Abstract: A geometric error identification method of multi-axis machine tool includes a measuring step of indexing a position of a target ball mounted on one of a main spindle and a table into a plurality of angles around an rotation axis, and measuring the position of the target ball at respective indexed positions by using a touch probe mounted on the other one of the main spindle and the table, a geometric error calculation step of calculating a geometric error from the measured position of the target ball, an ellipse-expression calculation step of calculating an ellipse approximate expression by an arc trajectory measured by operating the rotation axis, and an error correcting step of calculating and correcting a scaling error of translation axes from the calculated ellipse approximate expression.

Abstract: A measurement system identifies geometric errors by using an initial position measurement step for specifying coordinates and dimensions of a target sphere, and an indexing measurement step for positioning rotary axes according to a plurality of indexing conditions and identifying geometric errors from sensor measured coordinate values corresponding to coordinate values obtained by measuring the target sphere with a sensor of a touch probe. Then, in the indexing measurement step, coordinates of the target sphere can be obtained by simply measuring the target sphere with the sensor only three times, using dimensions of the target sphere obtained in the initial position measurement step.

Abstract: A geometric-error identification system includes a control unit configured to identify geometric errors in a machine. The machine controls three or more translational axes and one or more rotation axes so as to perform positioning for a positional relationship between a main spindle and an object. The control unit controls the rotation axis so as to index a measurement object jig, measures an indexed position of the indexed measurement object jig on a three-dimensional space using a position measurement sensor attached to the main spindle so as to acquire a measurement value, and identifies geometric errors of the machine related to the translational axis and/or the rotation axis based on the measurement values in a plurality of positions. The control unit measures an initial position of the measurement object jig and performs calibration of the position measurement sensor using an initial measurement value acquired for measuring the initial position.

Abstract: A measurement system identifies geometric errors by using an initial position measurement step for specifying coordinates and dimensions of a target sphere, and an indexing measurement step for positioning rotary axes according to a plurality of indexing conditions and identifying geometric errors from sensor measured coordinate values corresponding to coordinate values obtained by measuring the target sphere with a sensor of a touch probe. Then, in the indexing measurement step, coordinates of the target sphere can be obtained by simply measuring the target sphere with the sensor only three times, using dimensions of the target sphere obtained in the initial position measurement step.

Abstract: A geometric error identification method of multi-axis machine tool includes a measuring step of indexing a position of a target ball mounted on one of a main spindle and a table into a plurality of angles around an rotation axis, and measuring the position of the target ball at respective indexed positions by using a touch probe mounted on the other one of the main spindle and the table, a geometric error calculation step of calculating a geometric error from the measured position of the target ball, an ellipse-expression calculation step of calculating an ellipse approximate expression by an arc trajectory measured by operating the rotation axis, and an error correcting step of calculating and correcting a scaling error of translation axes from the calculated ellipse approximate expression.