Design of a Large-Range Compliant Rotary Micropositioning Stage With Angle and Torque Sensing

This paper presents the design, modeling, and experimental testing of a flexure-based compliant rotary micropositioning stage with a large rotational range. The rotary stage is devised based on multistage compound radial flexures. One uniqueness lies in that it owns both a compact size and a large rotary stroke. Dominant parameters of the stage are determined based on established analytical models to cater for the requirements on rotational angle and driving torque. These models are verified by conducting finite-element analysis simulations, which also demonstrate the stage performance. A prototype rotary stage is developed using a rotary voice coil motor. A strain-gauge sensor is designed to measure both rotational angle and experienced torque of the rotary stage. The sensitivities of the two-role sensor are derived analytically and calibrated experimentally. Results show that the developed stage is capable of rotary positioning with a resolution of 20 μrad over the range of 10° under an approximately infinite fatigue-life, while keeping a compact physical size. The torque sensor exhibits a resolution of 0.128 mN-m with a measuring range of 1.23 N-m. Moreover, the reported idea can be extended to the design of multiaxis rotary stage.