Analysis Of Motion Error Of 3 - PUU Parallel Coordinate Measuring Machine

Coordinate measuring technology has been developed for 50 years. The limitation of the traditional orthogonal coordinate measuring machine (CMM) has also gradually revealed. So, continuity studying coordinate measurement technology based on the new test principle and method has great significance and application value. Based on the principle of parallel mechanism, a new parallel mechanism 3-PUU CMM is studied. This paper is focus on measuring machine slider motion error.Firstly, the relationship between slider movement error and angle motion error is discussed and summarized, and the experimental angular motion error of measuring machine guideway has carried out to analysis the errors. Secondly, the mathematical basis of parallel mechanism error average effect is analyzed theoretically. The average effects of input parameters error and structure parameters error of parallel mechanism through the bars to the end of the probe are researched and verified the average effects of three slider motion straightness error through the bars to the end of the probe are also researched. Thirdly, the new transfer characteristics of abbe error in 3-PUU CMM are studied on theory and experiment. And theoretical analysis and probe error calculation has been accomplished. Then, double-frequency laser interferometer is used to measure the slider movement straightness error to analyze three slider motion errors at measuring head space position. And the corresponding error model has established. The influence and rule of slider movement error to instrument measurement error can be achieved. Finally, the theory of parallel mechanism is used to put forward a new approach to analyze the motion error of stage. The structure relation of slider and guideway can be abstracted as a 4-bar parallel mechanism; the stage motion error and angle motion error analysis are also transferred to moving platform position analysis in parallel kinematic mechanism (PKM). The corresponding experiments have been analyzed and verified.