Design, Modeling, and Evaluation of a 2-DOF Force-Sensing Fast Tool Servo for Adaptive Surface Texturing

Although the fast tool servo (FTS) exhibits unique advantages for surface texturing, its intrinsic form accuracy is capped by the position and motion accuracy of the manufacturing system. In this article, a novel FTS combining the sensing and control capability of 2-DOF tool position and cutting force is developed to enable the high-performance adaptive surface texturing. The proposed design of FTS features a motion-decoupled symmetric configuration and functions via leveraging the system dynamics and online position monitoring of two pairs of actuation-force sensing observers. Analytical models and the differential evolution algorithm are established to describe the essential working performances and guide the optimal structural parameter design, which are validated using finite element simulation. The performance assessments suggest positioning resolution around 20 nm and force-sensing resolution at the millinewton level for both cutting and thrust directions, along with motion strokes of tens of micrometers and resonant frequency of up to 4172 Hz. Moreover, the adaptive texturing of microgrooved surfaces with consistent geometry is demonstrated without prior knowledge of workpiece shapes. The outcomes of this article contribute to developing the next-generation of intelligent FTS for flexible and intelligent manufacturing.