Precision Stabilization of Large, Wide Field of View Imaging Sensors

Recent advancements in ship-mounted surveillance sensors have resulted in a need to stabilize the sensors against the ship’s natural motion while underway.  While existing narrow-field of view (NFOV) cameras are generally already equipped with stabilized, moving platforms for sector scanning and target tracking and identification, large, wide-field of view (WFOV) sensors are typically fixed in place and provide general situational awareness for a certain sector of coverage.  Currently these types of sensors lack a mounting platform that can counteract the ships natural motion and provide a stable horizon so that imagery from separate cameras can be combined to create one comprehensive, 360 degree view of the area around the ship. The Merge Plot suggested method relies on active motion control and the tried-and-true principle of gyroscopic stabilization; technology which is currently found in military-issue, mechanically stabilized binoculars and yacht-leveling systems.  Our proposed solution consists of an electrically powered spinning flywheel and counterweight assembly mounted to a actively-damped multi-axis gimbal frame which encompasses the WFOV sensor.  The gimbal assembly allows for a high degree of travel in the pitch and roll axes (relative to the longitudinal axis of the ship), and the spinning flywheel and associated eddy current create a damping action that counteracts the pitch and roll motions of the ship and maintains a level horizon so enables scene stitching from adjacent sensors.  Gyro-driven damping is combined with active rotary dampers to eliminate oscillations and overshoots to keep the sensor package level. This technology has proven quite effective in a handheld optic, where a similar gimbal and gyro assembly counteracts vessel movement and hand jitter in the pitch and yaw axes.  As a mechanical system, it can be linearly scaled up in size by changing the mass and revolution speed of the flywheel, and different axes can be targeted for stabilizing action by changing the mechanical structure of the gimbal.  Our solution will consist of the base gyroscope and gimbal assembly, along with active motion control, active magnetorheological damping, and vibration isolation in order to meet the threshold requirements.  Merge Plot will develop this by using our long history and expertise in the stabilization space, where we design and manufacture at scale electro-mechanical stabilized optics.  In addition to being an elegant solution to the shipboard sensor stabilization problem, our approach will be reliable and rugged enough to withstand the rigors of the environment topside of a ship at sea.