三轴气浮台重力梯度引起的不平衡力矩分析

Study on Unbalance Torque Raise by Gravity Gradient for Three Axis Air-bearing Testbed

为降低重力干扰力矩对三轴气浮台平衡及仿真精度的影响,提出了气浮台重力梯度不平衡力矩的计算方法。根据台体上各质点受到的重力大小存在略微的差别,建立了重力梯度引起的不平衡力矩计算模型,分析了重力梯度不平衡力矩对气浮台平衡过程的影响。仿真结果表明:重力梯度不平衡力矩是气浮台台体二倍倾斜角的正弦函数;随着台体质心趋近回转中心重力梯度不平衡力矩作用越来越显著。

To reduce the influence of gravity disturbance torque on the balance and simulation accuracy of the three axis air-bear-ing testbed, the calculation method for unbalance torque raise by gravity gradient of air-bearing testbed was presented. According to the existing slightly difference by gravity on each particle of the platform, the computational model of unbalanced torque caused by gravity gradient was established and the influence of gravity gradient unbalance torque on the equilibrium of air-bearing testbed was analyzed. The simulation results show that the gravity gradient unbalanced torque is the sine function as two times tilt angle of the platform. With the mass center approaching to rotation center, the gravity gradient unbalance torque is gradually becoming the main factor affecting the air-bearing platform balance.