Transcending the Acceleration-Bandwidth Trade-off: Lightweight Precision Stages with Active Control of Flexible Dynamics

Abstract: Micro/Nano-positioning stages are of great importance in a wide range of manufacturing machines and instruments. In recent years, the drastically growing demand for higher throughput and reduced power consumption in various IC manufacturing equipment calls for the development of next-generation precision positioning systems with unprecedented acceleration capability while maintaining exceptional positioning accuracy and high control bandwidth. Reducing the stage's weight is an effective approach to achieving this goal. However, the reduction of stages' weight tends to decrease its structural resonance frequency, which limits the closed-loop control bandwidth and can even cause stability issues. Aiming to overcome the aforementioned challenge and thus create new lightweight precision stages with substantially improved acceleration capability without sacrificing stage control performance, this research presents a novel sequential structure and control design framework for lightweight stages with low-frequency flexible modes of the stage being actively controlled. Additional actuators and sensors are placed to actively control the flexible structural dynamics of the lightweight stage to attain high control bandwidth. A case study is simulated to evaluate the effectiveness of the proposed approach, where a stage weight reduction of 24% is demonstrated compared to a baseline case, which demonstrates the potential of the proposed design framework. Experimental evaluation of the designed stage's motion performance will be performed on a magnetically levitated linear motor platform for performance demonstration.