Integral based sliding mode stabilizing a camera platform using Kalman filter attitude estimation

This paper proposes an Integral Sliding Mode Control (ISMC) strategy to stabilize a camera platform. The main goal of this research is to achieve precise inertial stabilization of the platform while attenuating wide range of perturbations including external rates and accelerations. So firstly, a mathematical model for the platform is developed. Then considering the available sensors, the unmeasurable terms are extracted as system uncertainties. The upper bounds of these uncertainties are calculated theoretically and based on them, an appropriate ISMC is designed to stabilize the camera platform and regulate its absolute attitude in local horizon. MEMS gyroscopes are utilized to feedback the angular rate and absolute attitude in inertial coordinate system. To overcome attitude deviations caused by integrating the MEMS gyro's output drift, the attitude is estimated through fusion of gyroscopes with accelerometers using Kalman filter. The closed loop system stability is proved mathematically and finally, performance of the proposed attitude estimation method and the ISMC are validated experimentally.