A novel low-friction pneumatic actuator optimization design method for high-precision position servo control in grinding processes

Abstract

Friction in traditional pneumatic actuator (TPA) limits high-precision positioning and force control in grinding. This study developed an aerostatically suspended low-friction pneumatic actuator (LFPA). An internal air film flow model was developed to relate radial load capacity to air consumption. A hybrid multi-objective optimization algorithm (NGC-HMWOA) was then used to optimize the piston geometry to improve load capacity and reduce air consumption. A prototype was built and tested, and friction benchmarking confirmed the stability of the hydrostatic gas film formation and demonstrated an approximately 99.7 % reduction in static friction compared to the TPA. In servo positioning experiments under constant, sinusoidal, and random references, the LFPA achieved approximately 55 % faster settling time and approximately 21.7 % lower root mean square error, consistently delivering faster transient response and higher accuracy. These results demonstrate the superior performance of a low-friction pneumatic actuator suitable for high-precision grinding and highlight its potential in high-precision grinding and polishing applications.