Vibration rejection for inertially stabilized double gimbal platform using acceleration feedforward

The paper documents a computational design and an experimental verification of a vibration rejection scheme for an inertially stabilized platform mounted on a mobile base. The mechanical configuration of the platform is that of a standard double gimbal, which realizes a mass stabilization of the line of sight of an optoelectronic payload such as a camera an/or laser ranger finder. Nonideal static balancing of the payload gives rise to projection of the carrier vibrations onto a disturbing torque acting on the payload around the joint axes. This disturbance can be left for the existing inertial angular rate feedback to attenuate but a better solution can be devised. The cause of this disturbing torque — the linear acceleration of the carrier — can be measured, filtered and fed forward to the two direct drive motors. Experiments prove that significant vibration rejection is achieved with this feedforward compensation scheme.