Batch Machining Compensation Using CMM Feedback

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Machine tools in batch production face non-repeatability due to internal wear and external thermal factors, affecting the quality of machined pieces, and existing control loops require complex manipulation of NC programs or tool compensation values, which are specific to each manufacturer and not easily generalized.

Innovation Solution

A batch production system and method that modify volumetric compensation data based on position measurements of machined pieces to compensate for both intrinsic and extrinsic errors, using measurement data from CMM to adjust compensation values within the machine tool's movement system, allowing for more efficient and accurate machining without altering the NC program or tool compensation values.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If control loop is implemented to improve machining accuracy by adjusting NC program or tool compensation values, then manufacturing precision is improved, but device complexity increases due to manufacturer-specific programming requirements

Engineering Contradiction:
Improvemachining accuracyVSAvoidcontrol loop complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent introduces a measurement device (CMM) as an intermediary between the machining process and control system. The CMM objectively measures workpiece geometry and provides data to a control loop that automatically adjusts tool compensation values, eliminating the need for complex manufacturer-specific NC program modifications while maintaining high machining accuracy

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The system implements a closed-loop feedback mechanism where the CMM measures actual workpiece dimensions, compares them to target values, and automatically adjusts tool compensation parameters. This automated feedback system simplifies the control process by eliminating manual intervention and manufacturer-specific programming complexity

Inventive Principle:
Principle #23Feedback

2Manufacturing precision

If traditional volumetric compensation is used to correct intrinsic machine tool errors, then manufacturing precision is improved, but loss of time occurs due to cumbersome configuration process and expensive hardware requirements

Engineering Contradiction:
Improvepositioning accuracyVSAvoidcompensation configuration time
Core Design Contradiction:
Manufacturing precisionVSLoss of time

Solution Approach 1:

The system enables self-service volumetric compensation by allowing the machine tool to automatically update its own compensation values based on CMM measurements of actual workpieces. This eliminates the need for external specialists to perform time-consuming compensation configurations using expensive dedicated hardware

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent replaces the traditional mechanical/procedural compensation configuration process with an automated digital system. The CMM provides digital measurement data that automatically updates compensation parameters through software, eliminating the need for physical measurement artifacts and manual configuration procedures

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Data Source

PatentEP4163743A1Batch production system and batch production method
Publication Date: 2023.04.12 HEXAGON INNOVATION HUB GMBH
  • EP4163743A1 patent drawingFigure 1~3
  • EP4163743A1 patent drawingFigure 4~5
  • EP4163743A1 patent drawing

AI summary

The invention relates to a batch production system comprising a machine tool for consecutively machining a batch of workpieces into machined pieces, said machine tool comprising a workpiece support configured for supporting the workpieces, a cutting tool, a movement system configured for providing a relative movement between the cutting tool and the workpiece support with at least two degrees of freedom, a control unit configured for controlling the movement system based on numerical control data and compensation data for compensating volumetric positioning errors of the movement system, wherein the numerical control data are based on nominal geometry data representing a target piece that is desired to be achieved when machining the batch of workpieces into the machined pieces, the batch production system further comprising a computer configured for receiving measurement data, said measurement data based on at least one geometrical property of at least one of the batch of machined pieces, modifying the compensation data based on the received measurement data and the nominal geometry data.