Authors: Feng Dong He Liao ChengLong Jia XiaoJing Xia
Publish Date: 2009/05/10
Volume: 52, Issue: 5, Pages: 1446-1449
Abstract
The electrostatic accelerometer assembled on gravity satellite serves to measure all nongravitational accelerations caused by atmosphere drag or solar radiation pressure etc The proofmass center of the accelerometer needs to be precisely positioned at the center of gravity satellite otherwise the offset between them will bring measurement disturbance due to angular acceleration of satellite and gradient Because of installation and measurement errors on the ground fuel consumption during the inflight phase and other adverse factors the offset between the proofmass center and the satellite center of mass is usually large enough to affect the measurement accuracy of the accelerometer even beyond its range Therefore the offset needs to be measured or estimated and then be controlled within the measurement requirement of the accelerometer by the center of mass COM adjustment mechanism during the life of the satellite The estimation algorithm based on EKF which uses the measurement of accelerometer gyro and magnetometer is put forward to estimate the offset and the COM adjustment mechanism then adjusts the satellite center of mass in order to make the offset meet the requirement With the special configuration layout the COM adjustment mechanism driven by the stepper motors can separately regulate X Y and Z axes The associated simulation shows that the offset can be controlled better than 003 mm for all the axes with the method mentioned above
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