Machining Time Prediction via Shape Group Segmentation

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing machining time prediction methods for wire discharge machining are inaccurate due to varying machining speeds caused by different workpiece thicknesses and shapes, leading to errors in predicting machining times, which complicates work cost estimation and machining plan management.

Innovation Solution

A machining time prediction device that classifies machining paths into shape groups based on their characteristics, calculates predicted machining times using a predicted machining speed table, and updates average machining speeds to provide accurate predictions for both total and remaining machining times.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a single predicted machining speed is used for all machining paths, then the prediction method is simple, but the prediction accuracy deteriorates due to varying machining speeds caused by different workpiece thicknesses and shapes

Engineering Contradiction:
Improveprediction method complexityVSAvoidmachining time prediction accuracy
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The machining path is divided into multiple segments based on shape characteristics (straight lines, arcs, corners). Each segment is assigned a specific predicted machining speed from a speed table corresponding to its shape type, allowing accurate prediction while maintaining systematic simplicity

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different predicted machining speeds are assigned to different portions of the machining path based on local shape characteristics. Straight line segments, arc segments, and corner segments each have their own speed values, reflecting the local machining conditions rather than using a uniform speed

Inventive Principle:
Principle #3Local quality

2Adaptability or versatility

If average machining speed is calculated from completed path length and execution time, then the method adapts to actual machining conditions, but large errors occur when high-speed and low-speed shapes are concentrated in different halves of the machining path

Engineering Contradiction:
Improveadaptation to actual machining conditionsVSAvoidcorrected predicted machining time accuracy
Core Design Contradiction:
Adaptability or versatilityVSMeasurement precision

Solution Approach 1:

The machining path is segmented by shape type (straight lines, arcs, corners), and the total machining time is calculated by summing the time for each segment type. This segmented approach prevents the averaging error that occurs when high-speed and low-speed segments are mixed in a single average calculation

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Predicted machining speeds for different shape segments are predetermined and stored in a speed table before machining begins. This preliminary preparation allows accurate time prediction without relying on post-machining average speed calculations that are susceptible to distribution biases

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP3196722B1Machining time prediction device
Publication Date: 2020.11.11 FANUC LTD
  • EP3196722B1 patent drawingFigure 1
  • EP3196722B1 patent drawingFigure 2
  • EP3196722B1 patent drawingFigure 3

AI summary

Provided is a machining time prediction device including a predicted machining speed table where predicted machining speeds are registered in association with shape groups used for classification based on a shape of a machining path, a machining path generation unit generating machining path data including the machining path based on the program, a shape group determination unit determining which shape groups partial machining paths belong to, a path length addition unit adding and summarizing path lengths of the partial machining paths for the respective shape groups, a predicted machining time calculation unit calculating predicted machining times of the respective shape groups on the basis of a predicted machining speed table and the path lengths of the respective shape groups, a predicted machining time summation unit calculating a predicted machining time of the machining path by adding the predicted machining times of the respective shape groups, and a display unit displaying the predicted machining time of the machining path.