With the development of a photoelectric system in the aviation field, the requirements for airborne equipment have increased accordingly. The photoelectric aiming and tracking turntable as a crucial component in the photoelectric system has stringent requirements on weight and volume. A new type of structure with the coaxial dual-axis turntable has been researched, it adopts a structural form with two rotating axes connected in series and rotating Risley gratings by two independent mechanical shaft axes to complete pointing, capturing and tracking functions. This type of structure features compactness, small moments of inertia and fast response speed; this miniaturized aiming and tracking system with Risley grating is more suitable for airborne equipment. The Risley grating aiming and tracking system adjusts the optical axis angle using two rotating Risley gratings; it realizes beam pointing within a conical range through polarization diffraction. The aiming and tracking system based on Risley grating has small moving parts so it is lighter; it has more advantages than the traditional turntable. Although the tracking range is relatively limited, it still offers significant lightweight effects for certain special applications and can effectively reduce weight and volume. In this paper, we research the system of aiming and tracking with Risley gratings, the influence of mechanical turntable parameters on the system’s tracking accuracy is analyzed based on its working principle; error analysis and allocation of turntable errors are carried out. Subsequently, the decoupling model of the system is analyzed and system errors are compensated; the miniaturized tracking and calibration system based on Risley gratings is developed. Then, the photoelectric testing method based on dual reference mirrors proposed by us is used to test the coaxiality and axis jitter accuracy of the turntable. The system has an effective aperture > Φ120 mm, weight < 10 kg and volume < Φ190 × 155 mm. Pointing accuracy and dynamic tracking test show that the system’s pointing accuracy is ≯10″ and tracking accuracy is ≯380 μrad. Finally, a field tracking test is carried out and verify the system’s capability and performance.
Li et al. (Thu,) studied this question.