Crossbow's inertial systems are used in conjunction with a series of motors and
gimbals for stabilization.
Antenna Stabilization systems typically use the Crossbow inertial
sensor data (azimuth and elevation) to actively point the antenna at a desired satellite position in the sky. Our Products are excellent choices because they measure absolute roll, pitch, and
azimuth.
Camera Stabilization systems require fine precision from an active
stabilization system like the Crossbow inertial systems to avoid errors caused by
sensor noise, bias, or bandwidth/phase delay.
Two common uses of Crossbow product are horizon leveling and jitter reduction. Horizon leveling is typical done on aerial cameras
as they zoom in on a particular target on the ground or distance. A Crossbow vertical
gyro is strapped
down to the aircraft and supplies roll and pitch data to the active gimbal. The
gimbal uses the roll, pitch data and the gimbal's azimuth location relative to the
aircraft in order to hold the camera at a constant angle relative to the horizon.
Jitter reduction is simply measuring the activity of the camera and applying corrective
signals to the motors. An Inertial Masurement Unit that measures rate only is typically used since no absolute position information
is required. In digital video applicaitons, jitter can be removed without the use
of motors but sophisticated signal processing and rate/accelerometer data from an IMU. Placing the sensor on the camera allows the controller to do closed loop control
around a zero rate / null sensor reading. In other words the sensor is actually
measuring the error signal for the controller.
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