Research on Measurement Method for Moment of Inertia of Large-Scale Projectiles and Spacecrafts

To investigate the approach to enhancing the measurement precision of moment of inertia of large-scale projectiles and spacecrafts,three measurement methods presently used home and abroad,torsion pendulum method,compound pendulum method,and three-string pendulum method,were reviewed.The precisions and error resources of the methods were summarized and compared.Results show that the friction resistance and air-drag are the major error resources for wings and rudders structure and large mass of tested object.There is little contribution to reduce the errors from friction resistance and air-drag by improving the sensors and electronic circuits.The friction resistance and air-drag can not be adequately represented by describing the torsion pendulum as a two-order linear system.With the expensive cost and complicated technology,the vacuum cabin and gas bearing are only effective ways to reduce the errors caused by the friction resistance and air-drag.