Batch Algorithm for Balancing the Air Bearing Platform

Abstract

This paper discusses the process of balancing the satellite simulator mounted on the spherical air bearing table. In order to accurately simulate the satellite motion with such a test stand it is necessary to bring the Center Of Mass (COM) of the system as close as possible to the Center Of Rotation (COR) of the air bearing by moving the balancing masses. This calibration process reduces the gravity torque influencing the system movements. A new batch method of determining the COM of the balancing platform is proposed, allowing for its later adjustment. The novelty of the method comes from the idea that the freely rotating system model can be divided into rigid part for which the center of mass is constant, and the balancing masses constituting the variable influence on the COM. Advantage of this approach is the fact, that while gathering data for the batch calibration counterweights can be actuated in a known way, which turns out to greatly improve the estimation precision. Potential disadvantage is, that estimate of the masses and paths of movement of the counterweights is required, which in practice constitutes additional sources of error. Sensitivity analysis is performed to asses the viability of this trade-of considering the inaccuracies in the balance masses paths, as well as sensor noises and misalignment.