陀螺飞轮转子的改进全矢动平衡方法及试验

Improved Full Vector Dynamic Balancing and Experiment of Gyro Wheel Rotor

陀螺飞轮转子的动不平衡会造成倾侧运动的抖动现象,降低航天器的指向稳定性与精度。为了实现各向异性下刚性转子偶不平衡辨识,提出一种改进全矢动平衡方法。根据拉格朗日方程建立陀螺飞轮转子动力学模型,使用复数法推导两轴倾侧角间的传递函数,分析陀螺飞轮转子内、外扭杆不等阻尼时两轴响应特性。考虑椭圆轨迹特征矢量相角与不平衡激励相角间的非线性关系,基于能量等效原理并利用椭圆正进动分量构造等效振矢,通过纯试重响应构造移相圆,给出基于等效振矢和移相圆的动平衡算法。在仿真中进行偶不平衡辨识,并在试验平台上完成偶不平衡的校正,数值分析和试验结果证明了所提方法的准确性和有效性。

The dynamic unbalance of the Gyro Wheel rotor will cause the jitter in the tilting motion and reduce the stable pointing precision of the spacecraft.In order to identify the couple unbalance of the rotor under the condition of anisotropic stiffness,an improved full vector dynamic balancing method is proposed.Firstly,the dynamic model of the Gyro Wheel is established according to the Lagrange equation.The transfer function between the two-axis tilting angle responses is derived using the complex coefficient method,and the response characteristics with unequal damping of inner and outer torsion bars of Gyro Wheel rotor are analyzed.Secondly,considering the nonlinear relationship between the phase angle of the characteristic vector of the elliptical trajectory and the phase angle of the unbalanced excitation,the equivalent vibration vector is constructed by using the forward precession component of the ellipse and based on the energy equivalence principle.In addition,the phase shift circle is constructed by the pure trial weight response.The dynamic balance algorithm based on the equivalent vibration vector and phase-shifting circle is given.Finally,the identification of couple unbalance is carried out in the simulation,and the correction is completed on the test platform.The numerical and experimental results show the effectiveness of the proposed method.