Four-in-Three-Out Coupling Serial Spherical Photoelectric Stabilization Platform and Its Adaptive Antidisturbance Control

The photoelectric stabilization platform is mounted on the moving carrier, which isolates the carrier's attitude fluctuations and maintains the stable pointing of the optical system's line of sight within it. This is the key to achieving dynamic imaging. However, the conventional mechanism adopts a closed-frame structure with orthogonal axes, which limits the load capacity. This article proposes a three-degrees-of-freedom serial spherical platform driven by four arc-shaped voice coil motors and its overall controller design. The kinematic and dynamic models of the 4-in-3-out serial spherical platform are formulated. The controller consists of two parts. The data-driven gravity compensation is designed to deal with the gravity-induced unbalance. The adaptive sliding-mode-assisted disturbance observer based control is designed to suppress the dynamic coupling and complex disturbances. Experimental results demonstrate the feasibility of the proposal.