含间隙卫星天线双轴驱动机构动力学特性分析

以某型点波束卫星天线双轴驱动机构为研究对象，研究关节间隙对驱动机构动力学特性的影响规律。通过建立关节间隙动力学模型，并将间隙模型嵌入到虚拟样机中，进一步建立含间隙的双轴驱动机构虚拟样机。利用虚拟样机进行动力学仿真，分析关节间隙对双轴驱动机构动力学特性的影响。同时，利用多项式拟合的方法给出间隙大小对系统动力学特性的影响规律。结果表明，关节间隙会使运动副构件间发生接触碰撞，导致驱动机构执行末端动力学特性变化，影响运行稳定性，降低定位精度。且随着关节间隙的增大，执行末端的速度误差和加速度误差峰值都随之增大，使系统的运行稳定性变差。所得结论对双轴驱动机构定位精度的分析与控制具有重要的理论价值及工程实际意义。

Research on Dynamic Characteristic of Two-Axis-Position Mechanism for Satellite Antenna with Joint Clearance

In order to research the dynamic characteristic of the two-axes-position mechanism for satellite antenna with joint clearance,a joint clearance dynamics model was established.A virtual prototype model of the two-axes-position mechanism with clearance was established by embedding clearance into virtual prototype.The effect of the joint clearance on dynamic characteristic was analysed by using virtual prototype.The function of the effect of clearance size on dynamic characteristic was obtained by curvefitting.The analysis results showed that the joint clearance lead to impact and contact,and affected the dynamic characteristic and pointing accuracy of the two-axis-position mechanism.With the enlargement of joint clearance,the error of velocity and acceleration increased,and it lead to descent of operation stability.The conclusion was important for pointing accuracy analysis and control of the two-axis-position mechanism.