precise trajectory tracking can be achieved by local closed-loop control of the control element GMAV merely. According to Pascal's principle, the diameter of the APDA is adjusted to change the transmission ratio, which can be adapted to a variety of working environments with different load and precision requirements. To ensure precise flow control and efficient fluid transmission, system dynamics were modeled to complete the prototype design. In addition, experiments were conducted to measure the output performance of the APDA, nanometer displacement resolution with submicron trajectory tracking accuracy was obtained in global open-loop conditions. This technology enables high-precision motion with expandable travel ranges, and is particularly suitable for hydrostatic transmission applications with high steady-state performance requirements.