平面微重力模拟气浮系统的侧向力测量与处理

Lateral Force Measurement and Processing of Planar Air-Bearing System for Microgravity Simulation

利用测力法可直接测量平面气浮系统的侧向力,该方法通过在系统周向布设加载了预紧力的横向张力计,根据浮起前后张力计的变化量可获得气浮系统侧向力及其绕中心转矩;为进一步估计搭接位置的摩擦力,对摩擦系数和侧向力进行联合估计,为解决最小二乘算法的矩阵亏秩,将求解状态问题转化为带约束的最小值问题。测试实例结果表明,在一定的预紧力范围内,当静摩擦力不改变测试的运动趋势时,静摩擦有无参与联合状态估计对侧向力的特性估计结果影响有限。

An approach of direct force measurement is proposed to estimate the lateral force of a planar air cushion system. Lateral force gauges are arranged around the planar air bearing platform with preloading force exerted before afloat. Lateral force and its torque with respect to the geometric center can be obtained from the gauge variations while the afloat system reaches balance. Friction coefficient in every touch-spot can be evaluated with least square state estimation, which changes to a generic minimum problem with constraints since its solution matrix has a rank deficit. The analysis based on the test of a specified platform reveals there is desirable difference between estimation with friction and one without, if the preloading force is less than the critical value across which the direction chanees.