Numerical Controller Corner Path Generation with Inward Turning Compensation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional numerical control methods fail to effectively suppress machine shock at corners during machining while maintaining machining accuracy, as they either rely on acceleration/deceleration processing that can deviate the path or insert curves without considering inward turning amounts due to post-interpolation acceleration/deceleration and servomotor delay, leading to reduced feed speed and machining accuracy issues.
Innovation Solution
A numerical controller that calculates and inserts a curved movement path into the corner section, considering the inward turning amount due to post-interpolation acceleration/deceleration and servomotor delay, by setting an allowable inward turning amount and using the formula S={( 1/24)T12+(½)T22}·(v2/r) to estimate and limit the inward turning amount, ensuring the path remains within tolerance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If post-interpolation acceleration/deceleration is performed to suppress machine shock, then shock on the machine is reduced, but the machining path deviates from the specified path causing inward turning error
Solution Approach 1:
The system performs preliminary calculation of the inward turning amount caused by post-interpolation acceleration/deceleration before generating the machining path. By predicting the deviation in advance, the system can pre-compensate for it, ensuring the final path accuracy while maintaining shock suppression benefits
Solution Approach 2:
The system uses feedback by calculating the inward turning amount based on the relationship between feed rate, cornering speed, and acceleration/deceleration characteristics. This calculated value is fed back into the path generation process to adjust and compensate for the expected deviation
2Object-affected harmful factors
If curve insertion is used to remove corners and suppress shock, then shock on the machine is reduced, but the inward turning amount changes depending on corner shape and feed speed making accuracy control difficult
Solution Approach 1:
The system changes the approach from geometric curve insertion to parameter-based control. By focusing on controlling the inward turning amount through feed rate and cornering speed parameters rather than inserting complex curves, the system simplifies the control mechanism while maintaining effectiveness in shock suppression and accuracy control
3Manufacturing precision
If feed speed is reduced to control inward turning amount within tolerance, then machining accuracy is maintained, but productivity decreases
Solution Approach 1:
The system applies partial action by only reducing feed speed at corner sections where inward turning occurs, rather than reducing it throughout the entire machining path. This localized approach maintains machining accuracy at critical points while preserving overall productivity
Data Source
AI summary
A numerical controller controls a machine tool with a plurality of control axes so as to compensate an inward turning error by inserting a curved movement path into a corner section between two consecutive blocks. An estimated inward turning amount generated as the corner section is subjected to post-interpolation acceleration/deceleration is calculated based on the radius of curvature of the curve and allowable accelerations of the axes of the machine tool, and such a curved movement path that its inward turning amount has a value obtained by subtracting the estimated inward turning amount from a tolerance is inserted into the corner section if the sum of the estimated inward turning and the inward turning amount of the curve is larger than the tolerance.