Visual Sensing Based Ultrahigh Precision Motion Control With Compensated Mechanical Drift Across Different Stages

Ultrahigh precision motion control across different stages in a multistage system plays a central role in many micro/nanoscale applications. However, it remains a challenge due to the mechanical drift. Here, we propose a visual sensing based approach to implement the cooperative motion control in a multistage platform. In this method, microsized beads are attached to individual stages and taken as visual sensing probes. By tracking the motion of visual sensing probes, the positions of individual stages are measured. The principle of the proposed method is presented, followed by the experimental demonstration of the real-time mechanical drift compensation and high-precision cooperative motion control in a home-made dual piezoelectric flexural stage platform. With the proposed method, ultrahigh precision motion control between the two stages are achieved in a 3-D manner, with closed-loop motion control resolution of 1.5, 1.3, and 4.2 nm for X, Y, and Z axes, respectively. The proposed method provides an effective approach for ultrahigh precision motion control across different stages, which is believed to be significant for nanoscale manipulation related applications.