A 2-DOF rotary platform with long stroke and minimized crosstalk based on reed-leaf-inspired constant-force guiding mechanism

Two-degrees-of-freedom (2-DOF) compliant rotary platforms have gained considerable attention in precision engineering due to their potential for frictionless, backlash- and wear-free motion. However, conventional piezoelectric actuator (PEA) and voice coil motor (VCM)-driven platforms remain constrained by limited stroke and significant crosstalk. To overcome these limitations, this study proposes a novel 2-DOF rotary platform with long stroke and minimized crosstalk, in which a reed-leaf-inspired compliant constant-force guiding mechanism (CFGM) is specifically employed as the translational guiding element of the rotary platform. The platform further incorporates a high-compliance needle-type transmission mechanism to suppress crosstalk. Firstly, the structural design of the proposed platform is presented. Subsequently, the mechanical modelling of the CFGM and needle-type transmission mechanism is conducted using Euler-Bernoulli beam theory and Castigliano’s second theorem. Finally, a prototype was fabricated and experimentally evaluated. The results demonstrate a rotational travel range of 188.3 mrad × 187.0 mrad, low crosstalk of 0.74%, and a fine resolution of 1.4 μ rad × 1.4 μ rad. The tested single-axis and 2D trajectory tracking experiments show RMS tracking errors below 80 μ rad.