Machine Tool Probe Compensation for Spindle Angle Measurement Error
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing position measurement methods in machine tools face errors due to changes in the probe's status relative to the main spindle after calibration, particularly from thermal distortion and external forces, which require frequent labor-intensive recalibration.
Innovation Solution
A position measurement method and system that utilize a probe mounted on a machine tool with three or more translational axes and a rotatable main spindle, where compensation values are obtained in two directions with different main spindle rotation angles, allowing for reduced measurement errors by adjusting the main spindle rotation angle during measurement to maintain accurate positioning.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If calibration is performed frequently to maintain measurement accuracy, then measurement precision is improved, but productivity deteriorates due to increased labor time
Solution Approach 1:
The system performs preliminary calibration by obtaining compensation values in at least two directions with 180° different main spindle rotation angles during an initial calibration phase. These pre-obtained compensation values are stored and automatically selected based on the measurement content, eliminating the need for frequent recalibration while maintaining measurement accuracy.
Solution Approach 2:
The system changes the main spindle rotation angle parameter to obtain different compensation values for different measurement contents. By storing compensation values corresponding to multiple rotation angles and automatically selecting the appropriate one based on the measurement task, the system adapts to different measurement requirements without requiring frequent recalibration.
2Measurement precision
If the probe status is kept fixed relative to the main spindle, then measurement precision is improved, but adaptability deteriorates when thermal distortion or external forces change the probe status
Solution Approach 1:
The system determines the measurement content and automatically selects the appropriate compensation value from stored values corresponding to different main spindle rotation angles. This feedback mechanism allows the system to adapt to different measurement tasks and compensate for probe status changes caused by thermal distortion or external forces without requiring manual recalibration.
Solution Approach 2:
The system dynamically selects compensation values based on the determined measurement content and corresponding main spindle rotation angles. Instead of using a fixed compensation value, the system adapts by choosing the most appropriate compensation value from multiple pre-obtained values, allowing it to handle probe status changes while maintaining measurement accuracy.
Data Source
AI summary
A position measurement method for an object in a machine tool measures a position of an object with a probe using a machine tool. The machine tool includes three or more translational axes, a rotatable main spindle, and a table. The probe is a position measurement sensor mountable to the main spindle. The position measurement method includes preliminarily obtaining compensation values of contact positions in a radial direction of the probe in at least two directions where main spindle rotation angles are different by 180°, determining the main spindle rotation angle at a contact with a measurement surface of the object corresponding to the measurement content, and calculating a measurement value of the position of the object from a position of the probe at the contact with the measurement surface and the compensation value in accordance with the determined main spindle rotation angle.