Research on a kind of precision rotary drive mechanism

The inner gimbal of electro-optical pod with two-axis and four-gimbal structure is usually driven directly by torque motor, its stability accuracy is only tens of micro radians. To achieve the stability accuracy of several micro radians, a flexure-based precision rotary drive mechanism driven by piezoelectric actuators was proposed, which acted as the inner drive of electro-optical pod. The configuration scheme of precision rotary drive mechanism was introduced, and the drive capability of piezoelectric ceramics was explored. The rotation stiffness, resonance frequency and geometric parameters were designed in detail. The electromechanical simulation model was obtained. In addition, a prototype was fabricated and tested for performance verification. The results show that the travel range is 509.1 μrad, the resolution is better than 0.5 μrad, the sinusoidal signal tracking error of 1 Hz and 100 μrad is less than 3 μrad, and the resonance frequency is about 1 KHz. These results can all meet the design goals.