A compact and lightweight two-dimensional gimbal for inter-satellite laser communication applications

To achieve precise alignment, tracking and pointing, inter-satellite laser communication generally requires a two-dimensional gimbal. To satisfy the requirements of space applications, the gimbal needs to be high-precision and as small as possible. To meet this need, we designed a small and lightweight gimbal assembly. We adopted piezoelectric ceramic motors instead of a torque motor to ensure driving precision and effectively reduce the mass of the drive unit. The yoke was made from low-volume fraction SiCp/Al with excellent specific stiffness, which ensured rigidity and reduced the mass of the structure. This allowed us to reduce the mass of the gimbal to just 5.8 kg. With a laser communication head mass of 5.55 kg, this gave a load-to-gimbal mass ratio of 95.7%. We carried out experiments on our small and lightweight gimbal, followed by a finite element analysis. The results of vibration test and shaking test showed that the structure has adequate stiffness and high precision.