CNC Probe Recalibration for In-Process Positional Error Compensation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing CNC machine technologies lack the ability to automatically recalibrate and compensate for positional errors during machining, relying on human intervention which can lead to production of nonconforming parts due to inherent shifts or movements in the machine tool.
Innovation Solution
A system that includes a measurement device and a processor to initially calibrate a known fixture, store calibration values, and subsequently perform in-process automatic recalibration by comparing initial and current values to calculate compensation for positional errors, adjusting the cutting tool path accordingly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If manual recalibration by operator intervention is used, then the machine can be recalibrated when out of calibration, but it requires human judgment and intervention which leads to production of nonconforming parts
Solution Approach 1:
The measurement probe automatically performs recalibration operations without operator intervention. The probe autonomously measures reference features, detects positional errors, and triggers compensation actions, enabling the system to self-calibrate during production cycles.
Solution Approach 2:
The system continuously monitors machine position using the measurement probe and automatically adjusts for detected errors. This closed-loop feedback mechanism compares actual positions against reference values and applies real-time compensation to maintain calibration accuracy.
2Manufacturing precision
If initial calibration is performed, then the machine starts in a calibrated state, but it does not enable automatic recalibration in response to inherent variations during machining
Solution Approach 1:
The calibration system transitions from a static initial calibration state to a dynamic continuous recalibration process. The measurement probe periodically re-measures reference features during machining operations, allowing the system to adapt to thermal expansion, mechanical drift, and other time-dependent variations.
Solution Approach 2:
The system performs preliminary measurements of reference features to establish baseline calibration values before production begins. These pre-established reference measurements enable the system to detect and compensate for deviations as they occur during machining.
3Measurement precision
If a touch trigger probe is used for measurement, then position data can be captured, but it requires programmed paths and does not automatically detect machine shifts
Solution Approach 1:
The measurement probe serves multiple functions: it performs initial calibration, conducts in-process measurements of workpieces, and automatically monitors machine position stability. This multi-functional probe eliminates the need for separate calibration and measurement systems.
Solution Approach 2:
The probe automatically detects machine positional shifts by re-measuring reference features without requiring programmed measurement paths. The system autonomously identifies when calibration drift occurs and triggers appropriate compensation actions.
Data Source
AI summary
An apparatus and associated method for a frame that is configured to rotate a workpiece around an axis of rotation. The apparatus has a measurement device, and a known fixture that is supported by the frame. A processor is configured to execute stored computer instructions to initially-calibrate the measurement device to the axis of rotation, to employ the initially-calibrated measurement device to obtain an initial-calibration value of the known fixture, to store the initial-calibration value in a digital memory, to subsequently use the initially-calibrated measuring device to obtain an in-process automatic recalibration (IPAR) value of the known fixture, and to compare the IPAR value to the initial-calibration value to calculate a compensation value indicating positional error of the apparatus.