CNC Positioning Error Determination Without Machine Control
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Solution Overview
Problem
Existing methods for determining positioning errors in CNC machines require a common interface with the CNC machine control, which can be limiting when different manufacturers are involved, and may not function independently.
Innovation Solution
A method and device that use a calibration element and sensors to determine positioning errors without relying on the CNC machine control, where the calibration element is positioned, sensor data is read before and after a calibration movement, and the sensor is moved to minimize the difference in data until it meets a threshold, allowing for independent determination of positioning errors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a common interface between sensors and CNC machine control is required, then data processing integration is improved, but device compatibility and ease of operation deteriorate when different manufacturers are involved
Solution Approach 1:
The system is divided into two independent parts: the sensor system for error measurement and the CNC machine control for movement execution. Each operates independently without requiring a common interface, allowing different manufacturers' components to work together while maintaining reliable data processing within each subsystem
Solution Approach 2:
A coordinate transformation algorithm acts as an intermediary between the sensor measurements and the CNC machine control. The algorithm processes sensor data to calculate positioning errors and generates compensation movements, bridging the gap between incompatible systems without requiring direct integration
2Measurement precision
If the CNC machine control must process sensor data, then measurement integration is improved, but device complexity increases
Solution Approach 1:
The data processing function is extracted from the CNC machine control and placed in the sensor system. The sensors independently process their own measurements to determine positioning errors, eliminating the need for the CNC control to handle sensor data and reducing overall system complexity
Solution Approach 2:
The sensor system performs self-service by independently processing its own measurement data without requiring external intervention from the CNC machine control. The sensors calculate positioning errors and generate compensation movements autonomously, simplifying the control system architecture
Data Source
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AI summary
The present invention provides a method for determining a positioning error of a a CNC machine, wherein the CNC machine is equipped with a calibration element, the calibration element being in a first position, the method comprising the steps of reading first sensor data from at least one sensor while the calibration element is at the first position, operating the CNC machine to perform a calibration movement that ideally leaves the calibration element at the first position, wherein the sensor data correspond to a distance between a point on the surface of the calibration element and the at least one sensor, or wherein a contact element of the at least one sensor is deflected by the calibration element and the sensor data correspond to a distance by which the contact element is deflected, reading second sensor data from the at least one sensor the calibration element is at a second position, wherein the second position denotes the actual position of the calibration element after the calibration movement has been performed, causing the at least one sensor to move so that the difference between the first and second sensor data decreases until the difference becomes less or equal to a pre-determined threshold value, and determining a positioning error of the tool head based on the movement of the at least one sensor.