Stewart机构在刚体6维测量中的精度

Precision analysis of 6D measurements of a rigid body based on the Stewart platform

为得到500米口径大型射电望远镜(FAST)馈源精调实验平台的位置姿态实现反馈控制,提出利用Stewart机构,通过测量其6条支链的长度,运用Stewart机构的运动学正解求得刚体6维的位姿信息的测量刚体位姿的方法。利用Stewart机构的Jacobin矩阵条件数分析传感器精度到刚体测量精度的影响。通过实验验证了精度分析的结果,即Stewart平台的Jacobin矩阵条件数增大将使测量精度降低,因此将Stewart平台Jacobin矩阵条件数做为衡量机构测量精度的指标是合理的。这种测量方法对同类6维测量方式的设计和应用具有指导意义。

A new measurement method based on the Stewart mechanism was used to measure the positioning of the feed fine-tuning test platform of the five-hundred-meter aperture spherical telescope (FAST). The position and attitude of a rigid body can be calculated from the forward mechanism when the Stewart mechanism leg lengths are known. The condition number of the Stewart mechanism Jacobian was used to analyze the measurement precision of the sensors and the system. The experimental data agrees well with the theoretical analysis. The measurement precision decreased as the condition number of the Stewart mechanism Jacobian increased. The condition number of the Stewart mechanism Jacobaian can be used as a precision index.