Multi-axis machine tool geometric error identification
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for identifying and correcting geometric errors in multi-axis machine tools are inefficient due to the need for multiple measuring instruments, skill-dependent accuracy, and the influence of environmental factors like temperature, making high-accuracy machining challenging.
Innovation Solution
A method that uses a control device to index a measured jig at multiple angles, calculate geometric errors, and correct scaling errors by calculating an ellipse approximate expression from the arc trajectory, distributing temperature-based corrections, and updating positioning error correction tables.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If multiple measuring instruments are used to identify geometric error, then measurement coverage is improved, but device complexity and measurement time increase
Solution Approach 1:
The patent combines multiple measuring instruments into a single integrated measurement system. Specifically, it integrates a laser length measuring instrument, touch probe, and rotary table into one coordinated system that can perform comprehensive geometric error measurements without requiring separate instruments for each type of measurement.
Solution Approach 2:
The measurement system is designed to perform multiple functions using a single integrated setup. The system can measure positioning errors, scaling errors, and geometric errors between adjacent axes all through one unified measurement process, eliminating the need for specialized instruments for each measurement type.
2Measurement precision
If conventional measurement methods are used, then geometric error can be identified, but measurement time becomes excessively long
Solution Approach 1:
The patent implements continuous measurement capability where the laser length measuring instrument and touch probe operate in an integrated manner without interruption. The system continuously tracks positional data and scaling errors throughout the measurement process, eliminating the need for repeated setup and measurement cycles required by conventional methods.
Solution Approach 2:
The system performs preliminary measurements of scaling errors using the laser length measuring instrument before conducting geometric error measurements. This preliminary action allows the system to pre-calculate correction values, thereby reducing the overall measurement time for subsequent geometric error identification.
3Manufacturing precision
If geometric error measurement is performed before high-accuracy machining, then machining precision can be improved, but measurement accuracy becomes dependent on operator skill
Solution Approach 1:
The patent replaces manual measurement operations with automated measurement systems. The laser length measuring instrument and touch probe are controlled automatically by a control device that coordinates their movements and data collection, eliminating the need for operator intervention and skill-dependent measurements.
Solution Approach 2:
The system incorporates feedback mechanisms where measurement data is automatically processed and used to generate correction values for geometric errors. The control device receives real-time data from the laser length measuring instrument and touch probe, processes it through calculation units, and applies corrections automatically, ensuring consistent measurement accuracy independent of operator skill.
4Ease of manufacture
If scaling error correction is not performed, then measurement process is simpler, but thermal displacement affects machining accuracy
Solution Approach 1:
The system performs preliminary measurement and correction of scaling errors using the laser length measuring instrument before conducting geometric error measurements. By measuring and correcting scaling errors in advance, the system eliminates thermal displacement effects that would otherwise compromise machining accuracy during subsequent operations.
Data Source
AI summary
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.