Cross-Coupled Repetitive Control of a Compliant Nanomanipulator for Micro-Stereolithography

This paper proposes an easy-implemented and high precision contouring control method for a self-developed compliant nanomanipulator supporting cost-effective micro-stereolithography (MSL). The proposed contouring control method is composed of a repetitive controller (RC) to achieve periodic trajectory tracking for each axis, and a cross-coupled control (CCC) for the coordination of contour errors. It is worth noting that the cross-coupled controller design and its integration to RC are not straightforward, as an incorrect feedback position may even deteriorate the contouring and an inappropriate design of the cross-coupled controller leads to instability of the system. For the proposed control structure, a correct feedback position is designed, hence a cross-coupled controller is constructed to ensure the stability and contour error reduction. Various simulations and real-time experiments are deployed on the nanomanipulator, and the comparative results validate the enhanced contour tracking performance of the proposed control method with the contour error 86 nm.