A precise rotary positioner driven by piezoelectric bimorphs: Design, analysis and experimental evaluation

A precise rotary positioner driven by piezoelectric bimorph elements with simple structure and high resolution was proposed, fabricated and tested in this work. The dimensional design was completed according to the theoretical model, and the simulations were conducted with finite element method. A prototype and an experimental set-up were fabricated to conduct some experiments. The experimental results showed that the positioner had a small mass of 20.5 g, and the output angle fitted a good linear relationship with the exciting voltage. Besides, the repeatability was measured as 0.180″ (0.873 μrad), and the resolution was higher than 0.0252″ (0.122 μrad), which reflected the high precision of the positioner. The dynamic performances were measured and the load characteristic was calibrated as well. Based on good extendibility, more bimorphs could be added to improve the load capability or increase the motion stroke. The proposed positioner had a good prospect in the field of precise rotary positioning.