三坐标GPS定位精度标定机结构设计与特性分析

Structure Design and Characteristics Analyzes of the Three Coordinates Measuring Machine for Calibrating GPS Positioning Precision

利用三坐标标定机快速标定GPS定位精度时,标定机的静动态特性在某种程度上会影响到三坐标标定机定位精度。为保证结构强度以及确定标定精度,利用三维CAD建立三坐标标定机模型,再应用Ansys有限元分析方法对机构进行了静力学、模态和瞬态动力学仿真分析,研究其相关动态特性及特定点的定位误差范围。仿真结果表明:标定机的三维静态定位误差不超过0.0001mm,不需误差补偿;标定机的固有频率较高,不会在所安装的激振器激励下产生共振;在施加的激振器的振动激励作用下,三坐标标定机的动态定位精度远小于设计定位精度0.1mm的要求,因此所设计的三坐标标定机可用于GPS的动态特性研究。

While using the three coordinates measuring machine to calibrate the positioning accuracy of GPS,the static and dynamic characteristics of machine will affect the positioning accuracy in some extent.To ensure the structural strength and confirm the positioning accuracy of the three coordinates measuring machine,the 3D model of three coordinates measuring machine was established in this paper,whose statics,modal and transient dynamics simulation analysis were processed by using Ansys FEA method in order to research its relevant dynamic characteristics and positioning error range of the specific point position. The simulations analysis results reveal that the three-dimensional static positioning error of the calibration machine is less than 0. 0001 mm and needn＇t to be compensated. The inherent frequencies of the three coordinates measuring machine are much higher than the vibration frequencies of the installed vibrator and resonance can not emerge under the excitation of installed vibrator. The dynamic positioning accuracy of the three coordinates measuring machine is far less than the requirement of design precision 0. 1mm under the vibration action of the vibrator. So the designed three coordinates measuring machine can be used in the research of GPS dynamic characteristics.