A 2-DOF lightweight piezoelectric gimbal with cross-scale and power-off locking capabilities

The acquisition, tracking, and pointing (ATP) system has been widely used in the field of free-space optical communication. The 2-DOF cross-scale gimbal is a key component of the ATP system. This work proposes a 2-DOF lightweight piezoelectric gimbal with cross-scale and power-off locking capabilities, which is driven by a longitudinal-bending-bending piezoelectric actuator instead of the traditional two-stage actuators with macro and micro actuators connected in series. The actuating force is controlled by the longitudinal unit of the actuator, which can lock the rotating platform at power-off state. The bending-bending unit are adopted to achieve the 2-DOF cross-scale motions based on the stick-slip and direct working principles. A dynamic model is established to evaluate the performances. Experimental results show that the gimbal achieves cross-scale motion capabilities of 187 nrad to ±436 mrad with coupling rate below 4.5 %. It can carry a load of up to 700 g and has the characteristics of compact structure and light weight (3.0 kg). Furthermore, laser scanning and tracking application demonstration experiments validate the potential in the ATP system.