Research on Identification Method of Rotational Inertia for Floated Inertial Platform

The sphere acting as a stable platform for the floated inertial platform needs to be controlled with high precision.In order to guarantee the controlling precision,the rotational inertia of the sphere should be identified with high precision.During the actual work of the floated inertial platform,the sphere is suspended in the liquid.The pipe and counterweight in the sphere are filled with liquid and rotate together with the sphere,thus changing the rotational inertia of the sphere.Therefore,a method should be found to identify the rotational inertia of the sphere in the floating state.In this paper,a method of identifying the rotational inertia of the sphere based on attitude algorithm is proposed.In this method,a small object is hanged on the surface of the sphere to derive the rotation of the sphere.Simultaneously,the gyroscopes assembled inside the sphere are adopted to measure the angular velocity.With the measuring data of the gyroscopes,the weighted recursive least squares method is used to identify the rotational inertia of the sphere.This approach has some advantages,such as simple operation,closing to real working environment,quick calculating speed and high precision.Finally,the influences of the measurement error of the gyroscope,the initial alignment error and the position error of the suspension point on the identification of the rotational inertia of the sphere are analyzed based on digital simulation,and the effectiveness of the method is verified.