含间隙天线折展机构模块精度分析

Deployment Precision Analysis of Antenna Folding Mechanism Module with Clearance

针对天线折展机构连接运动副间隙引起天线折展过程运动不确定、精度下降等问题,提出了基于"无质量杆"模型来模拟自由状态的含运动副间隙机构建模方法。该方法基于D-H法建立了天线3个闭环的几何关系模型,将无质量杆模型引入天线几何关系中,获得了展开误差的计算模型。通过综合运用蒙特卡洛法实现了自由状态折展机构展开误差计算。计算结果表明:转动副间隙对折展机构单元肋展开在Z方向上展开精度影响最大,单元肋展开最大误差为0.353 mm,可为天线折展机构设计提供了参考。

Aiming at the problems such as motion uncertainty and precision reduction in the antenna folding process caused by the connection clearance of a kinematic pair with a antenna folding mechanism,a method of modeling the kinematic pair mechanism with clearance in free state is proposed based on the"massless-link"model.First,based on the D-H method,the geometric relationship model of three closed-loop antennas is established.Second,the massless-link model is introduced into the geometric relationship,and the calculation model for deployment errors is obtained.Finally,the unfolding errors of the free-state folding mechanism are calculated by using the Monte Carlo method.The results show that the clearance of the rotating pair has the greatest influence on the unfolding accuracy of the element rib of the folding mechanism in the Z-direction.The maximum error of the element rib is 0.353 mm,which can provide a reference for the design of antenna folding mechanisms.