关键词: 旋转调制, 惯性平台, 圆锥运动, 附加误差

Abstract: The space stable platform modulated by rotation adopts the rolling technology of gyroscope housing. The servo tracking of the platform makes the gyroscope housing roll and form in a conical way. For a long voyage and high precision inertial navigation system, conical motion error leads to gyroscope drift, which in hence affect of its accuracy. In this paper, a high-precision and long-endurance rotary modulating inertial platform is firstly introduced with respect to its basic principle of. Secondly, the angular velocity of the gyroscope on the platform along the rotating principal axis is derived relative to the earth. Thirdly, the coning motion of gyroscope housing is modeled. The formula to calculate the drift error of coning motion caused by tracking error of shell rolling and frame servo with associated angular velocity is derived. Fourthly, the simulated curves based on numerical examples point out the effect of the error to the high precision inertial navigation system. Finally, the conclusion is drawn that in order to minimize the coning motion error and ensure the accuracy and reliability of the system running for a long time, the coning motion error caused by the associated angular velocity must be deducted in real time, and the shell rolling device and the platform servo system must be designed optimally.

Key words: rotary modulation, inertial platform, coning motion, additional error