Design and optimization of a large-stroke XY compliant positioning stage based on cross-axis flexure pivot

Abstract XY compliant positioning stages (CPS) are widely utilized in precision engineering for their high-precision, frictionless motion capability. However, existing XP CPSs face challenges in simultaneously achieving a large motion stroke, a compact structure, and minimal parasitic rotation. To address this challenge, this paper proposes a novel large-stroke XY CPS based on cross-axis flexure pivots (CAFP). The design employs a multi-layer, rotational mirror symmetry architecture to minimize parasitic rotation and footprint. To analyze its performance, a comprehensive static model is developed to predict the stage's kinematic behavior and stiffness properties. Subsequently, a multi-objective optimization is implemented, using key geometric parameters as variables, to systematically minimize both parasitic rotation and stiffness variation. The optimized prototype features a compact structure, achieving a substantial workspace of 1.69 cm × 1.71 cm with negligible parasitic errors and stiffness fluctuation. Experimental results validate both the accuracy of the static model and the effectiveness of the proposed design and optimization methodology, demonstrating its potential for advanced micro-positioning applications.