A systematic geometric model has been presented for calibration of a newly designed 5-axis turbine blade grinding machine. This machine is designed to serve a specific purpose to attain high accuracy and high efficien...A systematic geometric model has been presented for calibration of a newly designed 5-axis turbine blade grinding machine. This machine is designed to serve a specific purpose to attain high accuracy and high efficiency grinding of turbine blades by eliminating the hand grinding process. Although its topology is RPPPR （P： prismatic; R： rotary）, its design is quite distinct from the competitive machine tools. As error quantification is the only way to investigate, maintain and improve its accuracy, calibra- tion is recommended for its performance assessment and acceptance testing. Systematic geometric error modeling technique is implemented and 52 position dependent and position independent errors are identified while considering the machine as five rigid bodies by eliminating the set-up errors of workpiece and cutting tool. 39 of them are found to have influential errors and are accommodated for finding the resultant effect between the cutting tool and the workpiece in workspace volume. Rigid body kinematics techniques and homogenous transformation matrices are used for error synthesis.展开更多
高精度在轨几何定标是星载激光测高仪有效应用的基础,在参考国外冰、云和陆地高程卫星(Ice,cloud and land Elevation Satellite,ICESat)卫星搭载的地球科学激光测高系统(Geo-science Laser Altimeter System,GLAS)几何定标的基础上,提...高精度在轨几何定标是星载激光测高仪有效应用的基础,在参考国外冰、云和陆地高程卫星(Ice,cloud and land Elevation Satellite,ICESat)卫星搭载的地球科学激光测高系统(Geo-science Laser Altimeter System,GLAS)几何定标的基础上,提出了一种基于地面红外探测器的星载激光测高仪几何定标方法。采用资源三号02星上搭载的国内首台试验性对地观测激光测高仪的真实数据开展了实验验证。实验结果表明:地面红外探测器能有效捕捉到激光测高仪对地发射的激光信号,几何定标方法能有效消除指向角的系统误差项,标定后平面绝对精度可提高到15.0 m左右,而华北某地高精度地形数据验证表明其绝对高程精度可提高到1.09 m,少量点高程误差小于0.5 m。虽然精度水平离国外GLAS还有一定差距,但相关结论能为后续国产激光测高卫星的优化设计、数据处理与应用提供参考。展开更多
文摘A systematic geometric model has been presented for calibration of a newly designed 5-axis turbine blade grinding machine. This machine is designed to serve a specific purpose to attain high accuracy and high efficiency grinding of turbine blades by eliminating the hand grinding process. Although its topology is RPPPR （P： prismatic; R： rotary）, its design is quite distinct from the competitive machine tools. As error quantification is the only way to investigate, maintain and improve its accuracy, calibra- tion is recommended for its performance assessment and acceptance testing. Systematic geometric error modeling technique is implemented and 52 position dependent and position independent errors are identified while considering the machine as five rigid bodies by eliminating the set-up errors of workpiece and cutting tool. 39 of them are found to have influential errors and are accommodated for finding the resultant effect between the cutting tool and the workpiece in workspace volume. Rigid body kinematics techniques and homogenous transformation matrices are used for error synthesis.
