Five-Axis Machine Tool Error Identification via Parameter Changes
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Solution Overview
Problem
Existing methods for identifying geometric errors in five-axis controlled machine tools, such as those described in JP2016-155185 A1, are insufficient in identifying all 13 types of errors, particularly α ZY, β XB, and γ BS, which affects the accuracy of machine tool calibration.
Innovation Solution
The method involves changing the turning radius of the measurement point of the touch probe and the initial position of the reference sphere in specific measurement steps to enable comprehensive identification of all 13 types of geometric errors, allowing for individual impact analysis of each error component.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a standard measurement method is used to identify geometric errors, then the measurement process is simple, but only partial geometric errors can be identified (insufficient identification of α ZY, β XB, and γ BS)
Solution Approach 1:
The patent applies parameter changes by varying the turning radius of the touch probe measurement point and the initial position of the reference sphere in the Z direction across different measurement steps. These parameter variations enable the identification of all 13 types of geometric errors, including those (α ZY, β XB, γ BS) that cannot be identified with fixed parameters, thereby resolving the contradiction between measurement completeness and procedural simplicity.
Solution Approach 2:
The measurement process is segmented into multiple distinct steps, each with specific parameter configurations. The first measurement step uses initial parameters, the second step changes the turning radius, and the third step changes the reference sphere position. This segmentation allows systematic identification of different error types that would be indistinguishable in a single undifferentiated measurement process.
2Measurement precision
If multiple measurement steps with parameter changes are implemented to identify all geometric errors, then complete error identification is achieved, but the measurement process becomes more complex
Solution Approach 1:
The patent employs periodic action by implementing a cyclic measurement process with three distinct steps, where parameters are systematically varied and then reset. This structured periodic approach ensures all geometric errors are identified through repeated measurements with different configurations, achieving completeness while maintaining a systematic and efficient measurement rhythm that minimizes unnecessary time loss.
Data Source
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AI summary
The present invention relates to an error identification method for a five-axis controlled machine tool including three translational axes for translational control in X, Y, and Z axis directions and two rotation axes for rotation control about B and C axes. The method comprises a step of providing a reference sphere to the C axis and attaching a touch probe to the B axis; a first measurement step of measuring a center position of the reference sphere while indexing an angle of the B axis for each predetermined angle, with the C axis fixed; a second measurement step of measuring the center position of the reference sphere as in the first measurement step with a turning radius of a measurement point of the touch probe changed; a third measurement step of measuring the center position of the reference sphere while indexing an angle of the C axis for each predetermined angle, with the B axis fixed; and a fourth measurement step of measuring the center position of the reference sphere as in the third measurement step with a Z direction initial position of the reference sphere changed.