Dynamic modeling and coupling analysis of a multi-gimbal electro-optical platform

To extend target tracking range, airborne electro-optical (E-O) stabilizing and tracking platforms are often designed with a two-axis, four-gimbal structure. There is coupling between the inner and outer gimbals because of mechanical connections. In order to guide control system design, kinematic equations of this structure were established using coordinate transformation. In order to ensure positional servo precision of the outer gimbals, dynamic equations of each axis were derived based on the Euler kinetics equations. Characteristics of this E-O platform were examined through coupling analysis of kinematics, moments of inertia and inertial torque. System block diagrams for the elevation and azimuth channel were developed. The model and analytical results lay a foundation for improved mechanical and control system design for multi-gimbal E-O platforms.