Accuracy analysis and synthesis of 3-RPS parallel machine based on orthogonal design

To analyze the influence degree of pose parameters on pose errors, and to guarantee the accuracy requirements of 3-RPS parallel mechanism in the whole workspace, the orthogonal design method was adopted for accuracy analysis and accuracy synthesis. According to the orthogonal design method, three pose parameters of 3-RPS parallel mechanism were considered as three factors for pose errors, and the pose error values from range analysis were introduced as error sensitive indexes. The influence degree of pose parameters on pose errors were obtained through range analysis. The factors were divided into reasonable levels based on the ratio of error sensitive indexes, and then more reasonable poses from orthogonal table were provided for accuracy synthesis. Accuracy synthesis was carried out according to the orthogonal table and tolerance values of 21 geometry original errors were derived according to accuracy requirements. The result shows that: By applying the orthogonal design method in accuracy analysis and synthesis, the influence degree of pose parameters on pose errors was analyzed completely, the accuracy synthesis results ensure the accuracy requirements in the whole workspace and a reference was provided for the development of prototype.