Stewart次镜调整平台空间包络判定算法研究  

Study on the Envelope Space Determination Algorithm of the Stewart Platform in the Secondary Mirror Adjustment

作　　者：谭爽[1] 梁凤超[1] 鄢南兴 林喆[1] 康建兵[1] TAN Shuang;LIANG Fengchao;YAN Nanxing;LIN Zhe;KANG Jianbing(Beijing Institute of Space Mechanics&Electricity,Beijing 100094,China)

机构地区：[1]北京空间机电研究所,北京100094

出　　处：《航天返回与遥感》2021年第1期108-114,共7页Spacecraft Recovery & Remote Sensing

摘　　要：由于空间遥感相机受体积、质量和制造成本的限制,Stewart次镜调整平台需要在任意运动时刻不超出给定的包络尺寸,急需一种解决相机次镜平台空间运动约束的包络判定算法。文章根据结构参数建立了Stewart次镜调整平台运动模型,利用三角函数关系并考虑支杆长度的约束,推导模型中平移与旋转的极限位置,然后给出空间包络的判定方法。将该判定模型应用于某空间遥感相机的Stewart次镜调整平台实例中,运用解析法可快速计算出极限位置,节约了大量时间;运用数值法可进一步精确求出在有支杆长度约束时的极限位置,解析法和数值法结果均满足包络尺寸的要求,表明该包络判定算法适用于六自由度并联机构的空间包络判定。Since the space remote sensing camera is limited by size,weight and manufacturing costs,the secondary mirror pose during adjustment by the Stewart platform,must stay within the given envelope space at any time.An envelope space algorithm is urgently needed to judge whether the Stewart platform is within the given envelope space in real time.Considering the thickness of the moving platform,a kinematics model was firstly built up on the basis of the structure parameters.The extreme translations and orientations of the model were deduced by trigonometric functions respectively and they were added together to get the Stewart platform extreme positions.With the struts length constraint applied on the model,position coordinates that satisfy the constraint were calculated directly,and then the extreme positions were found to determine the envelope space.At last,with an example of the Stewart platform in a space remote sensing camera,the extreme positions were computed by the model in analytical and numerical methods.Both the results of the two methods satisfied the given envelope space.In practice,the analytical method can compute the extreme positions rapidly and efficiently,and the numerical method can have more accurate solutions than the analytical one.The envelope space determination algorithm is suitable for the envelope space judgment of the 6-DOF(6-degree-of-freedom)parallel mechanism.

关 键 词：六自由度并联机构 空间包络 包络模型 次镜调整 空间相机 

分 类 号：TP24[自动化与计算机技术—检测技术与自动化装置]