In the field of motion picture photography, camera stabilization devices are used to isolate the camera from the natural body movements of the operator, while providing fluid maneuverability across a set. The purpose of this project is to design, build and optimize a low cost, compact gyro-based servo stabilization device for a professional handheld motion picture camera.
This device uses MEMS based rate gyro sensors mounted to a gimbaled camera rig to measure the angular rate of the camera's rotation. The gyro signals are amplified to drive DC servo motors coupled to the camera's rotational axes. As a gyro measures the cameras rotation about an axis, the corresponding servo motor applies an opposing torque on the platform to oppose camera rotation.
The camera is mounted to a yaw and pitch gimbaled structure, adjustable so that the rotational axes can run through the cameras center of mass, thus minimizing the torque and power required to stabilize the camera.
Each gyro rate signal is amplified by a proportional gain amplifier. An integrator circuit acting on each rate signal, helps ensure that the rig does not drift due to extraneous forces. A pair of high current, high power operational amplifiers drive each servo motor from the sum of the proportional and integrated rate signals.
Dynamic tests confirm that the gyro stabilization dramatically and consistently decreases the peak yaw rotation and peak pitch rotation relative to the clamped configuration. Further enhancements include the addition of a third axis and the use of geared motors. Experimental results are validated with a MATLAB/Simulink simulation.